Factors influencing the technical difficulty of endoscopic clearance of bile duct stones

Background There has been no report concerning the factors that contribute to the technical difficulty of endoscopic clearance of common bile duct (CBD) stones. Objective Our purpose was to determine the factors that contribute to the technical difficulty of endoscopic clearance of CBD stones. Design Prospective study. Setting A tertiary referral endoscopy center. Patients A total of 102 patients who underwent ERCP, endoscopic biliary sphincterotomy, and CBD stone extraction at our institution from August 2004 to September 2006. Main Outcome Measurements The technical difficulty of CBD stone clearance was graded as follows: easy, moderately difficult, very difficult, and failed. Distal CBD angulation seen on cholangiogram was defined as the first angulation from the ampullary orifice with the patients in the prone position and the distal arm of CBD angulation as the length (in millimeters) between angular point and ampullary orifice. Results Older age (>65 years), previous gastrojejunostomy, larger CBD stone (≥15 mm), impacted CBD stone, use of mechanical lithotripsy, shorter length of the distal CBD arm (≤36 mm), and more acute distal CBD angulation (≤135 degrees) were all significant contributing factors to the technical difficulty of CBD stone clearance in exploratory univariate statistical tests. In the definitive multivariate analysis, more acute distal CBD angulation and a shorter length of the distal CBD arm were found to be significant, independent contributors to technical difficulty. Conclusions Complete clearance of CBD stones was technically more difficult for the patients with more acute distal CBD angulation and a shorter length of the distal CBD arm.