Background: Factors affecting diagnostic accuracy and comparison of patients in the follow-up period for negative outcomes are not thoroughly investigated in a randomized trial.
Objective: Our purpose was to compare diagnostic accuracy, complications, and number of interventions.
Design: Prospective, unicentric, single-blind, randomized study.
Setting: Single tertiary referral university hospital.
Patients: One hundred twenty patients with intermediate risk for common bile duct (CBD) stones were randomized to either an EUS-first, endoscopic retrograde cholangiography (ERC)-second (n = 60) versus an ERC-only (n = 60) procedure.
Interventions: EUS, ERC, sphincterotomy, and balloon sweeping of CBD when needed.
Main outcome measurements: Sensitivity of EUS versus ERC, factors affecting diagnostic capability, complications, total number of endoscopic procedures.
Results: The sensitivity and specificity of ERC were 75% (95% CI, 42%-93%) and 100% (95% CI, 95%-100%), respectively. The sensitivity and specificity of EUS were 91% (95% CI, 59%-99%) and 100% (95% CI, 95%-100%), respectively. EUS is more sensitive than ERC in detecting stones smaller than 4 mm (90% vs 23%, P < .01). Although not significant, there was a trend for an increased number of endoscopic procedures in the ERC group compared with the EUS group (98 vs 83). The post-ERC pancreatitis rate was 6 in 120 (5%) in all study patients, and the post-ERC pancreatitis rate in patients with an undilated CBD was 5 of 53 (9.43%). The independent factors for post-ERC pancreatitis are undilated CBD (risk ratio [RR] 6.320; 95% CI, 1.703-11.524, P = .009), allocation into the ERC group (RR 2.107; 95% CI, 1.330-3.339, P = .02), female sex (RR 1.803; 95% CI, 1.155-2.813, P = .03), and age less than 40 years (RR 1.888; 95% CI, 1.245-2.863, P = .01). Kaplan-Meier analysis revealed higher rate of negative outcome in the ERC group than in the EUS group (P = .049, log-rank test).
Conclusion: The EUS-first approach is not associated with further risk for subsequent endoscopic procedures. Patients with an undilated CBD should be investigated by the EUS-first approach to prevent post-ERC pancreatitis.