Pancreaticoduodenectomy for periampullary adenocarcinoma in a patient with a prepancreatic portal vein

Abstract

Background: Prepancreatic portal vein (PPPV) is a rare congenital anomaly that Results in the portal vein coursing anterior to the neck of the pancreas due to aberrant regression of the vitelline veins. The presence of this anomaly can present challenges when planning pancreatectomies, even for experienced surgeons. Previously, distal pancreatectomy and total pancreatectomy of an annular pancreas have been described in patients with PPPV. This case demonstrates that pancreaticoduodenectomy for malignancy can be successfully performed in a patient with a PPPV. Methods: An 80 year old woman presented with abdominal pain and obstructive jaundice. Endoscopy demonstrated a 2.7 centimeter periampullary mass that invaded the distal common bile duct requiring stent placement. Biopsy of the mass confirmed the diagnosis of adenocarcinoma. On pre-operative pancreatic protocol computed tomography, she was found to a have a PPPV without evidence of metastases. Given her good functional status and desire for curative therapy, she was consented for a pancreaticoduodenectomy. Results: After confirming the tumor was resectable, we created a tunnel around the pancreas to the left of the PPPV. Pancreatic dissection was continued in the standard fashion. The splenic vein was identified coursing behind the common hepatic artery and superior to the pancreatic body; it was followed to identify the take-off of the gastroduodenal artery which was adjacent to the splenic vein-portal vein confluence. After the bile duct and proximal duodenum were transected, the pancreatic neck was divided. The pancreas was freed from the retroperitoneum with Ligasure device, taking extreme care to preserve the superior mesenteric artery at the mesenteric root. The pancreas was adhered to the posterior superior mesenteric vein (SMV); it was able to be removed with ligation of the middle colic vein and controlled creation of a small venotomy in the SMV with less than five minutes of clamp time. Reconstruction was performed in the standard fashion. Conclusion: PPPV is a rare congenital vascular anomaly. Identification of unusual vascular anatomy is essential prior to undertaking any procedure in the right upper quadrant. Most descriptions of PPPV in the literature are in the pediatric population; there are two pancreatectomies reported in adults for malignancy but neither required a pancreatic anastomosis. We have shown that PPPV does not preclude successful pancreaticoduodenctomy for a malignant process. Pre-operative imaging and planning are essential when approaching any pancreatic procedure in a patient with PPPV.