The rare anatomical variant of upper lobe: clinical features of 46 cases with surgical procedure

The rare anatomical variant of upper lobe: clinical features of 46 cases with surgical procedure | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research The rare anatomical variant of upper lobe: clinical features of 46 cases with surgical procedure cheng shen, guowei che This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-32282/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Primary disease in thorax associated with an azygos lobe is extremely rare. It is usually identified incidentally on chest X-ray or CT during health checkups with an incidence of up to 0.2%. This is the first study involving 46 of patients found with azygos lobe in surgery of English literature from January 1931 to October 2018. Methods PubMed, EMBASE and the Web of Science databases were searched for full-text literatures met out inclusion criteria. We summarized the clinical data, radiological manifestation, accompanying disease and treatment strategy of all patients. Results 18 eligible studies involving 46 patients were selected for this research. The mean age was 36.5 years old. There were 26 male patients and 20 female patients and the male to female ratio nearly to 1.3:1. There were many different primary diseases with azygos lobe including lung cancer (n = 8), spontaneous pneumothorax (n = 5), esophageal cancer (n = 1), pulmonary sequestration (n = 1), esophageal atresia (n = 2), hyperhidrosis (n = 29). The azygos lobe (azygos lobe in Figs. 1 and 2) is an uncommon anomaly that is found in 1% of anatomic specimens, on about 0.4% of chest radiographs and 1.2% of high resolution CT. The azygos lobe is a developmental anomaly but not a true accessory lobe. Azygos lobe of all patients was diagnosed during the operation. Conclusions Azygos lobe occurs in 0.2% of the population and can make clinical diagnosis difficult. The detection of this anomaly and clarification of its precise anatomical features are important to alert the surgeon to potential problems during surgery. General Surgery Azygos lobe Clinical characteristics Imageology Surgery Figures Figure 1 Figure 2 Figure 3 Introduction An azygos lobe is a rare congenital variant. It is recognizedincidentally on chest X-ray or CT for the duration of healthcheckups. Wrisberg firstly described the azygos lobe in 1877 thatis a variant of pulmonary anatomy and presenting in 0.1-1% of thepopulation[ 1 ].The different from other accessory lobes of anomalies of the lungis that the abnormal azygos vein crosses the apex of thelung[ 2 ]. Theazygos lobe has been recognized in both the right and left lungsfrom the studies [ 3 , 4 ]. According to the review of the literatures from the universalelectronic databases, there are only some cases reports of azygoslobe with primary thorax disease have been reported. This is thefirst study containing all the series of patients with azygos lobediagnosed in surgery in English literature. The purpose of thisstudy was to study clinical data, radiological manifestation, andtreatment strategy of patients. Methods Data sources Three universal electronic databases, PubMed, EMBASE and Web ofScience, were selected to identify the full-text English literaturepublished from 1 January 1931 to 31 October 2018. Final searchcriteria included the following keywords that were “azygos lobe”and “surgery”. Furthermore, we also manually explored the referencelists of relevant papers to detect any one included study with noduplication. The summary of the findings is listed in Table. Inclusion and exclusion criteria Inclusion criteria (i) azygos lobe were not only found in X-rays or CT, but alsodiagnosed in surgery; (ii) azygos lobe was independentlyinvestigated in original literature; (iii) manuscripts wereaccessible in the full-text literature; and (iv) only Englishlanguage manuscripts were considered for the study. Exclusion criteria (i) Letters and conference abstracts were excluded; (ii)manuscripts without full-text were excluded; (iii) manuscripts innon-English languages were not accepted; and (iv) patient withoutsurgery in report of the literature. Statistical analysis The statistical analysis was performed using IBM SPSSStatistics, version 16.0 (IBM Corporation, Armonk, NY, USA). Results In our Table, there were 26 male patients and 20 female patientsand the male to female ratio nearly to 1.3:1. The mean age was36.5 years old. All the azygos lobes were located in the rightupper lobes. The presenting symptoms were dyspnea, excessivesweating, head injury, murmur in the mesocardiac area, hemoptysis,hoarseness, vomiting according to the Table. There were lots ofdifferent primary diseases with azygos lobe including lung cancer(n = 8), spontaneous pneumothorax (n = 5), esophageal cancer(n = 1), pulmonary sequestration (n = 1), esophageal atresia(n = 2) and hyperhidrosis (n = 29). Most of them were treated withVATS. One case was operated by Robot-assisted azygos lobectomy foradenocarcinoma (Case 3). The patients with esophageal diseases weretreated with thoracotomy (Case 15, 19 and 20). Discussion Epidemiology An azygos lobe is a well-known normal variant of the lung thatwas described by Wrisberg[ 4 ].The literature has pronounced its incidencefrom 0.4% on chest radiographs to 1.2% on chest CT[ 5 – 7 ]. It arises at any age, which varied from0.9 to 76 years(Table 1 ). As in our analysis, the male to femaleratio was 1.3:1 and the mean age was 36.5 years. Table 1 Characteristics of the patients Case Symptoms Localization Accompanying disease Treatment Author 1 none right lung Adenocarcinoma VATS Samancilar.O[ 33 ] 2 dyspnoea right lung Adenocarcinoma VATS Shakir.H.A[ 19 ] 3 cough right lung Adenocarcinoma RATS Fukuhara.S[ 20 ] 4 none right lung Adenocarcinoma VATS Arai.H[ 10 ] 5 dyspnoea right lung Spontaneous pneumothorax VATS Azoury.F.M[ 15 ] 6 excessive sweating right lung Hyperhidrosis VATS Kauffman.P[ 22 ] 7 excessive sweating right lung Hyperhidrosis VATS 8 excessive sweating right lung Hyperhidrosis VATS 9 excessive sweating right lung Hyperhidrosis VATS 10 excessive sweating right lung Hyperhidrosis VATS 11 excessive sweating right lung Hyperhidrosis VATS 12 excessive sweating right lung Hyperhidrosis VATS 13 none right lung Spontaneous pneumothorax Thoracic closed drainage Betschart.T[ 16 ] 14 head injury right lung Spontaneous pneumothorax