Cavernous transformation of the portal vein secondary to tumor thrombosis of hepatocellular carcinoma: spiral CT visualization of the collateral vessels

Background: We investigated the constituting collateral vessels in cavernous transformation of the portal vein (CTPV) caused by tumor thrombosis of hepatocellular carcinoma (HCC) by using contrast-enhanced spiral computed tomographic (CT) examination. Methods: Fifty-four histopathologically proven HCC patients with tumor thrombosis-induced CTPV were retrospectively included and assigned to cirrhosis negative (n= 31) and positive (n= 23) groups. Another 15 cirrhotic patients with portal hypertension but no HCC and CTPV were used for comparison. Standardized dual-phase contrast-enhanced spiral CT was performed for all patients. CT appearances of the collateral vessels of CTPV were observed, and their visualization rates were analyzed. Results: Biliary (cystic and paracholedochal veins) and gastric (left and right gastric veins) branches of the portal vein were the most frequently visualized collateral vessels of CTPV. There was a marked difference in CT visualization rates for biliary branches between patients with and without CTPV (83–94% vs. 0). No difference existed in visualization rates for gastric branches across the three groups (77–87% for left gastric, 58–61% for right gastric vein). Conclusions: Biliary and gastric branches of the portal vein are the major collateral vessels of CTPV. The intergroup differences in CT visualization rates may provide clues to the roles that they might play in the hemodynamic adaptation process of CTPV. Received: 13 October 1999/Accepted: 12 January 2000