Caput Medusae

CAPUT MEDUSAE, the designation given to the tortuously dilated subcutaneous venous vessels of the anterior abdominal wall, observed when portal circulation is impaired [see separate plate (for Granulomas), fig. 4]. They are so named because they resemble the image of the head of the mythological Medusa, from whose head grew twisting snakes instead of hair. The dilation of the venous vessels of the abdominal wall occurs as a result of collateral outflow of venous blood from the abdominal cavity through the mentioned vessels when there is an obstacle to blood flow in the portal vein system; this most commonly occurs in atrophic cirrhosis of the liver. In this disease, connective tissue grows in the liver, which subsequently leads to hardening and shrinkage of the liver, which significantly impedes the passage of blood through the liver, resulting in severe congestion in all the venous roots in the abdominal cavity and the phenomena of ascites. In some cases, such congestion in the portal vein does not occur or is alleviated due to the development of collateral outflow of blood through anastomoses of the portal vein with the esophageal veins, as well as through the preserved lumen of the umbilical vein or v. paraumbilicales, located in the round ligament of the liver, from where blood is directed through the subcutaneous veins of the anterior abdominal wall to the subclavian vein. The dilation of the serpentine subcutaneous veins of the abdomen gives the above-described picture of Caput Medusae.