Thoracic closed drainage 15 none right lung Esophageal cancer Esophagectomy Maldjian.P.D[ 27 ] 16 murmur in the mesocardiac area right lung Pulmonary sequestrations Thoracotomy Koksal.Y[ 29 ] 17 hemoptysis and hoarseness right lung Adenocarcinoma VATS Delalieux.S[ 9 ] 18 dyspnoea right lung Spontaneous pneumothorax VATS Internullo.E[ 17 ] 19 vomiting right lung Esophageal atresia Thoracotomy Eradi.B[ 28 ] 20 vomiting right lung Esophageal atresia Thoracotomy 21 none right lung SCLC VATS Sen.S[ 34 ] 22 excessive sweating right lung Hyperhidrosis VATS Gill.A.J[ 24 ] 23 none right lung NSCLC VATS Grismer.J.T[ 35 ] 24 excessive sweating right lung Hyperhidrosis Thoracotomy Sieunarine.K[ 26 ] 25 dyspnoea right lung Spontaneous pneumothorax VATS Sadikot.R.T[ 18 ] 26 excessive sweating right lung Hyperhidrosis VATS Reisfeld.R[ 23 ] 27 excessive sweating right lung Hyperhidrosis VATS 28 excessive sweating right lung Hyperhidrosis VATS 29 excessive sweating right lung Hyperhidrosis VATS 30 excessive sweating right lung Hyperhidrosis VATS 31 excessive sweating right lung Hyperhidrosis VATS 32 excessive sweating right lung Hyperhidrosis VATS 33 excessive sweating right lung Hyperhidrosis VATS 34 excessive sweating right lung Hyperhidrosis VATS 35 excessive sweating right lung Hyperhidrosis VATS 36 excessive sweating right lung Hyperhidrosis VATS 37 excessive sweating right lung Hyperhidrosis VATS 38 excessive sweating right lung Hyperhidrosis VATS 39 excessive sweating right lung Hyperhidrosis VATS 40 excessive sweating right lung Hyperhidrosis VATS 41 excessive sweating right lung Hyperhidrosis VATS 42 excessive sweating right lung Hyperhidrosis VATS 43 excessive sweating right lung Hyperhidrosis VATS 44 excessive sweating right lung Hyperhidrosis VATS 45 excessive sweating right lung Hyperhidrosis VATS 46 none right lung Adenocarcinoma VATS Our patient Anatomy The superior surface of the developing lung will be sliced bythe azygos vein if the normal medial migration of the rightposterior cardinal vein over the apex of the lung fails in theembryo. The lobe medial to the azygos vein is developed as theazygos lobe. The upper lobe is separated into two parts by aslanting fissure. This abnormal fissure closely looks like a normallung fissure, ranging from the lung substance to within. It isclosed by apposition of the surfaces bounding it and is oval onsection. The addition tongue-shaped lobe isolated by the fissureand the material of it is free from macroscopic pathological changewith normal lung. We can see the interior of the right pleural sac after removalof the right lung from picture 1(quote from Stibbe etal[ 8 ]). The upperpart of the pleural cavity is realized to be divided into twosections by a dome-like fold seen in picture 1. The fold is areduplication of the parietal pleura. Its bowed margin is attachedalong a line on the thoracic wall; the attachment that commencesposteriorly at the fifth thoracic vertebra in right thorax passesimplicitly upwards across the posterior parts of the intercostalspaces to the middle of the second rib[ 8 ]. After that it changes downwards andforwards to the first costal gristle. The azygos vein is containedbetween two layers in the fold and the pleural fold and azygos veinare related to one another[ 8 ]. The azygos vein lies behind the esophagusand on the right of the midline till it touches the level of thesixth thoracic vertebra[ 8 ]. It dips into the material of the upperlobe and pulls down with the pleural fold. Summarizing from the literatures, the azygos lobe is dividedinto three types[ 8 ]: Type a More or less horizontal and cutting the outer (lateral) surfaceof the lung at some point between the apex and a point two inchesbelow the apex. Type b More nearly vertical and dividing the apex of the lung intolaterals halves. Type c Vertical and cutting off a small tongue-shaped lobe from theinner surface, the pedicle being attached to the upper margin ofthe root of the lung. Clinical characteristics It is very rare to find an isolated case of azygos lobe withoutany associated anomaly. From our Table, there are many primarythorax diseases with azygos lobe, such as lung cancer (n = 8),spontaneous pneumothorax (n = 5), esophageal cancer (n = 1),pulmonary sequestration (n = 1), esophageal atresia (n = 2),hyperhidrosis (n = 29). The azygos lobe is typically asymptomatic.It tends to be incidentally discovered during radiologicalinvestigation of symptoms related to primary thorax disease. In theeight patients with lung cancer, half of them are asymptomatic,even in our case. In Delalieux et al.[ 9 ] report, however, the patient presented withhemoptysis and hoarseness. In the research of patients withspontaneous pneumothorax, most of them presented with dyspnea. 29cases diagnosed as hyperhidrosis presented with excessive sweatingtypically. Imaging characteristics Chest radiographs are the most generally performed imaginglearning to evaluate the mass in the thorax, but it may not bepossible to distinguish azygos lobe from others. Typical chestX-ray shows a fine, curved line suggesting the meso-azygos and asmall nodule shaped like a tear drop telling the azygosvein[ 9 , 10 ]. Azygos lobecan be dependably diagnosed by High-resolution chest computedtomography (HRCT). In our case, HRCT scans confirmed presence of anazygos lobe and a GGO measuring 1.2 × 1.0 cm in the anteriorsegment of the right upper lobe adjacent to the arch of the azygosvein (Figs. 2 A,B). On HDCT, the azygos vein is seen as a thicker structurefollowing the same path as the fissure. The position of the azygosarch is higher than normal one [ 11 ]. The visceral and parietal layers ofpleura forming the mesoazygos are not fused, as is shown by thecommon occurrence of pleural effusion extending into the azygosfissure [ 12 , 13 ]. This statefavors mobility of the azygos vein and enables it to jump from itsusual position in the fissure and migrate to the mediastinum[ 14 ]. Becausethe repositioned azygos vein is joined to a structure whoselocation is higher than the normal anatomic path of theintramediastinal azygos vein [ 15 – 18 ]. Treatment In the group of patients with lung cancer, 8 cases were treatedwith surgical procedure. The first report of a right upperlobectomy by video-assisted thoracic surgery (VATS) in a patientwith an azygos lobe was published by Arai et al [ 10 ]. Some tumors may originatedirectly from