Echo-endoscopy versus endoscopic retrograde cholangiography for the diagnosis of choledocholithiasis: the influence of the size of the stone and diameter of the common bile duct.

BACKGROUND: Endoscopic retrograde cholangiography is highly accurate in diagnosing choledocholithiasis, but it is the most invasive of the available methods. Endoscopic ultrasonography is a very accurate test for the diagnosis of choledocholithiasis with a risk of complications similar to that of upper gastrointestinal endoscopy.

AIM: To compare the accuracy of endoscopic ultrasonography and endoscopic retrograde cholangiography in the diagnosis of common bile duct stones before laparoscopic cholecystectomy and to analyze endoscopic ultrasound results according to stone size and common bile duct diameter.

PATIENTS AND METHODS: Two hundred and fifteen patients with symptomatic gallstones were admitted for laparoscopic cholecystectomy. Sixty-eight of them (31.7%) had a dilated common bile duct and/or hepatic biochemical parameter abnormalities. They were submitted to endoscopic ultrasonography and endoscopic retrograde cholangiography. Sphincterotomy and sweeping of the common bile duct were performed if endoscopic ultrasonography or endoscopic retrograde cholangiography were considered positive for choledocholithiasis. After sphincterotomy and common bile duct clearance the largest stone was retrieved for measurement. Endoscopic or surgical explorations of the common bile duct were considered the gold-standard methods for the diagnosis of choledocholithiasis.

RESULTS: All 68 patients were submitted to laparoscopic cholecystectomy with intraoperative cholangiography with confirmation of the presence of gallstones. Endoscopic ultrasonography was a more sensitivity test than endoscopic retrograde cholangiography (97% vs. 67%) for the detection of choledocholithiasis. When stones >4.0 mm were analyzed, endoscopic ultrasonography and endoscopic retrograde cholangiography presented similar results (96% vs. 90%). Neither the size of the stone nor the common bile duct diameter had influence on endoscopic ultrasonographic performance.

CONCLUSIONS: For a group of patients with an intermediate or moderate risk with respect to the likelihood of having common bile duct stones, endoscopic ultrasonography is a better test for the diagnosis of choledocholithiasis when compared to endoscopic retrograde cholangiography mainly for small-sized calculi.