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 cavernou s transformation of the portal vein (CTPV) caused by tumor thrombosis of he patocellular carcinoma (HCC) by using contrast-enhanced spiral computed tom ographic (CT) examination. Methods: Fifty-four histopathologically proven HCC patients with tumor thro mbosis-induced CTPV were retrospectively included and assigned to cirrhosis negative (n = 31) and positive (n = 23) groups. Another 15 cirrhotic patie nts with portal hypertension but no HCC and CTPV were used for comparison. Standardized dual-phase contrast-enhanced spiral CT was performed for all p atients. CT appearances of the collateral vessels of CTPV were observed, an d their visualization rates were analyzed. Results: Biliary (cystic and paracholedochal veins) and gastric (left and r ight gastric veins) branches of the portal vein were the most frequently vi sualized collateral vessels of CTPV. There was a marked difference in CT vi sualization rates for biliary branches between patients with and without CT PV (83-94% us. 0). No difference existed in visualization rates for gastric branches across the three groups (77-87% for left gastric, 58-61% for righ t 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 hemodynami c adaptation process of CTPV.