the azygos lobe reported in several research[ 9 , 19 , 20 ]. In Fukuharaet al [ 20 ]research, they firstly reported the case with operativedemonstration of a primary adenocarcinoma arising from an azygoslobe, which was treated with robot-assisted azygos lobectomy. Asthe azygos lobe is a portion of the right upper lobe isolated bythe azygos vein and not a developmentally separate lobe, lobectomyin the patient with azygos lobe without concurrent resection of theright upper lobe is considered to be a limited resection[ 20 ]. However,an azygos lobectomy with mediastinal lymph node dissection may bean acceptable healing alternative for elderly individuals with poorpulmonary function and this method is considered to be a better wayfor preserving of postoperative pulmonary function and reducingmorbidity and mortality [ 1 , 21 ]. Some other cardiopulmonary pathologymight be existing in patients with azygos lobe so that it isimportant to keep this in mind when examining such patients. Asshowed in our case from the Table, we approached the neoplasm withmediastinal lymph node dissection and then it was removed by VATS.The azygos lobe was visible during the operation. The upper part ofthe pleural cavity was seen to be divided into two compartments bya dome-like fold and occupied the fissure. The fold is areduplication of the parietal pleura (Fig. 3 ). The presence of an azygos lobe is considered a complicatingissue, especially in cases with hyperhidrosis or spontaneouspneumothorax. An azygos lobe might have a protective effect againstthe improvement of spontaneous pneumothorax reported from somestudies [ 3 , 12 , 14 ]. Threemechanisms were offered: the reflected pleura might be limiting thesize of a potential pneumothorax; the mechanical stressestransferred to the apex of the lung will be lessening with themeso-azygos; or the changed anatomy may essentially shield againstbullae formation. As it is relatively under-inflated, there isdecreased perfusion and ventilation of the azygos lobephysiologically. The anatomical explanation for the decreasedventilation is distortion of the bronchi caused by the azygosfissure. On the other hand, the similar bronchial anatomy coulddispose the azygos lobe to air trapping and develop into emphysema,bronchiectasis, or atelectasis. VATS is used for the management ofa spontaneous pneumothorax proposing its superiority to openthoracotomy [ 15 , 17 , 18 ]. Several researches also reported the surgical difficulty inpatient with azygos lobe [ 22 – 24 ]. As the azygos vein is a thinwall, blood flow and very breakable structure, it has to be pushedaside or ligated with extreme carefulness[ 5 – 7 , 25 ]. The first case was reported by Sieunarineet al [ 26 ] in1997. It was considered that difficulty would have been experiencedin achieving haemostasis in the event of injury[ 26 ]. Azygos covered thesympathetic chain between the second and fourth thoracic ganglia.The third ganglion was the most difficult one to identify duringthe surgery [ 22 ]. When there were no venous tributaries inthe curtain, it was useful to create a window to expose thesympathetic chain [ 22 ]. At the end of VATS, it is important tocheck whether the azygos lobe has gone back to its originallocation or there is a possibility of atelectasis[ 2 – 4 , 22 ]. In patients with esophageal diseases, azygos lobe was also foundin surgery [ 27 , 28 ]. Two caseswere babies diagnosed as esophageal atresia. The overarching of theazygos vein in the extrapleural plane compromises the preferredextrapleural approach to the posterior mediastinum. Its apparentpassage through the upper lobe may be disconcerting, and doubtabout the anatomy depresses the surgeon from simply dividing it[ 27 , 28 ]. Theysuggested that once the vessel is recognized, ligation and divisionare safe and permit dissection to continue. Then Koksal et al[ 29 ] firstlyreported a child with an extralobar pulmonary sequestrations (ELPS)located in the upper posterior mediastinum associated with theazygos lobe. ELPS is a rare congenital anomaly that commonly occurson the left side [ 30 – 32 ]. In their case, ELPS tissue was receivingblood supply from the ascending aorta and right brachiocephalicartery, and draining to the superior vena cava by an accompanyingvein[ 29 ]. Conclusions An azygos lobe is a rare anomaly of the lung. Anatomicvariations may misperceive routine operations while the surgeonperforms a thoracotomy or VATS on the right side. No matter whetherwe preserve the vein or not during the surgery, the surgeon must beinformed about the disparities in vascular drainage to the azygosvein. At the same time, we should pay more attention to where theazygos vein truly drains to so that the operation will beproceeding smoothly. Preoperative contrast CT of the chest isuseful to assess the anatomic variation of the vein. Declarations Ethics approval and consent to participate All the data supporting our findings in this paper were freelydownloaded from the PubMed, EMBASE, the Web of Science and ChinaNational Knowledge Infrastructure websites. No ethical approval orwritten informed consent for participation was required. Consent for publish Not applicable. Availability of data and materials All data for this study are publicly available and are ready forthe public to download at no cost from the official websites of thePubMed, EMBASE, the Web of Science and China National KnowledgeInfrastructure. There is no need to have the formal permission touse data for this study. The sources and data robustness have beendescribed in the section of “Methods”. Competing interests The authors declare that they have no competing interests. Funding The Science and Technology Project of the Health PlanningCommittee of Sichuan（No.19PJ242）Sichuan Province Science andTechnology Support Program（No.2019-YFYF-00090-SN） Authors' contributions CS were involved in drafting the manuscript. CS madecontributions to the concepts, acquisition and analysis of thedata. CS and GC were involved in acquisition of data and preparingthe figures. GC designed and revised the manuscript. All authorshave read and approved the final manuscript. Acknowledgements We greatly appreciate the assistance of the staff of theDepartment of Thoracic Surgery, West-China Hospital, SichuanUniversity, and thank them for their efforts. Authors' Information ­ 1 Department of Thoracic Surgery, West-ChinaHospital, Sichuan University, Chengdu 610041, China *Corresponding Author: Guowei Che References Schreiner W, Mykoliuk I, Dudek W, Sirbu H.