Portal venous system (MSLV)

1. Define portal vein

The portal vein is a vital blood vessel in the abdominal cavity that receives deoxygenated blood from the stomach, small intestine, pancreas, and spleen.

2. Describe its formation, course and relations

The portal vein is formed by the confluence of the superior mesenteric vein (SMV) and the splenic vein. It ascends through the transverse mesocolon, passes behind the neck of the pancreas, and then divides into two main branches: the right and left portal veins. The portal vein is related to the first part of the duodenum, the neck of the pancreas, and the portal vein divides into the right and left portal vein.

3. Mention the tributaries

Tributaries of the portal vein:

• Superior mesenteric vein (SMV)
• Splenic vein
• Right gastric vein
• Left gastric vein
• Gastroduodenal vein
• Pancreatic veins
• Hepatic veins

4. Mention the sites of portacaval anastomosis and its applied anatomy

Portacaval anastomosis is the connection between the portal vein and the inferior vena cava (IVC). Sites of portacaval anastomosis:

• Lower end of the esophagus
• Upper part of the stomach
• Lower part of the pancreas
• Upper part of the duodenum
• Umbilical vein (in fetal life) Applied anatomy: Portacaval anastomosis is important in the surgical management of portal hypertension. It provides a route for the shunting of blood from the portal vein to the IVC, which can relieve pressure in the portal system and prevent bleeding from esophageal varices.

Key points:

• Portal vein receives deoxygenated blood from the stomach, small intestine, pancreas, and spleen.
• It is formed by the confluence of the superior mesenteric vein and the splenic vein.
• It ascends through the transverse mesocolon and passes behind the neck of the pancreas.
• It divides into two main branches: the right and left portal veins.
• Tributaries of the portal vein include the superior mesenteric vein, splenic vein, and others.
• Portacaval anastomosis is the connection between the portal vein and the IVC, and it is important in the surgical management of portal hypertension.