Last reviewed 01/2018
The term Caput Medusae describes the appearance of distended and engorged umbilical veins which are seen radiating from the umbilicus across the abdomen to join systemic veins. It is a sign of severe portal hypertension with portal-systemic shunting through the umbilical veins. The name originates from the apparent similarity to Medusa's hair once Minerva had turned it into snakes.
Caput Medusae is distinguished from inferior vena cava obstruction by determining the direction of flow in the veins below the umbilicus; it is towards the legs in the former, and towards the head in the latter (as abdominal collaterals develop to bypass the blocked inferior vena cava and permit venous return from the legs).