[Videothoracoscopic Sympathetic Clipping in a Patient With AzygosLobe. 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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-32282","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research","associatedPublications":[],"authors":[{"id":636086,"identity":"17b7ac9c-e1ef-4ce4-873c-764b57ac27a2","order_by":0,"name":"cheng shen","email":"","orcid":"","institution":"Sichuan University West China Hospital","correspondingAuthor":false,"prefix":"","firstName":"cheng","middleName":"","lastName":"shen","suffix":""},{"id":636087,"identity":"4e1ebcb2-1128-40fa-8256-6e309a20f3c3","order_by":1,"name":"guowei che","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9ElEQVRIiWNgGAWjYDACCSjNxsDDwPCBwYKHNC2MMxgkSNDCANTCzIPExQn4Zzcffs1TcViOj4H3mLRNjYSMwY3cAww/KrbhtuTOsTRrnjOHjdkY+JKNc45J8BjcyEtg7DlzG6cWA4kcM2PettuJbQw8ho9z2EBacgyYGdvwacn/BtJSD9RicNjiH1FacpgfA7UksIFsYWwjQovEjTQzxjln/hsCbTE27O2T4JE888bgID6/8M9IfvzhTUWavHwDj5nEj2829nzHcwwf/KjArQUI2CBxIf8AwlU4wMBwAJ96IGD+gMKVbyCgfhSMglEwCkYcAABUPk3Sxu4azAAAAABJRU5ErkJggg==","orcid":"","institution":"Sichuan University West China Hospital","correspondingAuthor":true,"prefix":"","firstName":"guowei","middleName":"","lastName":"che","suffix":""}],"badges":[],"createdAt":"2020-05-29 03:18:41","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-32282/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-32282/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":2625097,"identity":"b9ba92bf-bdcc-476a-9dbd-1ceaeadf0706","added_by":"acdc","created_at":"2020-09-25 21:01:35","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":200324,"visible":true,"origin":"acdc-manuscripts-figure","legend":"A view of the interior of the right pleural sac after removal of the right lung.","description":"{\"primaryId\":\"undefined\",\"secondaryId\":\"MMRJ-D-20-00245\",\"acdcId\":\"undefined\",\"revision\":\"undefined\",\"timestamp\":\"2020-06-03T19:21:37\",\"document\":\"manuscripts\",\"linkRel\":\"figure\"}","filename":"figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-32282/v1/figure_1.jpg"},{"id":2625098,"identity":"b760d8e9-9ff9-4868-8952-4cbfe4e77da5","added_by":"acdc","created_at":"2020-09-25 21:01:35","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1578289,"visible":true,"origin":"acdc-manuscripts-figure","legend":"Computed tomography features of the case. \nA: Chest HRCT showing azygos lobe (AL) and azygos vein (arrow); GGO in right upper lobe adjacent to azygos lobe (arrowhead). \nB: Chest HRCT also showing the arch of the azygos vein (arrow) between the azygos vein (AV) and right brachial vein (RBV)","description":"{\"primaryId\":\"undefined\",\"secondaryId\":\"MMRJ-D-20-00245\",\"acdcId\":\"undefined\",\"revision\":\"undefined\",\"timestamp\":\"2020-06-03T19:21:37\",\"document\":\"manuscripts\",\"linkRel\":\"figure\"}","filename":"figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-32282/v1/figure_2.jpg"},{"id":2625096,"identity":"cf2479db-0421-4856-bfde-9127ebfa754a","added_by":"acdc","created_at":"2020-09-25 21:01:35","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":162659,"visible":true,"origin":"acdc-manuscripts-figure","legend":"Intraoperative image of the azygos lobe.","description":"{\"primaryId\":\"undefined\",\"secondaryId\":\"MMRJ-D-20-00245\",\"acdcId\":\"undefined\",\"revision\":\"undefined\",\"timestamp\":\"2020-06-03T19:21:37\",\"document\":\"manuscripts\",\"linkRel\":\"figure\"}","filename":"figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-32282/v1/figure_3.jpg"},{"id":13538120,"identity":"462eb1c8-1fe3-40e4-b143-8df1a3be76cf","added_by":"auto","created_at":"2021-09-17 01:38:19","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":793913,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-32282/v1/9d33c33e-cd73-4b09-86f8-0efd65af2103.pdf"}],"financialInterests":"","formattedTitle":"The rare anatomical variant of upper lobe: clinical features of 46 cases with surgical procedure","fulltext":[{"header":"Introduction","content":"\u003cp\u003eAn azygos lobe is a rare congenital variant. It is recognizedincidentally on chest X-ray or CT for the duration of healthcheckups. Wrisberg firstly described the azygos lobe in 1877 thatis a variant of pulmonary anatomy and presenting in 0.1-1% of thepopulation[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].The different from other accessory lobes of anomalies of the lungis that the abnormal azygos vein crosses the apex of thelung[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Theazygos lobe has been recognized in both the right and left lungsfrom the studies [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eAccording to the review of the literatures from the universalelectronic databases, there are only some cases reports of azygoslobe with primary thorax disease have been reported. This is thefirst study containing all the series of patients with azygos lobediagnosed in surgery in English literature. The purpose of thisstudy was to study clinical data, radiological manifestation, andtreatment strategy of patients.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eData sources\u003c/h2\u003e\u003cp\u003eThree universal electronic databases, PubMed, EMBASE and Web ofScience, were selected to identify the full-text English literaturepublished from 1 January 1931 to 31 October 2018. Final searchcriteria included the following keywords that were “azygos lobe”and “surgery”. Furthermore, we also manually explored the referencelists of relevant papers to detect any one included study with noduplication. The summary of the findings is listed in Table.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003eInclusion and exclusion criteria\u003c/h2\u003e\u003cp\u003eInclusion criteria\u003c/p\u003e\u003cp\u003e(i) azygos lobe were not only found in X-rays or CT, but alsodiagnosed in surgery; (ii) azygos lobe was independentlyinvestigated in original literature; (iii) manuscripts wereaccessible in the full-text literature; and (iv) only Englishlanguage manuscripts were considered for the study.\u003c/p\u003e\u003cp\u003eExclusion criteria\u003c/p\u003e\u003cp\u003e(i) Letters and conference abstracts were excluded; (ii)manuscripts without full-text were excluded; (iii) manuscripts innon-English languages were not accepted; and (iv) patient withoutsurgery in report of the literature.