Pre operative C-Reactive Protein / Albumin Ratio as a predictor of conversion to open among patients undergoing laparoscopic appendicectomy: A single center Cross Sectional Study

Pre operative C-Reactive Protein / Albumin Ratio as a predictor of conversion to open among patients undergoing laparoscopic appendicectomy: A single center Cross Sectional Study | 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 Article Pre operative C-Reactive Protein / Albumin Ratio as a predictor of conversion to open among patients undergoing laparoscopic appendicectomy: A single center Cross Sectional Study Kean Leong Koay, Azlanudin Azman This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8840461/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 Patients that underwent conversion to open appendicectomy tend to suffer a worse outcome when compared to patients that underwent full laparoscopic appendicectomy, or even those that underwent primary open appendicectomy. However, there is little information among available literatures on pre operative risk factors that can predict conversion to open appendicectomy. We aim to identify whether CRP/albumin ratio can be used as an independent predictor of conversion, thus becoming a useful adjunct in the clinical decision and approach to a patient with acute or perforated appendicitis. Methods A cross-sectional retrospective study was done in the National University of Malaysia Medical Centre. Patients that are listed for laparoscopic appendicectomy between June 2023 to December 2024 were recruited and are divided based on the eventual surgery performed: full laparoscopic appendicectomy vs conversion appendicectomy. The pre operative infective markers of these patients are recorded, alongside other secondary endpoints measured, including length of surgery and rates of post operative complications. Statistical analysis was performed using SPSS version 26. Results In this study, the CRP / albumin ratio, CRP and albumin are all statistically significantly different across both arms (P < 0.05). ROC and AUC analysis revealed that among the included infective markers, CRP/albumin ratio is the most powerful predictor of conversion to open appendicectomy, even after taking potential confounding factors into account using multivariate analysis. Patients with a CRP/albumin ratio of 0.111 and above have 24 times higher odds of requiring conversion to open appendicectomy. Conclusion This study concluded that CRP/albumin ratio is a robust independent predictor of conversion to open appendicectomy, and can be useful for pre operative assessment and surgical planning for patients suffering from acute appendicitis Clinical Trial Number Clinical trial number is not applicable as our research is a cross-sectional retrospective study. Laparoscopic appendicectomy conversion appendicectomy general surgery emergency surgery Figures Figure 1 Figure 2 Background Acute appendicitis is one of the most common surgical emergencies worldwide, with an incidence of approximately 100 per 100 000 person years in the US, and 160–206 per 100 000 person-years in Asia [1]. In Malaysia, acute appendicitis accounts for approximately 1% of all hospital discharges, and surgery performed for appendicitis and its related complications constitutes about 34% of all general surgery operations [2]. To date, surgery remains the mainstay for most patients with acute appendicitis [1]. Open appendicectomy was the first surgery described for treating this condition, but with technological advancements, a novel minimally invasive laparoscopic method was introduced in the 1990s [3, 4]. Since its introduction, laparoscopic appendicectomy has become the preferred approach for acute appendicitis [5]. Laparoscopic appendicectomy offers several advantages over the open approach, including reduced blood loss, shorter hospital stay, lower rates of surgical site infection and reduced post operative pain [6]. While older studies showed that laparoscopic appendicectomy took significantly longer than open appendicectomy via the Lanz approach, recent studies reveal no significant differences, owing to advancements in both technology and surgeon skillset [6, 7]. Despite its advantages, not all cases of appendicitis can be performed entirely laparoscopically due to severe inflammatory adhesions or obscured anatomy [8, 9]. Approximately 10% of patients undergoing laparoscopic appendicectomy will require conversion to open appendicectomy, although this rate may vary across surgical centers [10]. A recent study conducted locally in Universiti Sains Malaysia found that 27.5% of patients who underwent laparoscopic appendicectomy required conversion to open appendicectomy, with only the pre-operative diagnosis of perforated appendicitis being a statistically significant predictor of conversion [11]. Other studies have identified additional factors, such as age over 40 years old, male gender, presence of diabetes, inexperienced surgeons and presence of abscess or peritonitis, which are significantly associated with a higher conversion rates [9, 10]. Compared to patients that underwent full laparoscopic appendicectomy, patients requiring conversion to open tend to suffer from a higher incidence of post operative complications [10]. This is somewhat expected, as those requiring conversion generally have a more severe disease process [10]. However, even when compared to patients who undergo primary open appendicectomy, a group with more complex disease, patients who require conversion to open still tend to experience worse outcomes, including high rates of wound infection, intra-abdominal collections, hemorrhage requiring transfusion, and perioperative renal failure [10]. Moreover, conversion appendicectomy patients tend to have a longer hospital stay and higher rates of readmission, leading to increased healthcare cost when compared to patients undergoing primary open appendicectomy [10]. However, the decision to subject a patient to either laparoscopic appendicectomy or primary open appendicectomy remains subjective and varies from center to center. To date, available literatures with regards to factors that can predict conversion appendicectomy is scarce, and mostly inconclusive. However, a pre-operative diagnosis of perforated or complicated appendicitis has been consistent among literatures to be a strong risk factor for conversion among patients undergoing laparoscopic appendicectomy [10, 11]. Several studies have demonstrated a correlation between increased levels of certain inflammatory markers and likelihood of perforated appendicitis. Among these are total white count, procalcitonin level, C-reactive protein (CRP), absolute neutrophil count, mononuclear count, among others [12, 13]. However, when compared side by side, CRP/albumin ratio (CAR) has demonstrated the best predictive capability for perforation among patients with acute appendicitis, be it among the pediatric age group, or in the adult population [12, 13]. The CRP/albumin ratio (CAR) is an infective marker and a surrogate of inflammatory disease activity that has been extensively studied in recent years. Its utility ranges from predicting disease activity in Takayasu arteritis to predicting 90-day mortality in patients suffering from severe sepsis in critical care settings [14, 15]. Additionally, CAR has been shown to be a good predictor of post operative complications in patients undergoing colorectal, upper gastrointestinal, orthopedic and cardiothoracic surgeries [16–19]. The practicality of CAR lies in the opposing effects of CRP, an acute-phase protein that increases during inflammation, and serum albumin, a negative acute-phase reactant that reduces during pro-inflammatory states [15, 20]. A recent study in Japan showed that CAR is a good predictor of conversion to open in patients undergoing laparoscopic cholecystectomy [21]. At the time of writing, there is no existing literature on the application of CAR as a predictor of conversion to open in patients undergoing laparoscopic appendicectomy. Given that these tests are inexpensive and readily available, the primary objective of this study is to determine if CAR can aid in predicting conversion to open, thus helping clinicians select patients for primary open appendicectomy, and avoid the morbidities associated with conversion appendicectomy. Methods and Analysis Study Design and Setting This study is conducted using a cross-sectional approach and includes subjects listed for laparoscopic appendicectomy between June 2023 to December 2024 in a tertiary University Hospital in Kuala Lumpur. This study included all patients above the age of 12 scheduled for laparoscopic appendicectomy within the study period. Patients with the following conditions were excluded from the study and were not included in the final data analysis: 1/ Intra-operative findings other than appendicitis, such as ruptured ovarian cyst, endometriosis, perforated gastric ulcer, pelvic inflammatory disease, etc. 2/ Subjects with a histopathological finding of a white appendix 3/ Patients who underwent conversion to open appendicectomy for non-surgical reasons, such as technical malfunction of the laparoscopic unit 4/ Patients whose primary outcome (CRP or albumin) are not available Data Collection and Definitions Recruitment was carried out via the electronic medical record system using a retrospective approach, and patients that were listed for laparoscopic appendicectomy fulfilling the inclusion criteria were included. Relevant information was extracted, including pre-operative infective markers namely C-Reactive Protein (CRP), albumin, total white count (TWC), platelet count, lymphocyte count and neutrophil count, final operation performed (full laparoscopic vs conversion appendicectomy) as well as post operative complications. The following parameters were calculated based on the collected outcomes: CRP /albumin ratio, neutrophil / lymphocyte ratio, and lymphocyte / platelet ratio. CRP/albumin ratio is calculated by dividing the CRP level by the albumin level. The neutrophil / lymphocyte ratio is calculated by dividing the neutrophil count by the lymphocyte count, whereas the lymphocyte / platelet ratio is calculated by dividing the lymphocyte count by the platelet level. Postoperative complications accounted any re-admissions, surgical site infections requiring a visit to the emergency department, or any need for re-interventions (surgical or non-surgical, such as percutaneous drainage). Any intra-abdominal collection detected using imaging modalities or based on intra-operative findings from any repeat surgeries were considered. In most of our patients, the decision for surgery is made based on clinical diagnosis of appendicitis. A minority of the patients required further imaging including ultrasound abdomen and Computed Tomography, before there were planned for surgery. Laparoscopic appendicectomies are performed by either a medical officer, registrar or a surgeon, as defined below. The surgery is performed under general anesthesia, using the standard 3-port technique. A camera port is placed via a supra- or infra-umbilical incision, followed by 2 working ports, one in the left lower quadrant and the other either in the suprapubic region or the right lower quadrant [4]. Electrocautery is the only device used in all cases. After achieving pneumoperitoneum, the four quadrants of the abdomen are inspected carefully before focusing on the appendix. The appendix is identified and the meso-appendix divided near the base [4]. The appendix is transfixed at the base, divided, and then brought out via the camera port with or without an endopouch [4]. The appendix stump is reinspected, and any peritoneal contamination is aspirated or washed with normal saline until clear. If at any point during the surgery a decision to convert to open is made, the surgeon in charge is informed beforehand. If the surgeon agrees with the decision, the surgery will proceed