An Index Predicting Histological Acute Cholecystitis in Patients Undergoing an Urgent Laparoscopic Cholecystectomy

Background: It is important to predict acute cholecystitis (AC) before a laparoscopic cholecystectomy because inflammation of the gallbladder predicts the need for open conversion and subsequent morbidity after a laparoscopic cholecystectomy. Objectives: To create an index based on clinical, laboratory, and ultrasound criteria on admission that will predict AC on pathological examination in patients presenting acutely. Methods: We retrospectively reviewed consecutive cases of emergency laparoscopic cholecystectomies conducted by three experienced surgeons between 1 October 2014 and 31 January 2018. Independent variables were age, sex, presenting symptoms, admission laboratory tests, and ultrasound findings. The outcome variable was AC on histological examination. An index was created from all variables that added significantly to the logistic regression analysis. Results: Eight variables that contributed significantly to the model, included age, male sex, vomiting on admission, an increased proportion of neutrophils, a normal aspartate aminotransferase test, a normal serum amylase test result, a thick gall bladder wall, and pericholecystic fluid. An index of ≤2 to ≥8 created from those variables had a graded risk for AC of 1.8% to 92.0% with a c-statistic of 0.86 (95% confidence interval 0.81 -0.91). Operating time and bleeding increased in those with a higher index. Conclusions: An index including age, sex, symptoms, and selected laboratory results as well as ultrasound characteristics had an excellent graded risk in the prediction of histological AC that was associated with operating time and an increased risk of bleeding during the operation.