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.