Duplicated common bile duct: a recipe for biliary injury. Report of a new variant

A new variation of duplicated extrahepatic bile duct encountered intraoperatively on cholangiogram

A potentially devastating complication of laparoscopic cholecystectomy (LC) includes iatrogenic bile duct injury, the incidence of which has remained stable at 0.3% over the past three decades. Although there are several relative risks such as surgeon experience and patient factors (male sex, obesity, older age), misinterpretation of biliary tree anatomy contributes towards 80% of iatrogenic common bile duct (CBD) injuries. Although extremely rare, an isolated duplicated common hepatic duct anomaly with a normal CBD remains a potential variation to encounter during biliary surgery. With only one similar variation published worldwide, we report the second case encountered during LC and confirmed on cholangiogram. Given these anomalies are asymptomatic and perpetuate iatrogenic CBD injuries, awareness of this variation is crucial. Preoperative diagnosis is possible with the use of magnetic resonance cholangiopancreatography; however, such imaging is not routinely used prior to LC in Australia due to factors including expense and availability.

Successful diagnosis and treatment of double common bile duct with cholelithiasis by laparoscopic cholecystectomy

Double common bile duct (DCBD) is an extremely rare congenital anomaly of the biliary system associated with serious complications. An association between DCBD and inadvertent bile duct injury during surgery has been reported. However, DCBD is difficult to diagnose preoperatively. We report a rare case of DCBD (type 3b), combined with cholelithiasis and cholecystitis, diagnosed preoperatively, and treated safely by laparoscopic cholecystectomy. A 79-year-old woman was admitted with a 1-week history of chest pain. Abdominal computed tomography revealed gallbladder distension with obvious wall thickening. Laparoscopic cholecystectomy was planned to determine the presence of stones in the common bile duct and an anomalous biliary tract. Magnetic resonance cholangiopancreatography (MRCP) was performed, and anomalous anatomy of the biliary tract was suspected. Drip infusion cholangiography with computed tomography (DIC-CT) showed type 3b DCBD. On hospital day 7, laparoscopic cholecystectomy was performed without accessory common bile duct resection. The postoperative course was uneventful, and the patient was discharged on postoperative day 5. To our knowledge, this is the first report of the successful diagnosis of DCBD using DIC-CT. MRCP and DIC-CT can be useful for the pre-operative diagnosis of DCBD to decrease the risk of bile duct injury during surgery.

A new variant of double common bile duct associated with choledochal cyst

Extrahepatic bile duct duplication is a rare biliary anomaly often associated with conditions like cholecysto-choledocholithiasis, choledochal cyst and malignancy. Precise preoperative diagnosis using conventional radiologic imaging still remains a challenge and use of existing classification system is equally confusing. A female patient diagnosed with choledochal cyst by magnetic resonance cholangiopancreatography was found to have an associated new variant of double common bile duct during surgery. The variant discovered could not be classified by existing classification systems and was missed by preoperative imaging. Recognition of existence of this anomaly that warrants careful dissection during biliary surgery is necessary to avoid inadvertent biliary injury as preoperative diagnosis still remains a challenge. Review of existing classification systems is required to include newly discovered variants.

Extrahepatic biliary duplication with heterotopic gastric mucosa in a 46,XX male patient

Extrahepatic biliary duplication is a rare congenital biliary malformation, even more so when associated with heterotopic gastric mucosa. This case report highlights the difficulty of diagnosing such biliary abnormalities, in particular when the duplicated extrahepatic bile duct is the only structure visible by imaging as it is masking the common bile duct. This report shows that extrahepatic bile duct duplication may be a cause of chronic biliary obstruction and secondary sclerosing cholangitis. It has to be considered as a differential diagnosis of primary sclerosing cholangitis in children and adolescents. Furthermore, a potential link between the 46,XX karyotype and biliary duplication is discussed.