as a conversion to open appendicectomy. If the surgeon disagrees, the surgery is then taken over by the surgeon and proceed accordingly. Medical officers include all first and second-year candidates in the Masters of General Surgery training program, whereas registrar include third- and final-year candidates in training. Surgeons are those who have completed the 4-year Masters in General Surgery training program and have received the Malaysian National Specialist Register (NSR) recognition. Statistical analysis Analysis was performed using the latest version of SPSS (version 26; IBM Corp., USA). The demographic characteristics between the two groups are presented using descriptive statistics. Categorical data are presented in numbers and are analyzed using the Chi-squared test. Continuous data are presented as numbers or percentages and analyzed using the Student’s T-test or Mann Whitney U test, depending on whether the data follow a normal distribution (as determined by the Shapiro-Wilk test). Data that follow a normal distribution are presented as mean +/- standard deviation, whereas data that do not follow a normal distribution are displayed as median (Q1 - Q3). Significant pre-operative variables that may represent potential confounding factors (p < 0·2) are included in the multivariate analysis to determine whether these confounders influence the relationship between the infective markers and conversion rates to open appendicectomy. With conversion to open appendicectomy as the endpoint, we used receiver operating characteristic (ROC) analysis to determine and compare the area under the curve (AUC) values of each infective marker. The value with the greatest Youden index is then used to identify the ideal cutoff value for predicting conversion to open. Sensitivity, specificity, and positive and negative predictive values were calculated. Finally, we divide our data using the identified cut off value, and the odds ratio for that cutoff value was calculated. Statistical significance is defined as p < 0·05. Results Subject’s demographics and clinical characteristics Between June 2023 to December 2024, 224 patients were scheduled for laparoscopic appendicectomy in the general surgery unit at our institution. Of these, 72 patients were excluded from the study due to the following reasons: absence of primary outcome measurements (e.g., CRP or albumin levels not taken pr-operatively n = 38), histopathological diagnosis of a white appendix (n = 19), intra-operative finding of a diagnosis other than appendicitis (n = 14), and intra-operative desaturation following pneumoperitoneum (n = 1). This left a total of 152 included in the final analysis. Among the 152 included patients, 126 (82·8%) underwent full laparoscopic appendicectomy (FLA), while 26 (17·2%) required conversion to open appendicectomy (CA). Reasons for conversion included dense adhesions secondary to local inflammation preventing adequate visualization of the appendix base (n = 16), gross contamination necessitating open washout (n = 8), and an unhealthy base (n = 2). The clinical characteristics between the FLA and CA group are summarized in Table 1. Patients in the FLA group were younger on average, while the CA group had a significantly higher proportion of cases with clinically and histopathological confirmed perforated appendicitis. Across both arms, the majority of patients were Malay, followed by Chinese, Indian and others, with no statistical differences in racial distribution. This is consistent with the racial proportions of the population in Malaysia. Gender and comorbidity distribution were also similar between the groups. The FLA group had a higher percentage of cases performed by medical officers, whereas registrars and surgeons were more involved in CA cases, though this difference was not statistically significant. Expectedly, patients in the CA group had longer operative times, more postoperative complications, and extended hospital stays compared to those in the FLA group. Infective markers and ROC analysis Table 2 presents the median values and interquartile ranges (IQR) of several infective markers collected in our study, comparing their value between the 2 groups. (Table 2 .) Difference in infective markers across both FLA and CA groups, and their statistifical significance, demonstrated by the p value, based on the Mann Whitney U Test. Infective markers FLA CA Mann Whitney U Test CRP (mg/L) 2·81 (0·56–6·09) 13·5 (6·87–21·9) P < 0·001 Albumin (g/dL) 41 (39–44) 37·5 (31·8–39·3) P < 0·001 CAR 0·067 (0·123–0·159) 0·377 (0·169–0·697) P < 0·001 TWC (10 9 ) 14·05 (10·6–18) 14·45 (12·35–17·1) P = 0·261 Platelet (10 3 ) 304·5 (242·5–355) 320 (232·8–373·5) P = 0·661 NLR 6·753 (3·10–12·45) 6·870 (4·34–15·79) P = 0·24 LPR 0·006 (0·004–0·009) 0·006 (0·003–0·008) P = 0·33 CRP and the CAR were significantly higher in the CA group compared to the FLA group, and the opposite is true with albumin level, with P-values less than 0·01. Other measured infective markers, including total white cell count, platelet count, NLR and LPR, did not differ significantly between the groups. (Table 3.) Area under the Curve (AUC) value for each infective markers based on Receiver Operative Characteristic curve analysis Infective markers Area under Curve CAR 0·833 CRP 0·824 Albumin 0·766 TWC 0·570 Platelet count 0·527 NLR 0·573 LPR 0·440 Based on the receiver operator characteristic and area under the curve analysis, CAR demonstrated the highest predictive value for conversion to open appendicectomy, with an area-under the curve value at 0·833, followed by CRP (AUC: 0·824) and albumin (0·766), as shown in Table 3 and Fig. 1. Other infective markers exhibited limited predictive utility. Using the value with the highest Youden index, the optimal cutoff value is obtained, and the sensitivity, specificity, positive and negative predictive value are determined. Results are shown in Table 4. These results indicate that the CAR is the most robust predictor for conversion to open appendicectomy, outperforming CRP and albumin alone. (Fig. 1) ROC curve for CAR, CRP and Albumin (Table 4.) Optimal cut off values for CAR, CRP and albumin in predicting conversion to open based on the value with the highest Youden index. CAR CRP (mg/L) Albumin (g/dL) Optimal cutoff value 0·111 6·13 39·5 Sensitivity 92·3% 84·6% 76·9% Specificity 67·0% 77·0% 66·7% Positive predictive value (PPV) 36·4% 42·3% 32·3% Negative predictive value (NPV) 97·6% 96·0% 93·3% Odds Ratio (OR) 24 (95% CI 5–106; p < 0·001) 17·6 (95% CI: 5·6–55·1; p < 0·001) 6·67 (95% CI: 2·49 − 17·85; p < 0·001) Possible confounders and multivariate analysis Potential confounders (P < 0·2) were identified based on analysis of baseline characteristics, including Pre-operative clinical diagnosis Histopathological diagnosis Age Primary surgeon’s level of experience. Binary logistic regression was performed to account for these factors and assess their independent contributions to conversion rates, results are shown in Table 5. Elevated CAR > 0·111 remained a statistically significant independent predictor for conversion to open appendicectomy [OR = 12·857 (95% CI: 2·736–60·42; p = 0·001)] among patients undergoing laparoscopic appendicectomy. Other factors, such as age, surgeon experience and pre-operative clinical perforated appendicitis or histopathological perforated appendicitis were not statistically significant confounders. Repeated regression analysis is confirmed both CRP (p = 0·026) and albumin (p = 0·006), as independent predictor of conversion to open appendicectomy after accounting for confounders. (Table 5.) Potential confounding factors affecting prevalence of conversion to open appendicectomy and measurement of their statistical significance using binary logistic regression model analysis 95% CI for Exp (B) B SE Wald df Sig Exp (B) Lower Upper Age 0·012 0·015 0·666 1 0·415 1·012 0·983 1·041 Level of experience (MO) ·· ·· 0·638 2 0·727 ·· ·· ·· Level of experience (Reg vs MO) 0·689 0·870 0·627 1 0·428 1·991 0·362 10·947 Level of experience (Surgeon vs MO) 0·685 1·048 0·427 1 0·513 1·984 0·254 15·472 Pre-op clinical diagnosis: perforated appendicitis vs acute appendicitis 0·511 0·604 0·715 1 0·398 1·667 0·510 5·444 Histopathological diagnosis: perforated appendicitis vs acute appendicitis 1·097 0·606 3·282 1 0·070 2·996 0·914 9·821 CAR > 0·111 vs < 0·111 2·554 0·790 10·464 1 0·001 12·857 2·736 60·42 Constant -5·150 1·160 19·694 1 < 0·001 0·006 Variable(s) entered on step 1: Age, Level of Surgeon experience, pre op clinical diagnosis, histopathological diagnosis, CRP/albumin ratio level * Binary Logistic Regression statistical method is used. B: Beta coefficient for the constant in the null model SE: Standard error around the coefficient for the constant Wald and Sig: The Wald chi-square test that tests the null hypothesis that the constant is 0. df: Degrees of freedom for the Wald chi-square test Exp(B): Exponentiation of the B coefficient, which is also Odds Ratio. CRP/albumin ratio and post operative complications A Mann Whitney- U analysis revealed that CAR is not statistically different between patients who suffer from post-operative complications, and those who do not (p = 0·142). Even after dividing the dataset using CAR of 0·111 as a cut off value, the outcome remains the same: OR = 1·836 (95% CI: 0·773- 4·361; p = 0·165), as shown in Table 6. (Table 6.) CRP/albumin ratio (CAR) and prevalence of post-operative complications using cut-off value of 0.111 Post op complications No Yes Total CAR 0·111 52 14 66 Total 127 25 152 CRP/albumin ratio and duration of surgery A linear regression analysis was performed and it was found that CAR has a weak positive correlation to duration of surgery performed, with a Pearson correlation of 0·364. The scatter plot is depicted in Fig. 2. This result is statistically very significant, p 0·111, as compared to those with a value of < 0·111 (102·5 [65–145] vs 72·5 [55–90], p < 0·001) (Fig. 2) Scatterplot of duration of surgery to CRP/albumin ratio Discussion Laparoscopic appendicectomy remains the most common method of surgical treatment for patients suffering from acute appendicitis [4]. However, some patients will require conversion to open surgery due to severe inflammatory adhesions and obscuration of normal anatomy [8]. The conversion rate of laparoscopic to open appendicectomy ranges from one to ten percent, and is influenced by various factors, including perforated appendicitis, presence of intraperitoneal abscess and the experience level of the operating surgeons [9–11]. Studies comparing outcomes of patients undergoing appendicectomy indicate that patients requiring conversion suffer the most postoperative complications and morbidity compared to those undergoing either full laparoscopic appendicectomy or primary open appendicectomy. Thus, identifying risk factors for conversion is critical for better surgical planning and decision making [10]. Our study demonstrated a higher conversion to open rate among patients undergoing laparoscopic appendicectomy, at 17·2%, and there are several reasons for this. Firstly, our study excludes all patients with a histopathology of non-inflamed appendix, majority of which underwent a fully laparoscopic procedure. Moreover, our center has a high threshold for primary open appendicectomy, thus, many patients whose surgery is expected to be difficult, are still put up for laparoscopic appendicectomy, most of which eventually required conversion to open intra-operatively. In our study, CAR was significantly higher among patients who underwent conversion to open appendicectomy compared to those who had a full laparoscopic appendicectomy. Multivariate analysis revealed that CAR remained a strong independent predictor for conversion even after adjusting for potential confounders, including a clinical diagnosis and post operative histopathological diagnosis of perforated appendicitis. This finding underscores the utility of this readily