Minimally invasive pancreaticoduodenectomy for circumportal pancreas: literature review and report of two type IIIA cases.

Background: Circumportal pancreas is a rare morphological variant with clinical significance due to the high risk of postoperative pancreatic fistula in patients undergoing pancreaticoduodenectomy. Type IIIA (suprasplenic anteportal) is the most common type of circumportal pancreas. We present two cases of type IIIA treated with minimally invasive pancreaticoduodenectomy, and review the literature on patients with circumportal pancreas who underwent pancreatic surgery.

Case presentation: Case 1: Laparoscopic Pancreaticoduodenectomy for Non-functioning Pancreatic Neuroendocrine Neoplasm with Circumportal Pancreas. A 69-year-old female with no prior medical history presented with a pancreatic head mass detected during routine ultrasound. CT revealed a 20 mm hypervascular tumor in pancreas head and a suprasplenic circumportal pancreas with an anteportal duct. The main pancreatic duct (MPD) was not in the parenchyma on the dorsal side of the portal vein (PV). Laparoscopic pancreaticoduodenectomy was performed. The anteportal side was resected with an ultrasonic device, and the retroportal side with a mesh-reinforced stapler. Pancreaticojejunostomy was performed without complications. Case 2: Robot-assisted Pancreaticoduodenectomy for Pancreatic Head Cancer and Non-functioning Pancreatic Neuroendocrine Neoplasm in the pancreatic tail with Circumportal Pancreas. A 72-year-old male with no prior medical history presented with a dilated main pancreatic duct on ultrasound. Diagnosed with pancreatic head cancer (Stage IIA), he underwent neoadjuvant chemotherapy. Contrast-enhanced CT revealed pancreatic cancer in the head and a tumor in the tail with unknown pathology. Robot-assisted pancreaticoduodenectomy was performed, and pancreatectomy on the left side of the tail tumor was planned. Intraoperative findings revealed a circumportal pancreas with the MPD not running through the dorsal parenchyma. After resected the parenchyma on the left side of the tail tumor, parenchyma on the dorsal side of the PV was dissected using SynchroSeal®. Pancreaticojejunostomy was performed without complications. The postoperative course was uneventful.

Conclusions: The optimal location and method of pancreatic resection should be selected according to the type of circumportal pancreas and the location of the lesion to be resected to minimize the risk of pancreatic fistula. Minimally invasive surgery for circumportal pancreas remains challenging even for surgical teams with sufficient experience and skills, and careful consideration are necessary for its application.