Morphological variations of fissures, lobes, and hilar pattern of the lung in a select South African sample

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The mediastinal surface of each lung consists of the hilum which allows the bronchus, pulmonary vein, and pulmonary artery to enter and exit. This study aims to investigate and record the variations in the morphology of lung fissures, lobes, and hilar patterns observed in a South African sample. Methods and Materials: This was a cross-sectional observational study with a descriptive analysis. A total of 48 formalin-fixed bodies comprising females (n = 24) and males (n = 24) from the Department of Human Biology at the University of Cape Town were studied. The fissures were classified according to the Craig and Walker criteria. Permission to conduct the study was given by the Cadaveric Research Governance Committee: CRGC 2023/006. Results and Discussion The Craig and Walker classification was used to describe the frequencies of variations observed in the study. 25 right sided and 30 left sided lungs had incomplete oblique fissures. Incomplete horizontal fissures were observed in 39 right lungs. One right lung had both an absent horizontal and oblique fissure. Accessory fissures were found in five right and 7 left lungs. Regarding the hilar pattern, variations were seen in the number and arrangement of structures of both the right and left lungs. Conclusion Variations in the completeness of fissures as well as the hilar pattern are a common occurrence. Thus, surgeons and radiologist need to be aware of these morphological variations as they may cause misdiagnosis and complications during surgical procedures. Accessory fissures Lung fissures Lung lobes Hilum pattern Variations Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction The lungs, vital for respiration are positioned on either side of the mediastinum and are enclosed within their pleural sac [5]. The lungs are cone-shaped organs that consists of a concave base, an apex, three surfaces and three borders [2]. The base of each lung is positioned on the upper surface of the diaphragm, while the apex extends beyond the first rib [39]. The three surfaces of the lungs includes the costal surface lying next to the ribs and intercostal space of the thoracic wall, the mediastinal surface lie in contact with the mediastinum anteriorly and the diaphragmatic surface lie on the dome of the diaphragm [5].The borders of the lungs include the inferior border that separates the base of the lung from the costal surface, and the anterior and posterior borders converging from the costal mediastinal surfaces [3]. The left lung is smaller and has a greater length compared to the right lung due to the dome of the diaphragm being higher on the right side while the right lung has a greater width than the left lung due to the positioning of the heart extending towards the left side [38]. The lungs are divided into lobes by fissures, such as the horizontal and oblique fissures which are invaginations of visceral pleura. These fissures separate the lobes almost to the hilum, allowing for easy movement and uniform expansion of the lungs during respiration [15,16]. The right lung is divided into three lobes: the superior, middle, and inferior lobes separated by horizontal and oblique fissures [25]. The left lung on the other hand, is divided into two lobes: the superior and inferior lobe, separated by an oblique fissure [8]. Additionally, the inferior border of the superior lobe of the left lung has a small tongue-like process called the lingula [27]. The mediastinal surface of the lung features a triangular depression known as the hilum, through which important structures enter and exit [16]. These structures include a principal bronchus, bronchial vessels, two pulmonary veins, a pulmonary artery, lymphatics, and nerves [5]. Both the right and left lung consists of two pulmonary veins and one pulmonary artery at the hilum, however, the bronchi differ in their subdivision between the right and left lung [37]. The right bronchus branches off into the superior lobe approximately 2.5cm from the bifurcation of the trachea, with divisions above the pulmonary artery and is therefore termed the eparterial bronchus while other divisions will be below the pulmonary artery and thus termed the hyparterial bronchus [9,30]. The left bronchus branches off below the pulmonary artery therefore named the hyparterial bronchus [9]. The structures at the hilum are arranged in different patterns between the right and left lung [16]. At the right lung, from superior to inferior, the structures are arranged as follows: eparterial bronchus, pulmonary artery, hyparterial bronchus and pulmonary veins, respectively [7]. At the left lung from superior to inferior, the structures are arranged as follows: pulmonary artery, hyparterial bronchus and pulmonary veins, respectively [30]. At both the lungs, from anterior to posterior, the structures are arranged as follows: pulmonary vein, pulmonary artery, and principal bronchus [7]. Any deviations from the normal embryological development will bring about variations in the morphology of the lobes and fissures as well as the hilum pattern [27,7]. Knowledge of these variations, which may include absent, incomplete, and accessory fissures as well as variations in the number and arrangement of structures at the hilum is essential for planning different operative strategies for various surgical procedures such as thoracoscopic pulmonary resection or pulmonary lobectomy where a variation may cause complications [8]. Variability within the lung fissure morphology is well reported in the literature with studies conducted from the United States of America, Turkey, Nepal, and Ethiopia [47]. However, only a few studies have been conducted on the African population, with only three case reports from Kenya, Nigeria and Tanzania, as well as a cadaveric study conducted in Kenya have been published on this topic. Additionally, only one study by Mpolokeng et al. [28] has investigated anatomical variations in lung fissures within a South African sample. The morphology of the hilum is not well documented in the literature [37], and no paper has yet documented hilum anatomy in a South African sample. This study aims to address the variations in the morphology of lung fissures, lobes and hilar pattern observed in a South African sample. Methods and Materials A descriptive observational study was conducted at the Department of Human Biology Dissection halls, located in the Anatomy Building at the Faculty of Health Sciences, University of Cape Town. The study examined a total of 48 formalin-fixed bodies consisting of both females (n = 24) and males (n = 24), that had been previously dissected and examined by medical and postgraduate honours students. Poorly dissected lungs that lead to the destruction of lobes, fissures and the hilum structures were excluded from the study. Lungs that showed signs of surgical procedures and had severe pathologies were also excluded from the study. The lungs were analysed and recorded for the presence or absence of fissures and lobes, the completeness of fissures, the presence of accessory fissures, and the number and arrangement of structures at the hilum. Digital photographs were taken to further record the findings. The completeness of the lung fissures was analysed according to the Craig and Walker criteria, seen in Table 1 . Table 1 Grading of completeness of a fissure according to Craig and Walker criteria Grades Craig and Walker criteria of completeness of fissure Grade I Complete fissure with entire separate lobes Grade II Complete visceral cleft but parenchymal fusion at the base of the fissure Grade III Visceral cleft evident for part of the fissure Grade IV Complete fusion of the lobes with no evident fissural line Permission to conduct the study was granted by the Cadaver Research Governance Committee: CRGC 2023/006. Every effort was made to follow all ethical guidelines and laws according to the Human Tissue Act of 2004 and the Declaration of Helsinki that pertain to the use of human cadaveric donors in anatomical research. The statistical analysis for this study was conducted using the IBM SPSS Statistics version 28 software. For the categorical data, both Chi-squared test and frequency analysis were conducted. The Chi-squared test was run to analyse the association between each pulmonary fissure variations and sex. Nevertheless, it is worth noting that all the fissure variations had expected counts of less than five, thus failing to meet the Chi-squared test criterion, which requires each subcategory to have five or more counts. Thus, it was not possible to make any valuable deductions from the Chi-squared test. Furthermore, normality tests were conducted on the categorical data using a significance level of p < 0.05 and a 95% confidence interval. The results indicated that all the data had p-values below 0.05, suggesting that the fissure variations and sex had no significant relationship. For the numerical data, frequency analysis and normality tests were run with similar significant values to determine the relationship between hilar pattern variation and sex. The p-value for all the data was below 0.05, suggesting that hilar pattern variation and sex had no significant relationship. Results Anatomical variations of the lung fissures and lobes A total of 96 lungs were examined and among 92 lungs, the prevalence of variations in the oblique and horizontal fissures of 45 right and 47 left lungs were observed and recorded according to the Craig and Walker criteria in Table 2 . Table 2 Prevalence of oblique, and horizontal fissure variations according to Craig and Walker criteria Lungs Fissures Grade I n (%) Grade II n (%) Grade III n (%) Grade IV n (%) Right Oblique 19 (42.2%) 7 (15.6%) 18 (40.0%) 1 (2.2%) Horizontal 5 (11.1%) 2 (4.4%) 37 (82.2%) 1 (2.2%) Left Oblique 17 (36.2%) 12 (25.5%) 18 (38.3%) 0 Out of the 45 right lungs studied, 11.1% (n = 5/45) had Grade I horizontal fissures, 4.4% (n = 2/45) had Grade II, 82.2% (n = 37/45) had Grade III and 2.2% (n = 1/45) had Grade IV. For the oblique fissure, 42.2% (n = 19/45) had Grade I, 15.6% (n = 7/45) had Grade II, 40.0% (n = 18/45) had Grade III and 2.2% (n = 1/45) had Grade IV. No right lung had only an absent horizontal fissure, nor was a right lung observed with solely an absent oblique fissure. However, both the horizontal and oblique fissure were absent in one lung (Fig. 1 E). Among the 47 left lungs, 36.2% (n = 17/47) had Grade I oblique fissures, 25.5% (n = 12/47) had Grade II and 38.3% (n = 18/47) had Grade III oblique fissures. No Grade IV oblique fissure was seen in any of the left lungs. The study also recorded the number of lobes in the left and right lungs. In the right lungs, 84.4% (n = 38/45) showed the usual morphology of three lobes (Fig. 1 A), 6.4% (n = 2/45) had two lobes due an incomplete horizontal fissure, 6.7% (n = 3/45) had four lobes due to the presence of accessory fissures and 2.2% (n = 1/45) had a single lobe due to absence of both the horizontal and oblique fissures. In the left lungs, 93.6% (n = 44/47) had the usual morphology of two lobes (Fig. 2 A), 2.1% (n = 1/47) had a single lobe due to an incomplete oblique fissure while 4.3% (n = 2/47) had three lobes due to the presence of accessory fissures. Figure 1 shows some of the anatomical variations found at the right lungs of different individuals. Accessory fissures were observed in both the right and left lungs in the present study. Some of the accessory fissures are represented in Figure 3. The superior accessory fissure (SAF) was found in 8.9% (n=4/45) and 4.3% (n=2/47) of the right and left lungs respectively. The inferior accessory fissure (IAF) was found in 2.2% (n=1/45) and 2.1% (n=1/47) of the right and left lungs respectively. The left minor fissure was found in 8.5% (n=4/47) left lungs. One left lung had two left minor accessory fissures (Figure 3C). Anatomical variations at the hilum A total of 96 lungs were examined and among 90 lungs, the incidence of variations in the hilar pattern of 46 left and 45 right lungs was observed and recorded. Variations were seen in the number and arrangement of structures found at the hilum and presented in Tables 3 and 4. Table 3 shows a summary of the frequency of variations in the number of structures at the hilum of both the left and right lungs. Table 3: Frequency of variations in the number of structures at the hilum of both the right and left lungs Hilar structure Left lung n (%) Right lung n (%) One Two Three Four Five One Two Three Four Five Bronchus 42 (91.3%) 4 (8.7%) 0 0 0 15 (34.1%) 29 (65.9%) 0 0 0 Pulmonary artery 45 (97.8%) 1 (2.2%) 0 0 0 42 (95.5%) 2 (4.5%) 0 0 0 Pulmonary vein 11 (23.9%) 29 (63.0%) 5 (10.9%) 0 1 (2.2%) 6 (13.6%) 13 (29.5%) 21 (47.7%) 3 (6.8%) 1 (2.3%) The hilar pattern of the left and right lungs showed varying percentages regarding the number of bronchi, pulmonary arteries, and pulmonary veins. Among these, the pulmonary vein was the most variable, ranging from a minimum of one to a maximum five pulmonary veins. Furthermore, the right lung showed the highest prevalence of unusual morphology of three pulmonary veins, seen in 47.7% (n=21/45) lungs. Table 4 shows the variations in the arrangement of the bronchi, pulmonary artery, and pulmonary vein at the hilum of both the left and right lungs. Table 4: Frequency of variations in the arrangement of structures at the hilum of both the left and right lungs. Arrangement of structures at hilum Right lung n (%) Left lung n (%) Usual Variant Usual Variant Superior to inferior 35 (79.5%) 9 (20.5%) 45 (97.8%) 1 (2.2%) Anterior to posterior 33 (75.0%) 11 (25.0%) 36 (78.3%) 10 (21.7%) In the right lungs, 79.5% (n=35/45) and 75.0% (n=33/46) lungs showed the usual pattern of structural arrangement from superior to inferior and anterior to posterior respectively (Figure 5A). However, 20.5% (n=9/45) of the right lungs deviated from the usual superior to inferior arrangement. Among the nine lungs, seven showed the following arrangement from superior to inferior: superior pulmonary vein, eparterial bronchus, pulmonary artery, hyparterial bronchus and inferior pulmonary vein (Figure 5C). One lung displayed the following arrangement: pulmonary artery, bronchus and pulmonary vein. The remaining lung showed arrangement as superior pulmonary vein, eparterial bronchus, pulmonary artery, hyparterial bronchus and inferior pulmonary vein. Furthermore, 25.0% (n=11/45) deviated from the usual anterior to posterior arrangement of structures by having the following pattern: pulmonary artery, pulmonary vein, and bronchus (Figure 5E). In the left lungs, 97.8% (n=45/46) and 78.3% (n=36/46) lungs had the usual structural arrangement from superior to inferior and anterior to posterior respectively (Figure 4A). Only 2.2% (n=1/46) of the left lungs had a variant superior to inferior arrangement of structures as follows: accessory pulmonary veins, pulmonary artery, eparterial bronchus, hyparterial bronchus and inferior pulmonary vein (Figure 4C). Ten lungs (21.7%) displayed a variant anterior to posterior arrangement of structures by having the following pattern: pulmonary artery, pulmonary vein and bronchus (Figure 4E). Variant morphology of some hilum can be seen in Figure 4 and 5. Figure 4 shows some of the variant morphology in terms of the number and arrangement of structures at the hilum of the left lungs. Discussion The lungs develop from a combination of two types of tissue, the endodermal and mesodermal tissue [44]. The endodermal tissue develops into the mucosal lining of the bronchi, as well as the epithelial cells of the alveoli. The mesodermal tissue develops into the vasculature of the lung along with the muscles and cartilage which support the bronchi [44]. Around the fourth week of embryonic development, the respiratory diverticulum (lung bud) grows caudally from the ventral wall of the foregut into the surrounding mesenchyme [18]. The lung bud will form the trachea and two (right and