Intraductal papillary mucinous carcinoma with portal annular pancreas anomaly treated by middle-preserving pancreatectomy

Cases of portal annular pancreas treated by pancreatectomy are very rare. We report a surgical case of intraductal papillary mucinous carcinoma of the pancreas head and intraductal papillary mucinous adenoma of the pancreas tail with portal annular pancreas Type III a. A 72-year-old woman was admitted for treatment of intraductal papillary mucinous carcinoma of the pancreas head and intraductal papillary mucinous adenoma of the pancreas tail. Preoperative enhanced CT showed the uncinated process connecting with the pancreas body completely and surrounding the portal vein at the cranial side of the splenic vein. Middle-preserving pancreatectomy was performed. Anterior pancreas and posterior pancreas relative to the portal vein were cut separately. The main pancreatic duct was in the anterior pancreas, and Roux-en-Y reconstruction was performed. The incidence of portal annular pancreas is about 2%. However, to the best of our knowledge, only 20 cases of portal annular pancreas underwent pancreatectomy, including this case, have been reported. This suggests that the posterior pancreas tissue of the portal vein is ligated without being noticed in many cases, which may cause postoperative pancreatic fistula and subsequent surgical site infection. It is easy to diagnose the anomaly of portal annular pancreas by enhanced CT preoperatively. In cases of portal annular pancreas, it is necessary to diagnose the anomaly preoperatively and decide on the surgical procedure.