DIAGNOSIS OF ASYMPTOMATIC COMMON BILE-DUCT STONES - PREOPERATIVE ENDOSCOPIC ULTRASONOGRAPHY VERSUS INTRAOPERATIVE CHOLANGIOGRAPHY - A MULTICENTER, PROSPECTIVE CONTROLLED-STUDY

Background. In patients with symptomatic cholelithiasis, preoperative diagnosis of common bile duct (CBD) stones can modify the therapeutic strategy. The aims of this prospective, controlled multicenter study w ere to assess the feasibility, concordance, discordance, and indexes s uch as sensitivity, specificity, positive and negative predictive valu es, and accuracy of preoperative endoscopic ultrasonography compared w ith those of intraoperative cholangiography (IOC) in the diagnosis of asymptomatic CBD stones (i.e., patients undergoing cholecystectomy wit h no clinical or biologic evidence of CBD stones). Methods. From Octob er 1993 to October 1995, 240 consecutive patients with symptomatic cho lelithiasis, scheduled for cholecystectomy in 14 surgical centers, wer e enrolled in this study. All patients were selected for this study ac cording to a preoperative high-risk CBD stone predictive score. Each p atient underwent both endoscopic ultrasonography and IOC, as well as s urgical exploration of the CBD when stones were detected during one or both preoperative investigations. All patients were seen 1 month and I year after operation to check for residual stones. Results. The feas ibility of endoscopic ultrasonography was significantly higher overall than that of IOC (99% vs 90 %; p < 0.001) except when IOC was through a laparotomy (97% vs 93 %; P = 0.16). The number of patients availabl e for study was 215 In 198 cases (92 %), results of both investigation s were in concordance (161 negative and 37 positive values). Seventeen cases (8%) were discordant. There was overall concordance between the two investigations (kappa coefficient 0. 764; 95% confidence interval 0. 66 to 0. 87), but the percentage of discordance was in favor of IO C. Sensitivity and specificity of IOC were significantly higher than t hose of endoscopic ultrasonography (1.00 and 0. 98 vs 0. 85 and 0.93, respectively). With a prevalence of CBD stones of 19%, positive and ne gative predictive values of IOC were significantly higher than those o f endoscopic ultrasonography (0. 93 and 1. 00 vs 0. 75 and 0.96 respec tively). Conclusions. Although endoscopic ultrasonography is feasible more often than IOC, IOC is associated with a slightly lower degree of discordance and better information indexes and remains an efficient m ethod of investigation for CBD stones. Endoscopic ultrasonography can be suggested in preference to endoscopic retrograde cholangiography wh en postoperative residual stones are suspected but need not be perform ed routinely before cholecystectomy.