left) primary bronchial buds [26]. At the beginning of the fifth week, the right bronchial bud divides into three secondary bronchial buds while the left bronchial bud divides into two [17]. During the sixth week, the secondary bronchial buds repeatedly branch into tertiary bronchial buds eventually forming bronchopulmonary segments [18]. The bronchopulmonary segments are separated by gaps which eventually get obliterated except along two planes in the right lung, forming the horizontal and oblique fissure and one plane in the left lung which becomes the oblique fissure [24]. Along these fissures, the visceral pleura is reflected and envelops the individual lobes [26]. If non-obliteration of the gaps occurs, accessory fissures may persist while complete or partial obliteration will lead to absent or incomplete fissures [23]. Furthermore, pulmonary vessels initially develop within the mesenchyme by the process vasculogenesis [7]. Pulmonary arteries develop adjacent to the conducting airways, joining the angiogenic mesenchyme of the sixth aortic arch arteries [41]. Pulmonary veins develop from mediastinal mesenchyme in the dorsal mesocardium and become separated from the airways by the growth of alveoli and lymphatic vessels [41]. Deviations from the branching morphogenesis during embryonic and early fetal periods will result in variations in the hilum [7]. Various researchers have studied and reported their findings on variant lung anatomy as represented in Table 5, 6, and 7, which are compared to the findings of the present study. Table 5: Comparative prevalence of variations of oblique and horizontal fissures in both the left and right lungs Author, year Type of study Region Sample (n) Right lung Left lung Horizontal fissure (%) Oblique fissure (%) Oblique fissure (%) Complete Incomplete Absent Complete Incomplete Absent Complete Incomplete Absent Gesase, 2006 cadaveric Tanzania 102 - 7.84 - - 0.98 - - 10.78 - Nene et al., 2011 cadaveric India 50 78 8 14 92 6 2 88 12 0 Ghosh et al., 2013 cadaveric India 82 26 26 47.8 79 19.56 2.17 79 13.88 5.55 Dutta et al., 2013 cadaveric India 102 26.49 38.89 34.62 26.92 61.54 11.54 44 48 8 Jacob and Pillay 2013 cadaveric India 48 10 83.4 6.6 46.6 50 3.4 61.1 38.9 0 George et al., 2014 cadaveric India 138 61.55 35.38 3.07 96.93 3.07 0 84.94 15.06 0 Magadum et al., 2015 cadaveric India 40 35 52.2 12.5 30 60 10 50 42.5 7.5 Mamatha et al., 2016 cadaveric India 40 50 50 0 85 15 0 60 35 5 Kc et al., 2018 cadaveric Nepal 50 52.18 34.78 13.04 69.57 30.43 0 48.15 51.85 0 Jacobs et al., 2019 cadaveric India 96 15 70 15 49 51 0 34 62 4 Mutua et al., 2021 cadaveric Kenya 48 47.3 42.1 10.5 63.1 36.8 0 65.6 34.4 0 West et al., 2021 cadaveric United Kingdom 82 22.2 66.7 11.1 64.2 35.8 0 81.5 16.0 2.47 Ranaweeera et al., 2022 cadaveric Sri Lankan 50 0 84.61 15.38 42.3 57.69 0 66.67 33.33 0 Mpolokeng et al., 2022 cadaveric South Africa 82 40.2 39.0 7.3 57.3 29.3 - 57.3 29.3 1.2 Present study cadaveric South Africa 96 11.1 86.6 2.2 42.2 55.6 2.2 36.2 63.8 0 (- Indicates that the data was not provided) Analysis of the studies tabulated in Table 5 reveal that incomplete fissures are common in lungs, with a higher prevalence seen in the right lung compared to the left lung. Based on the findings from the current study, incomplete horizontal fissures had a higher prevalence of 86.6%. This is comparable to studies by Jacob and Pillay [14] and Ranaweeera et al. [36] where 83.4% and 84.6% of incomplete horizontal fissures was found, respectively. In contrast, Nene et al. [32] who examined 100 lungs, reported a relatively low prevalence of incomplete horizontal fissures, found in only 8% of the lung specimens. Similarly, a study carried out on an African sample size by Mutua et al. [31] contradicted the findings of the current study, reporting a lower incidence of incomplete horizontal fissures, present in 42.1% of the right lungs. A CT imaging study that analysed 560 cases by Manjunath et al. [25] reported an even lower incidence of 2.3% incomplete horizontal fissures while a study by Shinde and Patel [40] reported no incomplete horizontal fissures. The present study found a low prevalence of absent horizontal fissures, with only 2.2% Grade IV horizontal fissures observed. This is comparatively similar to a study by George et al. [9] with a sample size of 138 lungs which reported absent horizontal fissures in 3.07% of right lungs. The highest prevalence was reported by Ghosh et al. [11], which had a relatively smaller sample size of 82 lungs, compared to the 96 lungs in the present study. In their study, Ghosh et al. [11] found absent horizontal fissure in 47.8% of lungs. Another study by Mamatha et al. [24] reported no absent horizontal fissures. In the present study, the prevalence of right incomplete oblique fissures (Grade II and III) was found in 55.6% lungs, which is lower than that of incomplete horizontal fissures. This is comparable to studies by Dutta et al. [6] and Jacobs et al. [15] which reported 61.54% and 51% incomplete oblique fissures, respectively. Magadum et al. [23] deviated from this observation by having a higher incidence of incomplete oblique fissures compared to incomplete horizontal fissures. Gesase et al. [10], who investigated 102 lungs reported an even lower prevalence of incomplete right oblique fissures, present in 0.98% of the right lungs. According to Dutta et al. [6] a higher frequency of incomplete oblique fissures in the right lung could suggest an early onset of fusion of antenatal fissures, potentially proceeding further before birth, resulting in fusion along the base of the oblique fissure. Similar to the horizontal fissures, the right oblique fissure was uncommonly absent. In this study, only 2.2% of Grade IV oblique fissures were observed in the right lungs, which is similar to findings by Nene et al. [32] which reported 2% of absent left oblique fissure. This is lower than what other studies found. Studies by Prakash et al. [34]; Dutta et al. [6] and Magadum et al. [23] reported absent right oblique fissures in 7.14%, 11.54% and 10% of the lungs, respectively. On the other hand, George et al. [9]; Mamatha et al. [24]; Wahane and Satpute [45]; West et al. [47] and Mutua et al., [30] found no absent oblique fissures. In the current study, it was observed that incomplete oblique fissures were more prevalent in the left lungs when compared to the right lungs. Among the left lungs, 25.5% and 38.3% were Grade II and Grade III oblique fissures, respectively. This is similar to findings by Kc et al. [18] with a sample of 50 lungs, which reported incomplete oblique fissures in 51.85% of left lungs as opposed to 30.43% of right lungs. Notably, none of the left lungs had an absent (Grade IV) oblique fissure in this study. This is consistent with what most studies reported (Table 5). On the contrary, Prakash et al. [34]; Dutta et al. [6]; West et al. [47] reported absent left oblique fissures in 10.7%, 8%, and 2.47% of the left lungs, respectively. Surgeons should be aware of these fissure variations that may occur as they can cause problems. As reported by Li et al. [21], an incomplete interlobar fissure increases the surgical difficulty and the probability of prolonged air leaks. Patients that had incomplete interlobar fissures and went through a video-assisted thoracoscopic lobectomy had increased overall post-operative morbidity rate and were greatly associated with pneumothorax, pleural effusion, and atelectasis [20]. Huang et al. [13] reported that incomplete pulmonary fissures were greatly associated with post-operative complications such as prolonged length of chest tube drainage and hospital stay. Koster and Slebos [19] demonstrated that the possibility of collateral ventilation is high with incomplete pulmonary fissures. Furthermore, Okamoto et al. [33] reported that patients diagnosed with stage I non-small cell lung cancer (NSCLC), with incomplete fissures had higher occurrence of ipsilateral lung and lymph node metastases as well as poor prognosis compared to those with complete fissures. Similarly, Lee et al. [20] reported that patients with resected stage I adenocarcinoma with incomplete fissures had a reduced overall 5-year survival rate. Supernumerary fissures also known as accessory fissures were found in the present study. Accessory fissures are described anatomically as clefts of varying depth lined by visceral pleura [18]. Literature describes accessory fissures as superior accessory fissure (SAF), inferior accessory fissure (IAF) also termed medial basal fissure and left minor fissure (LMF) also known as the left horizontal fissure [26]. The presence of accessory fissures at unusual locations in the lung result in anomalous lobes of the lung aerated by usual bronchus, which is commonly found in infants [27]. Accessory fissures found in the current study were compared to other studies summarised in Table 6. Table 6: Incidence of accessory fissures in both the right and left lungs Author Right lung (%) Left lung (%) SAF IAF SAF IAF LMF Nene et al., 2011 4 14 - 24 26 Quadros et al., 2014 8.33 5.55 - 5 17.5 Magadum et al., 2015 2.5 5 - 8 7.5 Kc et al., 2018 4.34 21.73 - 3.70 29.62 Wahengbam et al., 2019 7.14 21.43 2.70 43.24 29.73 Mutua et al., 2021 - 5.26 - - 37.5 Present study 8.9 2.2 4.3 2.1 8.5 (- indicates that the data was not found) In the present study, accessory fissures were present in both the left and right lungs. Among the right lungs, superior accessory fissures (SAF) were found in 8.9% of the lungs while they were found in 4.3% of the left lungs. These findings agree with studies by Quadros et al., [34] and Wahengbam et al., [46] who reported higher incidences of superior accessory fissures in the right lungs of 8.33% and 7.14%, respectively. A study by Godwin and Tarver [12] reported that superior accessory fissures (SAF) were present in 30% of the right lungs compared to the left lungs where an incidence ranging between 5% and 14% was observed. On the contrary, Mutua et al. [31] with a sample size of 96 lungs found no superior accessory fissures in both the left and right lungs. Inferior accessory fissures (IAF) were observed in this study, with 2.2% found at the right lungs. This observation disagrees with majority of the studies which found higher incidences of IAF at the right lungs. Magadum et al. [23]; Quadros et al. [35] and Nene et al. [32] reported IAF in 5%, 5.5.% and 14% of the right lungs respectively. Kc et al., [18] and Wahengbam et al. [46] reported high incidence of IAF in 21.73% and 21.43% of the right lungs respectively. A CT imaging study by Manjunath et al. [25] reported inferior accessory fissures in 66.7% of the right lungs. In the present study, 8.5% of the accessory fissures were left minor fissures (LMF) while 4.3% were left inferior accessory fissures (IAF). This incidence is lower compared to studies by Kc et al. [18] and Nene et al. [32] who reported high frequencies of LMF with 29.62% and 26% incidences. In contrast, a study conducted by Wahengbam et al. [46] deviated from this observation, reporting a higher prevalence (43.24%) of inferior accessory fissures (IAF) as opposed to left minor fissures (LMF). A rare anatomical variation known as an azygous lobe, formed by the presence of an azygous fissure may be encountered in the right lung [14]. This variant is characterized by the partitioning of the right upper lobe due to the atypical course of the azygos vein, forming an additional lobe [26]. The prevalence of this variant lobe ranges from 0.4% to 1% in the general population [15]. Kc et al., [18] reported one case of an azygous lobe. However, this azygous lobe was not encountered in this study. Presence of accessory fissures may form a barrier that will prevent the spread of infection, therefore causing marginated pneumonia [46]. Accessory fissures can be misdiagnosed as atelectasis, pleural scars, pleural effusion, or walls of bullae [22]. According to Dutta et al. [6] accessory fissures can change the typical pattern of lung collapse in patients with endobronchial lesions, making it difficult to diagnose a lesion and its extent. The findings from the current study and their comparison with the previous studies show that there is wide variation in the prevalence of variant fissures and accessory fissures between and among populations. According to Mamatha et al. [24] these differences may be a result of genetic variations and environmental factors. Furthermore, Van der Molen et al. [43] who conducted a study on 9, 926 participants to determine environmental, clinical, and genetic determinants contributing to fissure completeness concluded that fissure completeness is genetically determined and independent on sex, age, and smoking status. Dogan et al. [4] states that lobar pattern abnormalities occur in conditions such as, polysplenia, and asplenia situs inversus viscerum, where these conditions cause defects in the determination of left-right asymmetry. Variations of the hilum structures Variations at the hilum of the lungs were observed in the present study, seen in the number and arrangement of structures at both the left and right lungs. The observed findings were compared with studies tabulated in Tables 7 and 8. Table 7: Comparative prevalence of variations of the number of structures at the hilum of the right lung Author, year Region Sample size (n) Right lung structures (%) 1 Bronchus 2 Bronchi 3 Bronchi 1 Vein 2 Veins 3 Veins 4 Veins 5 Veins 1 Artery 2 Arteries 3 Arteries George et al., 2014 India 138 - 98.46 1.53 - 63.07 32.30 - - 29.23 67.69 3.07 Murlimanju et al., 2017 India 110 1.8 83.9 1.8 - - - 1.8 - 83.9 8.9 - Jacobs et al., 2019 India 96 2 87 9 2 29 56 13 - 62 33 4 James et al., 2019 India 50 16 - - - - 8 - - - - - Saha and Srimani 2019 India 103 0 79.59 16.33 6.12 63.27 22.45 4.08 4.08 63.27 6.12 0 Amin, 2020 Egypt 40 - 76 24 - 62 - - - 71 29 38 Present study South Africa 90 34.1 65.9 0 13.6 29.5 47.7 6.8 2.3 95.5 4.5 0 (- indicates that the data was not provided) Table 8 shows the variations of the number of hilum structures found at the left lung by previous studies. Table 8: Comparative prevalence of variations of the number of structures at the hilum of the left lungs Author, year Region Sample size (n) Left lung structures (%) 1 Bronchus 2 Bronchi 3 Bronchi 1 Vein 2 Veins 3 Veins 4 Veins 5 Veins 1 Artery 2 Arteries 3 Arteries George et al., 2014 India 138 76.74 21.91 - - 80.82 19.17 - - 94.52 5.47 - Murlimanju et al., 2017 India 110 51.8 35.2 7.4 - 51.8 1.8 - - 51.8 5.5 - Jacobs et al., 2019 India 96 43 49 8 4 75 17 2 2 83 17 - James et al., 2019 India 50 - - - - - - - - - - - Saha and Srimani 2019 India 103 53.70 37.04 9.26 9.26 68.52 14.81 3.70 3.70 62.96 27.78 9.26E Amin, 2020 Egypt 40 79 21 - - 63 37 - - 84 16 - Present study South Africa 90 91.3 8.7 0 23.9 63.0 10.9 0 2.2 97.8 2.2 0 (- indicates that the data was not provided) Variations at the hilum of the lungs were observed in the present study, with majority seen in the number of pulmonary veins of both the left and right lungs. These variations may cause complications during surgical procedures, thus, it is pivotal for surgeons and clinicians to know them [29]. Variant anatomy of the bronchi arising from the trachea or from the primary bronchi like the tracheal bronchus and accessory cardiac bronchus are uncommon. Nonetheless, knowing such congenital bronchial variations is vital for diagnosis and surgical interventions involving the trachea and bronchi [36]. In the present study, the usual morphology of two bronchi (eparterial and hyparterial) in the hilum of the right lung was observed in 65.9% of the specimens. This incidence is lower compared to studies by Murlimanju et al. [30]; George et al. [9]; Jacobs et al., [15] and Saha and Srimani [36] who reported two bronchi at the right hilum of 83.9%; 98%, 87% and 79.59% lungs respectively. The present study reported the highest frequency of one bronchus at the right hilum, seen in 34.1% lungs. Previous studies by Murlimanju et al. [30]; George et al. [9]; Jacobs et al., (2019); Saha and Srimani [36] and James et