The value of contrast-enhanced ultrasound guiding normal saline injection in the detection of residual common bile duct stones

Abstract

Objective To investigate the diagnostic value of contrast-enhanced ultrasound (CEUS) guiding normal saline (NS) injection through endoscopic nasobiliary drainage duct(ENBD) on evaluation for residual stones in common bile duct. Methods Fifty-five patients with bile duct stones were treated by endoscopic retrograde cholangio-pancreatography (ERCP) and duodenoscopic sphincterotomy incision surgery (EST) and ENBD. All patients received normal ultrasonography and CEUS guiding NS injection ultrasonography after EST. The length and width of common bile duct and the detection rate of residual stones before and after NS injection were compared. Results In the 55 patients, 1 patient failed in injection of contrast agent into the ENBD.In the other 54 patients, the difference of the length and width of common blie duct before and after NS injection were statistically significant [(2.94±1.76)cm vs (6.09±1.46)cm, (0.58±0.30)cm vs (1.11±0.98)cm](all P<0.001). The full display rate of the common bile duct before and after NS injection were 13.0%(7/54) and 90.7%(49/54), respectively. Before injection, none of common bile duct stones was suspected.After injection, 5 cases of common bile duct stones were suspected. Three cases were confirmed by ERCP, 1 case was confirmed by operation and 1 case was false positive. Conclusions CEUS of the common bile duct through ENBD performs its patency and course. On this basis the injection of NS increases the display rates of common bile duct, thus improving the detection rate of residual stones. Key words: Contrast-enhanced ultrasound; Choledocholithiasis; Endoscopic nasobiliary drainage duct