Bile duct size after cholecystectomy: an endoscopic retrograde cholangiopancreatographic study

Endoscopic retrograde cholangiopancreatography (ERCP) was performed in 43 patients before and 4-14 months after cholecystectomy. All patients had a normal common bile duct and were asymptomatic after the operation. Preoperative and postoperative films of adequate quality were available for scrutiny in 35 patients. The largest mean(s.d.) diameter of the common duct, after correcting for magnification, was 0.96(0.27) cm before cholecystectomy and 1.16(0.29) cm after surgery (P less than 0.0001). Thirty-one of the 35 patients showed increased duct size after cholecystectomy, and the difference was 1 mm or more in 26 patients. There was a positive correlation between the increase in bile duct size and the time interval after cholecystectomy. After cholecystectomy a small but significant increase in bile duct diameter is demonstrable on ERCP.