A Terpene Preparation for the Pharmacological Prevention of Common Bile Duct Stone Recurrence after Endoscopic...

Endoscopic retrograde cholangiopancreatography with stone extraction is the standard treatment for common bile duct (CBD) stones. However, few studies have evaluated medical strategies to reduce CBD stone recurrence after endoscopic clearance. We performed a prospective, multicenter, randomized pilot trial to explore the potential effect of a terpene preparation in this setting.

Thirty patients who had undergone endoscopic management of CBD stones within 4 weeks were enrolled from four Korean university hospitals and randomized 1:1 to receive either the terpene preparation (200 mg three times daily for 24 weeks) or no medication. The primary outcome was the recurrence of CBD stones at 48 weeks confirmed by imaging. The analysis was performed according to the per-protocol principle.

Twenty-one patients (9 in the treatment group and 12 in the control group) completed the study; attrition was 40.0% and 20.0%, respectively. Baseline characteristics were comparable between the groups, although the maximal CBD diameter was numerically greater in the treatment group (12.3 mm vs 9.3 mm; p=0.074). No CBD stone recurrence occurred in the treatment group, whereas recurrence occurred in two patients in the control group. The absolute risk difference was -16.7% (95% confidence interval, -37.8% to 4.4%; Fisher exact, p=0.486).

In this pilot trial, no CBD stone recurrence occurred in the treatment group despite a numerically higher baseline anatomic risk, whereas two of 12 control-group patients experienced recurrence. The trial was not powered to detect a treatment effect; therefore, no conclusions regarding efficacy can be drawn. The primary contribution is to inform the feasibility and design of a confirmatory trial. (cris.nih.go.kr, KCT0002289).