available and cost-effective biochemical test in routine surgical decision-making and planning for acute or perforated appendicitis. Our ROC and AUC demonstrated that, among various infective markers, the CAR was the best predictor of conversion to open appendicectomy. The rationale for using CAR lies in the biological response to inflammation: CRP is an acute phase protein that increases at times of inflammation and infection, while albumin, the denominator in this ratio, is a negative acute phase reactant and decreases during pro-inflammatory states [15, 20]. The pathophysiology behind this rise in CRP is mediated by cytokines such as interleukin-1, interleukin-6 and interleukin-17, which stimulates liver production of CRP[22]. Conversely, albumin levels drop due to increased capillary permeability causing leakage of albumin out of the intra-vascular compartment, and the diversion of resources toward the production of other acute phase proteins [20, 23]. In severe cases of appendicitis, this divergence between CRP and albumin levels results in an elevated CAR. In this study, the primary reasons for conversion were severe inflammatory adhesions obscuring normal anatomy of the appendix and gross purulent contamination of the peritoneal cavity, both of which reflect higher disease severity. Previous studies have explored the utility of CAR in predicting complicated or perforated appendicitis. In pediatric populations, CAR has been shown to be a useful marker for predicting complicated and perforated appendicitis and outperformed other infective markers [12]. Similar findings were reported in adult populations [13]. However, to the best of our knowledge, no prior study has specifically identified CAR as a predictor of conversion to open appendicectomy. In this study, a cut-off value of 0·111 provided high sensitivity (92·3%) and moderate specificity (67%) in predicting conversion to open. The high negative predictive value (97·6%) makes it particularly effective in ruling out patients who may require conversion. CAR > 0·111 is associated with a 24-fold increased odds of requiring conversion [OR: 24 (95% CI: 5·4–106·4; p < 0·001)], even after taking into consideration other associated factors using multivariate analysis [OR : 12·9 (95% CI: 2·73–60·42; p = 0·001)]. Given the widespread availability and low cost of CRP and albumin tests, CAR can be a valuable addition to pre-operative assessment and surgical planning of patients with appendicitis. In managing appendicitis patients with a pre operative CAR of more than 0·111, heavy consideration should be given for a primary open appendicectomy, especially for inexperienced surgeons and in scenarios where the patient is critically ill. However, upfront laparoscopic appendicectomy remains a feasible option, and in the hand of an experienced surgeon, allows patients to evade the morbidity associated with open surgeries. Thus, if laparoscopic surgery is planned for this group of patients, the surgery should be carried out by, or under the supervision of an experienced surgeon. This study also revealed that older patients were more likely to undergo conversion. This could be due to diminished pain perception and a blunted inflammatory response in elderly individuals, leading to delayed diagnosis and a more severe disease state upon presentation [24]. Additionally, patients with perforated appendicitis had higher conversion rates in both pre-operative clinical and post-operative histopathological diagnoses, reflecting the more severe nature of the disease. On top of that, studies have demonstrated that CAR is a good predictor of complicated and perforated appendicitis, making perforation a possible confounder in our study [12, 13]. However, after binary logistic regression analysis to partial out all the possible confounders, neither age, preoperative nor histopathological diagnosis significantly affected our results, indicating that CAR remains a robust predictor regardless of these variables. While surgeon experience did not emerge as a statistically significant predictor of conversion to open appendicectomy, the distribution of cases among different experience levels warrants consideration. In our center, laparoscopic appendicectomies are typically performed by medical officers and registrars, with surgeons stepping in for anticipated or encountered complications. This practice may not be the same in other institutions, and further studies are needed to explore this variable. This study found that CAR does not predict post-operative complications; however, it does predict a longer operative period, with a median operating time of 72·5 minutes among patients with a CAR of 0·111. This study has several limitations. First, the single centre cross-sectional retrospective design resulted in a small sample size, and an unequal distribution of subjects between the full laparoscopic and conversion groups as well as a disparity in demographics between the two groups, including age, clinical and histological diagnosis. However, regression analysis mitigated the effect of this disparity. Second, due to the small sample size, secondary findings such as CRP/albumin ratio in predicting post op complications and duration of surgery may not be accurately concluded. Future multicenter prospective cohort studies are needed to validate our findings and generalize them to clinical practice. Third, our study did not take into account the timing in which surgery is performed, and the duration between diagnosis and surgery. Surgeries done in odd timings could possibly lead to a higher chance of conversion in order to hasten the surgery, whereas a longer waiting duration between diagnosis and surgery may cause an initial acute appendicitis to become perforated, leading to a more complex surgery. These factors can be included in future multicenter studies. Our study however, does have its strength: our categorization into pre-operative clinical diagnosis and histopathological diagnosis of acute versus perforated appendicitis allows these factors to be taken into account using binary logistic regression, thus results can be generalized to all patients suffering from appendicitis. On top of that, this study is by far the first to investigate CAR, an objective marker in predicting conversion to open among patients undergoing laparoscopic appendicectomy. . Conclusion CAR, CRP and albumin are independent predictors of conversion to open appendicectomy, with CAR demonstrating the strongest predictive power. Specifically, a CAR of > 0·111 is associated with a 24-fold higher likelihood of requiring conversion. As a low-cost and widely available marker, CAR can be integrated into clinical practice to guide surgical decision-making and improve patient outcomes in cases of acute appendicitis. Further multicenter studies are needed to validate these findings. Declarations Ethics approval and consent to participate This study was submitted to and approved by the Research Ethics committee of the Research and Innovation Secretariat of the Medical Faculty of National University of Malaysia. The project code is FF-2024-025, and the authors are given ethical approval to conduct research in the National University of Malaysia, with the ethics reference number of JEP-2023-970. This research adheres to the Declaration of Helsinki. The requirement for consent was waived owing to the retrospective nature of this study, in accordance to the guidelines coded: UKM-JEP-GP00 by the Research Ethics Committee, National University of Malaysia. Research Registration Code: JEP-2023-970 Project Code: FF-2024-025 Trial Registration Number: Not applicable Consent for Publication Patient consent is not applicable to our research, patient and /or the public are not involved in the design, conduct or dissemination of this research. Availability of data and materials All data relevant to this study is uploaded as online supplemental information and is made available at Harvard Dataverse Repository, [https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/D6VEOH] Competing Interest The authors declare that they have no competing interest. Funding No funding was received for conducting this study. Funding from the University, however, is made available solely for the purpose of publication. Author Contributions Kean Leong Koay conceived the idea of this study. Kean Leong Koay and Azlanudin Azman designed the study. Kean Leong Koay is a postgraduate student who worked on the study and administered the research under the guidance of Azlanudin Azman, who acted as his supervisor for this postgraduate project. Kean Leong Koay and Azlanudin Azman analyzed the data, Kean Leong Koay wrote the paper and all authors have read and approved this paper. Acknowledgements The authors thank the medical records and information technology departments of Hospital Canselor Tuanku Muhriz, UKM. References Baird DLH, Simillis C, Kontovounisios C, Rasheed S, Tekkis PP. Acute appendicitis. Bmj. 2017;357:j1703. doi: 10.1136/bmj.j1703. Lee HY, Jayalakshmi P, Noori SH. Acute appendicitis--the University Hospital experience. Med J Malaysia. 1993;48(1):17-27. McBurney C. II. The Indications for Early Laparotomy in Appendicitis. Ann Surg. 1891;13(4):233-54. doi: 10.1097/00000658-189101000-00061. Gangal HT, Gangal MH. Laparoscopic appendicectomy. Endoscopy. 1987;19(3):127-9. doi: 10.1055/s-2007-1018257. Korndorffer JR, Jr., Fellinger E, Reed W. SAGES guideline for laparoscopic appendectomy. Surg Endosc. 2010;24(4):757-61. doi: 10.1007/s00464-009-0632-y. Shimoda M, Maruyama T, Nishida K, Suzuki K, Tago T, Shimazaki J, et al. Comparison of clinical outcome of laparoscopic versus open appendectomy, single center experience. Heliyon. 2018;4(5):e00635. doi: https://doi.org/10.1016/j.heliyon.2018.e00635. Martin LC, Puente I, Sosa JL, Bassin A, Breslaw R, McKenney MG, et al. Open versus laparoscopic appendectomy. A prospective randomized comparison. Ann Surg. 1995;222(3):256-61; discussion 61-2. doi: 10.1097/00000658-199509000-00004. Sakpal SV, Bindra SS, Chamberlain RS. Laparoscopic appendectomy conversion rates two decades later: an analysis of surgeon and patient-specific factors resulting in open conversion. J Surg Res. 2012;176(1):42-9. doi: 10.1016/j.jss.2011.07.019. Liu SI, Siewert B, Raptopoulos V, Hodin RA. Factors associated with conversion to laparotomy in patients undergoing laparoscopic appendectomy. J Am Coll Surg. 2002;194(3):298-305. doi: 10.1016/s1072-7515(01)01164-4. Finnerty BM, Wu X, Giambrone GP, Gaber-Baylis LK, Zabih R, Bhat A, et al. Conversion-to-open in laparoscopic appendectomy: A cohort analysis of risk factors and outcomes. Int J Surg. 2017;40:169-75. doi: 10.1016/j.ijsu.2017.03.016. Pushpanathan NR, Hashim MNM, Zahari Z, Aziz S, Zain WZW, Ramely R, et al. Conversion rate and risk factors of conversion to open in laparoscopic appendicectomy. Ann Coloproctol. 2022;38(6):409-14. doi: 10.3393/ac.2020.00437.0062. Hou J, Feng W, Liu W, Hou J, Die X, Sun J, et al. The use of the ratio of C-reactive protein to albumin for the diagnosis of complicated appendicitis in children. The American Journal of Emergency Medicine. 2022;52:148-54. doi: https://doi.org/10.1016/j.ajem.2021.12.007. Yuksel ME, Ozkan N, Avci E. C-reactive protein/albumin ratio greater than 7.1 is a good candidate to be used as an inflammation biomarker to predict perforation in appendicitis. Eur Rev Med Pharmacol Sci. 2022;26(22):8333-41. doi: 10.26355/eurrev_202211_30366. Seringec Akkececi N, Yildirim Cetin G, Gogebakan H, Acipayam C. The C-Reactive Protein/Albumin Ratio and Complete Blood Count Parameters as Indicators of Disease Activity in Patients with Takayasu Arteritis. Med Sci Monit. 2019;25:1401-9. doi: 10.12659/msm.912495. Ranzani OT, Zampieri FG, Forte DN, Azevedo LC, Park M. C-reactive protein/albumin ratio predicts 90-day mortality of septic patients. PLoS One. 2013;8(3):e59321. doi: 10.1371/journal.pone.0059321. Ge X, Cao Y, Wang H, Ding C, Tian H, Zhang X, et al. Diagnostic accuracy of the postoperative ratio of C-reactive protein to albumin for complications after colorectal surgery. World J Surg Oncol. 