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eThe statistical analysis was performed using IBM SPSSStatistics, version 16.0 (IBM Corporation, Armonk, NY, USA).\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eIn our Table, there were 26 male patients and 20 female patientsand the male to female ratio nearly to 1.3:1. The mean age was36.5\u0026nbsp;years old. All the azygos lobes were located in the rightupper lobes. The presenting symptoms were dyspnea, excessivesweating, head injury, murmur in the mesocardiac area, hemoptysis,hoarseness, vomiting according to the Table. There were lots ofdifferent primary diseases with azygos lobe including lung cancer(n = 8), spontaneous pneumothorax (n = 5), esophageal cancer(n = 1), pulmonary sequestration (n = 1), esophageal atresia(n = 2) and hyperhidrosis (n = 29). Most of them were treated withVATS. One case was operated by Robot-assisted azygos lobectomy foradenocarcinoma (Case 3). The patients with esophageal diseases weretreated with thoracotomy (Case 15, 19 and 20).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eEpidemiology\u003c/h2\u003e\u003cp\u003eAn azygos lobe is a well-known normal variant of the lung thatwas described by Wrisberg[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].The literature has pronounced its incidencefrom 0.4% on chest radiographs to 1.2% on chest CT[\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e–\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. It arises at any age, which varied from0.9 to 76 years(Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). As in our analysis, the male to femaleratio was 1.3:1 and the mean age was 36.5\u0026nbsp;years.\u003c/p\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\u003eCharacteristics of the patients\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCase\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSymptoms\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLocalization\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAccompanying disease\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eTreatment\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eAuthor\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003enone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAdenocarcinoma\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eSamancilar.O[\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003edyspnoea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAdenocarcinoma\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eShakir.H.A[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ecough\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAdenocarcinoma\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eRATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eFukuhara.S[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003enone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAdenocarcinoma\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eArai.H[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003edyspnoea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSpontaneous pneumothorax\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eAzoury.F.M[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\" morerows=\"6\" rowspan=\"7\"\u003e\u003cp\u003eKauffman.P[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003enone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSpontaneous pneumothorax\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eThoracic closed drainage\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eBetschart.T[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ehead injury\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSpontaneous pneumothorax\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eThoracic closed drainage\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003enone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eEsophageal cancer\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eEsophagectomy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eMaldjian.P.D[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003emurmur in the mesocardiac area\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003ePulmonary sequestrations\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eThoracotomy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eKoksal.Y[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ehemoptysis and hoarseness\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAdenocarcinoma\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eDelalieux.S[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003edyspnoea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSpontaneous pneumothorax\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eInternullo.E[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003evomiting\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eEsophageal atresia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eThoracotomy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eEradi.B[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003evomiting\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eEsophageal atresia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eThoracotomy\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003enone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSCLC\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eSen.S[\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eGill.A.J[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003enone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eNSCLC\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eGrismer.J.T[\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eThoracotomy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eSieunarine.K[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003edyspnoea\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSpontaneous pneumothorax\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eSadikot.R.T[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\" morerows=\"19\" rowspan=\"20\"\u003e\u003cp\u003eReisfeld.R[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e40\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e41\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e43\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e44\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eexcessive