Preoperative predictors of choledocholithiasis in patients presenting with acute calculous cholecystitis

Background and Aims: Markedly increased liver chemistries in patients presenting with acute calculous cholecystitis (AC) often prompt an evaluation for concomitant choledocholithiasis (CDL). However, current guidelines directing the workup for CDL fail to address this unique population. The aims of this study are to define the range of presenting laboratory values and imaging findings in AC, develop a model to predict the presence of concurrent CDL, and develop a management algorithm that can be easily applied on presentation. Methods: We conducted a retrospective review of patients presenting with AC to a large tertiary hospital over a 3.5-year period. CDL was defined as common bile duct (CBD) stone(s), sludge, or debris seen on any of the following studies: US, CT, magnetic resonance imaging/MRCP, EUS, ERCP, or intraoperative cholangiogram. A multivariable model to predict CDL was developed on 70% of the patients and validated on the remaining 30%. Results: A total of 366 patients were identified and 65 (17.8%) had concurrent CDL. Univariable analysis was used to predict CDL and demonstrated statistically significant odds ratios for transaminases > 3 times the upper limit of normal, alkaline phosphatase (AlkPhos) above normal, lipase > 3 times the upper limit of normal, total bilirubin >= 1.8 mg/dL, and CBD diameter > 6 mm. In the validation cohort, an optimal model containing alanine transaminase (ALT) > 3 times the upper limit of normal, abnormal AlkPhos, and CBD diameter > 6 mm was found to have an area under the receiver operating curve of 0.91. When 0 or 1 risk factors were present, 98.6% of patients did not have CDL. When all 3 risk factors were present, 77.8% were found to have CDL. Conclusions: The prevalence of CDL is high among patients with AC. When a validated model is used, application of cutoffs for ALT, AlkPhos, and CBD diameter can effectively triage patients with low and high likelihood for CDL to surgery or ERCP, respectively.