RESUMEN
Obstruction of the common bile duct by impaction of a gallstone in the neck or the cystic duct of the gallbladder results into repeated attacks of cholangitis (Mirizzi's syndrome). In suspected cases preoperative diagnosis can be made by ultrasonography and cholangiography. We report two patients of a variant of Mirizzi's syndrome. The common bile duct was obstructed by a stone impacted in the neck and causing extrinsic compression from behind. Ultrasonography and endoscopic retrograde cholangiography diagnosed the condition as common bile duct stone in both the cases. The anomaly could be diagnosed only after choledochotomy. Stones were retrieved by transcholedochal cholecystolithotomy--an innovative surgical procedure for this variant of Mirizzi's syndrome.