al. [16] with varying sample sizes of 110, 138, 96, 103 and 50 lungs, respectively, reported lower incidences of one bronchus ranging between 0%- 16%. At the left hilum of this study, usual morphology of one bronchus was observed in 91.3% lungs while two bronchi were observed in 8.7% of the left hilum. This is not consistent with findings by George et al. [9] and Murlimanju et al. [30] who reported two bronchi in and 21.9% and 35.2% of the left lungs respectively. Unforeseen bleeding originating from the pulmonary artery may be occasionally encountered by surgeons, thus knowledge of the pulmonary artery anatomy as well as their variations is vital to avoid complications [36]. The present study observed a single pulmonary artery in 95.5% right lungs. This frequency is higher compared to a study by George et al., [9] which reported one pulmonary artery in 29.23% right lungs. Among the left lungs, 97.8% had one pulmonary artery which is similar to reports by George et al., [9] and Jacobs et al. [15] who reported an incidence of 94.52% and 83% respectively. The incidence of more than one pulmonary artery was low in this study. Two pulmonary arteries were observed in 4.5% and 2.2% of the right and left lungs respectively. Ganapathy et al. [7] with a sample size of 75 lungs reported a higher incidence of two pulmonary arteries, seen in 19.44% and 7.69% of the right and left lung. George e t al. [9] reported the highest incidence in the right lung with 67.69% of the specimens having two pulmonary arteries. Understanding the anatomy and drainage pattern of pulmonary veins is important when performing procedures such as lobar resection [37]. Among the right lungs of this study, one pulmonary vein was observed in 13.6% of the lungs. This frequency is higher compared to the study by Saha and Srimani [37] who reported an incidence of 9.26%. The incidence of three pulmonary veins was found to be 47.7% in the right lungs of this study. This is similar to studies by Jacobs et al. [15] and George et al. [9] who reported three pulmonary veins in 56% and 32.30% right lungs, respectively. Four pulmonary veins were found in 6.8% of the right lungs while 2.3% had five. This is comparable to findings by Saha and Srimani [37] who reported four pulmonary veins in 4.08% of the right lungs and five pulmonary veins in 4.08% of the right lungs. Similarly, George et al. [9] reported more than three pulmonary veins in 4.61% of the right lungs. In the left lungs, three pulmonary veins were observed in 10.9% of the cases, which is comparable to findings by Jacobs et al. [15] which reported three pulmonary veins in 17% of the left lungs. Five pulmonary veins were observed in 2.2% of the left lungs in the present study, which is similar to findings by Jacobs et al. [15] which reported an incidence of 2%. Variations in the arrangement of the structures was observed in the current study. Deviations from the usual arrangement of structures (superior-inferior and anterior-posterior) was seen in 45.5% right lungs and 23.9% left lungs. This observation does not agree with a study by Ganapathy et al. [7] which reported deviations from the usual arrangement of structures in 22.22% right lungs and 2.56% left lungs. In the present study, one right lung showed a variant superior-inferior arrangement of structures as pulmonary artery, bronchus, and pulmonary vein. A similar observation was reported by Ganapathy et al. [7] in six right lungs. According to Murlimanju et al. [29], the presence of multiple pulmonary veins, pulmonary arteries, and multiple bronchi indicates a divergence in these structures prior to reaching the lung hilum. This divergence can be caused by deviations from the usual embryonic development. Displacement of the hilum is a significant sign of pulmonary volume change (Saha and Srimani 2019). Wahengbam et al. [46] states that variant pulmonary veins are a dominant source of ectopic depolarisation, which can trigger atrial fibrillation in patients with paroxysmal atrial fibrillation. Additionally, Wahengbam et al. [46] stated that variations at the pulmonary artery increases the risk for vessel injury and procedure errors during pulmonary artery resection. Furthermore, variations at the hilum may resemble hilar masses which may potentially present difficulties for pulmonologists during clinical diagnosis [30]. Conclusion Variations in the completeness of fissures are a common occurrence, with the highest frequency of variations seen in incomplete fissures, specifically the horizontal fissure. The presence of accessory fissures was observed in both the left and right lungs, with a high prevalence of SAF and LMF. Additionally, variations in the number and arrangement of structures at the hilum are common, with the most frequent variation being the number of pulmonary veins at the right lung. It is important for surgeons and radiologist to be aware of these morphological variations as they may cause misdiagnosis and complications during surgical procedures. Declarations Declaration of interest The authors declare no conflict of interest. Funding This research received grant from the Postgraduate Publication Incentive, awarded by the Faculty Research Committee (FRC). Author Contribution The research tasks were divided among the authors as follows:• Seleka Refilwe: Conducted data collection, performed initial analysis, and drafted the original draft.• Petersen Megan: Conceptualized the study, funding acquisition, provided supervision and resources, reviewed and edited the manuscript.• Mpolokeng Kentse: Conceptualized the study, acquired funding, provided supervision and resources, reviewed and edited the manuscript. Acknowledgement The authors wish to sincerely thank those who donated their bodies to science so that anatomical research could be performed. Results from such research can potentially improve patient care and increase mankind's overall knowledge. Therefore, these donors and their families deserve our highest gratitude. References Betts JG, Desaix P, Johnson JE, Korol O, Kruse D, Poe B, Wise JA, Womble M, Young KA. (2017). Anatomy and Physiology . 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Cite Share Download PDF Status: Published Journal Publication published 10 Oct, 2024 Read the published version in Surgical and Radiologic Anatomy → Version 1 posted Editorial decision: Revision requested 22 Jul, 2024 Reviews received at journal 22 Jul, 2024 Reviewers agreed at journal 22 Jul, 2024 Reviews received at journal 22 Jul, 2024 Reviewers agreed at journal 02 Jul, 2024 Reviews received at journal 06 Jun, 2024 Reviewers agreed at journal 05 Jun, 2024 Reviewers agreed at journal 05 Jun, 2024 Reviewers invited by journal 05 Jun, 2024 Editor assigned by journal 27 May, 2024 Submission checks completed at journal 27 May, 2024 First submitted to journal 20 May, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4448370","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":311139550,"identity":"5ffecd40-5765-48cc-a921-2c740c9fb5f2","order_by":0,"name":"Kentse Mpolokeng","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABG0lEQVRIiWNgGAWjYBACCQSTuYGxAUjxE6EFrJABRINZkg1wEWK1GBwgoEWyvff4wx8VDNHm7I2ND2dU3LHbfCP5+QOGGjsG+fYDWLVI85xLbOY5w5C7s+dgs+GGM8+St91IM2xgOJbMwNiTgFWLnESOYTNjG0PuhhuJbZIP2w4nm93IATqM7QADMwMOLfJvDBt//oNp+Xc42XgGSMu/Awxs/A+wO0yCx7CBtwGqZWPDYTsDCaAWxrYDDDwS2G2R7MkxnM1zTALilxnHDidInHlmOCOxL5lHQgK7LRLHzxh8/FFjk7udvfngw56aw/b87ckPPnz4Zicn34/dFphOBgMoK7EBRAIV8+BTDwYwLfYEVY6CUTAKRsGIAwBkumTGI9QGHQAAAABJRU5ErkJggg==","orcid":"","institution":"University of Cape Town","correspondingAuthor":true,"prefix":"","firstName":"Kentse","middleName":"","lastName":"Mpolokeng","suffix":""},{"id":311139551,"identity":"aecc3b57-73ed-4c3f-b150-4e71cf326abd","order_by":1,"name":"Megan Petersen","email":"","orcid":"","institution":"University of Cape Town","correspondingAuthor":false,"prefix":"","firstName":"Megan","middleName":"","lastName":"Petersen","suffix":""},{"id":311139552,"identity":"49fef9f3-3daf-4e4a-8ec9-e7b46e4cce3b","order_by":2,"name":"Refilwe Seleka","email":"","orcid":"","institution":"University of Cape Town","correspondingAuthor":false,"prefix":"","firstName":"Refilwe","middleName":"","lastName":"Seleka","suffix":""}],"badges":[],"createdAt":"2024-05-20 10:12:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4448370/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4448370/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00276-024-03497-5","type":"published","date":"2024-10-10T15:57:43+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":58154499,"identity":"b0c31231-7323-4fd8-a60b-999f31d367bd","added_by":"auto","created_at":"2024-06-11 20:39:46","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":763909,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eMorphological variations of the right lung\u003c/strong\u003e. A) Grade I oblique and horizontal fissure separating the RSL, RML and RIL completely. B) Incomplete development of the oblique fissure causing the RSL tissue to be attached to RIL, as indicated by the white arrow. C) Grade II horizontal fissure. The horizontal fissure is partially incomplete as it does not reach the hilum. White arrow indicates where it ends. D) Grade II horizontal fissure, as indicated by the white arrow. E) Grade IV oblique and horizontal fissures, forming one lobe.\u003c/p\u003e\n\u003cp\u003eAbbreviations: RSL=right superior lobe, RML= right middle lobe, RIL= right inferior lobe.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4448370/v1/c9043eaf887165a874f9dd36.png"},{"id":58155367,"identity":"f23970cf-8912-47f2-9f2d-a0e2fe42f3bd","added_by":"auto","created_at":"2024-06-11 20:47:46","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":727577,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eMorphological variations of the left lung\u003c/strong\u003e. A) Grade I oblique fissure separating the LSL and LIL completely. B) Mediastinal surface showing Grade II oblique fissure that is partially incomplete. The oblique fissure reaches the hilum on the superior part but not on the inferior side, as indicated by the white arrowhead. C) Grade III oblique fissure. The oblique fissure is incomplete, ending at the area indicated by the white arrowhead.\u003c/p\u003e\n\u003cp\u003eAbbreviations: LIL=left inferior lobe, LSL=left superior lobe\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4448370/v1/5d8e6176d3e381e98e2cc45e.png"},{"id":58154498,"identity":"73ef1d91-d7a5-46ad-a439-91414bd951f0","added_by":"auto","created_at":"2024-06-11 20:39:46","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":839158,"visible":true,"origin":"","legend":"\u003cp\u003eAccessory fissures and lobes found in both the right and left lungs of different individuals. A) Right lung showing a superior accessory fissure, indicated by the white arrow, separating the RIL into two lobes thus resulting in four lobes. B) Mediastinal surface of the left lung showing a complete oblique fissure along with a superior accessory fissure indicated by the white arrow, forming an accessory lobe. C) The mediastinal surface of the left lung showing two left minor fissures, as indicated by the white arrows. D) Mediastinal surface of the left lung showing an inferior accessory fissure as indicated by the white arrow. Abbreviations: RSL=right superior lobe, RIL=right inferior lobe, LSL=left superior lobe; LIL= left inferior lobe, AL=accessory lobe.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4448370/v1/cb7af7149bad25bf668a5c3e.png"},{"id":58154500,"identity":"7be971b0-ac7c-42f9-b0f1-12651b1fad21","added_by":"auto","created_at":"2024-06-11 20:39:46","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":966811,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eAnatomical variations of the left pulmonary hila\u003c/strong\u003e. A) Usual morphology of the number and arrangement of structures. B) Hilum with two bronchi, one pulmonary artery and five pulmonary veins as well as a variant superior to inferior arrangement of structures (accessory pulmonary veins, pulmonary artery, eparterial bronchus, hyparterial bronchus and inferior pulmonary vein. C) Hilum with one pulmonary artery, bronchus, and pulmonary vein. D) Variant anterior-posterior arrangement of structures at hilum (pulmonary artery, pulmonary vein, and bronchus. E) Hilum with a bronchus, two pulmonary veins and two pulmonary veins.\u003c/p\u003e\n\u003cp\u003eAbbreviations: B= bronchus, PA=pulmonary artery, PV=pulmonary vein.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4448370/v1/a11f23b8fc505a0bccd6c667.png"},{"id":58154502,"identity":"f1563b8b-1431-4491-a979-f627fa3627e0","added_by":"auto","created_at":"2024-06-11 20:39:46","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":966888,"visible":true,"origin":"","legend":"\u003cp\u003eAnatomical variations of the right pulmonary hila. A) Usual morphology of the number and arrangement of the structures. B) Hilum with one bronchus, pulmonary artery and pulmonary vein. C) Hilum with four pulmonary veins and variant superior-inferior arrangement of structures (pulmonary vein and eparterial bronchus, pulmonary artery, hyparterial bronchus, pulmonary veins). D) Hilum with two pulmonary arteries, one pulmonary vein and the eparterial and hyparterial bronchus. E) Hilum with three pulmonary veins and a variant anterior-posterior arrangement of structures (pulmonary artery, pulmonary veins, bronchus).\u003c/p\u003e\n\u003cp\u003eAbbreviations: EPB= eparterial bronchus, HPA=hyparterial bronchus, PA=pulmonary artery, PV=pulmonary vein\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-4448370/v1/9bcfec0b020ad9c56a8ee77e.png"},{"id":66597413,"identity":"7a6c42a4-9508-4892-a7f8-d0bd5df2fbd1","added_by":"auto","created_at":"2024-10-14 16:10:34","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":6207107,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4448370/v1/26c0d6a6-6377-43de-93fe-d8740eeef563.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Morphological variations of fissures, lobes, and hilar pattern of the lung in a select South African sample","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe lungs, vital for respiration are positioned on either side of the mediastinum and are enclosed within their pleural sac [5]. The lungs are cone-shaped organs that consists of a concave base, an apex, three surfaces and three borders [2]. The base of each lung is positioned on the upper surface of the diaphragm, while the apex extends beyond the first rib [39]. The three surfaces of the lungs includes the costal surface lying next to the ribs and intercostal space of the thoracic wall, the mediastinal surface lie in contact with the mediastinum anteriorly and the diaphragmatic surface lie on the dome of the diaphragm [5].The borders of the lungs include the inferior border that separates the base of the lung from the costal surface, and the anterior and posterior borders converging from the costal mediastinal surfaces [3]. The left lung is smaller and has a greater length compared to the right lung due to the dome of the diaphragm being higher on the right side while the right lung has a greater width than the left lung due to the positioning of the heart extending towards the left side [38].\u003c/p\u003e \u003cp\u003eThe lungs are divided into lobes by fissures, such as the horizontal and oblique fissures which are invaginations of visceral pleura. These fissures separate the lobes almost to the hilum, allowing for easy movement and uniform expansion of the lungs during respiration [15,16]. The right lung is divided into three lobes: the superior, middle, and inferior lobes separated by horizontal and oblique fissures [25]. The left lung on the other hand, is divided into two lobes: the superior and inferior lobe, separated by an oblique fissure [8]. Additionally, the inferior border of the superior lobe of the left lung has a small tongue-like process called the lingula [27].