Risk of intra-abdominal seeding after laparoscopic-assisted thermal ablation of exophytic hepatocellular carcinoma tumors.

Abstract

Laparoscopic-assisted thermal ablation has been used successfully to treat early hepatocellular carcinoma (HCC) tumors, defined as < 3cm in diameter. This approach allows for ablation of tumors located in areas of the liver that are otherwise inaccessible for a percutaneous approach. Thermal ablation of exophytic tumors remains controversial due to a reported increased risk of tumor seeding of the abdominal cavity and incomplete ablation. This cohort study consisted of 663 HCC tumors treated with thermal ablation at a single, quaternary academic medical center between 2/2001 and 1/2021. Post treatment, patients were followed at a defined interval schedule beginning at one month post treatment, then every 3months for 2years, every 6months in year 3, followed by yearly studies. Patients' medical records were reviewed for three years post ablation for evidence of complete ablation and intra-abdominal dissemination of disease. 326 patient records met the inclusion criteria. Comparing the exophytic and non-exophytic groups, there were statistically significant differences in etiology of liver disease (p = 0.048) and TNM stage (p = 0.03), as well as a higher rate of incomplete ablation in the non-exophytic group (10.2% vs 3.3%; p = 0.045). Otherwise, there were no statistically significant differences in baseline characteristics, tumor characteristics, or use of thermal ablation technology. Rates of intra-abdominal dissemination of HCC were low in both groups: 1.1% (n = 1) in the exophytic group and 1.7% (n = 4) in the non-exophytic group. There was no significant difference in intra-abdominal dissemination of HCC between the groups (p > 0.99, RR = 0.66; 95% CI 0.07-5.79). Additionally, no differences were seen in dissemination between microwave ablation and radiofrequency ablation (p > 0.99). This study demonstrates that laparoscopic-assisted thermal ablation of small, exophytic tumors is safe and does not increase the risk for disseminated intra-abdominal HCC disease.