Endoscopic ultrasound of bile duct hydatid membrane

Abstract

Background:Hepatic hydatid cyst rupture into the bile ducts (intrabiliary rupture) is the most common and serious complication of hepatic hydatid disease, occurring in 2%–42% of cases. Intrabiliary rupture (IBR) can be diagnosed by ultrasonography, computerized tomography, or magnetic resonance imaging.Methods:Transabdominal ultrasonography showed a 3.2 cm × 3.4 cm cyst in the right lobe of the liver, dilatation of the biliary system up to the lower end of the common bile duct (CBD), and biliary sludge in the gallbladder. Linear EUS was performed before endoscopic retrograde cholangiopancreatography (ERCP) to know the etiology of cholangitis.Results:Linear EUS from stomach revealed multiple curvilinear, leaflet-shaped, rounded, and irregular structures within dilated CBD and common hepatic duct. These structures were hyperechoic, multilayered, with intervening anechoic areas without acoustic shadowing indicating membranous structures folded many times. The structures were floating inside the CBD suggestive of hydatid membranes. Cholangiogram revealed a dilated CBD with multiple irregular filling defects formed by the hydatid membranes. ERCP with biliary sphincterotomy and balloon sweeping resulted in CBD clearance with expulsion of the multiple bile stained and whitish hydatid membranes. There was a significant improvement in clinical condition after ERCP. Follow-up USG after 2 weeks revealed normal CBD with decreased size of liver cyst.Conclusions:EUS by demonstrating the presence of mobile hydatid membranes or cyst-like material may be useful when other imaging modalities are inconclusive or unavailable in IBR. ERCP is both diagnostic and therapeutic in IBR, with removal of hydatid membranes relieving jaundice and cholangitis.