2017;15(1):15. doi: 10.1186/s12957-016-1092-1. Lee JW, Sharma AR, Lee SS, Chun WJ, Kim HS. The C-reactive protein to albumin ratio predicts postoperative complication in patients who undergo gastrectomy for gastric cancer. Heliyon. 2020;6(6):e04220. doi: 10.1016/j.heliyon.2020.e04220. Kim HJ, Lee S, Kim SH, Lee S, Sim JH, Ro YJ. Association of C-reactive protein to albumin ratio with postoperative delirium and mortality in elderly patients undergoing hip fracture surgery: A retrospective cohort study in a single large center. Exp Gerontol. 2023;172:112068. doi: 10.1016/j.exger.2022.112068. Karabacak K, Kubat E, Akyol FB, Kadan M, Erol G, Doğancı S, et al. The C-reactive protein/albumin ratio as a new predictor for postoperative atrial fibrillation after coronary artery bypass graft surgery. J Card Surg. 2020;35(10):2747-53. doi: 10.1111/jocs.14898. Quinlan GJ, Martin GS, Evans TW. Albumin: biochemical properties and therapeutic potential. Hepatology. 2005;41(6):1211-9. doi: 10.1002/hep.20720. Utsumi M, Inagaki M, Kitada K, Tokunaga N, Yunoki K, Sakurai Y, et al. C-reactive Protein-to-Albumin Ratio Predicts Conversion from Laparoscopic to Open Cholecystectomy in Acute Cholecystitis. In Vivo. 2023;37(2):887-93. doi: 10.21873/invivo.13157. Eklund CM. Proinflammatory cytokines in CRP baseline regulation. Adv Clin Chem. 2009;48:111-36. doi: 10.1016/s0065-2423(09)48005-3. Soeters PB, Wolfe RR, Shenkin A. Hypoalbuminemia: Pathogenesis and Clinical Significance. JPEN J Parenter Enteral Nutr. 2019;43(2):181-93. doi: 10.1002/jpen.1451. Lapsa S, Ozolins A, Strumfa I, Gardovskis J. Acute Appendicitis in the Elderly: A Literature Review on an Increasingly Frequent Surgical Problem. Geriatrics (Basel). 2021;6(3). doi: 10.3390/geriatrics6030093. Table 1 Table 1 is available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Table1.docx Cite Share Download PDF Status: Posted Version 1 posted 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-8840461","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":615977490,"identity":"bf3046f5-81a7-4161-8d81-7e9921b317e5","order_by":0,"name":"Kean Leong Koay","email":"","orcid":"","institution":"National University of Malaysia","correspondingAuthor":false,"prefix":"","firstName":"Kean","middleName":"Leong","lastName":"Koay","suffix":""},{"id":615977492,"identity":"1f3878a1-5c3c-455f-9af8-170b49032fa1","order_by":1,"name":"Azlanudin Azman","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0ElEQVRIiWNgGAWjYDCCA0D8gIFBjoEHxGMjVksCA4Mx6VoSG4jWwnf78OMPCTV30jecOZ3A8KHsMIPujAT8WiTPpRkYJBx7lrvhbO8GxhnnDjOY3SCgxeAMg0FCAtvh3A3neTcw87YRpYX9w4GEf4fTDUBa/hKnhcewIbHtcIIB0GHMjMRokTzDU8yQ2HfYcOaZsxsO9pxL5zE78wC/Fr4z7Js/fPh2WJ7vTO7GBz/KrOXMjhOwBQUcAGIeBgFStEAA/wGStYyCUTAKRsHwBgCHNU7L8vsthwAAAABJRU5ErkJggg==","orcid":"","institution":"National University of Malaysia","correspondingAuthor":true,"prefix":"","firstName":"Azlanudin","middleName":"","lastName":"Azman","suffix":""}],"badges":[],"createdAt":"2026-02-10 11:42:50","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8840461/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8840461/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106403397,"identity":"1fd03734-68c8-4b87-b9cd-d518b28a95a4","added_by":"auto","created_at":"2026-04-08 09:14:12","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":56351,"visible":true,"origin":"","legend":"\u003cp\u003eROC curve for CAR, CRP and Albumin\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8840461/v1/9adf79bb05650a8bba8f8dc8.png"},{"id":106255394,"identity":"9959e872-0e87-47ff-b877-df237c4612af","added_by":"auto","created_at":"2026-04-06 18:43:14","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":94076,"visible":true,"origin":"","legend":"\u003cp\u003eScatterplot of duration of surgery to CRP/albumin ratio\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8840461/v1/31b7170cf127c865d536d17f.png"},{"id":108421358,"identity":"c61f5281-3866-48fe-88f6-85a35fd70545","added_by":"auto","created_at":"2026-05-04 12:40:42","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":428120,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8840461/v1/de155fd1-aa5a-47d1-9a91-d5d3ae2b19fd.pdf"},{"id":106255392,"identity":"96fca888-28aa-4365-b9cb-271f3a4e8a35","added_by":"auto","created_at":"2026-04-06 18:43:14","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":16921,"visible":true,"origin":"","legend":"","description":"","filename":"Table1.docx","url":"https://assets-eu.researchsquare.com/files/rs-8840461/v1/1a7e08e230da2a96fd26d8c5.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Pre operative C-Reactive Protein / Albumin Ratio as a predictor of conversion to open among patients undergoing laparoscopic appendicectomy: A single center Cross Sectional Study","fulltext":[{"header":"Background","content":"\u003cp\u003eAcute appendicitis is one of the most common surgical emergencies worldwide, with an incidence of approximately 100 per 100 000 person years in the US, and 160\u0026ndash;206 per 100 000 person-years in Asia [1]. In Malaysia, acute appendicitis accounts for approximately 1% of all hospital discharges, and surgery performed for appendicitis and its related complications constitutes about 34% of all general surgery operations [2]. To date, surgery remains the mainstay for most patients with acute appendicitis [1]. Open appendicectomy was the first surgery described for treating this condition, but with technological advancements, a novel minimally invasive laparoscopic method was introduced in the 1990s [3, 4]. Since its introduction, laparoscopic appendicectomy has become the preferred approach for acute appendicitis [5].\u003c/p\u003e \u003cp\u003eLaparoscopic appendicectomy offers several advantages over the open approach, including reduced blood loss, shorter hospital stay, lower rates of surgical site infection and reduced post operative pain [6]. While older studies showed that laparoscopic appendicectomy took significantly longer than open appendicectomy via the Lanz approach, recent studies reveal no significant differences, owing to advancements in both technology and surgeon skillset [6, 7]. Despite its advantages, not all cases of appendicitis can be performed entirely laparoscopically due to severe inflammatory adhesions or obscured anatomy [8, 9]. Approximately 10% of patients undergoing laparoscopic appendicectomy will require conversion to open appendicectomy, although this rate may vary across surgical centers [10]. A recent study conducted locally in Universiti Sains Malaysia found that 27.5% of patients who underwent laparoscopic appendicectomy required conversion to open appendicectomy, with only the pre-operative diagnosis of perforated appendicitis being a statistically significant predictor of conversion [11]. Other studies have identified additional factors, such as age over 40 years old, male gender, presence of diabetes, inexperienced surgeons and presence of abscess or peritonitis, which are significantly associated with a higher conversion rates [9, 10].\u003c/p\u003e \u003cp\u003eCompared to patients that underwent full laparoscopic appendicectomy, patients requiring conversion to open tend to suffer from a higher incidence of post operative complications [10]. This is somewhat expected, as those requiring conversion generally have a more severe disease process [10]. However, even when compared to patients who undergo primary open appendicectomy, a group with more complex disease, patients who require conversion to open still tend to experience worse outcomes, including high rates of wound infection, intra-abdominal collections, hemorrhage requiring transfusion, and perioperative renal failure [10]. Moreover, conversion appendicectomy patients tend to have a longer hospital stay and higher rates of readmission, leading to increased healthcare cost when compared to patients undergoing primary open appendicectomy [10]. However, the decision to subject a patient to either laparoscopic appendicectomy or primary open appendicectomy remains subjective and varies from center to center.\u003c/p\u003e \u003cp\u003eTo date, available literatures with regards to factors that can predict conversion appendicectomy is scarce, and mostly inconclusive. However, a pre-operative diagnosis of perforated or complicated appendicitis has been consistent among literatures to be a strong risk factor for conversion among patients undergoing laparoscopic appendicectomy [10, 11]. Several studies have demonstrated a correlation between increased levels of certain inflammatory markers and likelihood of perforated appendicitis. Among these are total white count, procalcitonin level, C-reactive protein (CRP), absolute neutrophil count, mononuclear count, among others [12, 13]. However, when compared side by side, CRP/albumin ratio (CAR) has demonstrated the best predictive capability for perforation among patients with acute appendicitis, be it among the pediatric age group, or in the adult population [12, 13].\u003c/p\u003e \u003cp\u003eThe CRP/albumin ratio (CAR) is an infective marker and a surrogate of inflammatory disease activity that has been extensively studied in recent years. Its utility ranges from predicting disease activity in Takayasu arteritis to predicting 90-day mortality in patients suffering from severe sepsis in critical care settings [14, 15]. Additionally, CAR has been shown to be a good predictor of post operative complications in patients undergoing colorectal, upper gastrointestinal, orthopedic and cardiothoracic surgeries [16\u0026ndash;19]. The practicality of CAR lies in the opposing effects of CRP, an acute-phase protein that increases during inflammation, and serum albumin, a negative acute-phase reactant that reduces during pro-inflammatory states [15, 20].\u003c/p\u003e \u003cp\u003eA recent study in Japan showed that CAR is a good predictor of conversion to open in patients undergoing laparoscopic cholecystectomy [21]. At the time of writing, there is no existing literature on the application of CAR as a predictor of conversion to open in patients undergoing laparoscopic appendicectomy. Given that these tests are inexpensive and readily available, the primary objective of this study is to determine if CAR can aid in predicting conversion to open, thus helping clinicians select patients for primary open appendicectomy, and avoid the morbidities associated with conversion appendicectomy.\u003c/p\u003e"},{"header":"Methods and Analysis","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Design and Setting\u003c/h2\u003e \u003cp\u003eThis study is conducted using a cross-sectional approach and includes subjects listed for laparoscopic appendicectomy between June 2023 to December 2024 in a tertiary University Hospital in Kuala Lumpur. This study included all patients above the age of 12 scheduled for laparoscopic appendicectomy within the study period.\u003c/p\u003e \u003cp\u003ePatients with the following conditions were excluded from the study and were not included in the final data analysis:\u003c/p\u003e \u003cp\u003e1/ Intra-operative findings other than appendicitis, such as ruptured ovarian cyst, endometriosis, perforated gastric ulcer, pelvic inflammatory disease, etc.\u003c/p\u003e \u003cp\u003e2/ Subjects with a histopathological finding of a white appendix\u003c/p\u003e \u003cp\u003e3/ Patients who underwent conversion to open appendicectomy for non-surgical reasons, such as technical malfunction of the laparoscopic unit\u003c/p\u003e \u003cp\u003e4/ Patients whose primary outcome (CRP or albumin) are not available\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eData Collection and Definitions\u003c/h3\u003e\n\u003cp\u003eRecruitment was carried out via the electronic medical record system using a retrospective approach, and patients that were listed for laparoscopic appendicectomy fulfilling the inclusion criteria were included. Relevant information was extracted, including pre-operative infective markers namely C-Reactive Protein (CRP), albumin, total white count (TWC), platelet count, lymphocyte count and neutrophil count, final operation performed (full laparoscopic vs conversion appendicectomy) as well as post operative complications.