porto-systemic shunts

Last reviewed 01/2018

Porto-systemic shunts occur where there is obstruction to the portal outflow of blood in portal hypertension. This results in an increased blood flow at the sites of anastomosis between the portal and systemic systems, at:

• the gastro-oesophageal junction, where there is flow between the left gastric and short gastric veins of the portal system and the intercostal, diaphragmatic and azygous veins of the systemic circulation, with the development of oesophageal varices

• the anus, where there is flow between the superior haemorrhoidal veins of the portal system and the middle and inferior haemorrhoidal veins of the systemic circulation

• the porta hepatis and the umbilicus

• in the retroperitoneal space around the kidneys, spleen, ascending and descending colons and duodenum