\u003c/p\u003e \u003cp\u003eThe mediastinal surface of the lung features a triangular depression known as the hilum, through which important structures enter and exit [16]. These structures include a principal bronchus, bronchial vessels, two pulmonary veins, a pulmonary artery, lymphatics, and nerves [5]. Both the right and left lung consists of two pulmonary veins and one pulmonary artery at the hilum, however, the bronchi differ in their subdivision between the right and left lung [37]. The right bronchus branches off into the superior lobe approximately 2.5cm from the bifurcation of the trachea, with divisions above the pulmonary artery and is therefore termed the eparterial bronchus while other divisions will be below the pulmonary artery and thus termed the hyparterial bronchus [9,30]. The left bronchus branches off below the pulmonary artery therefore named the hyparterial bronchus [9]. The structures at the hilum are arranged in different patterns between the right and left lung [16]. At the right lung, from superior to inferior, the structures are arranged as follows: eparterial bronchus, pulmonary artery, hyparterial bronchus and pulmonary veins, respectively [7]. At the left lung from superior to inferior, the structures are arranged as follows: pulmonary artery, hyparterial bronchus and pulmonary veins, respectively [30]. At both the lungs, from anterior to posterior, the structures are arranged as follows: pulmonary vein, pulmonary artery, and principal bronchus [7].\u003c/p\u003e \u003cp\u003eAny deviations from the normal embryological development will bring about variations in the morphology of the lobes and fissures as well as the hilum pattern [27,7]. Knowledge of these variations, which may include absent, incomplete, and accessory fissures as well as variations in the number and arrangement of structures at the hilum is essential for planning different operative strategies for various surgical procedures such as thoracoscopic pulmonary resection or pulmonary lobectomy where a variation may cause complications [8].\u003c/p\u003e \u003cp\u003eVariability within the lung fissure morphology is well reported in the literature with studies conducted from the United States of America, Turkey, Nepal, and Ethiopia [47]. However, only a few studies have been conducted on the African population, with only three case reports from Kenya, Nigeria and Tanzania, as well as a cadaveric study conducted in Kenya have been published on this topic. Additionally, only one study by Mpolokeng et al. [28] has investigated anatomical variations in lung fissures within a South African sample. The morphology of the hilum is not well documented in the literature [37], and no paper has yet documented hilum anatomy in a South African sample. This study aims to address the variations in the morphology of lung fissures, lobes and hilar pattern observed in a South African sample.\u003c/p\u003e"},{"header":"Methods and Materials","content":"\u003cp\u003eA descriptive observational study was conducted at the Department of Human Biology Dissection halls, located in the Anatomy Building at the Faculty of Health Sciences, University of Cape Town. The study examined a total of 48 formalin-fixed bodies consisting of both females (n\u0026thinsp;=\u0026thinsp;24) and males (n\u0026thinsp;=\u0026thinsp;24), that had been previously dissected and examined by medical and postgraduate honours students. Poorly dissected lungs that lead to the destruction of lobes, fissures and the hilum structures were excluded from the study. Lungs that showed signs of surgical procedures and had severe pathologies were also excluded from the study. The lungs were analysed and recorded for the presence or absence of fissures and lobes, the completeness of fissures, the presence of accessory fissures, and the number and arrangement of structures at the hilum. Digital photographs were taken to further record the findings. The completeness of the lung fissures was analysed according to the Craig and Walker criteria, seen in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eGrading of completeness of a fissure according to Craig and Walker criteria\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrades\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCraig and Walker criteria of completeness of fissure\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade I\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eComplete fissure with entire separate lobes\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade II\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eComplete visceral cleft but parenchymal fusion at the base of the fissure\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade III\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eVisceral cleft evident for part of the fissure\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade IV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eComplete fusion of the lobes with no evident fissural line\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003ePermission to conduct the study was granted by the Cadaver Research Governance Committee: CRGC 2023/006. Every effort was made to follow all ethical guidelines and laws according to the Human Tissue Act of 2004 and the Declaration of Helsinki that pertain to the use of human cadaveric donors in anatomical research.\u003c/p\u003e \u003cp\u003eThe statistical analysis for this study was conducted using the IBM SPSS Statistics version 28 software. For the categorical data, both Chi-squared test and frequency analysis were conducted. The Chi-squared test was run to analyse the association between each pulmonary fissure variations and sex. Nevertheless, it is worth noting that all the fissure variations had expected counts of less than five, thus failing to meet the Chi-squared test criterion, which requires each subcategory to have five or more counts. Thus, it was not possible to make any valuable deductions from the Chi-squared test. Furthermore, normality tests were conducted on the categorical data using a significance level of p\u0026thinsp;\u0026lt;\u0026thinsp;0.05 and a 95% confidence interval. The results indicated that all the data had p-values below 0.05, suggesting that the fissure variations and sex had no significant relationship. For the numerical data, frequency analysis and normality tests were run with similar significant values to determine the relationship between hilar pattern variation and sex. The p-value for all the data was below 0.05, suggesting that hilar pattern variation and sex had no significant relationship.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eAnatomical variations of the lung fissures and lobes\u003c/h2\u003e \u003cp\u003eA total of 96 lungs were examined and among 92 lungs, the prevalence of variations in the oblique and horizontal fissures of 45 right and 47 left lungs were observed and recorded according to the Craig and Walker criteria in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePrevalence of oblique, and horizontal fissure variations according to Craig and Walker criteria\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLungs\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFissures\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGrade I\u003c/p\u003e \u003cp\u003en (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGrade II\u003c/p\u003e \u003cp\u003en (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eGrade III\u003c/p\u003e \u003cp\u003en (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eGrade IV\u003c/p\u003e \u003cp\u003en (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eRight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOblique\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e19 (42.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7 (15.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e18 (40.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1 (2.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHorizontal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5 (11.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2 (4.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e37 (82.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1 (2.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOblique\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e17 (36.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12 (25.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e18 (38.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eOut of the 45 right lungs studied, 11.1% (n\u0026thinsp;=\u0026thinsp;5/45) had Grade I horizontal fissures, 4.4% (n\u0026thinsp;=\u0026thinsp;2/45) had Grade II, 82.2% (n\u0026thinsp;=\u0026thinsp;37/45) had Grade III and 2.2% (n\u0026thinsp;=\u0026thinsp;1/45) had Grade IV. For the oblique fissure, 42.2% (n\u0026thinsp;=\u0026thinsp;19/45) had Grade I, 15.6% (n\u0026thinsp;=\u0026thinsp;7/45) had Grade II, 40.0% (n\u0026thinsp;=\u0026thinsp;18/45) had Grade III and 2.2% (n\u0026thinsp;=\u0026thinsp;1/45) had Grade IV. No right lung had only an absent horizontal fissure, nor was a right lung observed with solely an absent oblique fissure. However, both the horizontal and oblique fissure were absent in one lung (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e1\u003c/span\u003eE). Among the 47 left lungs, 36.2% (n\u0026thinsp;=\u0026thinsp;17/47) had Grade I oblique fissures, 25.5% (n\u0026thinsp;=\u0026thinsp;12/47) had Grade II and 38.3% (n\u0026thinsp;=\u0026thinsp;18/47) had Grade III oblique fissures. No Grade IV oblique fissure was seen in any of the left lungs.\u003c/p\u003e \u003cp\u003eThe study also recorded the number of lobes in the left and right lungs. In the right lungs, 84.4% (n\u0026thinsp;=\u0026thinsp;38/45) showed the usual morphology of three lobes (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e1\u003c/span\u003eA), 6.4% (n\u0026thinsp;=\u0026thinsp;2/45) had two lobes due an incomplete horizontal fissure, 6.7% (n\u0026thinsp;=\u0026thinsp;3/45) had four lobes due to the presence of accessory fissures and 2.2% (n\u0026thinsp;=\u0026thinsp;1/45) had a single lobe due to absence of both the horizontal and oblique fissures. In the left lungs, 93.6% (n\u0026thinsp;=\u0026thinsp;44/47) had the usual morphology of two lobes (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e2\u003c/span\u003eA), 2.1% (n\u0026thinsp;=\u0026thinsp;1/47) had a single lobe due to an incomplete oblique fissure while 4.3% (n\u0026thinsp;=\u0026thinsp;2/47) had three lobes due to the presence of accessory fissures. Figure\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows some of the anatomical variations found at the right lungs of different individuals.\u003c/p\u003e \u003cp\u003eAccessory fissures were observed in both the right and left lungs in the present study. Some of the accessory fissures are represented in Figure 3. The superior accessory fissure (SAF) was found in 8.9% (n=4/45) and 4.3% (n=2/47) of the right and left lungs respectively. The inferior accessory fissure (IAF) was found in 2.2% (n=1/45) and 2.1% (n=1/47) of the right and left lungs respectively. The left minor fissure was found in 8.5% (n=4/47) left lungs. One left lung had two left minor accessory fissures (Figure 3C).\u0026nbsp;\u003c/p\u003e\u003c/div\u003e\n\u003ch2\u003e\u003cstrong\u003eAnatomical variations at the hilum\u003c/strong\u003e\u003c/h2\u003e\n\u003cp\u003eA total of 96 lungs were examined and among 90 lungs, the incidence of variations in the hilar pattern of 46 left and 45 right lungs was observed and recorded. Variations were seen in the number and arrangement of structures found at the hilum and presented in Tables 3 and 4.\u003c/p\u003e\n\u003cp\u003eTable 3 shows a summary of the frequency of variations in the number of structures at the hilum of both the left and right lungs.\u003c/p\u003e\n\u003cp\u003eTable 3: Frequency of variations in the number of structures at the hilum of both the right and left lungs\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"690\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.014492753623188%\" rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eHilar structure\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"43.04347826086956%\" colspan=\"5\"\u003e\n \u003cp\u003e\u003cstrong\u003eLeft lung\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003en (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"45.94202898550725%\" colspan=\"5\"\u003e\n \u003cp\u003e\u003cstrong\u003eRight lung\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003en (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.227272727272727%\"\u003e\n \u003cp\u003e\u003cstrong\u003eOne\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.714285714285714%\"\u003e\n \u003cp\u003e\u003cstrong\u003eTwo\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.902597402597403%\"\u003e\n \u003cp\u003e\u003cstrong\u003eThree\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.253246753246753%\"\u003e\n \u003cp\u003e\u003cstrong\u003eFour\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.279220779220779%\"\u003e\n \u003cp\u003e\u003cstrong\u003eFive\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.714285714285714%\"\u003e\n \u003cp\u003e\u003cstrong\u003eOne\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.688311688311689%\"\u003e\n \u003cp\u003e\u003cstrong\u003eTwo\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.714285714285714%\"\u003e\n \u003cp\u003e\u003cstrong\u003eThree\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.253246753246753%\"\u003e\n \u003cp\u003e\u003cstrong\u003eFour\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.253246753246753%\"\u003e\n \u003cp\u003e\u003cstrong\u003eFive\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.982658959537572%\"\u003e\n \u003cp\u003eBronchus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.104046242774567%\"\u003e\n \u003cp\u003e42 (91.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.53757225433526%\"\u003e\n \u003cp\u003e4 (8.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.815028901734104%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.236994219653178%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.369942196531792%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.53757225433526%\"\u003e\n \u003cp\u003e15 (34.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.404624277456648%\"\u003e\n \u003cp\u003e29 (65.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.53757225433526%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.236994219653178%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.236994219653178%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.982658959537572%\"\u003e\n \u003cp\u003ePulmonary artery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.104046242774567%\"\u003e\n \u003cp\u003e45 (97.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.53757225433526%\"\u003e\n \u003cp\u003e1 (2.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.815028901734104%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.236994219653178%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.369942196531792%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.53757225433526%\"\u003e\n \u003cp\u003e42 (95.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.404624277456648%\"\u003e\n \u003cp\u003e2 (4.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.53757225433526%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.236994219653178%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.236994219653178%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.982658959537572%\"\u003e\n \u003cp\u003ePulmonary vein\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.104046242774567%\"\u003e\n \u003cp\u003e11 (23.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.53757225433526%\"\u003e\n \u003cp\u003e29 (63.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.815028901734104%\"\u003e\n \u003cp\u003e5 (10.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.236994219653178%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.369942196531792%\"\u003e\n \u003cp\u003e1 (2.