\u003c/p\u003e \u003cp\u003eThe following parameters were calculated based on the collected outcomes: CRP /albumin ratio, neutrophil / lymphocyte ratio, and lymphocyte / platelet ratio. CRP/albumin ratio is calculated by dividing the CRP level by the albumin level. The neutrophil / lymphocyte ratio is calculated by dividing the neutrophil count by the lymphocyte count, whereas the lymphocyte / platelet ratio is calculated by dividing the lymphocyte count by the platelet level.\u003c/p\u003e \u003cp\u003ePostoperative complications accounted any re-admissions, surgical site infections requiring a visit to the emergency department, or any need for re-interventions (surgical or non-surgical, such as percutaneous drainage). Any intra-abdominal collection detected using imaging modalities or based on intra-operative findings from any repeat surgeries were considered.\u003c/p\u003e \u003cp\u003eIn most of our patients, the decision for surgery is made based on clinical diagnosis of appendicitis. A minority of the patients required further imaging including ultrasound abdomen and Computed Tomography, before there were planned for surgery.\u003c/p\u003e \u003cp\u003eLaparoscopic appendicectomies are performed by either a medical officer, registrar or a surgeon, as defined below. The surgery is performed under general anesthesia, using the standard 3-port technique. A camera port is placed via a supra- or infra-umbilical incision, followed by 2 working ports, one in the left lower quadrant and the other either in the suprapubic region or the right lower quadrant [4]. Electrocautery is the only device used in all cases. After achieving pneumoperitoneum, the four quadrants of the abdomen are inspected carefully before focusing on the appendix. The appendix is identified and the meso-appendix divided near the base [4]. The appendix is transfixed at the base, divided, and then brought out via the camera port with or without an endopouch [4]. The appendix stump is reinspected, and any peritoneal contamination is aspirated or washed with normal saline until clear. If at any point during the surgery a decision to convert to open is made, the surgeon in charge is informed beforehand. If the surgeon agrees with the decision, the surgery will proceed as a conversion to open appendicectomy. If the surgeon disagrees, the surgery is then taken over by the surgeon and proceed accordingly.\u003c/p\u003e \u003cp\u003eMedical officers include all first and second-year candidates in the Masters of General Surgery training program, whereas registrar include third- and final-year candidates in training. Surgeons are those who have completed the 4-year Masters in General Surgery training program and have received the Malaysian National Specialist Register (NSR) recognition.\u003c/p\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eAnalysis was performed using the latest version of SPSS (version 26; IBM Corp., USA). The demographic characteristics between the two groups are presented using descriptive statistics.\u003c/p\u003e \u003cp\u003eCategorical data are presented in numbers and are analyzed using the Chi-squared test. Continuous data are presented as numbers or percentages and analyzed using the Student\u0026rsquo;s T-test or Mann Whitney U test, depending on whether the data follow a normal distribution (as determined by the Shapiro-Wilk test). Data that follow a normal distribution are presented as mean +/- standard deviation, whereas data that do not follow a normal distribution are displayed as median (Q1 - Q3).\u003c/p\u003e \u003cp\u003eSignificant pre-operative variables that may represent potential confounding factors (p\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;2) are included in the multivariate analysis to determine whether these confounders influence the relationship between the infective markers and conversion rates to open appendicectomy. With conversion to open appendicectomy as the endpoint, we used receiver operating characteristic (ROC) analysis to determine and compare the area under the curve (AUC) values of each infective marker. The value with the greatest Youden index is then used to identify the ideal cutoff value for predicting conversion to open. Sensitivity, specificity, and positive and negative predictive values were calculated. Finally, we divide our data using the identified cut off value, and the odds ratio for that cutoff value was calculated.\u003c/p\u003e \u003cp\u003eStatistical significance is defined as p\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;05.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec7\"\u003e\n \u003ch2\u003eSubject’s demographics and clinical characteristics\u003c/h2\u003e\n \u003cp\u003eBetween June 2023 to December 2024, 224 patients were scheduled for laparoscopic appendicectomy in the general surgery unit at our institution. Of these, 72 patients were excluded from the study due to the following reasons: absence of primary outcome measurements (e.g., CRP or albumin levels not taken pr-operatively n = 38), histopathological diagnosis of a white appendix (n = 19), intra-operative finding of a diagnosis other than appendicitis (n = 14), and intra-operative desaturation following pneumoperitoneum (n = 1). This left a total of 152 included in the final analysis.\u003c/p\u003e\n \u003cp\u003eAmong the 152 included patients, 126 (82·8%) underwent full laparoscopic appendicectomy (FLA), while 26 (17·2%) required conversion to open appendicectomy (CA). Reasons for conversion included dense adhesions secondary to local inflammation preventing adequate visualization of the appendix base (n = 16), gross contamination necessitating open washout (n = 8), and an unhealthy base (n = 2).\u003c/p\u003e\n \u003cp\u003eThe clinical characteristics between the FLA and CA group are summarized in Table 1.\u003c/p\u003e\u003cp\u003ePatients in the FLA group were younger on average, while the CA group had a significantly higher proportion of cases with clinically and histopathological confirmed perforated appendicitis. Across both arms, the majority of patients were Malay, followed by Chinese, Indian and others, with no statistical differences in racial distribution. This is consistent with the racial proportions of the population in Malaysia. Gender and comorbidity distribution were also similar between the groups.\u003c/p\u003e \u003cp\u003eThe FLA group had a higher percentage of cases performed by medical officers, whereas registrars and surgeons were more involved in CA cases, though this difference was not statistically significant. Expectedly, patients in the CA group had longer operative times, more postoperative complications, and extended hospital stays compared to those in the FLA group.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eInfective markers and ROC analysis\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003epresents the median values and interquartile ranges (IQR) of several infective markers collected in our study, comparing their value between the 2 groups. (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e2\u003c/span\u003e.) Difference in infective markers across both FLA and CA groups, and their statistifical significance, demonstrated by the p value, based on the Mann Whitney U Test.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\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=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInfective markers\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFLA\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCA\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMann Whitney U Test\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCRP (mg/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2\u0026middot;81 (0\u0026middot;56\u0026ndash;6\u0026middot;09)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13\u0026middot;5 (6\u0026middot;87\u0026ndash;21\u0026middot;9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlbumin (g/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e41 (39\u0026ndash;44)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37\u0026middot;5 (31\u0026middot;8\u0026ndash;39\u0026middot;3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCAR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;067 (0\u0026middot;123\u0026ndash;0\u0026middot;159)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u0026middot;377 (0\u0026middot;169\u0026ndash;0\u0026middot;697)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTWC (10\u003csup\u003e9\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14\u0026middot;05 (10\u0026middot;6\u0026ndash;18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14\u0026middot;45 (12\u0026middot;35\u0026ndash;17\u0026middot;1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP\u0026thinsp;=\u0026thinsp;0\u0026middot;261\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePlatelet (10\u003csup\u003e3\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e304\u0026middot;5 (242\u0026middot;5\u0026ndash;355)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e320 (232\u0026middot;8\u0026ndash;373\u0026middot;5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP\u0026thinsp;=\u0026thinsp;0\u0026middot;661\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNLR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6\u0026middot;753 (3\u0026middot;10\u0026ndash;12\u0026middot;45)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6\u0026middot;870 (4\u0026middot;34\u0026ndash;15\u0026middot;79)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP\u0026thinsp;=\u0026thinsp;0\u0026middot;24\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLPR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;006 (0\u0026middot;004\u0026ndash;0\u0026middot;009)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u0026middot;006 (0\u0026middot;003\u0026ndash;0\u0026middot;008)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP\u0026thinsp;=\u0026thinsp;0\u0026middot;33\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\u003eCRP and the CAR were significantly higher in the CA group compared to the FLA group, and the opposite is true with albumin level, with P-values less than 0\u0026middot;01. Other measured infective markers, including total white cell count, platelet count, NLR and LPR, did not differ significantly between the groups.\u003c/p\u003e \u003cp\u003e(Table\u0026nbsp;3.) Area under the Curve (AUC) value for each infective markers based on Receiver Operative Characteristic curve analysis\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabb\" border=\"1\"\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\u003eInfective markers\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eArea under Curve\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCAR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;833\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCRP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;824\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlbumin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;766\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTWC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;570\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePlatelet count\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;527\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNLR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;573\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLPR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;440\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\u003eBased on the receiver operator characteristic and area under the curve analysis, CAR demonstrated the highest predictive value for conversion to open appendicectomy, with an area-under the curve value at 0\u0026middot;833, followed by CRP (AUC: 0\u0026middot;824) and albumin (0\u0026middot;766), as shown in Table\u0026nbsp;3 and Fig.