Common bile duct diameter and complications of endoscopic sphincterotomy.

To assess the relationship between distal common bile duct (CBD) diameter and the incidence of an immediate complication following endoscopic sphincterotomy (ES), all patients undergoing ES between January 1986 and October 1990 were studied. The overall risk of an immediate complication following ES in 655 patients was 5.6 per cent (37 patients). Patients with calculi were at greater risk if the distal CBD was dilated (P < 0.001); the complication in those with stones was most likely to be haemorrhage (81 per cent). The relative risk of a complication increased ten times if the distal bile duct diameter was > 0.8 cm. Patients with stricture of the distal CBD did not have a significantly greater risk of complication than those with stones (9.7 versus 4.9 per cent). There was no significant difference between the mean distal CBD diameter of those with stricture and controls (0.61 versus 0.44 cm).