Axial CT showing portosystemic collateral circulation via the umbilical vein: caput medusae in liver cirrhosis
|Classification and external resources|
|ICD-10||I86.8 (ILDS I86.820)|
Caput medusae, also known as palm tree sign, 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 head, which had venomous snakes in place of hair.
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.
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:
- flow toward the legs -> Caput Medusae
- flow toward the head-> Inferior Vena cava obstruction .