Predictors of common bile duct stones prior to cholecystectomy: A meta- analysis

Background: The decision of whether or not to investigate for common bile duct stones before cholecystectomy utilizes clinical, laboratory, and radiologic information (indicators). There is tremendous individual variation among clinicians in the criteria used for making this decision. Our aim was to perform a meta-analysis of published data to estimate the performance characteristics of the most commonly used preoperative indicators of common bile duct stones. Methods: Using predetermined exclusion criteria, we selected articles from a MEDLINE search and bibliographic review. Weighted averages were used to determine summary sensitivity, specificity, and positive and negative likelihood ratios for each indicator for stones. Results: From 2221 citations identified, 22 studies met inclusion criteria. The 10 indicators examined were reported in a common fashion in three or more articles, and could be assessed preoperatively. Seven exhibited a specificity greater than 90%. Indicators with positive likelihood ratios of 10 or above were cholangitis, preoperative jaundice, and ultrasound evidence of common bile duct stones. Positive likelihood ratios for dilated common bile duct on ultrasound, hyperbilirubinemia, and jaundice ranged from almost 4 to almost 7. Elevated levels of alkaline phosphatase, pancreatitis, cholecystitis, and hyperamylasemia exhibited positive likelihood ratios of less than 3. Conclusions: This meta-analysis has identified indicators for duct stones and ranked them according to likelihood ratios. These findings can be applied as guidelines for whether to investigate for duct stones before cholecystectomy.