|Classification and external resources|
Axial CT showing portosystemic collateral circulation via the umbilical vein: caput medusae in liver cirrhosis
|ICD-10||I86.8 (ILDS I86.820)|
Caput medusae is the appearance of distended and engorged paraumbilical veins, which are seen radiating from the umbilicus across the abdomen to join systemic veins. The name caput medusae (Latin for "head of Medusa") originates from the apparent similarity to Medusa's hair once Athena had turned it into snakes.
The umbilical vein carries oxygenated blood from mother to fetus in utero, and normally closes within one week of birth. In portal hypertension, the umbilical vein can become re-canalized.
Differential diagnosis 
Inferior vena cava obstruction 
- Produces abdominal collateral veins to bypass the blocked inferior vena cava and permit venous return from the legs.
How to differentiate 
Determine the direction of flow in the veins below the umbilicus. After pushing down on the prominent vein, blood will:
- Caput Medusae - flow is towards the legs
- Inferior vena cava obstruction - flow is towards the head.
See also