Robotic Pancreaticoduodenectomy Using the hinotori Surgical System with Extended Resection for Type II Circumportal...

Circumportal pancreas (CP) is a rare congenital anomaly in which pancreatic parenchyma encases the portal vein. CP poses significant technical challenges during pancreatic surgery, particularly in safely isolating the pancreas from the portal vein, determining the optimal transection line, and managing the pancreatic stump. This report describes a case of CP identified intraoperatively during a robotic pancreaticoduodenectomy (RPD), in which an extended resection was required to achieve a single pancreatic duct for safe reconstruction.

A 77-year-old man diagnosed with distal bile duct cancer underwent RPD using the hinotori Surgical Robot System (Medicaroid, Hyogo, Japan). Preoperative contrast-enhanced CT demonstrated circumferential encasement of the portal vein by pancreatic parenchyma, findings that could have suggested the presence of a CP. However, these findings were not recognized at the preoperative stage, and the diagnosis of CP had not been established before surgery. During surgery, when the pancreas was found to encircle the portal vein, retrospective review of the imaging confirmed the presence of CP. However, the courses of the main and accessory pancreatic ducts remained indeterminate on both imaging and intraoperative findings, making classification according to Karasaki's system difficult. After careful dissection and mobilization of the pancreatic body from the portal vein, an extended resection was performed to obtain a single pancreatic duct for reconstruction. Pancreaticojejunostomy was performed using a standard duct-to-mucosa anastomosis with the modified Blumgart technique for a single pancreatic duct. The operation time was 1050 minutes, and the estimated blood loss was 795 mL. Histopathological examination revealed distal bile duct adenocarcinoma (pStage IIA, T2N0M0) with type II CP, in which the main pancreatic duct traversed the dorsal pancreas and the accessory duct ran ventrally. The postoperative course was uneventful, and the patient remains disease-free 18 months after surgery.

When the MPD course is unclear in CP, extended resection represents a rational and safe surgical strategy to achieve single-duct reconstruction. Although such complex cases have traditionally been managed by open surgery, robotic surgery enables safe and minimally invasive pancreaticoduodenectomy even in anatomically challenging conditions. To our knowledge, this is the 1st reported case of robotic pancreaticoduodenectomy for type II CP.