sweating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eHyperhidrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003enone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eright lung\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAdenocarcinoma\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eVATS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eOur patient\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003eAnatomy\u003c/h2\u003e\u003cp\u003eThe superior surface of the developing lung will be sliced bythe azygos vein if the normal medial migration of the rightposterior cardinal vein over the apex of the lung fails in theembryo. The lobe medial to the azygos vein is developed as theazygos lobe. The upper lobe is separated into two parts by aslanting fissure. This abnormal fissure closely looks like a normallung fissure, ranging from the lung substance to within. It isclosed by apposition of the surfaces bounding it and is oval onsection. The addition tongue-shaped lobe isolated by the fissureand the material of it is free from macroscopic pathological changewith normal lung.\u003c/p\u003e\u003cp\u003eWe can see the interior of the right pleural sac after removalof the right lung from picture 1(quote from Stibbe etal[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]). The upperpart of the pleural cavity is realized to be divided into twosections by a dome-like fold seen in picture 1. The fold is areduplication of the parietal pleura. Its bowed margin is attachedalong a line on the thoracic wall; the attachment that commencesposteriorly at the fifth thoracic vertebra in right thorax passesimplicitly upwards across the posterior parts of the intercostalspaces to the middle of the second rib[\u003cspan citationid=\"CR8\"class=\"CitationRef\"\u003e8\u003c/span\u003e]. After that it changes downwards andforwards to the first costal gristle. The azygos vein is containedbetween two layers in the fold and the pleural fold and azygos veinare related to one another[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. The azygos vein lies behind the esophagusand on the right of the midline till it touches the level of thesixth thoracic vertebra[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. It dips into the material of the upperlobe and pulls down with the pleural fold.\u003c/p\u003e\u003cp\u003eSummarizing from the literatures, the azygos lobe is dividedinto three types[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]:\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eType a\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eMore or less horizontal and cutting the outer (lateral) surfaceof the lung at some point between the apex and a point two inchesbelow the apex.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eType b\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eMore nearly vertical and dividing the apex of the lung intolaterals halves.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eType c\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eVertical and cutting off a small tongue-shaped lobe from theinner surface, the pedicle being attached to the upper margin ofthe root of the lung.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\u003ch2\u003eClinical characteristics\u003c/h2\u003e\u003cp\u003eIt is very rare to find an isolated case of azygos lobe withoutany associated anomaly. From our Table, there are many primarythorax diseases with azygos lobe, such as lung cancer (n = 8),spontaneous pneumothorax (n = 5), esophageal cancer (n = 1),pulmonary sequestration (n = 1), esophageal atresia (n = 2),hyperhidrosis (n = 29). The azygos lobe is typically asymptomatic.It tends to be incidentally discovered during radiologicalinvestigation of symptoms related to primary thorax disease. In theeight patients with lung cancer, half of them are asymptomatic,even in our case. In Delalieux et al.[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] report, however, the patient presented withhemoptysis and hoarseness. In the research of patients withspontaneous pneumothorax, most of them presented with dyspnea. 29cases diagnosed as hyperhidrosis presented with excessive sweatingtypically.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003eImaging characteristics\u003c/h2\u003e\u003cp\u003eChest radiographs are the most generally performed imaginglearning to evaluate the mass in the thorax, but it may not bepossible to distinguish azygos lobe from others. Typical chestX-ray shows a fine, curved line suggesting the meso-azygos and asmall nodule shaped like a tear drop telling the azygosvein[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Azygos lobecan be dependably diagnosed by High-resolution chest computedtomography (HRCT). In our case, HRCT scans confirmed presence of anazygos lobe and a GGO measuring 1.2 × 1.0\u0026nbsp;cm in the anteriorsegment of the right upper lobe adjacent to the arch of the azygosvein (Figs.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA,B).\u003c/p\u003e\u003cp\u003eOn HDCT, the azygos vein is seen as a thicker structurefollowing the same path as the fissure. The position of the azygosarch is higher than normal one [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. The visceral and parietal layers ofpleura forming the mesoazygos are not fused, as is shown by thecommon occurrence of pleural effusion extending into the azygosfissure [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e,\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. This statefavors mobility of the azygos vein and enables it to jump from itsusual position in the fissure and migrate to the mediastinum[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Becausethe repositioned azygos vein is joined to a structure whoselocation is higher than the normal anatomic path of theintramediastinal azygos vein [\u003cspan additionalcitationids=\"CR16 CR17\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e–\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003eTreatment\u003c/h2\u003e\u003cp\u003eIn the group of patients with lung cancer, 8 cases were treatedwith surgical procedure. The first report of a right upperlobectomy by video-assisted thoracic surgery (VATS) in