CASE REPORT The subvesical duct of Luschka a source of bile leakage following gallbladder removal Ian C Duncan FFRad(D)SA Basil J Sher FCRad(D)SA SunninghilI Medical Institute Sandton Abstract We describe a case of bile leakage fol- lowing laparoscopic cholecystectomy further complicated by iatrogenic central bile duct obstruction. The site ofleakage was identified not from the site of the inadvertent proper hepatic duct ligation but from a damaged aberrant subvesical duct communi- cating with the gallbladder fossa. The anatomy of these subvesical ducts is explained as is their surgical impor- tance with relation to the aetiology of bil~ leaks after cholecystectomy. Introduction Bileleaks are recognised complica- tions following cholecystectomy or other hepatobiliary surgery. They can result from direct trauma to a duct or from an anastomotic or cystic duct remnant leakage. The presence of an aberrant bile duct leak may make the radiological detection of the presence and site of the leakage more difficult.I One such example involves the sub- vesical duct of Luschka. Case report A 3D-year-old woman presented 1 week after laparoscopic cholecystecto- my with jaundice, upper abdominal pain and abdominal distension. A provisional diagnosis of bile duct injury was made. Abdominal ultra- sonography showed fluid in the gall- bladder fossa and subhepatic space (Fig. 1) and a large volume of free intraperitoneal fluid. The intrahepat- ic bile ducts were not dilated. An abdominal MR scan was per- formed which again showed the fluid Fig. 1. Axial upper abdominal ultrasound scan showing fluid in the gal/bladder fossa and no dila- tion of the intrahepatic bile ducts. 44 SA JOURNAL OF RADIOLOGY • June 2003 Fig. 2. Axial T2 MR scan through the lower liver again shows fluid in the gal/bladder fossa as weI/ as the large volume of free intraperitoneal fluid particularly around the right hepatic lobe. in the gallbladder fossa and peritoneal cavity (Fig. 2). A MR cholangiogram was attempted to try and show conti- nuity between the right and left main hepatic bile ducts and although the proper hepatic duct was shown to be occluded, no definite answer could be given concerning the existence of free communication between the right and left hepatic ducts or about the site of the bile leakage (Fig. 3). Fig. 3. MR cholangiogram showing the gal/blad- der fossa and free fluid in the subhepatic space. Although the intrahepatic ducts are seen, continu- ity between the hepatic ducts across the conflu- ence cannot be confirmed. The proper hepatic duct is not visualised. These studies were followed by percutaneous transhepatic cholan- giography (PTC). This was per- formed from a left sided approach due to the large volume of perihepatic free fluid around the right lobe, also pre- empting possible conversion of the CASE REPORT procedure into a percutaneous drain insertion. During the contrast injec- tion leakage of contrast from a duct- like structure communicating with the anterio-inferior segmental duct (segment 5) and running inferiorly towards the gallbladder fossa was noted (Fig. 4). The contrast accumu- lated progressively in the gallbladder fossa and subhepatic space (Fig. 5). This aberrant duct was identified as the subvesical duct of Luschka. Also Fig. 4. Percutaneous transhepatle cholangiogram showing leakage of contrast via the damaged sub- vesical duct of Luschka communicating between the anterioinferior segmental duct and the gall- bladder fossa. Fig. 5. Further contrast injection confirms commu- nication between the right and left hepatic ducts with obstruction at the duct confluence. The pres- ence of a clip at this point indicates inadvertent surgical ligation. There is further accumulation of contrast in the subhepatic space. identified was total occlusion of the proper hepatic duct at the confluence of the right and left hepatic ducts but with free communication between the two ducts. A surgical clip was seen at the level of the obstruction confirm- ing an iatrogenic injury. No contrast leak was seen from the site of this obstruction. An external drain was placed into the hepatic duct system via a second more peripheral left-sided access. Two days later a choledochojejunosto- my was performed by anastomosing a Raux: loop to the bile duct confluence. The opening at the subvesical duct was also oversewn at the same time so as to avoid further bile leakage. Discussion There are a large number of con- genital variants of the intrahepatic and extrahepatic bile ducts" all of which are related to the complex embryological development of the biliary tree. They are seen in up to 42 - 47% of cases. Anomalous or aberrant bile ducts are seen in around 28% of cases.' These ducts are often erroneously referred to as 'accessory' ducts. However they provide the sole path of bile drainage from normal areas of the liver with which they are associated and are more correctly termed 'anom- alous' or 'aberrant' ducts. The cholecystohepatic or subvesi- cal duct is a small aberrant intrallepat - ic duct that runs close to the wall of the gallbladder just below the surface of the liver in the gallbladder fossa. The original description of this duct was by Luschka and it is thus often referred to as 'Luschka's duct'. Occasionally the subvesical duct may extend into the wall of the gallbladder, but almost never communicates with 45 SA JOURNAL OF RADIOLOGY • June 2003 the gallbladder lumen (although it probably did during embryological development). It is present in between 15% and 35% of cases." These ducts drain an area of the inferior right lobe in the vicinity of the gallbladder fossa usually into a segmental tributary of the right hepatic duct, less commonly into the right hepatic duct itself or more rarely into the cystic or com- mon hepatic ducts. These ducts are small, being 1 - 2 mm in diameter and are typically not accompanied by a portal venous branch. They are usual- ly not seen at cholangiography, partic- ularly MR cholangiography. The greatest clinical significance attached to the presence of these ducts is that they may be damaged during chole- cystectomy, whether open or laparo- scopic, as the gallbladder is dissected away from its bed." This can then result in a bile leak into the gallbladder bed and subhepatic space. This leak is often limited in extent but many result in the leakage of a considerable vol- ume of bile, as in our case. Postoperative bile leaks can occur due to direct duct trauma at a number of sites other than the subvesical duct often related to the presence of other aberrant bile duct variations. I Leaks can also occur from a hepaticojejunal anastomosis, common bile duct-to- common bile duct anastomosis, hepatic resection site or leakage from a ligated cystic duct remnant. Postoperative bile leaks, regardless of their site, usually respond well to bile drainage. This can be done inter- nally by placement of a bile duct stent or externally by percutaneous tran- shepatic biliary drainage.' , Radiologists involved in the inves- .tigation of bile leakage following cholecystectomy should therefore be aware of the presence of the subvesical CASE REPORT duct as potential source of bile leakage into the gallbladder fossa. The pre- ferred method of investigation is per- cutaneous transhepatic cholangiogra- phy, particularly as this can then be followed immediately by percuta- neous biliary drain insertion to allow external bile diversion thereby facili- tating closure of the leak. References 1. Suhocki PV;Meyers Wc. Injury to aberrant bile ducts during cholecystectomy: A common cause of diagnostic error and treatment delay. AfR 1999; 172: 955-959. 2. Healey JE, Schroy pc. Anatomy of the biliary ducts within the human liver: Analysis of the prevailing patterns ofbranchings and the major variations of the biliary ducts. Arch Surg 1953; 66: 599-616. 3. Hayes MA, Goldenberg IS, Bishop Cc. The development basis for bile duct anomalies. Surg Gynaecol Obstet 1958; 107: 447-456. 4. Goor DA, Ebert PA. Anomalies of the biliary tree. Arch Surg 1972; 104: 302-309. 5. Ernest 0, Sergent G, Mizrahi D, Delernazure 0, [Hermine C. Biliary leaks: Treatment by means of percutaneous transhepatic biliary drainage. 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