Preoperative determinants of common bile duct stones during laparoscopic cholecystectomy

Abstract

The aim of this study is to determine whether there are any clinical or biochemical predictors of common bile duct (CBD) stones in patients undergoing laparoscopic cholecystectomy. A prospective database of nearly 1000 laparoscopic cholecystectomies performed under the care of a single surgeon with a standardised technique between 1999 and 2006, was analysed. Clinical presentation, ultrasound and immediate preoperative biochemical results as well as the operative cholangiogram findings were reviewed. Routine cholangiography was attempted in most patients and the primary outcome variable was the detection of bile duct stones. The data was analysed using chi-squared test for categorical variables. The significant variables on univariate analysis were further characterised to identify the independent predictors of bile duct stones using a logistic regression model (significance p < 0.05). A total of 757 of 988 patients (77%) underwent cholangiography. Male-to-female ratio was 1 : 3 with a median age of 54 years (range: 17-93). Ten per cent of patients had bile duct stones identified on cholangiography. On univariate analysis, jaundice (p = 0.019), cholangitis (p < 0.001), alanine transaminase > 100 (p = 0.024), alkaline phosphatase (ALP) > 350 (p < 0.001) and CBD > 10 mm (p = 0.01) were significant markers for predicting bile duct stones. Bilirubin > 30 (x2 normal) was found not to be significant (p = 0.145). On a logistic regression model, ALP > 350 and/or cholangitis were found to be independent predictive factors of CBD stones (odds ratio 6.1). If a policy of routine intra-operative cholangiography is not adopted, a history of cholangitis or a raised ALP immediately preoperatively should lead to a high suspicion of CBD stones.