S1482 Anomaly of the Common Bile Duct, More Than Just About Biliary Drainage

Abstract

Introduction: The drainage of biliary drain into the duodenal bulb is a rare anatomic abnormality accounting for 0.1%-2.72% cases of all anomalous biliary drains. The common bile duct (CBD) can be seen draining into the stomach, pyloric canal, or the other parts of duodenum. We present a rare case of CBD draining into the duodenal bulb. Case Description/Methods: A 36-year-old female with a history of cholecystectomy presented with fever, right upper quadrant abdominal colic and vomiting for two days. Laboratory data revealed ALT 1180 U/l, AST 1606 U/l, total bilirubin 2.5 mg/dl, ALP 216 U/l and serum lactate 3.1 mg/dl. CT of the abdomen and pelvis demonstrated severe intrahepatic and CBD dilatation to 1.5 cm. She was started on piperacillin-tazobactam for suspected ascending cholangitis. ERCP was unsuccessful as the duodenoscope could not be passed beyond the pylorus, likely due to inflammation. An internal-external biliary drain was performed for biliary decompression. She was transferred to our institution for further management. An upper endoscopy with endoscopic ultrasound revealed a duodenal bulb insertion side of the biliary drain (Fig. 1A). There was no discernible papilla where the drain entered the duodenal bulb nor at the second portion of the duodenum. There was dilation in the CBD which measured up to 7 mm (Figure 1B & 1C). A cholangiogram demonstrated biliary configuration with a distal CBD stricture with contrast drainage to the duodenal lumen, arguing against a choledochoduodenal fistula (Figure 1D). Discussion: The pathogenesis although not completely understood is believed to result from early subdivision of the hepatic diverticulum into pars hepatica and pars cystica (Boyden’s theory). The presentations vary from asymptomatic finding to gallstones, cholangitis, pancreatitis, recurrent duodenal ulcers, and can also lead to cholangiocarcinoma. This results from biliary stasis, reflux of duodenal contents into the CBD and subsequent chronic inflammation. Diagnosis is largely based on imaging modalities with ERCP being the gold standard. Older case reports recommend surgical management, while newer reports corroborate successful management with endoscopic therapies. This rare condition should be considered in patients with recurrent duodenal ulcers; recurrent cholangitis; biliary obstruction without definite obstructing stone; or duodenal deformity.Figure 1.: Anomalous CBD drain into duodenal bulb (A, Endoscopic view of the duodenal bulb demonstrating the biliary drain insertion site; B, 7 mm dilation in the common bile duct with hypoechogenicity surrounding the drain; C, 7 mm dilation in the common bile duct with hypoechogenicity surrounding the drain; D, Cholangiogram revealing a distal common bile duct stricture with contrast drainage into the duodenal lumen).