Intraductal US-directed management of bile duct stones without radiocontrast cholangiography.

Background/aims: Intraductal US (IDUS) is an examination of the bile duct by using a thin-caliber ultrasonic probe, yielding real-time, high-quality cross-sectional images. We prospectively evaluated the feasibility and safety of IDUS-directed stone removal without radiocontrast cholangiography (RC) in naïve patients with common bile duct (CBD) stones.

Methods: A total of 38 naïve patients with suspected CBD stones (<20 mm) were enrolled in this study. If IDUS showed CBD stones, we performed endoscopic sphincterotomy and removed the identified CBD stones without RC. The primary outcome was success rate of CBD stone removal without RC. The secondary outcomes were conversion rate to conventional ERCP with RC, fluoroscopy time, clinical responses, and adverse events.

Results: IDUS was successfully performed in all enrolled patients (38/38, 100%). No echogenic material was observed in 3 patients (1 Mirizzi syndrome, 2 spontaneous passages of CBD stones). After endoscopic sphincterotomy, IDUS-directed stone removal was successfully performed without RC in 26 patients (74.3%) in the first session. In the 9 patients, after deployment of plastic stents, IDUS-directed stone removal was successfully completed without RC in a second session. There was no conversion to conventional ERCP with RC. Median fluoroscopy time was 10 seconds. There were no immediate and delayed adverse events related to the IDUS-directed stone removal. However, asymptomatic hyperamylasemia developed in 3 patients (7.9%), who recovered without adverse events.

Conclusions: IDUS-directed stone removal without RC is feasible and safe for patients with CBD stones. We anticipate a potentially important role of IDUS in the field of various therapeutic interventions.