Influence of bile duct diameter on the therapeutic quality of endoscopic balloon sphincteroplasty

Background and Study Aims: Endoscopic balloon sphincteroplasty (EBS) has be en reported to be a safe alternative to sphincterotomy for the treatment of bile duct stones. We evaluated the factors which influence the therapeutic efficacy of EBS. Patients and Methods: A total of 118 consecutive patients with bile duct st ones were treated by EBS. After conventional endoscopic retrograde cholangi ography (ERC), EBS was done using a biliary dilation catheter (balloon diam eter, 8 mm). The duct was then cleared using Dormia baskets or retrievel ba lloon catheters. When the stones were greater than 8 mm in diameter, mechan ical lithotripsy was performed before extraction. Complete stone clearance was assessed by balloon-ERC and intraductal ultrasonography. Therapeutic ef ficacy was assessed using univariate and multivariate analysis. Patients we re classified into three groups according to the bile duct diameter: nondil ated (bile duct less than or equal to 10 mm), mildly dilated (10 mm < bile duct less than or equal to 15 mm), and severely dilated group (bile duct > 15 mm). Results: In 113 of 118 (96%) patients, the stones were completely cleared w ith one to six endoscopic sessions (mean 1.6 sessions). In the nondilated g roup, 24 of 28 (85%) patients were cleared of stones in one session (mean 1 .2 sessions), without the use of mechanical lithotripsy in 23 of 28 (82%) p atients. In the mildly dilated group, 23 of 38 (61%) patients were cleared of stones in one session (mean 1.5 sessions). In contrast, in the severely dilated group, only 16 of 52 (31%) patients were cleared of stones in one s ession (mean 2.0 sessions). Stone size, number of stones, and use of mechan ical lithotripsy were independent variables which influenced the success of stone clearance in one session after EBS, Conclusion: When EBS is done in patients with bile duct stones, bile duct d iameter may be a good indicator of therapeutic efficacy. In patients with s everely dilated bile ducts (> 15 mm), EBS is of limited effectiveness.