A duplicate gallbladder masquerading as a colodocal cyst. Primary author, Ian Holmes. Co-authors, Jennifer Kincaid, Wilbur Bone, Anand Kumar. These are our disclosures. A 45-year-old otherwise healthy male presented to our center with epigastric pain and anorexia. He reported three weeks of pain radiating to his back and a 12-pound weight loss. A basic metabolic panel and liver function test were unremarkable. An abdominal ultrasound was ordered for further evaluation. An abdominal ultrasound revealed cholelithiasis within the gallbladder. In retrospect, an additional cystic structure was also present. However, this was not noted on initial review of the images. He was referred for laparoscopic cholecystectomy due to suspected biliary colic. Intraoperatively, he was noted to have a short cystic duct with a cystic structure adjacent to the common bile duct. Initially suspected to be a type 2 colodocal cyst. The cholecystectomy was completed, and a magnetic resonance cholangiopancreatography was ordered. For more information, visit www.FEMA.gov. The MRCP showed a cystic structure in the gallbladder fossa with a possible connection to the common bile duct. He then underwent ERCP with cholangioscopy. An occlusion cholangiogram revealed that the cystic duct filled followed by the cystic structure. Thus, the cystic structure communicated with the cystic duct remnant, not the common bile duct as previously suspected, and was thought to be more consistent with a duplicate gallbladder. Phalangioscopy was performed. Phalangioscopy confirmed that there was no communication of the cystic structure to the common vial duct or common hepatic duct. He was briefly hospitalized with transient bacteremia post-ERCP due to enterobacter droviae, which improved with antibiotics. He continued to have intermittent right upper quadrant abdominal pain associated with fatty meals. Due to persistent biliary colic, removal of duplicate gallbladder was planned with intraoperative ERCP and prophylactic common bile duct stem placement to reduce post-surgical complications. His post-operative course was uneventful, and the biliary stem was later removed without complications. The duplicate gallbladder was identified. An encolocystectomy of the duplicate gallbladder was performed, during which the Y-shaped cystic duct could be clearly seen. A duplicate gallbladder is a rare congenital defect with an estimated incidence of 1 in 4,000 births. They develop due to embryological defects in the 5th and 6th pharyngeal patches. They can mimic coelodocal cysts, but unlike coelodocal cysts, they are not associated with an increased malignancy risk. They can present with biliary colic, cholecystitis, biliary pancreatitis, or any of the pathology that can occur with a single gallbladder. During cholecystectomy, the presence of a duplicate gallbladder increases the risk of intraoperative bile leaks. Removal of asymptomatic duplicate gallbladders is not currently recommended, as opposed to coelodocal cysts, where operative intervention is necessary to decrease the patient's lifetime risk of cholangiocarcinoma. Indications for cholecystectomy of duplicate gallbladders in this population are generally identical to those with only one gallbladder. However, careful attention must be paid intraoperatively to the biliary anatomy to avoid bile duct injury. Duplicate gallbladders were first classified by Boyden in 1929, who described 20 cases between 1674 and 1929. He classified duplicate gallbladders into Vesica phylae divisa, in which the gallbladder share a common cystic duct, and Vesica phylae duplex, separate cystic ducts. Vesica phylae duplex gallbladders were subclassified into Y-shaped, where the cystic ducts joined together into a common cystic duct, and H-shaped configurations, where both cystic ducts enter the common bile duct separately. A modern classification was proposed by Harloftus in 1977. In the Harloftus classification, type I duplicate gallbladders have a common cystic duct that drains both gallbladders. Both gallbladders arise from the same primordium, but split later in development. Within type I, there are septate, V-shaped, and Y-shaped subtypes. Type II duplicate gallbladders have separate cystic ducts, and arise from different primordium. The ductular subtype drains into the common bile duct, while the trabecular subtype drains into the left or right hepatic duct. The patient in this case had a type I, Y-shaped duplicate gallbladder. In conclusion, a duplicate gallbladder is a rare congenital defect, and may mimic choledocal cysts, but do not increase a patient's malignancy risk. ERCP, with or without phalangioscopy, may be used to differentiate duplicate gallbladder from choledocal cysts. Prophylactic common bile duct stenting may allow for safer removal of the symptomatic duplicate gallbladder.

duplicate gallbladder

laparoscopic cholecystectomy

congenital defect

colodocal cyst

bacteremia