Choledocholithiasis: a prospective study of spontaneous common bile duct stone migration

The rate of spontaneous migration of bile duct stones through the duodenal papilla is not well known. Endoscopic retrograde cholangiography (ERC) has been the standard method to diagnose bile duct stones, but accumulating data show there is a good agreement between ERC and endoscopic ultrasonography (EUS). The aim of the study was to evaluate the incidence and time course of stone migration in patients with bile duct stones by analyzing discrepancies between EUS and ERC as a function of the elapsed time between these two procedures. Stone migration was considered as the absence of stones at time of ERC regardless of the number of stones seen at EUS.

The main criterion for inclusion was the presence of bile duct stone as shown by EUS. Ninety-two consecutive patients were prospectively included in this study.

Choledocholithiasis was absent at ERC in 12 patients. In univariate analysis, presence of gallbladder was significantly associated with an increased rate of stone migration (correction for multiple testing would remove this statistical significance). The size of the stone was the only independent factor to predict migration.

Migration occurred in about 21% of cases within 1 month. Our study emphasizes the need to analyze carefully the results of comparative imaging studies of bile duct stones.