The ABCdE score for PREdicting Lithotripsy Assistance during transcystic Bile duct Exploration by Laparoendoscopy (PRE-LABEL)

Abstract

Background: Common bile duct (CBD) stones are reported in ~ 15% of patients who undergo laparoscopic cholecystectomy for symptomatic gallstones. Prior to lithotripsy techniques, transcystic laparoscopic common bile duct exploration (LCBDE) was limited to smaller CBD stones. The addition of lithotripsy to LCBDE increases cost, operative time and staffing requirements. Predicting which patients might require lithotripsy would be useful in operative planning. The primary aim was to investigate clinical variables for predicting lithotripsy assistance during transcystic bile duct exploration by laparoendoscopy (PRE-LABEL). Secondary aims were to develop and validate a predictive scoring tool.

Methods: A retrospective review of a prospectively collected database of consecutive patients who underwent transcystic LCBDE at a single centre in the UK was performed to investigate clinical variables for PRE-LABEL and develop a scoring tool (ABCdE score: age, bilirubin, CBD diameter, ERCP). Binary logistic regression was used to investigate which independent variables (predictors) were associated with lithotripsy assistance during transcystic LCBDE. The ABCdE score was applied to both UK and Spain patient cohorts to determine its sensitivity, specificity and accuracy.

Results: From 8 pre-operative clinical variables analysed, age ≤ 40 years, bilirubin > two-times upper limit of normal, CBD diameter ≥ 10 mm and ERCP failure of stone extraction were independent predictors of requiring lithotripsy during transcystic LCBDE and formed the ABCdE score. The hazard ratios were 2.87, 3.79, 2.78 and 10.06, respectively. An ABCdE score ≥ 2 resulted in 71% sensitivity, 81% specificity and 79% accuracy in predicting lithotripsy during LCBDE (UK cohort). Validation using a contemporary cohort from Spain yielded similar sensitivity, specificity and accuracy.

Conclusions: This study represents the only study to date reporting independent predictors of requiring lithotripsy assistance during transcystic LCBDE. ABCdE score ≥ 2 can highlight patients that may require lithotripsy in order to avoid failure of transcystic LCBDE and therefore avoid choledochotomy or post-operative ERCP.

Keywords: ABCdE (age, bilirubin, CBD diameter, ERCP) score; Choledocholithiasis; Common bile duct stones; Laparoscopic common bile duct exploration; Lithotripsy-assisted bile duct exploration by laparoendoscopy (LABEL); Predicting lithotripsy assistance during transcystic bile duct exploration by laparoendoscopy (PRE-LABEL); Transcystic choledochoscopy.