a patientwith an azygos lobe was published by Arai et al [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Some tumors may originatedirectly from the azygos lobe reported in several research[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e,\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e,\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. In Fukuharaet al [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]research, they firstly reported the case with operativedemonstration of a primary adenocarcinoma arising from an azygoslobe, which was treated with robot-assisted azygos lobectomy. Asthe azygos lobe is a portion of the right upper lobe isolated bythe azygos vein and not a developmentally separate lobe, lobectomyin the patient with azygos lobe without concurrent resection of theright upper lobe is considered to be a limited resection[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. However,an azygos lobectomy with mediastinal lymph node dissection may bean acceptable healing alternative for elderly individuals with poorpulmonary function and this method is considered to be a better wayfor preserving of postoperative pulmonary function and reducingmorbidity and mortality [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Some other cardiopulmonary pathologymight be existing in patients with azygos lobe so that it isimportant to keep this in mind when examining such patients. Asshowed in our case from the Table, we approached the neoplasm withmediastinal lymph node dissection and then it was removed by VATS.The azygos lobe was visible during the operation. The upper part ofthe pleural cavity was seen to be divided into two compartments bya dome-like fold and occupied the fissure. The fold is areduplication of the parietal pleura (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\"class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe presence of an azygos lobe is considered a complicatingissue, especially in cases with hyperhidrosis or spontaneouspneumothorax. An azygos lobe might have a protective effect againstthe improvement of spontaneous pneumothorax reported from somestudies [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e,\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e,\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Threemechanisms were offered: the reflected pleura might be limiting thesize of a potential pneumothorax; the mechanical stressestransferred to the apex of the lung will be lessening with themeso-azygos; or the changed anatomy may essentially shield againstbullae formation. As it is relatively under-inflated, there isdecreased perfusion and ventilation of the azygos lobephysiologically. The anatomical explanation for the decreasedventilation is distortion of the bronchi caused by the azygosfissure. On the other hand, the similar bronchial anatomy coulddispose the azygos lobe to air trapping and develop into emphysema,bronchiectasis, or atelectasis. VATS is used for the management ofa spontaneous pneumothorax proposing its superiority to openthoracotomy [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e,\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e,\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eSeveral researches also reported the surgical difficulty inpatient with azygos lobe [\u003cspan additionalcitationids=\"CR23\"citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e–\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. As the azygos vein is a thinwall, blood flow and very breakable structure, it has to be pushedaside or ligated with extreme carefulness[\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e–\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. The first case was reported by Sieunarineet al [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e] in1997. It was considered that difficulty would have been experiencedin achieving haemostasis in the event of injury[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Azygos covered thesympathetic chain between the second and fourth thoracic ganglia.The third ganglion was the most difficult one to identify duringthe surgery [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. When there were no venous tributaries inthe curtain, it was useful to create a window to expose thesympathetic chain [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. At the end of VATS, it is important tocheck whether the azygos lobe has gone back to its originallocation or there is a possibility of atelectasis[\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e–\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn patients with esophageal diseases, azygos lobe was also foundin surgery [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e,\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Two caseswere babies diagnosed as esophageal atresia. The overarching of theazygos vein in the extrapleural plane compromises the preferredextrapleural approach to the posterior mediastinum. Its apparentpassage through the upper lobe may be disconcerting, and doubtabout the anatomy depresses the surgeon from simply dividing it[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e,\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Theysuggested that once the vessel is recognized, ligation and divisionare safe and permit dissection to continue. Then Koksal et al[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e] firstlyreported a child with an extralobar pulmonary sequestrations (ELPS)located in the upper posterior mediastinum associated with theazygos lobe. ELPS is a rare congenital anomaly that commonly occurson the left side [\u003cspan additionalcitationids=\"CR31\" citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e–\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. In their case, ELPS tissue was receivingblood supply from the ascending aorta and right brachiocephalicartery, and draining to the superior vena cava by an accompanyingvein[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e].\u003c/p\u003e\u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eAn azygos lobe is a rare anomaly of the lung. Anatomicvariations may misperceive routine operations while the surgeonperforms a thoracotomy or VATS on the right side. No matter whetherwe preserve the vein or not during the surgery, the surgeon must beinformed about the disparities in vascular drainage to the azygosvein. At the same time, we should pay more attention to where theazygos vein truly drains to so that the operation will beproceeding smoothly. Preoperative contrast CT of the chest isuseful to assess the anatomic variation of the vein.