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.53757225433526%\"\u003e\n \u003cp\u003e6 (13.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.404624277456648%\"\u003e\n \u003cp\u003e13 (29.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.53757225433526%\"\u003e\n \u003cp\u003e21 (47.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.236994219653178%\"\u003e\n \u003cp\u003e3 (6.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.236994219653178%\"\u003e\n \u003cp\u003e1 (2.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003eThe hilar pattern of the left and right lungs showed varying percentages regarding the number of bronchi, pulmonary arteries, and pulmonary veins. Among these, the pulmonary vein was the most variable, ranging from a minimum of one to a maximum five pulmonary veins. Furthermore, the right lung showed the highest prevalence of unusual morphology of three pulmonary veins, seen in 47.7% (n=21/45) lungs.\u003c/p\u003e\n\u003cp\u003eTable 4 shows the variations in the arrangement of the bronchi, pulmonary artery, and pulmonary vein at the hilum of both the left and right lungs.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4: Frequency of variations in the arrangement of structures at the hilum of both the left and right lungs.\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"21.02376599634369%\" rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eArrangement of structures at hilum\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.48811700182815%\" colspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eRight lung\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003en (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"39.48811700182815%\" colspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eLeft lung\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003en (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25%\"\u003e\n \u003cp\u003e\u003cstrong\u003eUsual\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25%\"\u003e\n \u003cp\u003e\u003cstrong\u003eVariant\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25%\"\u003e\n \u003cp\u003e\u003cstrong\u003eUsual\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25%\"\u003e\n \u003cp\u003e\u003cstrong\u003eVariant\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"21.02376599634369%\"\u003e\n \u003cp\u003eSuperior to inferior\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.744058500914075%\"\u003e\n \u003cp\u003e35 (79.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.744058500914075%\"\u003e\n \u003cp\u003e9 (20.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.744058500914075%\"\u003e\n \u003cp\u003e45 (97.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.744058500914075%\"\u003e\n \u003cp\u003e1 (2.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"21.02376599634369%\"\u003e\n \u003cp\u003eAnterior to posterior\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.744058500914075%\"\u003e\n \u003cp\u003e33 (75.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.744058500914075%\"\u003e\n \u003cp\u003e11 (25.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.744058500914075%\"\u003e\n \u003cp\u003e36 (78.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.744058500914075%\"\u003e\n \u003cp\u003e10 (21.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003eIn the right lungs, 79.5% (n=35/45) and 75.0% (n=33/46) lungs showed the usual pattern of structural arrangement from superior to inferior and anterior to posterior respectively (Figure 5A). However, 20.5% (n=9/45) of the right lungs deviated from the usual superior to inferior arrangement. Among the nine lungs, seven showed the following arrangement from superior to inferior: superior pulmonary vein, eparterial bronchus, pulmonary artery, hyparterial bronchus and inferior pulmonary vein (Figure 5C). One lung displayed the following arrangement: pulmonary artery, bronchus and pulmonary vein. The remaining lung showed arrangement as superior pulmonary vein, eparterial bronchus, pulmonary artery, hyparterial bronchus and inferior pulmonary vein. Furthermore, 25.0% (n=11/45) deviated from the usual anterior to posterior arrangement of structures by having the following pattern: pulmonary artery, pulmonary vein, and bronchus (Figure 5E).\u003c/p\u003e\n\u003cp\u003eIn the left lungs, 97.8% (n=45/46) and 78.3% (n=36/46) lungs had the usual structural arrangement from superior to inferior and anterior to posterior respectively (Figure 4A). Only 2.2% (n=1/46) of the left lungs had a variant superior to inferior arrangement of structures as follows: accessory pulmonary veins, pulmonary artery, eparterial bronchus, hyparterial bronchus and inferior pulmonary vein (Figure 4C). Ten lungs (21.7%) displayed a variant anterior to posterior arrangement of structures by having the following pattern: pulmonary artery, pulmonary vein and bronchus (Figure 4E).\u003c/p\u003e\n\u003cp\u003eVariant morphology of some hilum can be seen in Figure 4 and 5.\u003c/p\u003e\n\u003cp\u003eFigure 4 shows some of the variant morphology in terms of the number and arrangement of structures at the hilum of the left lungs.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe lungs develop from a combination of two types of tissue, the endodermal and mesodermal tissue [44]. The endodermal tissue develops into the mucosal lining of the bronchi, as well as the epithelial cells of the alveoli. The mesodermal tissue develops into the vasculature of the lung along with the muscles and cartilage which support the bronchi [44]. Around the fourth week of embryonic development, the respiratory diverticulum (lung bud) grows caudally from the ventral wall of the foregut into the surrounding mesenchyme [18]. The lung bud will form the trachea and two (right and left) primary bronchial buds [26]. At the beginning of the fifth week, the right bronchial bud divides into three secondary bronchial buds while the left bronchial bud divides into two [17]. During the sixth week, the secondary bronchial buds repeatedly branch into tertiary bronchial buds eventually forming bronchopulmonary segments [18]. The bronchopulmonary segments are separated by gaps which eventually get obliterated except along two planes in the right lung, forming the horizontal and oblique fissure and one plane in the left lung which becomes the oblique fissure [24]. Along these fissures, the visceral pleura is reflected and envelops the individual lobes [26]. If non-obliteration of the gaps occurs, accessory fissures may persist while complete or partial obliteration will lead to absent or incomplete fissures [23].\u003c/p\u003e\n\u003cp\u003eFurthermore, pulmonary vessels initially develop within the mesenchyme by the process vasculogenesis [7]. Pulmonary arteries develop adjacent to the conducting airways, joining the angiogenic mesenchyme of the sixth aortic arch arteries [41]. Pulmonary veins develop from mediastinal mesenchyme in the dorsal mesocardium and become separated from the airways by the growth of alveoli and lymphatic vessels [41]. Deviations from the branching morphogenesis during embryonic and early fetal periods will result in variations in the hilum [7].\u003c/p\u003e\n\u003cp\u003eVarious researchers have studied and reported their findings on variant lung anatomy as represented in Table 5, 6, and 7, which are compared to the findings of the present study.\u003c/p\u003e\n\u003cp\u003eTable 5:\u0026nbsp;Comparative prevalence of variations of oblique and horizontal fissures\u0026nbsp;in both the left and right lungs\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.70878578479763%\" rowspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003eAuthor, year\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.5153010858835145%\" rowspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003eType of study\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.08193484698914%\" rowspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003eRegion\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.62685093780849%\" rowspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003eSample (n)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"42.34945705824284%\" colspan=\"6\"\u003e\n \u003cp\u003e\u003cstrong\u003eRight lung\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.71767028627838%\" colspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003eLeft lung\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"32.76923076923077%\" colspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003eHorizontal fissure (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.38461538461539%\" colspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003eOblique fissure (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"33.84615384615385%\" colspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003eOblique fissure (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.419753086419753%\"\u003e\n \u003cp\u003e\u003cstrong\u003eComplete\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.191358024691358%\"\u003e\n \u003cp\u003e\u003cstrong\u003eIncomplete\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.104938271604938%\"\u003e\n \u003cp\u003e\u003cstrong\u003eAbsent\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.037037037037036%\"\u003e\n \u003cp\u003e\u003cstrong\u003eComplete\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.191358024691358%\"\u003e\n \u003cp\u003e\u003cstrong\u003eIncomplete\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.104938271604938%\"\u003e\n \u003cp\u003e\u003cstrong\u003eAbsent\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.037037037037036%\"\u003e\n \u003cp\u003e\u003cstrong\u003eComplete\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.191358024691358%\"\u003e\n \u003cp\u003e\u003cstrong\u003eIncomplete\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.722222222222221%\"\u003e\n \u003cp\u003e\u003cstrong\u003eAbsent\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eGesase, 2006\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eTanzania\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e102\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e7.84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e0.98\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e10.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eNene \u003cem\u003eet al.,\u003c/em\u003e 2011\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eIndia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e88\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eGhosh \u003cem\u003eet al.,\u003c/em\u003e 2013\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eIndia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e47.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e19.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e2.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e13.88\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e5.55\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eDutta \u003cem\u003eet al.,\u003c/em\u003e 2013\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eIndia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e102\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e26.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e38.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e34.62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e26.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e61.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e11.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eJacob and Pillay 2013\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eIndia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e83.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e6.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e46.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e3.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e61.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e38.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eGeorge \u003cem\u003eet al.,\u003c/em\u003e 2014\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eIndia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e138\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e61.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e35.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e3.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e96.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e3.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e84.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e15.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eMagadum \u003cem\u003eet al.,\u003c/em\u003e 2015\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eIndia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e52.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e12.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e42.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e7.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eMamatha \u003cem\u003eet al.,\u003c/em\u003e 2016\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eIndia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eKc \u003cem\u003eet al.,\u003c/em\u003e 2018\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eNepal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e52.18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e34.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e13.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e69.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e30.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e48.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e51.85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eJacobs \u003cem\u003eet al.,\u003c/em\u003e 2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eIndia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eMutua \u003cem\u003eet al.,\u003c/em\u003e 2021\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eKenya\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e47.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e42.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e10.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e63.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e36.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e65.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e34.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eWest \u003cem\u003eet al.,\u003c/em\u003e 2021\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eUnited Kingdom\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e22.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e66.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e11.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e64.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e35.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e81.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e16.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e2.47\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eRanaweeera \u003cem\u003eet al.,\u003c/em\u003e 2022\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eSri Lankan\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e84.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e15.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e42.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e57.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e66.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e33.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003eMpolokeng \u003cem\u003eet al.,\u003c/em\u003e 2022\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eSouth Africa\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e40.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e39.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e7.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e57.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e29.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e57.