The Role of Transaminases in Predicting Choledocholithiasis. A Novel Predictive Composite Score Development in a Cohort of 1089 Patients Undergoing Laparoscopic Cholecystectomy

Background Optimal use of interventional procedures and diagnostic tests for patients with suspected choledocholithiasis depends on accurate pretest risk estimation. We sought to define sensitivity/specificity of transaminases in identifying choledocholithiasis and to incorporate them into a biochemical marker composite score that could accurately predict choledocholithiasis. Methods All adult patients who underwent laparoscopic cholecystectomy by our Emergency Surgery Service between 2010 and 2018 were reviewed. Admission total bilirubin (TB), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) was captured. Choledocholithiasis was confirmed via intraoperative cholangiogram, endoscopic retrograde cholangiopancreatography, or magnetic resonance cholangiopancreatography. Area under receiver operating characteristic curve (AUC) or C-statistic for AST, ALT, ALP, and TB as a measure of detecting choledocholithiasis was calculated. For score development, our database was randomly dichotomized to derivation and validation cohort and a score was derived. The score was validated by calculating its C-statistic. Results 1089 patients were included; 210 (20.3%) had confirmed choledocholithiasis. The AUC was .78 for TB, .77 for ALP and AST, and .76 for ALT. 545 and 544 patients were included in the derivation and the validation cohort, respectively. The elements of the derived score were TB, AST, and ALP. The score ranged from 0 to 4. The AUC was .82 in the derivation and .77 in the validation cohort. The probability of choledocholithiasis increased from 8% to 89% at scores 0 to 4, respectively. Conclusions Aspartate aminotransferase predicted choledocholithiasis adequately and should be featured in choledocholithiasis screening algorithms. We developed a biochemical composite score, shown to be accurate in preoperative choledocholithiasis risk assessment in an emergency surgery setting.