Endoscopic ultrasound versus endoscopic retrograde cholangiography for patients with intermediate probability of bile duct stones: a randomized trial comparing two management strategies.

BACKGROUND AND STUDY AIMS: Diagnostic endoscopic retrograde cholangiography (ERC) is being replaced by endoscopic ultrasonography (EUS) in patients with suspected bile duct stones. The assumption that such an approach is advantageous, however, has never been tested in a randomized trial.

PATIENTS AND METHODS: 100 patients with intermediate probability of bile duct stones were randomly allocated to EUS or ERC. Two patients in the ERC group were excluded; the remaining 98 patients received the allocated intervention and were entered into the analysis (EUS, 50 patients; ERC, 48 patients). Detected stones were removed endoscopically; patients without stones were followed for 1 year. The primary end point was the proportion of patients with a negative outcome, related to either endoscopic procedures (complications) or to false-negative diagnosis of stones. Investigators assessing the negative outcomes were not blinded to group assignment. The secondary end point was the total number of endoscopic procedures (EUS and ERC) performed in each group to diagnose and treat stones.

RESULTS: Bile duct stone prevalence was 28% and 25% in the EUS and ERC groups, respectively (P > 0.05). In the EUS group, 71 endoscopic procedures were performed, and 63 in the ERC group (mean per patient, 1.42 +/- 0.76, and 1.31 +/- 0.55, respectively; P > 0.05). In the EUS group, these included 49 successful and one failed initial EUS, 15 ERCs for bile duct stone treatment, and six procedures required during follow-up. In the ERC group there were 36 successful and 12 failed initial ERCs, 13 repeat procedures (EUS or ERC) performed after failed or equivocal initial ERC, and two procedures during follow-up. Five patients in the EUS group (10%, 95% CI 4-22) and 19 patients in the ERC group (40%, 95% CI 27-54) experienced a negative outcome (P < 0.001). No difference was observed when only moderate to severe complications were considered (6%, 95% CI 1-17, and 10%, 95% CI 4-23, respectively).

CONCLUSIONS: In patients with intermediate probability of bile duct stones, the management strategy based on EUS (with selective ERC in patients with confirmed stones) is safer and not associated with an excess of endoscopic procedures compared with a strategy based on ERC alone.