Validation of CLOC Score in Predicting the Risk of Conversion from Laparoscopic to Open Cholecystectomy in Dr Cipto Mangunkusumo Hospital

Introduction: Laparoscopic cholecystectomy is the gold standard for treatment of symptomatic cholelithiasis. Although relatively safe and effective, laparoscopic cholecystectomy is a difficult procedure. The rate of conversion to open cholecystectomy is estimated to be 1–15%. A preoperative predictive model may be helpful in determining whether open cholecystectomy is preferred over laparoscopic cholecystectomy to prevent morbidity and mortality associated with conversion. Conversion from laparoscopic to open cholecystectomy (CLOC) score can potentially predict the risk of conversion based on preoperative parameters. The purpose of this study is to validate the application of CLOC score in Dr Cipto Mangunkusumo Hospital’s patient population. Materials and methods: This was a retrospective study of patients undergoing laparoscopic cholecystectomy from January 2018 to December 2019 in Dr Cipto Mangunkusumo Hospital. Patient data were obtained from medical records. Descriptive analysis, Chi-square test, logistic regression analysis, and score validation using receiver-operating characteristic (ROC) curve by calculating the area under curve (AUC), sensitivity, and specificity were conducted. Based on the CLOC Score, the patients were stratified into two groups: low-risk (<6) and high-risk (>6). Results: There were 163 subjects with a mean age of 51.06 ± 13.3 years. The rate of conversion was 3.1% (n = 5). Most of the subjects were 40–69 years of age (111 subjects, 68.1%). Of all 163 subjects, 103 (63.2%) were female. The indications for surgery were colicky pain (symptomatic gallstone disease) in 144 subjects (88.3%). Based on the logistic regression analysis, common bile duct dilation was found to be the only statistically significant variable [odds ratio (OR) = 10.97; 95% confidence interval (CI): 1.72–69.95]. The AUC approached 78.8% (fair) (95% CI: 58.2–99.4%; p = 0.029) for a cut-off value of 6.5 (sensitivity = 80.0%; specificity = 79.1%). The median duration of procedure in the low-risk group vs the high-risk group was 120 minutes (30–330) vs 180 minutes (45–405) (p = 0.001), respectively. Conclusion: Common bile duct dilation was the only risk factor found to be significantly associated with conversion of laparoscopic cholecystectomy to open surgery. Other factors, such as age, sex, indication for surgery, gallbladder wall thickness, and ASA score were not found to be statistically significant risk factors. Conversion from laparoscopic to open cholecystectomy score was considered valid and useful in predicting the risk of conversion. A CLOC score of 7 or more was associated with a higher risk of conversion to open surgery.