\u0026nbsp;1. Other infective markers exhibited limited predictive utility. Using the value with the highest Youden index, the optimal cutoff value is obtained, and the sensitivity, specificity, positive and negative predictive value are determined. Results are shown in Table\u0026nbsp;4.\u003c/p\u003e \u003cp\u003eThese results indicate that the CAR is the most robust predictor for conversion to open appendicectomy, outperforming CRP and albumin alone.\u003c/p\u003e \u003cp\u003e \u003cb\u003e(Fig.\u0026nbsp;1)\u003c/b\u003e ROC curve for CAR, CRP and Albumin\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e(Table\u0026nbsp;4.) Optimal cut off values for CAR, CRP and albumin in predicting conversion to open based on the value with the highest Youden index.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabc\" border=\"1\"\u003e \u003ccolgroup cols=\"4\"\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=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCAR\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCRP (mg/L)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAlbumin (g/dL)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOptimal cutoff value\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;111\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6\u0026middot;13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e39\u0026middot;5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSensitivity\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e92\u0026middot;3%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e84\u0026middot;6%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e76\u0026middot;9%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSpecificity\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e67\u0026middot;0%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e77\u0026middot;0%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e66\u0026middot;7%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePositive predictive value (PPV)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36\u0026middot;4%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e42\u0026middot;3%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32\u0026middot;3%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNegative predictive value (NPV)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e97\u0026middot;6%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e96\u0026middot;0%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e93\u0026middot;3%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOdds Ratio (OR)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24 (95% CI 5\u0026ndash;106; p\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;001)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17\u0026middot;6 (95% CI: 5\u0026middot;6\u0026ndash;55\u0026middot;1; p\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;001)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6\u0026middot;67 (95% CI: 2\u0026middot;49\u0026thinsp;\u0026minus;\u0026thinsp;17\u0026middot;85; p\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;001)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003ePossible confounders and multivariate analysis\u003c/h3\u003e\n\u003cp\u003ePotential confounders (P\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;2) were identified based on analysis of baseline characteristics, including\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003ePre-operative clinical diagnosis\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eHistopathological diagnosis\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003ePrimary surgeon\u0026rsquo;s level of experience.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eBinary logistic regression was performed to account for these factors and assess their independent contributions to conversion rates, results are shown in Table\u0026nbsp;5.\u003c/p\u003e \u003cp\u003eElevated CAR\u0026thinsp;\u0026gt;\u0026thinsp;0\u0026middot;111 remained a statistically significant independent predictor for conversion to open appendicectomy [OR\u0026thinsp;=\u0026thinsp;12\u0026middot;857 (95% CI: 2\u0026middot;736\u0026ndash;60\u0026middot;42; p\u0026thinsp;=\u0026thinsp;0\u0026middot;001)] among patients undergoing laparoscopic appendicectomy.\u003c/p\u003e \u003cp\u003eOther factors, such as age, surgeon experience and pre-operative clinical perforated appendicitis or histopathological perforated appendicitis were not statistically significant confounders.\u003c/p\u003e \u003cp\u003eRepeated regression analysis is confirmed both CRP (p\u0026thinsp;=\u0026thinsp;0\u0026middot;026) and albumin (p\u0026thinsp;=\u0026thinsp;0\u0026middot;006), as independent predictor of conversion to open appendicectomy after accounting for confounders.\u003c/p\u003e \u003cp\u003e(Table\u0026nbsp;5.) Potential confounding factors affecting prevalence of conversion to open appendicectomy and measurement of their statistical significance using binary logistic regression model analysis\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabd\" border=\"1\"\u003e \u003ccolgroup cols=\"9\"\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=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003e95% CI for Exp (B)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSE\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eWald\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003edf\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eSig\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eExp (B)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eLower\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eUpper\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;012\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u0026middot;015\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0\u0026middot;666\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u0026middot;415\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1\u0026middot;012\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0\u0026middot;983\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1\u0026middot;041\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLevel of experience (MO)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026middot;\u0026middot;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026middot;\u0026middot;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0\u0026middot;638\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u0026middot;727\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026middot;\u0026middot;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u0026middot;\u0026middot;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u0026middot;\u0026middot;\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLevel of experience (Reg vs MO)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;689\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u0026middot;870\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0\u0026middot;627\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u0026middot;428\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1\u0026middot;991\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0\u0026middot;362\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e10\u0026middot;947\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLevel of experience (Surgeon vs MO)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;685\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u0026middot;048\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0\u0026middot;427\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u0026middot;513\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1\u0026middot;984\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0\u0026middot;254\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e15\u0026middot;472\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePre-op clinical diagnosis: perforated appendicitis vs acute appendicitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026middot;511\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u0026middot;604\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0\u0026middot;715\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u0026middot;398\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1\u0026middot;667\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0\u0026middot;510\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e5\u0026middot;444\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistopathological diagnosis: perforated appendicitis vs acute appendicitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u0026middot;097\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u0026middot;606\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3\u0026middot;282\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u0026middot;070\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2\u0026middot;996\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0\u0026middot;914\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e9\u0026middot;821\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCAR\u0026thinsp;\u0026gt;\u0026thinsp;0\u0026middot;111 vs\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;111\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e2\u0026middot;554\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e0\u0026middot;790\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e10\u0026middot;464\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0\u0026middot;001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e12\u0026middot;857\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e2\u0026middot;736\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cb\u003e60\u0026middot;42\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eConstant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-5\u0026middot;150\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u0026middot;160\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19\u0026middot;694\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0\u0026middot;001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0\u0026middot;006\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"9\" nameend=\"c9\" namest=\"c1\"\u003e \u003cp\u003eVariable(s) entered on step 1: Age, Level of Surgeon experience, pre op clinical diagnosis, histopathological diagnosis, CRP/albumin ratio level\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"9\" nameend=\"c9\" namest=\"c1\"\u003e \u003cp\u003e* Binary Logistic Regression statistical method is used.\u003c/p\u003e \u003cp\u003eB: Beta coefficient for the constant in the null model\u003c/p\u003e \u003cp\u003eSE: Standard error around the coefficient for the constant\u003c/p\u003e \u003cp\u003eWald and Sig: The Wald chi-square test that tests the null hypothesis that the constant is 0.\u003c/p\u003e \u003cp\u003edf: Degrees of freedom for the Wald chi-square test\u003c/p\u003e \u003cp\u003eExp(B): Exponentiation of the B coefficient, which is also Odds Ratio.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\n\u003ch3\u003eCRP/albumin ratio and post operative complications\u003c/h3\u003e\n\u003cp\u003eA Mann Whitney- U analysis revealed that CAR is not statistically different between patients who suffer from post-operative complications, and those who do not (p\u0026thinsp;=\u0026thinsp;0\u0026middot;142).\u003c/p\u003e \u003cp\u003eEven after dividing the dataset using CAR of 0\u0026middot;111 as a cut off value, the outcome remains the same: OR\u0026thinsp;=\u0026thinsp;1\u0026middot;836 (95% CI: 0\u0026middot;773- 4\u0026middot;361; p\u0026thinsp;=\u0026thinsp;0\u0026middot;165), as shown in Table\u0026nbsp;6.