Congenital portal venous system aneurysms associated with caput medusae
Authors: Tao Li, Xu-Ting Zhi, San-Yuan Hu
Journal: Hepatology (2010)

A 47-year-old man was admitted to our hospital because of a painless abdominal wall mass that had been increasing in size for the last 10 years. One month before he came to our hospital, he suffered from sever upper gastrointestinal bleeding and was treated in the local hospital by pharmacological therapy. He denied any use of alcohol, had no history of chronic hepatitis B or C infection, and had no history of living in an area endemic for schistosomiasis. His physical examination revealed splenomegaly and massive tortuous veins on his chest and abdominal wall, especially above the umbilicus (Fig. 1A). A laboratory evaluation revealed a white blood cell count of 1.18 × 109/L, a red blood cell count of 2.44 × 1012/L, and a platelet count of 51 × 109/L. His liver function was normal, and his serology for viral hepatitis B and C was negative. Repeated stool and urine examinations did not find any parasites or eggs. Marked dilation of thrombosed portal and splenic veins, esophageal varices, splenomegaly, and a dilated splenic artery were demonstrated by computed tomography scanning and angiography (Fig. 1B-H). Computed tomography scanning also demonstrated the dilation of a paraumbilical vein, which extended to the anterior abdominal wall, caused tortuous varices in the epigastrium, and formed caput medusae (Fig. 1B,H). There was no outflow obstruction of the hepatic veins on angiography, and the portal and splenic blood flow volumes were 7625 and 3882 mL/minute, respectively, according to Doppler ultrasonography. Because the patient had no history of trauma, surgery, hepatitis, pancreatitis, or hepatic tumor and there were concomitant abnormalities of the celiac trunk and splenic artery, a diagnosis of portal hypertension (PH) caused by a congenital portal venous system aneurysm (PVSA) was rendered. PH, portal hypertension; PVSA, portal venous system aneurysm. An operation was performed to prevent rehemorrhaging. Splenectomy, distal pancreatectomy, pericardial devascularization, wedged liver biopsy, and excision of the splenic venous and arterial aneurysms were performed successfully. The portal pressure was 31 and 24 cm of H2O before and after the operation, respectively. After the operation, the patient suffered from severe inflammation and ascites, and he died 2 months later. PVSA is a rare vascular abnormality defined as a focal saccular or fusiform dilatation of the portal venous system. It represents less than 3% of all venous aneurysms and is diagnosed when the anteroposterior diameter of the portal vein exceeds 20 mm.1 PVSA is frequently extrahepatic,1 and the most common locations are the splenomesenteric venous confluence, the main portal vein, and the intrahepatic portal vein branches at bifurcation sites; the rarest locations are the splenic, mesenteric, and paraumbilical veins. Our case demonstrated a very rare PVSA that involved the total portal vein, splenic vein, and paraumbilical vein, and it was associated with extremely large caput medusae. Caput medusae is the appearance of distended and engorged paraumbilical veins that radiate from the umbilicus across the abdomen to join systemic veins. It takes its name from Medusa, the mythical gorgon of Greek mythology, because of its similarity to Medusa's snakelike hair. The pathogenesis of PVSA remains controversial. It may be congenital or acquired as a result of cirrhosis, PH, pancreatitis, trauma, or surgery.1 However, the lack of proportion between the rates of PH and PVSA suggests that cirrhosis and PH may be contributory but not essential to the development of PVSA.2 In this case, PVSA was considered to be congenital, and PH was the result of portal vein thrombosis, which occurs in approximately 30% of PVSA cases because of turbulent flow and stasis1 and can lead to PH with clinically severe consequences. Therefore, although most PVSA cases are asymptomatic and require no treatment, when PVSA is associated with thrombosis, PH, rupture, or compression of the common bile duct or duodenum, surgical intervention is indicated.