Venous thrombosis after radiofrequency ablation for hepatocellular carcinoma.

Objective: This study was designed to evaluate the frequency, morphological patterns, sequential changes, and clinical significance of venous thrombosis after radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC).

Materials And Methods: A total of 1379 RFAs performed in 1046 patients with HCC (mean tumor size, 1.93 cm) were surveyed. We retrospectively reviewed all radiologic reports before and after RFA and selected 15 patients with newly developed procedure-related venous thrombosis. Procedure-related thrombosis was defined as being adjacent to the ablation zone and developing within 4 months after the procedure. We evaluated the frequency, morphological patterns, sequential changes, and clinical course of venous thrombosis (mean follow-up, 662.9 days). Four cases with local tumor progression were identified among the 15 patients, and their clinical implications were evaluated.

Results: A total of 15 venous thromboses (1.08%; 12 portal and three hepatic veins) developed after RFA (range, 0-128 days; mean, 37 days). The thromboses were found in central (n = 10), peripheral (n = 4), and both central and peripheral (n = 1) locations in the ablation zones. Thrombosis was decreased in nine (69.2%), persisted in one (7.6%), and increased in three (23.0%) of 13 patients who underwent follow-up CT for more than 12 months. Local tumor progression was noted in four patients (26.6%); it abutted to venous thrombosis in two patients, separated from the venous thrombosis in one patient, and exhibited malignant thrombosis in one patient.

Conclusion: The development of portal or hepatic venous thromboses after RFA in patients with HCC is rare and usually is associated with favorable prognoses. Further investigation is warranted to elucidate whether venous thrombosis after RFA is related to local tumor progression around ablation zones.