[Rare malformation of the bile ducts of surgical interest].

Variations from normal anatomy of extrahepatic biliary tract, especially if on the basis of a congenital defect, are often dangerous for the surgeon, as hidden cause of a possible injury during surgery. During a cholecystectomy performed for lithiasis in non functioning gallbladder, whose preoperative cholangiogram revealed nothing of suspect, the dissection of cystic duct was regular at its normal junction with the Common Bile Duct (CBD). Because of the scheduled intraoperative cholangiogram, it was however not severed but only dissected free. The gallbladder was therefore detached from the liver in anterograde progression, after hemostasis and section of a normal cystic artery. During the detaching of gallbladder from the liver what seemed a very large "hepato-cystic" duct coming to the infundibulum was met: for caution the cholangiogram was then made proximally to such "hepato-cystic" duct that instead revealed to be the main right hepatic duct coming to the infundibulum of gallbladder without confluence with the left hepatic duct. The biliary tract going from the gallbladder to the supposed CBD was in fact the cystic duct, as the Heister's valvulae clearly show on the cholangiograms. Cholecystectomy was therefore performed proximally to the confluence of right hepatic duct, and the postoperative course was uneventful. Such kind of extrahepatic tract derangement must be very rare, because of the apparent lacking in literature of any similar case, also if the possibility is mentioned.(ABSTRACT TRUNCATED AT 250 WORDS)