\u003c/p\u003e \u003cp\u003e(Table\u0026nbsp;6.) CRP/albumin ratio (CAR) and prevalence of post-operative complications using cut-off value of 0.111\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabe\" border=\"1\"\u003e \u003ccolgroup cols=\"4\"\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=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePost op complications\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCAR\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;111\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e86\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCAR\u0026thinsp;\u0026gt;\u0026thinsp;0\u0026middot;111\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e66\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e127\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e152\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eCRP/albumin ratio and duration of surgery\u003c/h2\u003e \u003cp\u003eA linear regression analysis was performed and it was found that CAR has a weak positive correlation to duration of surgery performed, with a Pearson correlation of 0\u0026middot;364. The scatter plot is depicted in Fig.\u0026nbsp;2. This result is statistically very significant, p\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;001.\u003c/p\u003e \u003cp\u003eA further analysis using CAR of 0\u0026middot;111 as a cut off value revealed that the average duration of surgery is statistically significantly longer among patients with CAR of \u0026gt;\u0026thinsp;0\u0026middot;111, as compared to those with a value of \u0026lt;\u0026thinsp;0\u0026middot;111 (102\u0026middot;5 [65\u0026ndash;145] vs 72\u0026middot;5 [55\u0026ndash;90], p\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;001)\u003c/p\u003e \u003cp\u003e \u003cb\u003e(Fig.\u0026nbsp;2)\u003c/b\u003e Scatterplot of duration of surgery to CRP/albumin ratio\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eLaparoscopic appendicectomy remains the most common method of surgical treatment for patients suffering from acute appendicitis [4]. However, some patients will require conversion to open surgery due to severe inflammatory adhesions and obscuration of normal anatomy [8]. The conversion rate of laparoscopic to open appendicectomy ranges from one to ten percent, and is influenced by various factors, including perforated appendicitis, presence of intraperitoneal abscess and the experience level of the operating surgeons [9\u0026ndash;11]. Studies comparing outcomes of patients undergoing appendicectomy indicate that patients requiring conversion suffer the most postoperative complications and morbidity compared to those undergoing either full laparoscopic appendicectomy or primary open appendicectomy. Thus, identifying risk factors for conversion is critical for better surgical planning and decision making [10].\u003c/p\u003e \u003cp\u003eOur study demonstrated a higher conversion to open rate among patients undergoing laparoscopic appendicectomy, at 17\u0026middot;2%, and there are several reasons for this. Firstly, our study excludes all patients with a histopathology of non-inflamed appendix, majority of which underwent a fully laparoscopic procedure. Moreover, our center has a high threshold for primary open appendicectomy, thus, many patients whose surgery is expected to be difficult, are still put up for laparoscopic appendicectomy, most of which eventually required conversion to open intra-operatively.\u003c/p\u003e \u003cp\u003eIn our study, CAR was significantly higher among patients who underwent conversion to open appendicectomy compared to those who had a full laparoscopic appendicectomy. Multivariate analysis revealed that CAR remained a strong independent predictor for conversion even after adjusting for potential confounders, including a clinical diagnosis and post operative histopathological diagnosis of perforated appendicitis. This finding underscores the utility of this readily available and cost-effective biochemical test in routine surgical decision-making and planning for acute or perforated appendicitis.\u003c/p\u003e \u003cp\u003eOur ROC and AUC demonstrated that, among various infective markers, the CAR was the best predictor of conversion to open appendicectomy. The rationale for using CAR lies in the biological response to inflammation: CRP is an acute phase protein that increases at times of inflammation and infection, while albumin, the denominator in this ratio, is a negative acute phase reactant and decreases during pro-inflammatory states [15, 20]. The pathophysiology behind this rise in CRP is mediated by cytokines such as interleukin-1, interleukin-6 and interleukin-17, which stimulates liver production of CRP[22]. Conversely, albumin levels drop due to increased capillary permeability causing leakage of albumin out of the intra-vascular compartment, and the diversion of resources toward the production of other acute phase proteins [20, 23]. In severe cases of appendicitis, this divergence between CRP and albumin levels results in an elevated CAR. In this study, the primary reasons for conversion were severe inflammatory adhesions obscuring normal anatomy of the appendix and gross purulent contamination of the peritoneal cavity, both of which reflect higher disease severity.\u003c/p\u003e \u003cp\u003ePrevious studies have explored the utility of CAR in predicting complicated or perforated appendicitis. In pediatric populations, CAR has been shown to be a useful marker for predicting complicated and perforated appendicitis and outperformed other infective markers [12]. Similar findings were reported in adult populations [13]. However, to the best of our knowledge, no prior study has specifically identified CAR as a predictor of conversion to open appendicectomy.\u003c/p\u003e \u003cp\u003eIn this study, a cut-off value of 0\u0026middot;111 provided high sensitivity (92\u0026middot;3%) and moderate specificity (67%) in predicting conversion to open. The high negative predictive value (97\u0026middot;6%) makes it particularly effective in ruling out patients who may require conversion. CAR\u0026thinsp;\u0026gt;\u0026thinsp;0\u0026middot;111 is associated with a 24-fold increased odds of requiring conversion [OR: 24 (95% CI: 5\u0026middot;4\u0026ndash;106\u0026middot;4; p\u0026thinsp;\u0026lt;\u0026thinsp;0\u0026middot;001)], even after taking into consideration other associated factors using multivariate analysis [OR : 12\u0026middot;9 (95% CI: 2\u0026middot;73\u0026ndash;60\u0026middot;42; p\u0026thinsp;=\u0026thinsp;0\u0026middot;001)]. Given the widespread availability and low cost of CRP and albumin tests, CAR can be a valuable addition to pre-operative assessment and surgical planning of patients with appendicitis.\u003c/p\u003e \u003cp\u003eIn managing appendicitis patients with a pre operative CAR of more than 0\u0026middot;111, heavy consideration should be given for a primary open appendicectomy, especially for inexperienced surgeons and in scenarios where the patient is critically ill. However, upfront laparoscopic appendicectomy remains a feasible option, and in the hand of an experienced surgeon, allows patients to evade the morbidity associated with open surgeries. Thus, if laparoscopic surgery is planned for this group of patients, the surgery should be carried out by, or under the supervision of an experienced surgeon.\u003c/p\u003e \u003cp\u003eThis study also revealed that older patients were more likely to undergo conversion. This could be due to diminished pain perception and a blunted inflammatory response in elderly individuals, leading to delayed diagnosis and a more severe disease state upon presentation [24]. Additionally, patients with perforated appendicitis had higher conversion rates in both pre-operative clinical and post-operative histopathological diagnoses, reflecting the more severe nature of the disease. On top of that, studies have demonstrated that CAR is a good predictor of complicated and perforated appendicitis, making perforation a possible confounder in our study [12, 13]. However, after binary logistic regression analysis to partial out all the possible confounders, neither age, preoperative nor histopathological diagnosis significantly affected our results, indicating that CAR remains a robust predictor regardless of these variables.\u003c/p\u003e \u003cp\u003eWhile surgeon experience did not emerge as a statistically significant predictor of conversion to open appendicectomy, the distribution of cases among different experience levels warrants consideration. In our center, laparoscopic appendicectomies are typically performed by medical officers and registrars, with surgeons stepping in for anticipated or encountered complications. This practice may not be the same in other institutions, and further studies are needed to explore this variable.\u003c/p\u003e \u003cp\u003eThis study found that CAR does not predict post-operative complications; however, it does predict a longer operative period, with a median operating time of 72\u0026middot;5 minutes among patients with a CAR of \u0026lt;\u0026thinsp;0\u0026middot;111, compared to 102\u0026middot;5 minutes among those with a CAR of \u0026gt;\u0026thinsp;0\u0026middot;111.\u003c/p\u003e \u003cp\u003eThis study has several limitations. First, the single centre cross-sectional retrospective design resulted in a small sample size, and an unequal distribution of subjects between the full laparoscopic and conversion groups as well as a disparity in demographics between the two groups, including age, clinical and histological diagnosis. However, regression analysis mitigated the effect of this disparity. Second, due to the small sample size, secondary findings such as CRP/albumin ratio in predicting post op complications and duration of surgery may not be accurately concluded. Future multicenter prospective cohort studies are needed to validate our findings and generalize them to clinical practice. Third, our study did not take into account the timing in which surgery is performed, and the duration between diagnosis and surgery. Surgeries done in odd timings could possibly lead to a higher chance of conversion in order to hasten the surgery, whereas a longer waiting duration between diagnosis and surgery may cause an initial acute appendicitis to become perforated, leading to a more complex surgery. These factors can be included in future multicenter studies.\u003c/p\u003e \u003cp\u003eOur study however, does have its strength: our categorization into pre-operative clinical diagnosis and histopathological diagnosis of acute versus perforated appendicitis allows these factors to be taken into account using binary logistic regression, thus results can be generalized to all patients suffering from appendicitis. On top of that, this study is by far the first to investigate CAR, an objective marker in predicting conversion to open among patients undergoing laparoscopic appendicectomy.\u003c/p\u003e \u003cp\u003e.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eCAR, CRP and albumin are independent predictors of conversion to open appendicectomy, with CAR demonstrating the strongest predictive power. Specifically, a CAR of \u0026gt;\u0026thinsp;0\u0026middot;111 is associated with a 24-fold higher likelihood of requiring conversion. As a low-cost and widely available marker, CAR can be integrated into clinical practice to guide surgical decision-making and improve patient outcomes in cases of acute appendicitis. Further multicenter studies are needed to validate these findings.