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eAll the data supporting our findings in this paper were freelydownloaded from the PubMed, EMBASE, the Web of Science and ChinaNational Knowledge Infrastructure websites. No ethical approval orwritten informed consent for participation was required.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConsent for publish\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eNot applicable.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eAll data for this study are publicly available and are ready forthe public to download at no cost from the official websites of thePubMed, EMBASE, the Web of Science and China National KnowledgeInfrastructure. There is no need to have the formal permission touse data for this study. The sources and data robustness have beendescribed in the section of “Methods”.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eThe Science and Technology Project of the Health PlanningCommittee of Sichuan（No.19PJ242）Sichuan Province Science andTechnology Support Program（No.2019-YFYF-00090-SN）\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eAuthors' contributions\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eCS were involved in drafting the manuscript. CS madecontributions to the concepts, acquisition and analysis of thedata. CS and GC were involved in acquisition of data and preparingthe figures. GC designed and revised the manuscript. All authorshave read and approved the final manuscript.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eWe greatly appreciate the assistance of the staff of theDepartment of Thoracic Surgery, West-China Hospital, SichuanUniversity, and thank them for their efforts.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eAuthors' Information\u003c/strong\u003e\u003c/p\u003e\u003cp\u003e­\u003csup\u003e1\u003c/sup\u003eDepartment of Thoracic Surgery, West-ChinaHospital, Sichuan University, Chengdu 610041, China\u003c/p\u003e\u003cp\u003e*Corresponding Author: Guowei Che\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSchreiner W, Mykoliuk I, Dudek W, Sirbu H.[Videothoracoscopic Sympathetic Clipping in a Patient With AzygosLobe. 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European radiology. 2017;27(6):2489–96.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSamancilar O, Akcam TI, Kaya SO, Sevinc S, Akcay O,Ceylan KC. Video-assisted thoracoscopic surgery (VATS) right upperlobectomy for non-small-cell lung cancer with an azygos lobe.Kardiochirurgia i torakochirurgia polska = Polish journal ofcardio-thoracic surgery. 2016;13(4):373–4.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSen S, Barutca S, Meydan N. Azygos lobe small cellcarcinoma. European journal of cardio-thoracic surgery: officialjournal of the European Association for Cardio-thoracic Surgery.2004;26(5):1041.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGrismer JT, Read RC. \u003cb\u003eDoes the mediastinal anatomycomplementing azygos lobe facilitate endotracheal balloon ruptureof the trachea?\u003c/b\u003e \u003cem\u003eSurgery\u003c/em\u003e 1998,123(2):243–244.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Azygos lobe, Clinical characteristics, Imageology, Surgery","lastPublishedDoi":"10.21203/rs.3.rs-32282/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-32282/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003ePrimary disease in thorax associated with an azygos lobe is extremely rare. It is usually identified incidentally on chest X-ray or CT during health checkups with an incidence of up to 0.2%. This is the first study involving 46 of patients found with azygos lobe in surgery of English literature from January 1931 to October 2018.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003ePubMed, EMBASE and the Web of Science databases were searched for full-text literatures met out inclusion criteria. We summarized the clinical data, radiological manifestation, accompanying disease and treatment strategy of all patients.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003e18 eligible studies involving 46 patients were selected for this research. The mean age was 36.5\u0026nbsp;years old. There were 26 male patients and 20 female patients and the male to female ratio nearly to 1.3:1. There were many different primary diseases with azygos lobe including lung cancer (n\u0026thinsp;=\u0026thinsp;8), spontaneous pneumothorax (n\u0026thinsp;=\u0026thinsp;5), esophageal cancer (n\u0026thinsp;=\u0026thinsp;1), pulmonary sequestration (n\u0026thinsp;=\u0026thinsp;1), esophageal atresia (n\u0026thinsp;=\u0026thinsp;2), hyperhidrosis (n\u0026thinsp;=\u0026thinsp;29). The azygos lobe (azygos lobe in Figs.\u0026nbsp;1 and 2) is an uncommon anomaly that is found in 1% of anatomic specimens, on about 0.4% of chest radiographs and 1.2% of high resolution CT. The azygos lobe is a developmental anomaly but not a true accessory lobe. Azygos lobe of all patients was diagnosed during the operation.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eAzygos lobe occurs in 0.2% of the population and can make clinical diagnosis difficult. The detection of this anomaly and clarification of its precise anatomical features are important to alert the surgeon to potential problems during surgery.\u003c/p\u003e","manuscriptTitle":"The rare anatomical variant of upper lobe: clinical features of 46 cases with surgical procedure","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2020-06-05 22:49:48","doi":"10.21203/rs.3.rs-32282/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e9e24cc0-3b24-49bf-be24-0ba5e84b387f","owner":[],"postedDate":"June 5th, 2020","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":114614,"name":"General Surgery"}],"tags":[],"updatedAt":"2020-06-05T22:49:49+00:00","versionOfRecord":[],"versionCreatedAt":"2020-06-05 22:49:48","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-32282","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-32282","identity":"rs-32282","version":["v1"]},"buildId":"J0_U0BvcaRcwD8yVFaRlm","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}