13th Annual Global Embolization Symposium & Technologies
Purpose : Thermal ablation has been established as a mainstay of treatment for both primary and secondary malignancies of the liver. Multiple studies have shown that ablation can be equivalent to surgical resection in terms of meaningful oncologic outcomes, while providing less peri-operative complications in well selected patients with hepatocellular carcinoma (HCC). However, as with all techniques ablation has associated risks, one of the infrequently reported complications of thermal ablation is portal or hepatic venous thrombosis. Further data is needed to establish the frequency and factors which may predict this uncommon complication. That is the goal of this retrospective single center study.
Material and Methods : One-hundred eighty-one ablations in 136 patients which occurred between 1/1/2010 and 1/1/2018 were retrospectively reviewed. The cohort consisted of 89 men (34.6%) and 47 women (65.4%). The average age was 62.6 years (range 30-89 years). Patient charts and imaging were reviewed for laboratory values, imaging, and oncologic outcomes. New portal or hepatic vein thrombosis was determined to have occurred when a hepatic or portal vein which was patent on pre-treatment imaging was found to be thrombosed on one month post-treatment imaging. Ablation zone size was also measured on follow up imaging; predicted ablation zone volumes were obtained from manufacturer specifications, based on time and wattage of the ablation procedure.
Results : Five of 181 (2.8%) ablations developed post ablation hepatic vein thrombosis. Similarly, 5 of 181 (2.8%) ablations developed post ablation portal vein thrombosis. Proximity to the edge of the ablation zone to the hepatic vein was significantly associated with hepatic vein thrombosis (p=0.01). However, proximity of the ablation zone to the portal vein was not shown to be significantly associated with thrombosis (p=0.12). Ablation zone volume was statistically larger in patients with portal vein thrombosis than patients without (p=0.02) but not in patients with hepatic vein thrombosis (p=0.99). Other factors including, size of lesion (p=0.55) and predicted ablation zone volume (p=0.34) were not found to be significantly different.
Conclusions : Portal and hepatic venous thrombosis is an uncommon complication of thermal ablation. Proximity to hepatic vein may predict hepatic vein thrombosis. Portal vein thrombosis may be associated with larger than expected ablation zones.