Prepancreatic postduodenal portal vein: a case report and review of the literature

Abstract

Background: Prepancreatic postduodenal portal vein is extremely rare, with only 13 cases reported in the literature.

Case presentation: A 55-year-old white woman presented to our emergency department with abdominal pain. She underwent a computed tomography of her abdomen, which showed a portal vein coursing anterolaterally to her pancreas and posteriorly to the first portion of her duodenum, constituting a prepancreatic postduodenal portal vein. Imaging revealed choledocholithiasis, requiring endoscopic sphincterotomy, but due to a history of a gastric bypass procedure, she was lost to follow-up after being referred to an advanced endoscopist. This represents the 14th reported case of prepancreatic postduodenal portal vein.

Conclusions: Awareness of this rare anomaly is paramount, and will help surgeons and interventional radiologists to avoid complications related to inadvertent injury to the portal vein, which could be life-threatening.

Keywords: Anomaly; Case report; Literature review; Pancreatic surgery; Portal vein.

Fig. 1

Axial images of computed tomography scan of the abdomen. The images show the portal vein in between the duodenum and the pancreatic duct. Three sequential cuts shown: a–c caudal to cephalad. PD pancreatic duct, PV portal vein

Fig. 2

Coronal images of computed tomography of the abdomen. The images show linear configuration of the portal vein and common bile duct, with the pancreatic duct coursing posterior to the portal vein. Three sequential cuts shown: a–c anterior to posterior. CBD common bile duct, PD pancreatic duct, PV portal vein

Fig. 3

Sagittal images of computed tomography of the abdomen. The images show the pancreatic duct coursing posterior to the portal vein. Three sequential cuts shown: a–c right to left. PD pancreatic duct, PV portal vein

Fig. 4

Normal development of the portal vein. The two vitelline veins are connected by three anastomoses (cranial, middle, and caudal). The dorsal pancreatic bud lies cephalad and ventral to the middle anastomosis. The duodenum lies ventral to the middle anastomosis and dorsal to the caudal anastomosis. During embryogenesis the caudal segment of the right vitelline vein and cranial segment of the left vitelline vein regress along with the caudal anastomosis. The pancreatic buds rotate in a clockwise fashion (viewed from caudal perspective) and fuse together resulting in a portal vein in the usual position posterior to the duodenum and the pancreas. C1 caudal anastomosis, C2 cranial anastomosis, D duodenum, DP dorsal pancreatic bud, LPV left portal vein, LVV left vitelline vein, M middle anastomosis, P pancreas, PV portal vein, RVV right vitelline vein, VP ventral pancreatic bud

Fig. 5

Development of the prepancreatic postduodenal portal vein. In this variant the dorsal pancreatic bud lies not cephalad and ventral, as is in normal development (Fig. 4), but rather the opposite: caudal and dorsal to the middle anastomosis and the caudal segment of the left vitelline vein, respectively. Rotation of the pancreatic buds in a clockwise fashion results in a portal vein posterior to the duodenum but anterior to the pancreas. C1 caudal anastomosis, C2 cranial anastomosis, D duodenum, DP dorsal pancreatic bud, LPV left portal vein, LVV left vitelline vein, M middle anastomosis, P pancreas, PV portal vein, RVV right vitelline vein, VP ventral pancreatic bud

Fig. 6

Development of the preduodenal portal vein. In the preduodenal variant, the middle anastomosis involutes and the caudal anastomosis forms the portal vein. The ventral pancreas rotates in a counter clockwise direction to fuse with the dorsal pancreatic bud. This results in a portal vein anterior to the duodenum. C1 caudal anastomosis, C2 cranial anastomosis, D duodenum, DP dorsal pancreatic bud, LPV left portal vein, LVV left vitelline vein, M middle anastomosis, P pancreas, PV portal vein, RVV right vitelline vein, VP ventral pancreatic bud