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e29.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e1.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"14.723320158102768%\"\u003e\n \u003cp\u003ePresent study\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.521739130434782%\"\u003e\n \u003cp\u003ecadaveric\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.090909090909092%\"\u003e\n \u003cp\u003eSouth Africa\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.632411067193676%\"\u003e\n \u003cp\u003e96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.312252964426878%\"\u003e\n \u003cp\u003e11.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e86.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e2.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e42.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e55.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.830039525691699%\"\u003e\n \u003cp\u003e2.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.707509881422925%\"\u003e\n \u003cp\u003e36.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.8063241106719365%\"\u003e\n \u003cp\u003e63.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.225296442687747%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e(- Indicates that the data was not provided)\u003c/p\u003e\n\u003cp\u003eAnalysis of the studies tabulated in Table 5 reveal that incomplete fissures are common in lungs, with a higher prevalence seen in the right lung compared to the left lung.\u003c/p\u003e\n\u003cp\u003eBased on the findings from the current study, incomplete horizontal fissures had a higher prevalence of 86.6%. This is comparable to studies by Jacob and Pillay [14] and Ranaweeera \u003cem\u003eet al.\u003c/em\u003e [36] where 83.4% and 84.6% of incomplete horizontal fissures was found, respectively. In contrast, Nene et al. [32] who examined 100 lungs, reported a relatively low prevalence of incomplete horizontal fissures, found in only 8% of the lung specimens. Similarly, a study carried out on an African sample size by Mutua et al. [31] contradicted the findings of the current study, reporting a lower incidence of incomplete horizontal fissures, present in 42.1% of the right lungs. A CT imaging study that analysed 560 cases by Manjunath et al. [25] reported an even lower incidence of 2.3% incomplete horizontal fissures while a study by Shinde and Patel [40] reported no incomplete horizontal fissures.\u003c/p\u003e\n\u003cp\u003eThe present study found a low prevalence of absent horizontal fissures, with only 2.2% Grade IV horizontal fissures observed. This is comparatively similar to a study by George \u003cem\u003eet al.\u0026nbsp;\u003c/em\u003e[9] with a sample size of 138 lungs which reported absent horizontal fissures in 3.07% of right lungs. The highest prevalence was reported by Ghosh \u003cem\u003eet al.\u0026nbsp;\u003c/em\u003e[11], which had a relatively smaller sample size of 82 lungs, compared to the 96 lungs in the present study. In their study, Ghosh \u003cem\u003eet al.\u003c/em\u003e [11] found absent horizontal fissure in 47.8% of lungs. Another study by Mamatha \u003cem\u003eet al.\u003c/em\u003e [24] reported no absent horizontal fissures.\u003c/p\u003e\n\u003cp\u003eIn the present study, the prevalence of right incomplete oblique fissures (Grade II and III) was found in 55.6% lungs, which is lower than that of incomplete horizontal fissures. This is comparable to studies by Dutta \u003cem\u003eet al.\u0026nbsp;\u003c/em\u003e[6] and Jacobs \u003cem\u003eet al.\u003c/em\u003e [15] which reported 61.54% and 51% incomplete oblique fissures, respectively. Magadum \u003cem\u003eet al.\u0026nbsp;\u003c/em\u003e[23] deviated from this observation by having a higher incidence of incomplete oblique fissures compared to incomplete horizontal fissures. Gesase \u003cem\u003eet al.\u003c/em\u003e [10], who investigated 102 lungs reported an even lower prevalence of incomplete right oblique fissures, present in 0.98% of the right lungs. According to Dutta \u003cem\u003eet al.\u0026nbsp;\u003c/em\u003e[6] a higher frequency of incomplete oblique fissures in the right lung could suggest an early onset of fusion of antenatal fissures, potentially proceeding further before birth, resulting in fusion along the base of the oblique fissure.\u003c/p\u003e\n\u003cp\u003eSimilar to the horizontal fissures, the right oblique fissure was uncommonly absent. In this study, only 2.2% of Grade IV oblique fissures were observed in the right lungs, which is similar to findings by Nene et al. [32] which reported 2% of absent left oblique fissure. This is lower than what other studies found. Studies by Prakash et al. [34]; Dutta \u003cem\u003eet al.\u003c/em\u003e [6] and\u003c/p\u003e\n\u003cp\u003eMagadum \u003cem\u003eet al.\u0026nbsp;\u003c/em\u003e[23] reported absent right oblique fissures in 7.14%, 11.54% and 10% of the lungs, respectively. On the other hand, George \u003cem\u003eet al.\u003c/em\u003e [9]; Mamatha \u003cem\u003eet al.\u003c/em\u003e [24]; Wahane and Satpute [45]; West et al. [47] and Mutua \u003cem\u003eet al.,\u003c/em\u003e [30] found no absent oblique fissures.\u003c/p\u003e\n\u003cp\u003eIn the current study, it was observed that incomplete oblique fissures were more prevalent in the left lungs when compared to the right lungs. Among the left lungs, 25.5% and 38.3% were Grade II and Grade III oblique fissures, respectively. This is similar to findings by Kc \u003cem\u003eet\u003c/em\u003e \u003cem\u003eal.\u003c/em\u003e [18] with a sample of 50 lungs, which reported incomplete oblique fissures in 51.85% of left lungs as opposed to 30.43% of right lungs.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eNotably, none of the left lungs had an absent (Grade IV) oblique fissure in this study. This is consistent with what most studies reported (Table 5). On the contrary, Prakash et al. [34]; Dutta et al. [6]; West et al. [47] reported absent left oblique fissures in 10.7%, 8%, and 2.47% of the left lungs, respectively.\u003c/p\u003e\n\u003cp\u003eSurgeons should be aware of these fissure variations that may occur as they can cause problems. As reported by Li et al. [21], an incomplete interlobar fissure increases the surgical difficulty and the probability of prolonged air leaks. Patients that had incomplete interlobar fissures and went through a video-assisted thoracoscopic lobectomy had increased overall post-operative morbidity rate and were greatly associated with pneumothorax, pleural effusion, and atelectasis [20]. Huang \u003cem\u003eet al.\u0026nbsp;\u003c/em\u003e[13] reported that incomplete pulmonary fissures were greatly associated with post-operative complications such as prolonged length of chest tube drainage and hospital stay. Koster and Slebos [19] demonstrated that the possibility of collateral ventilation is high with incomplete pulmonary fissures. Furthermore, Okamoto \u003cem\u003eet al.\u003c/em\u003e [33] reported that patients diagnosed with stage I non-small cell lung cancer (NSCLC), with incomplete fissures had higher occurrence of ipsilateral lung and lymph node metastases as well as poor prognosis compared to those with complete fissures. Similarly, Lee \u003cem\u003eet al.\u0026nbsp;\u003c/em\u003e[20] reported that patients with resected stage I adenocarcinoma with incomplete fissures had a reduced overall 5-year survival rate.\u003c/p\u003e\n\u003cp\u003eSupernumerary fissures also known as accessory fissures were found in the present study. Accessory fissures are described anatomically as clefts of varying depth lined by visceral pleura [18]. Literature describes accessory fissures as superior accessory fissure (SAF), inferior accessory fissure (IAF) also termed medial basal fissure and left minor fissure (LMF) also known as the left horizontal fissure [26]. The presence of accessory fissures at unusual locations in the lung result in anomalous lobes of the lung aerated by usual bronchus, which is commonly found in infants [27]. Accessory fissures found in the current study were compared to other studies summarised in Table 6.\u003c/p\u003e\n\u003cp\u003eTable 6: Incidence of accessory fissures in both the right and left lungs\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.78369384359401%\" rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eAuthor\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"31.44758735440932%\" colspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eRight lung\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"38.76871880199667%\" colspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003eLeft lung\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.14218009478673%\"\u003e\n \u003cp\u003e\u003cstrong\u003eSAF\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.644549763033176%\"\u003e\n \u003cp\u003e\u003cstrong\u003eIAF\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.14218009478673%\"\u003e\n \u003cp\u003e\u003cstrong\u003eSAF\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.009478672985782%\"\u003e\n \u003cp\u003e\u003cstrong\u003eIAF\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.061611374407583%\"\u003e\n \u003cp\u003e\u003cstrong\u003eLMF\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.78369384359401%\"\u003e\n \u003cp\u003eNene \u003cem\u003eet al.,\u003c/em\u003e 2011\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.645590682196339%\"\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.980033277870216%\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.78369384359401%\"\u003e\n \u003cp\u003eQuadros \u003cem\u003eet al.,\u003c/em\u003e 2014\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e8.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\"\u003e\n \u003cp\u003e5.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.645590682196339%\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.980033277870216%\"\u003e\n \u003cp\u003e17.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.78369384359401%\"\u003e\n \u003cp\u003eMagadum \u003cem\u003eet al.,\u003c/em\u003e 2015\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.645590682196339%\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.980033277870216%\"\u003e\n \u003cp\u003e7.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.78369384359401%\"\u003e\n \u003cp\u003eKc \u003cem\u003eet al.,\u003c/em\u003e 2018\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e4.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\"\u003e\n \u003cp\u003e21.73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.645590682196339%\"\u003e\n \u003cp\u003e3.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.980033277870216%\"\u003e\n \u003cp\u003e29.62\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.78369384359401%\"\u003e\n \u003cp\u003eWahengbam \u003cem\u003eet al.,\u003c/em\u003e 2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e7.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\"\u003e\n \u003cp\u003e21.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e2.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.645590682196339%\"\u003e\n \u003cp\u003e43.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.980033277870216%\"\u003e\n \u003cp\u003e29.73\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.78369384359401%\"\u003e\n \u003cp\u003eMutua \u003cem\u003eet al.,\u003c/em\u003e 2021\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\"\u003e\n \u003cp\u003e5.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.645590682196339%\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.980033277870216%\"\u003e\n \u003cp\u003e37.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.78369384359401%\"\u003e\n \u003cp\u003ePresent study\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e8.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.3044925124792%\"\u003e\n \u003cp\u003e2.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.143094841930116%\"\u003e\n \u003cp\u003e4.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.645590682196339%\"\u003e\n \u003cp\u003e2.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.980033277870216%\"\u003e\n \u003cp\u003e8.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e(- indicates that the data was not found)\u003c/p\u003e\n\u003cp\u003eIn the present study, accessory fissures were present in both the left and right lungs. Among the right lungs, superior accessory fissures (SAF) were found in 8.9% of the lungs while they were found in 4.3% of the left lungs. These findings agree with studies by Quadros \u003cem\u003eet al.,\u003c/em\u003e [34] and Wahengbam \u003cem\u003eet al.,\u003c/em\u003e [46] who reported higher incidences of superior accessory fissures in the right lungs of 8.33% and 7.14%, respectively. A study by Godwin and Tarver [12] reported that superior accessory fissures (SAF) were present in 30% of the right lungs compared to the left lungs where an incidence ranging between 5% and 14% was observed. On the contrary, Mutua et al. [31] with a sample size of 96 lungs found no superior accessory fissures in both the left and right lungs.\u003c/p\u003e\n\u003cp\u003eInferior accessory fissures (IAF) were observed in this study, with 2.2% found at the right lungs. This observation disagrees with majority of the studies which found higher incidences of IAF at the right lungs. Magadum \u003cem\u003eet al.\u0026nbsp;\u003c/em\u003e[23]; Quadros \u003cem\u003eet al.\u003c/em\u003e [35] and Nene \u003cem\u003eet al.\u003c/em\u003e [32] reported IAF in 5%, 5.5.% and 14% of the right lungs respectively. Kc \u003cem\u003eet al.,\u003c/em\u003e [18] and Wahengbam \u003cem\u003eet al.\u003c/em\u003e [46] reported high incidence of IAF in 21.73% and 21.43% of the right lungs respectively. A CT imaging study by Manjunath et al. [25] reported inferior accessory fissures in 66.7% of the right lungs.\u003c/p\u003e\n\u003cp\u003eIn the present study, 8.5% of the accessory fissures were left minor fissures (LMF) while 4.3% were left inferior accessory fissures (IAF). This incidence is lower compared to studies by Kc \u003cem\u003eet al.\u003c/em\u003e [18] and Nene et al. [32] who reported high frequencies of LMF with 29.62% and 26% incidences. In contrast, a study conducted by Wahengbam \u003cem\u003eet al.\u003c/em\u003e [46] deviated from this observation, reporting a higher prevalence (43.24%) of inferior accessory fissures (IAF) as opposed to left minor fissures (LMF).\u003c/p\u003e\n\u003cp\u003eA rare anatomical variation known as an azygous lobe, formed by the presence of an azygous fissure may be encountered in the right lung [14]. This variant is characterized by the partitioning of the right upper lobe due to the atypical course of the azygos vein, forming an additional lobe [26]. The prevalence of this variant lobe ranges from 0.4% to 1% in the general population [15]. Kc \u003cem\u003eet al.,\u003c/em\u003e [18] reported one case of an azygous lobe. However, this azygous lobe was not encountered in this study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePresence of accessory fissures may form a barrier that will prevent the spread of infection, therefore causing marginated pneumonia [46]. Accessory fissures can be misdiagnosed as atelectasis, pleural scars, pleural effusion, or walls of bullae [22]. According to Dutta \u003cem\u003eet al.\u0026nbsp;\u003c/em\u003e[6] accessory fissures can change the typical pattern of lung collapse in patients with endobronchial lesions, making it difficult to diagnose a lesion and its extent.\u003c/p\u003e\n\u003cp\u003eThe findings from the current study and their comparison with the previous studies show that there is wide variation in the prevalence of variant fissures and accessory fissures between and among populations. According to Mamatha \u003cem\u003eet al.\u003c/em\u003e [24] these differences may be a result of genetic variations and environmental factors. Furthermore, Van der Molen \u003cem\u003eet al.