Caput Medusae
Caput medusae is a clinical sign characterized by the appearance of dilated, tortuous veins radiating from the umbilicus across the abdominal wall. This condition is named after Medusa, a figure from Greek mythology known for her hair of snakes, due to its resemblance to the radiating pattern of veins.
Caput medusae is a manifestation of severe portal hypertension, which is defined as an increase in the pressure gradient between the portal vein and inferior vena cava. This increased pressure leads to the development of portosystemic collaterals, including those around the umbilicus.
As portal pressure rises, blood seeks alternative routes to return to the systemic circulation. The paraumbilical vein, which normally closes after birth, can reopen and dilate, leading to the characteristic appearance of caput medusae.