Optimal dilation time for combined small endoscopic sphincterotomy and balloon dilation for common bile duct stones: a multicentre, single-blinded, randomised controlled trial

Abstract

Background Endoscopic sphincterotomy is the established treatment for common bile duct stones. Balloon dilation offers an alternative. Prolonged dilation (300 s) with a 10 mm diameter balloon decreases the occurrence of pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP). We aimed to determine the optimal duration of dilation for combined endoscopic sphincterotomy and balloon dilation for the removal of common bile duct stones.

Methods We did a multicentre, single-blinded, randomised controlled trial at 15 tertiary surgical centres in China. Eligible patients (≥18 years) with native papilla and common bile duct stones (≤1·5 cm in size and <2 cm in diameter) undergoing ERCP were randomly assigned (1:1:1:1:1) to receive balloon dilation for 0, 30, 60, 180, or 300 s after deep bile duct cannulation. Randomisation was done by an independent statistician using a computer-generated randomisation list with a block size of ten, stratified by centre. Patients and outcome assessors, but not endoscopists and investigators, were masked to treatment allocation. Balloon dilation was done with controlled radial expansion balloons according to common bile duct stone size. Stones were removed using stone retrieval balloons or baskets. The primary endpoint was overall frequency of post-ERCP pancreatitis. The primary efficacy analysis and safety analyses were done in the modified intention-to-treat population, which included all randomly assigned patients with successful cannulation, but excluded those who withdrew consent after randomisation. This study was registered with ClinicalTrials.gov, number NCT02510495, and is complete.