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cu\u003eEthics approval and consent to participate \u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eThis study was submitted to and approved by the Research Ethics committee of the Research and Innovation Secretariat of the Medical Faculty of National University of Malaysia. The project code is FF-2024-025, and the authors are given ethical approval to conduct research in the National University of Malaysia, with the ethics reference number of JEP-2023-970. This research adheres to the Declaration of Helsinki. The requirement for consent was waived owing to the retrospective nature of this study, in accordance to the guidelines coded: UKM-JEP-GP00 by the Research Ethics Committee, National University of Malaysia.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResearch Registration Code: \u003c/strong\u003eJEP-2023-970\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eProject Code: \u003c/strong\u003eFF-2024-025\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial Registration Number: \u003c/strong\u003eNot applicable\u003c/p\u003e\n\n\n\u003cp\u003e\u003cu\u003eConsent for Publication\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003ePatient consent is not applicable to our research, patient and /or the public are not involved in the design, conduct or dissemination of this research.\u003c/p\u003e\n\n\u003cp\u003e\u003cu\u003eAvailability of data and materials\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eAll data relevant to this study is uploaded as online supplemental information and is made available at Harvard Dataverse Repository, [https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/D6VEOH]\u003c/p\u003e\n\n\u003cp\u003e\u003cu\u003eCompeting Interest\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interest.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003e \u003c/u\u003e\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eFunding\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eNo funding was received for conducting this study. Funding from the University, however, is made available solely for the purpose of publication.\u003c/p\u003e\n\n\n\u003cp\u003e\u003cu\u003eAuthor Contributions\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eKean Leong Koay conceived the idea of this study. Kean Leong Koay and Azlanudin Azman designed the study. Kean Leong Koay is a postgraduate student who worked on the study and administered the research under the guidance of Azlanudin Azman, who acted as his supervisor for this postgraduate project. Kean Leong Koay and Azlanudin Azman analyzed the data, Kean Leong Koay wrote the paper and all authors have read and approved this paper.\u003c/p\u003e\n\n\u003cp\u003e\u003cu\u003eAcknowledgements\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eThe authors thank the medical records and information technology departments of Hospital Canselor Tuanku Muhriz, UKM. \u003c/p\u003e\n"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBaird DLH, Simillis C, Kontovounisios C, Rasheed S, Tekkis PP. Acute appendicitis. Bmj. 2017;357:j1703. doi: 10.1136/bmj.j1703.\u003c/li\u003e\n\u003cli\u003eLee HY, Jayalakshmi P, Noori SH. Acute appendicitis--the University Hospital experience. Med J Malaysia. 1993;48(1):17-27. \u003c/li\u003e\n\u003cli\u003eMcBurney C. II. The Indications for Early Laparotomy in Appendicitis. Ann Surg. 1891;13(4):233-54. doi: 10.1097/00000658-189101000-00061.\u003c/li\u003e\n\u003cli\u003eGangal HT, Gangal MH. Laparoscopic appendicectomy. Endoscopy. 1987;19(3):127-9. doi: 10.1055/s-2007-1018257.\u003c/li\u003e\n\u003cli\u003eKorndorffer JR, Jr., Fellinger E, Reed W. SAGES guideline for laparoscopic appendectomy. Surg Endosc. 2010;24(4):757-61. doi: 10.1007/s00464-009-0632-y.\u003c/li\u003e\n\u003cli\u003eShimoda M, Maruyama T, Nishida K, Suzuki K, Tago T, Shimazaki J, et al. Comparison of clinical outcome of laparoscopic versus open appendectomy, single center experience. Heliyon. 2018;4(5):e00635. doi: https://doi.org/10.1016/j.heliyon.2018.e00635.\u003c/li\u003e\n\u003cli\u003eMartin LC, Puente I, Sosa JL, Bassin A, Breslaw R, McKenney MG, et al. Open versus laparoscopic appendectomy. A prospective randomized comparison. Ann Surg. 1995;222(3):256-61; discussion 61-2. doi: 10.1097/00000658-199509000-00004.\u003c/li\u003e\n\u003cli\u003eSakpal SV, Bindra SS, Chamberlain RS. Laparoscopic appendectomy conversion rates two decades later: an analysis of surgeon and patient-specific factors resulting in open conversion. J Surg Res. 2012;176(1):42-9. doi: 10.1016/j.jss.2011.07.019.\u003c/li\u003e\n\u003cli\u003eLiu SI, Siewert B, Raptopoulos V, Hodin RA. Factors associated with conversion to laparotomy in patients undergoing laparoscopic appendectomy. J Am Coll Surg. 2002;194(3):298-305. doi: 10.1016/s1072-7515(01)01164-4.\u003c/li\u003e\n\u003cli\u003eFinnerty BM, Wu X, Giambrone GP, Gaber-Baylis LK, Zabih R, Bhat A, et al. Conversion-to-open in laparoscopic appendectomy: A cohort analysis of risk factors and outcomes. Int J Surg. 2017;40:169-75. doi: 10.1016/j.ijsu.2017.03.016.\u003c/li\u003e\n\u003cli\u003ePushpanathan NR, Hashim MNM, Zahari Z, Aziz S, Zain WZW, Ramely R, et al. Conversion rate and risk factors of conversion to open in laparoscopic appendicectomy. Ann Coloproctol. 2022;38(6):409-14. doi: 10.3393/ac.2020.00437.0062.\u003c/li\u003e\n\u003cli\u003eHou J, Feng W, Liu W, Hou J, Die X, Sun J, et al. The use of the ratio of C-reactive protein to albumin for the diagnosis of complicated appendicitis in children. The American Journal of Emergency Medicine. 2022;52:148-54. doi: https://doi.org/10.1016/j.ajem.2021.12.007.\u003c/li\u003e\n\u003cli\u003eYuksel ME, Ozkan N, Avci E. C-reactive protein/albumin ratio greater than 7.1 is a good candidate to be used as an inflammation biomarker to predict perforation in appendicitis. Eur Rev Med Pharmacol Sci. 2022;26(22):8333-41. doi: 10.26355/eurrev_202211_30366.\u003c/li\u003e\n\u003cli\u003eSeringec Akkececi N, Yildirim Cetin G, Gogebakan H, Acipayam C. The C-Reactive Protein/Albumin Ratio and Complete Blood Count Parameters as Indicators of Disease Activity in Patients with Takayasu Arteritis. Med Sci Monit. 2019;25:1401-9. doi: 10.12659/msm.912495.\u003c/li\u003e\n\u003cli\u003eRanzani OT, Zampieri FG, Forte DN, Azevedo LC, Park M. C-reactive protein/albumin ratio predicts 90-day mortality of septic patients. PLoS One. 2013;8(3):e59321. doi: 10.1371/journal.pone.0059321.\u003c/li\u003e\n\u003cli\u003eGe X, Cao Y, Wang H, Ding C, Tian H, Zhang X, et al. Diagnostic accuracy of the postoperative ratio of C-reactive protein to albumin for complications after colorectal surgery. World J Surg Oncol. 2017;15(1):15. doi: 10.1186/s12957-016-1092-1.\u003c/li\u003e\n\u003cli\u003eLee JW, Sharma AR, Lee SS, Chun WJ, Kim HS. The C-reactive protein to albumin ratio predicts postoperative complication in patients who undergo gastrectomy for gastric cancer. Heliyon. 2020;6(6):e04220. doi: 10.1016/j.heliyon.2020.e04220.\u003c/li\u003e\n\u003cli\u003eKim HJ, Lee S, Kim SH, Lee S, Sim JH, Ro YJ. Association of C-reactive protein to albumin ratio with postoperative delirium and mortality in elderly patients undergoing hip fracture surgery: A retrospective cohort study in a single large center. Exp Gerontol. 2023;172:112068. doi: 10.1016/j.exger.2022.112068.\u003c/li\u003e\n\u003cli\u003eKarabacak K, Kubat E, Akyol FB, Kadan M, Erol G, Doğancı S, et al. The C-reactive protein/albumin ratio as a new predictor for postoperative atrial fibrillation after coronary artery bypass graft surgery. J Card Surg. 2020;35(10):2747-53. doi: 10.1111/jocs.14898.\u003c/li\u003e\n\u003cli\u003eQuinlan GJ, Martin GS, Evans TW. Albumin: biochemical properties and therapeutic potential. Hepatology. 2005;41(6):1211-9. doi: 10.1002/hep.20720.\u003c/li\u003e\n\u003cli\u003eUtsumi M, Inagaki M, Kitada K, Tokunaga N, Yunoki K, Sakurai Y, et al. C-reactive Protein-to-Albumin Ratio Predicts Conversion from Laparoscopic to Open Cholecystectomy in Acute Cholecystitis. In Vivo. 2023;37(2):887-93. doi: 10.21873/invivo.13157.\u003c/li\u003e\n\u003cli\u003eEklund CM. Proinflammatory cytokines in CRP baseline regulation. Adv Clin Chem. 2009;48:111-36. doi: 10.1016/s0065-2423(09)48005-3.\u003c/li\u003e\n\u003cli\u003eSoeters PB, Wolfe RR, Shenkin A. Hypoalbuminemia: Pathogenesis and Clinical Significance. JPEN J Parenter Enteral Nutr. 2019;43(2):181-93. doi: 10.1002/jpen.1451.\u003c/li\u003e\n\u003cli\u003eLapsa S, Ozolins A, Strumfa I, Gardovskis J. Acute Appendicitis in the Elderly: A Literature Review on an Increasingly Frequent Surgical Problem. Geriatrics (Basel). 2021;6(3). doi: 10.3390/geriatrics6030093.\u003cstrong\u003e\u003c/strong\u003e\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Table 1","content":"\u003cp\u003eTable 1 is available in the Supplementary Files section.\u003c/p\u003e\n"}],"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":"Laparoscopic appendicectomy, conversion appendicectomy, general surgery, emergency surgery","lastPublishedDoi":"10.21203/rs.3.rs-8840461/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8840461/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients that underwent conversion to open appendicectomy tend to suffer a worse outcome when compared to patients that underwent full laparoscopic appendicectomy, or even those that underwent primary open appendicectomy. However, there is little information among available literatures on pre operative risk factors that can predict conversion to open appendicectomy. We aim to identify whether CRP/albumin ratio can be used as an independent predictor of conversion, thus becoming a useful adjunct in the clinical decision and approach to a patient with acute or perforated appendicitis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA cross-sectional retrospective study was done in the National University of Malaysia Medical Centre. Patients that are listed for laparoscopic appendicectomy between June 2023 to December 2024 were recruited and are divided based on the eventual surgery performed: full laparoscopic appendicectomy vs conversion appendicectomy. The pre operative infective markers of these patients are recorded, alongside other secondary endpoints measured, including length of surgery and rates of post operative complications. Statistical analysis was performed using SPSS version 26.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn this study, the CRP / albumin ratio, CRP and albumin are all statistically significantly different across both arms (P \u0026lt; 0.05). ROC and AUC analysis revealed that among the included infective markers, CRP/albumin ratio is the most powerful predictor of conversion to open appendicectomy, even after taking potential confounding factors into account using multivariate analysis. Patients with a CRP/albumin ratio of 0.111 and above have 24 times higher odds of requiring conversion to open appendicectomy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study concluded that CRP/albumin ratio is a robust independent predictor of conversion to open appendicectomy, and can be useful for pre operative assessment and surgical planning for patients suffering from acute appendicitis\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical Trial Number\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eClinical trial number is not applicable as our research is a cross-sectional retrospective study.\u003c/p\u003e","manuscriptTitle":"Pre operative C-Reactive Protein / Albumin Ratio as a predictor of conversion to open among patients undergoing laparoscopic appendicectomy: A single center Cross Sectional Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-06 18:43:10","doi":"10.21203/rs.3.rs-8840461/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":"2ee2b83e-f076-418d-a3bc-f5cbb85ae4ac","owner":[],"postedDate":"April 6th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-04T12:40:25+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-06 18:43:10","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8840461","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8840461","identity":"rs-8840461","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}