\u003c/em\u003e [43] who conducted a study on 9, 926 participants to determine environmental, clinical, and genetic determinants contributing to fissure completeness concluded that fissure completeness is genetically determined and independent on sex, age, and smoking status. \u0026nbsp;Dogan \u003cem\u003eet al.\u003c/em\u003e [4] states that lobar pattern abnormalities occur in conditions such as, polysplenia, and asplenia situs inversus viscerum, where these conditions cause defects in the determination of left-right asymmetry.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eVariations of the hilum structures\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eVariations at the hilum of the lungs were observed in the present study, seen in the number and arrangement of structures at both the left and right lungs. The observed findings were compared with studies tabulated in Tables 7 and 8.\u003c/p\u003e\n\u003cp\u003eTable 7:\u0026nbsp;Comparative prevalence of variations of the number of structures at the hilum of the right lung\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.817204301075268%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAuthor, year\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.913978494623656%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eRegion\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.559139784946237%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSample size\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"78.70967741935483%\" colspan=\"11\"\u003e\n \u003cp\u003e\u003cstrong\u003eRight lung structures (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.596180081855389%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1 Bronchus\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.368349249658936%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e2 Bronchi\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.368349249658936%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e3 Bronchi\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.776261937244202%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1 Vein\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.004092769440655%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e2 Veins\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.004092769440655%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e3 Veins\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.776261937244202%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e4 Veins\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.776261937244202%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e5 Veins\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.004092769440655%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1 Artery\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.004092769440655%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e2 Arteries\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.321964529331515%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e3 Arteries\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.807733619763695%\" valign=\"top\"\u003e\n \u003cp\u003eGeorge \u003cem\u003eet al.,\u003c/em\u003e 2014\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.907626208378088%\" valign=\"top\"\u003e\n \u003cp\u003eIndia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e138\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.129967776584317%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e98.46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e1.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e63.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e32.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e29.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e67.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e3.07\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.807733619763695%\" valign=\"top\"\u003e\n \u003cp\u003eMurlimanju \u003cem\u003eet al.,\u003c/em\u003e 2017\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.907626208378088%\" valign=\"top\"\u003e\n \u003cp\u003eIndia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e110\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.129967776584317%\" valign=\"top\"\u003e\n \u003cp\u003e1.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e83.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e1.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e1.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e83.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e8.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.807733619763695%\" valign=\"top\"\u003e\n \u003cp\u003eJacobs et al., 2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.907626208378088%\" valign=\"top\"\u003e\n \u003cp\u003eIndia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.129967776584317%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.807733619763695%\" valign=\"top\"\u003e\n \u003cp\u003eJames et al., 2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.907626208378088%\" valign=\"top\"\u003e\n \u003cp\u003eIndia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.129967776584317%\" valign=\"top\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.807733619763695%\" valign=\"top\"\u003e\n \u003cp\u003eSaha and Srimani 2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.907626208378088%\" valign=\"top\"\u003e\n \u003cp\u003eIndia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e103\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.129967776584317%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e79.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e16.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e6.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e63.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e22.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e4.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e4.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e63.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e6.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.807733619763695%\" valign=\"top\"\u003e\n \u003cp\u003eAmin, 2020\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.907626208378088%\" valign=\"top\"\u003e\n \u003cp\u003eEgypt\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.129967776584317%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e38\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"8.807733619763695%\" valign=\"top\"\u003e\n \u003cp\u003ePresent study\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.907626208378088%\" valign=\"top\"\u003e\n \u003cp\u003eSouth Africa\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.129967776584317%\" valign=\"top\"\u003e\n \u003cp\u003e34.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e65.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.16326530612245%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e13.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e29.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e47.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e6.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.122448979591836%\" valign=\"top\"\u003e\n \u003cp\u003e2.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e95.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.089151450053706%\" valign=\"top\"\u003e\n \u003cp\u003e4.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.552094522019334%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e(- indicates that the data was not provided)\u003c/p\u003e\n\u003cp\u003eTable 8 shows the variations of the number of hilum structures found at the left lung by previous studies.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 8: Comparative prevalence of variations of the number of structures at the hilum of the left lungs\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.118406889128094%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAuthor, year\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eRegion\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" rowspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSample size\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"75.67276641550053%\" colspan=\"11\"\u003e\n \u003cp\u003e\u003cstrong\u003eLeft lung structures (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.948790896159316%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1 Bronchus\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.091038406827881%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e2 Bronchi\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.668563300142248%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e3 Bronchi\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.965860597439545%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1 Vein\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.815078236130867%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e2 Veins\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.108108108108109%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e3 Veins\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.112375533428165%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e4 Veins\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.827880512091038%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e5 Veins\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.108108108108109%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e1 Artery\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.677098150782362%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e2 Arteries\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.677098150782362%\" valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e3 Arteries\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.118406889128094%\" valign=\"top\"\u003e\n \u003cp\u003eGeorge \u003cem\u003eet al.,\u003c/em\u003e 2014\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003eIndia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003e138\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.041980624327234%\" valign=\"top\"\u003e\n \u003cp\u003e76.74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.14962325080732%\" valign=\"top\"\u003e\n \u003cp\u003e21.91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.073196986006458%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.027987082884822%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.427341227125942%\" valign=\"top\"\u003e\n \u003cp\u003e80.82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e19.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.382131324004305%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.166846071044134%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e94.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e5.47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.118406889128094%\" valign=\"top\"\u003e\n \u003cp\u003eMurlimanju \u003cem\u003eet al.,\u003c/em\u003e 2017\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003eIndia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003e110\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.041980624327234%\" valign=\"top\"\u003e\n \u003cp\u003e51.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.14962325080732%\" valign=\"top\"\u003e\n \u003cp\u003e35.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.073196986006458%\" valign=\"top\"\u003e\n \u003cp\u003e7.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.027987082884822%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.427341227125942%\" valign=\"top\"\u003e\n \u003cp\u003e51.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e1.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.382131324004305%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.166846071044134%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e51.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e5.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.118406889128094%\" valign=\"top\"\u003e\n \u003cp\u003eJacobs et al., 2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003eIndia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003e96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.041980624327234%\" valign=\"top\"\u003e\n \u003cp\u003e43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.14962325080732%\" valign=\"top\"\u003e\n \u003cp\u003e49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.073196986006458%\" valign=\"top\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.027987082884822%\" valign=\"top\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.427341227125942%\" valign=\"top\"\u003e\n \u003cp\u003e75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.382131324004305%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.166846071044134%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.118406889128094%\" valign=\"top\"\u003e\n \u003cp\u003eJames et al., 2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003eIndia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.041980624327234%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.14962325080732%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.073196986006458%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.027987082884822%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.427341227125942%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.382131324004305%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.166846071044134%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.118406889128094%\" valign=\"top\"\u003e\n \u003cp\u003eSaha and Srimani 2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003eIndia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003e103\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.041980624327234%\" valign=\"top\"\u003e\n \u003cp\u003e53.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.14962325080732%\" valign=\"top\"\u003e\n \u003cp\u003e37.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.073196986006458%\" valign=\"top\"\u003e\n \u003cp\u003e9.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.027987082884822%\" valign=\"top\"\u003e\n \u003cp\u003e9.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.427341227125942%\" valign=\"top\"\u003e\n \u003cp\u003e68.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e14.81\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.382131324004305%\" valign=\"top\"\u003e\n \u003cp\u003e3.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.166846071044134%\" valign=\"top\"\u003e\n \u003cp\u003e3.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e62.96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e27.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e9.26E\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.118406889128094%\" valign=\"top\"\u003e\n \u003cp\u003eAmin, 2020\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003eEgypt\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.041980624327234%\" valign=\"top\"\u003e\n \u003cp\u003e79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.14962325080732%\" valign=\"top\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.073196986006458%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.027987082884822%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.427341227125942%\" valign=\"top\"\u003e\n \u003cp\u003e63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.382131324004305%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.166846071044134%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.118406889128094%\" valign=\"top\"\u003e\n \u003cp\u003ePresent study\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003eSouth Africa\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.104413347685684%\" valign=\"top\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.041980624327234%\" valign=\"top\"\u003e\n \u003cp\u003e91.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.14962325080732%\" valign=\"top\"\u003e\n \u003cp\u003e8.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.073196986006458%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.027987082884822%\" valign=\"top\"\u003e\n \u003cp\u003e23.