We attempted to evaluate the relationship between transarteiral chemoembolization (TACE) and injury to the peribiliary plexus by evaluating the number of microvessels in the peribiliary plexus of surgical specimen.

Surgical specimens were obtained from 78 hepatocellular carcinoma patients and 22 patients with liver metastases. They were divided into 4 groups (Group 1; hepatocellular carcinoma without TACE [n=30], Group 2; hepatocellular carcinoma receiving preoperative TACE once [n=37], Group 3; hepatocellular carcinoma receiving preoperative TACE more than two times [n=11] and Group 4; metastatic carcinoma of the liver patients without a history of liver disease [n=22]). Immunohistochemical staining for factor VIII-related antigen was performed in all the specimens and the number of microvessels in the inner capillary layer and the outer venous layer of the bile duct (> 200 micrometer in diameter) was counted.

The mean numbers of microvessels in the inner capillary layer were 4.50, 4.08, 1.64 and 2.05, and those in the outer venous layer were 25.23, 20.00, 18.36 and 12.32 for the 4 groups, respectively. The number of microvessels in group 4 was statistically fewer than that of group 1 (p<0.01). In the hepatocellular carcinoma patients, the number of microvessels was decreased as the number of TACE sessions was increased.

The number of microvessels in the peribiliary plexus is increased in chronic liver disease patients. It may be from the increased portal pressure and flow stagnation in the sinusoidal and portal venules. TACE can have an effect on microvascular injury of the peibiliary plexus, and this can be a cause of bile duct necrosis and biloma.