Portal vein duplication

Portal vein duplication is a rare congenital/developmental anomaly.

Clinical presentation

Portal vein duplication is often incidentally diagnosed on imaging, less commonly at laparotomy or autopsy but has been reported to present with portal hypertension, inhomogeneous fatty liver, and liver dysfunction ^2,6.

Pathology

Etiology

Portal vein duplication is thought to be the result of remodeling of the embryological vitelline veins on both sides of the primitive duodenum ^1,6. In some cases, it is difficult to explain by persistence of vitelline veins ².

Classification

• all portal veins run through the hepatoduodenal mesentery

  • two portal veins both with retropancreatic course

  • one portal vein has retropancreatic course and the other has a prepancreatic, post-duodenal or preduodenal course

• one portal vein runs through the hepatoduodenal mesentery and the other portal vein is considered as third inflow

  • third inflow directly enters the liver parenchyma (especially right lobe)

  • third inflow is the aberrant left gastric vein

Radiographic features

On cross-sectional imaging, the number of vessels in the hepatoduodenal mesentery is increased. In some cases, the aberrant portal vein directly enters the hepatic parenchyma and anastomoses between the two portal veins may exist. Can present as mass-like densities at the porta hepatis ⁵.

History and etymology

The first case reported by Snavely and Breakell was associated with esophageal varices from portal hypertension and diagnosed by autopsy ³.

Differential diagnosis

• cavernous transformation of the portal vein

• portal venous varix

• porta hepatis lymphadenopathy ⁵

• prominent aberrant left gastric vein ⁴

• peripancreatic aneurysms associated with median arcuate ligament syndrome