Portocaval Anastomosis

Portocaval anastomosis
Anastomosis is the connection between two blood vessels. Portocaval anastomosis includes all the connections made between veins of the portal circulation and the systemic circulation. The major areas where the two systems anastomose are the following:

1. Esophageal region:
Is the area where veins of the abdomen meet the azygos system. The esophageal branch of the portal circulation includes the left gastric vein which arises from the the portal vein. And from the systemic circulation we have the azygos vein which rises from the left brachiocephalic vein

2. Paraumbilical region:
Is the area around the umbilicus where the paraumbilical veins of the portal circulation which arise from the left branch of the portal vein meet the superior epigastric vein of the systemic circulation which arises from the internal thoracic vein.

3. Rectal region:
Is the area where the superior rectal vein which arises from the inferior mesenteric from the portal vein circulation meets the systemic circulation and the middle and inferior rectal veins which arise from the internal iliac vein.

4. Retroperitoneal region:
Is the area around the peritoneal where the portal circulation veins: right and middle colic which arises from the superior mesenteric and left colic vein which arises from the inferior mesenteric meet with the systemic circulation and the veins: gonadal vein ( testicular or ovarian based on gender) which arise from the inferior vena cava on the right and from the renal vein on the left, lumbar veins which are part of the azygos vein.

In the case that the liver is blocked or diseased and the blood finds difficulty passing through the portal system then the blood pressure in the system will increase. This is called portal hypertension. In cases of portal hypertension areas of anastomosing veins can become enlarged from the pressure or even rupture causing bleeding and varices.

Medical Terminology

 * At the esophageal region this condition is called esophageal verices.
 * In the paraumbilical region it's called  caput Medusa (head of Medusa since it resembles the snakes on the head of Medusa the Greek mythological creature which turned men to stone if they gazed into her eyes),
 * At the rectal region they are called anorectal varices (haemorrhoids) and
 * there is no clinical name for the retroperitoneal swelling vessels