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.427341227125942%\" valign=\"top\"\u003e\n \u003cp\u003e63.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e10.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.382131324004305%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.166846071044134%\" valign=\"top\"\u003e\n \u003cp\u003e2.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.135629709364909%\" valign=\"top\"\u003e\n \u003cp\u003e97.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e2.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.566200215285253%\" valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e(- indicates that the data was not provided)\u003c/p\u003e\n\u003cp\u003eVariations at the hilum of the lungs were observed in the present study, with majority seen in the number of pulmonary veins of both the left and right lungs. These variations may cause complications during surgical procedures, thus, it is pivotal for surgeons and clinicians to know them [29].\u003c/p\u003e\n\u003cp\u003eVariant anatomy of the bronchi arising from the trachea or from the primary bronchi like the tracheal bronchus and accessory cardiac bronchus are uncommon. Nonetheless, knowing such congenital bronchial variations is vital for diagnosis and surgical interventions involving the trachea and bronchi [36]. In the present study, the usual morphology of two bronchi (eparterial and hyparterial) in the hilum of the right lung was observed in 65.9% of the specimens. This incidence is lower compared to studies by Murlimanju et al. [30]; George \u003cem\u003eet al.\u003c/em\u003e [9]; Jacobs \u003cem\u003eet al.,\u003c/em\u003e [15] and Saha and Srimani [36] who reported two bronchi at the right hilum of 83.9%; 98%, 87% and 79.59% lungs respectively. The present study reported the highest frequency of one bronchus at the right hilum, seen in 34.1% lungs. Previous studies by Murlimanju \u003cem\u003eet al.\u003c/em\u003e [30]; George \u003cem\u003eet al.\u003c/em\u003e [9]; Jacobs \u003cem\u003eet al.,\u003c/em\u003e (2019); Saha and Srimani [36] and James \u003cem\u003eet al.\u003c/em\u003e [16] with varying sample sizes of 110, 138, 96, 103 and 50 lungs, respectively, reported lower incidences of one bronchus ranging between 0%- 16%. At the left hilum of this study, usual morphology of one bronchus was observed in 91.3% lungs while two bronchi were observed in 8.7% of the left hilum. This is not consistent with findings by George \u003cem\u003eet al.\u003c/em\u003e [9] and Murlimanju et al. [30] who reported two bronchi in and 21.9% and 35.2% of the left lungs respectively.\u003c/p\u003e\n\u003cp\u003eUnforeseen bleeding originating from the pulmonary artery may be occasionally encountered by surgeons, thus knowledge of the pulmonary artery anatomy as well as their variations is vital to avoid complications [36]. The present study observed a single pulmonary artery in 95.5% right lungs. This frequency is higher compared to a study by George \u003cem\u003eet al.,\u003c/em\u003e [9] which reported one pulmonary artery in 29.23% right lungs. Among the left lungs, 97.8% had one pulmonary artery which is similar to reports by George \u003cem\u003eet al.,\u003c/em\u003e [9] and Jacobs \u003cem\u003eet al.\u003c/em\u003e [15] who reported an incidence of 94.52% and 83% respectively. The incidence of more than one pulmonary artery was low in this study. Two pulmonary arteries were observed in 4.5% and 2.2% of the right and left lungs respectively. Ganapathy \u003cem\u003eet al.\u003c/em\u003e [7] with a sample size of 75 lungs reported a higher incidence of two pulmonary arteries, seen in 19.44% and 7.69% of the right and left lung. George e\u003cem\u003et al.\u0026nbsp;\u003c/em\u003e[9] reported the highest incidence in the right lung with 67.69% of the specimens having two pulmonary arteries.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eUnderstanding the anatomy and drainage pattern of pulmonary veins is important when performing procedures such as lobar resection [37]. Among the right lungs of this study, one pulmonary vein was observed in 13.6% of the lungs. This frequency is higher compared to the study by Saha and Srimani [37] who reported an incidence of 9.26%. The incidence of three pulmonary veins was found to be 47.7% in the right lungs of this study. This is similar to studies by Jacobs \u003cem\u003eet al.\u003c/em\u003e [15] and George \u003cem\u003eet al.\u003c/em\u003e [9] who reported three pulmonary veins in 56% and 32.30% right lungs, respectively. Four pulmonary veins were found in 6.8% of the right lungs while 2.3% had five. This is comparable to findings by Saha and Srimani [37] who reported four pulmonary veins in 4.08% of the right lungs and five pulmonary veins in 4.08% of the right lungs. Similarly, George \u003cem\u003eet al.\u003c/em\u003e [9] reported more than three pulmonary veins in 4.61% of the right lungs. In the left lungs, three pulmonary veins were observed in 10.9% of the cases, which is comparable to findings by Jacobs \u003cem\u003eet al.\u003c/em\u003e [15] which reported three pulmonary veins in 17% of the left lungs. Five pulmonary veins were observed in 2.2% of the left lungs in the present study, which is similar to findings by Jacobs \u003cem\u003eet al.\u003c/em\u003e [15] which reported an incidence of 2%.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eVariations in the arrangement of the structures was observed in the current study. Deviations from the usual arrangement of structures (superior-inferior and anterior-posterior) was seen in 45.5% right lungs and 23.9% left lungs. This observation does not agree with a study by Ganapathy \u003cem\u003eet al.\u0026nbsp;\u003c/em\u003e[7] which reported deviations from the usual arrangement of structures in 22.22% right lungs and 2.56% left lungs. In the present study, one right lung showed a variant superior-inferior arrangement of structures as pulmonary artery, bronchus, and pulmonary vein. A similar observation was reported by Ganapathy \u003cem\u003eet al.\u0026nbsp;\u003c/em\u003e[7] in six right lungs.\u003c/p\u003e\n\u003cp\u003eAccording to Murlimanju \u003cem\u003eet al.\u003c/em\u003e [29], the presence of multiple pulmonary veins, pulmonary arteries, and multiple bronchi indicates a divergence in these structures prior to reaching the lung hilum. This divergence can be caused by deviations from the usual embryonic development.\u003c/p\u003e\n\u003cp\u003eDisplacement of the hilum is a significant sign of pulmonary volume change (Saha and Srimani 2019). Wahengbam \u003cem\u003eet al.\u0026nbsp;\u003c/em\u003e[46] states that variant pulmonary veins are a dominant source of ectopic depolarisation, which can trigger atrial fibrillation in patients with paroxysmal atrial fibrillation. Additionally, Wahengbam \u003cem\u003eet al.\u003c/em\u003e [46] stated that variations at the pulmonary artery increases the risk for vessel injury and procedure errors during pulmonary artery resection. Furthermore, variations at the hilum may resemble hilar masses which may potentially present difficulties for pulmonologists during clinical diagnosis [30].\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eVariations in the completeness of fissures are a common occurrence, with the highest frequency of variations seen in incomplete fissures, specifically the horizontal fissure. The presence of accessory fissures was observed in both the left and right lungs, with a high prevalence of SAF and LMF. Additionally, variations in the number and arrangement of structures at the hilum are common, with the most frequent variation being the number of pulmonary veins at the right lung. It is important for surgeons and radiologist to be aware of these morphological variations as they may cause misdiagnosis and complications during surgical procedures.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eDeclaration of interest\u003c/h2\u003e \u003cp\u003eThe authors declare no conflict of interest.\u003c/p\u003e \u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis research received grant from the Postgraduate Publication Incentive, awarded by the Faculty Research Committee (FRC).\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eThe research tasks were divided among the authors as follows:\u0026bull; Seleka Refilwe: Conducted data collection, performed initial analysis, and drafted the original draft.\u0026bull; Petersen Megan: Conceptualized the study, funding acquisition, provided supervision and resources, reviewed and edited the manuscript.\u0026bull; Mpolokeng Kentse: Conceptualized the study, acquired funding, provided supervision and resources, reviewed and edited the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e \u003cp\u003eThe authors wish to sincerely thank those who donated their bodies to science so that anatomical research could be performed. Results from such research can potentially improve patient care and increase mankind's overall knowledge. Therefore, these donors and their families deserve our highest gratitude.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eBetts JG, Desaix P, Johnson JE, Korol O, Kruse D, Poe B, Wise JA, Womble M, Young KA. (2017). \u003cem\u003eAnatomy and Physiology\u003c/em\u003e. OpenStax , Texas https://openstax.org/books/anatomy-and-physiology/pages/1-introduction\u003c/li\u003e\n \u003cli\u003eBranca, J. J. V., Veltro, C., Guarnieri, G., Pacini, A., \u0026amp; Paternostro, F. (2023). Morphological variations of the lung: Accessory fissures and lobes. \u003cem\u003eAnatomia, Histologia, Embryologia\u003c/em\u003e. https://doi.org/10.1111/ahe.12958\u003c/li\u003e\n \u003cli\u003eChaudhry R, Bordoni B. (2022). Anatomy, Thorax, Lungs. In: StatPearls. 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Satpute C. (2015). A cadaveric study of morphological variations of lung in Vidarbha region\u003cem\u003e. International Journal of Science and Research\u003c/em\u003e (Raipur), 4(1), pp.2163-2166 https://www.ijsr.net/archive/v4i1/SUB15750.pdf\u003c/li\u003e\n \u003cli\u003eWahengbam S, Devi HR, Sharma GT, Gangmei G, Devi ND. (2019). Morphological Study of Human Lungs. \u003cem\u003eInternational Journal of Anatomy and Research\u0026nbsp;\u003c/em\u003e7(2.1):6345-6352 CT, Slim N, Steele D, Chowdhury A, Brassett C. 2021. Are textbook lungs really normal?. A cadaveric study on the anatomical and clinical importance of variations in the major lung fissures, and the incomplete right horizontal fissure. \u003cem\u003eClinical Anatomy\u003c/em\u003e 34:387 https://doi.org/10.16965/ijar.2019.115\u003c/li\u003e\n \u003cli\u003eWest CT, Slim N, Steele D, Chowdhury A, Brassett C. (2021). Are textbook lungs really normal?. A cadaveric study on the anatomical and clinical importance of variations in the major lung fissures, and the incomplete right horizontal fissure. \u003cem\u003eClinical Anatomy\u003c/em\u003e 34:387 https://doi.org/10.1002/ca.23661\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"surgical-and-radiologic-anatomy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sara","sideBox":"Learn more about [Surgical and Radiologic Anatomy](http://link.springer.com/journal/276)","snPcode":"276","submissionUrl":"https://submission.nature.com/new-submission/276/3","title":"Surgical and Radiologic Anatomy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Accessory fissures, Lung fissures, Lung lobes, Hilum pattern, Variations","lastPublishedDoi":"10.21203/rs.3.rs-4448370/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4448370/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eIntroduction:\u003c/h2\u003e \u003cp\u003eThe lungs are essential respiratory organs divided into lobes by the horizontal and oblique fissures. The mediastinal surface of each lung consists of the hilum which allows the bronchus, pulmonary vein, and pulmonary artery to enter and exit. This study aims to investigate and record the variations in the morphology of lung fissures, lobes, and hilar patterns observed in a South African sample.\u003c/p\u003e\u003ch2\u003eMethods and Materials:\u003c/h2\u003e \u003cp\u003eThis was a cross-sectional observational study with a descriptive analysis. A total of 48 formalin-fixed bodies comprising females (n\u0026thinsp;=\u0026thinsp;24) and males (n\u0026thinsp;=\u0026thinsp;24) from the Department of Human Biology at the University of Cape Town were studied. The fissures were classified according to the Craig and Walker criteria. Permission to conduct the study was given by the Cadaveric Research Governance Committee: CRGC 2023/006.\u003c/p\u003e\u003ch2\u003eResults and Discussion\u003c/h2\u003e \u003cp\u003eThe Craig and Walker classification was used to describe the frequencies of variations observed in the study. 25 right sided and 30 left sided lungs had incomplete oblique fissures. Incomplete horizontal fissures were observed in 39 right lungs. One right lung had both an absent horizontal and oblique fissure. Accessory fissures were found in five right and 7 left lungs. Regarding the hilar pattern, variations were seen in the number and arrangement of structures of both the right and left lungs.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eVariations in the completeness of fissures as well as the hilar pattern are a common occurrence. Thus, surgeons and radiologist need to be aware of these morphological variations as they may cause misdiagnosis and complications during surgical procedures.\u003c/p\u003e","manuscriptTitle":"Morphological variations of fissures, lobes, and hilar pattern of the lung in a select South African sample","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-06-11 20:39:41","doi":"10.21203/rs.3.rs-4448370/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-07-22T12:36:04+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-07-22T12:22:36+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"53794344922086979937864507202181220052","date":"2024-07-22T12:07:07+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-07-22T12:04:04+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"163677974986639078754883651805162548724","date":"2024-07-02T12:19:47+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-06-06T04:07:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"306125575571456903074850778788605651279","date":"2024-06-06T03:57:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"9373262528628641577011308749970110453","date":"2024-06-06T03:10:38+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-06-05T10:32:05+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-05-27T11:14:32+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-05-27T09:50:31+00:00","index":"","fulltext":""},{"type":"submitted","content":"Surgical and Radiologic Anatomy","date":"2024-05-20T10:10:57+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"surgical-and-radiologic-anatomy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sara","sideBox":"Learn more about [Surgical and Radiologic Anatomy](http://link.springer.com/journal/276)","snPcode":"276","submissionUrl":"https://submission.nature.com/new-submission/276/3","title":"Surgical and Radiologic Anatomy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"4aa001b1-0df5-4b6f-afd9-e7061bb3b219","owner":[],"postedDate":"June 11th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-10-14T16:05:48+00:00","versionOfRecord":{"articleIdentity":"rs-4448370","link":"https://doi.org/10.1007/s00276-024-03497-5","journal":{"identity":"surgical-and-radiologic-anatomy","isVorOnly":false,"title":"Surgical and Radiologic Anatomy"},"publishedOn":"2024-10-10 15:57:43","publishedOnDateReadable":"October 10th, 2024"},"versionCreatedAt":"2024-06-11 20:39:41","video":"","vorDoi":"10.1007/s00276-024-03497-5","vorDoiUrl":"https://doi.org/10.1007/s00276-024-03497-5","workflowStages":[]},"version":"v1","identity":"rs-4448370","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4448370","identity":"rs-4448370","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}