Portocaval Shunts

Portal vein

Drains from organs supplied by unpaired visceral branches of abdominal aorta (celiac trunk, superior and inferior mesenteric aa.)

IVC

drain from all structure below diaphragm except those supplied by unpaired visceral branches of the abdominal aorta.

Hemoirrhoidal/rectal nodes - inferiorly

Portal part: Superior rectal v. (-> inferior mesenteric v. -> portal v.) Caval part: middle + inferior rectal vv. (-> internal iliac v. -> IVC)

Esophageal varices - superiorly

Portal part: gastric vv. Caval part: esophageal vv. (--> azygous --> SVC)

Paraumbilical/caput medusae - anteriorly

Portal part: paraumbilical vv. (round lig. - umbilical v.) Caval part: superficial thoracic v. (-> femoral v. -> IVC) or thoracoepigastric v. (-> axillary v. -> SVC)

Retroperitoneal - posteriorly

Portal part: splenic v. Caval part: lumbar vv (-> azygous -> SVC)

Portocaval shunt

if blood flow through portal system is obstructed, the BP in portal systems increase and leads to portal hypertension. Blood can then be directed through portocaval anastomoses. If it happens over a long period of time, veins can become overly dilated. This can lead to varices which can rupture.