Portal annular pancreas. A rare variant and a new classification

Abstract

Context: Portal annular pancreas is a rare congenital anomaly resulting from fusion of the pancreatic parenchyma around the portal vein/superior mesenteric vein. It is asymptomatic, but could have serious consequences during pancreatic surgery, if unrecognized. We describe a variant of this anomaly encountered during pancreaticoduodenectomy and propose a new classification.

Case report: We report a 51-year-old male who underwent a pancreaticoduodenectomy for periampullary carcinoma. After division of the pancreatic neck, a sheath of tissue was found posterior and extending to the left of the portal vein. When we divided this tissue, a large duct was encountered; this duct communicated with the main pancreatic duct. On review of the CT images, the main pancreatic duct was seen to be passing posterior to the portal vein and a smaller accessory pancreatic duct was present anterior to the portal vein. We describe the surgical implications.

Conclusion: This variant of portal annular pancreas has not yet been reported during pancreaticoduodenectomy and we propose a new classification for this fusion anomaly.