Local control of hepatocellular carcinoma and colorectal liver metastases after surgical microwave ablation without concomitant hepatectomy

Purpose Microwave ablation (MWA) is an accepted technique in the multimodal treatment of hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM). Study endpoints were to evaluate the local efficacy of surgical MWA in selected patients with oligonodular disease without the combination of liver resection to allow a clear interpretation of the follow-up imaging and compare it to the results on percutaneous MWA available in the literature. Methods Consecutive MWA-only procedures performed between May 2013 and May 2018 for HCC and CRLM with free-hand ultrasound guidance were identified. MWA systems with 2450 MHz were used. Incomplete ablation (IA) was defined as residual disease within 1 cm of the ablation site at the first post-ablation imaging and local recurrence (LR) as the presence of disease after at least one tumor-free imaging. Results A total of 70 tumors in 47 patients were treated with 46 laparoscopic and 1 open procedures. Each patient had no more than 3 tumors, and median size of the lesions was 15 mm (IQR: 10–22). After a median follow-up of 26 months (IQR: 12–40), IA rate was 8.6% and LR rate was 29.4%. Multivariable analysis showed that vascular proximity (OR = 3.4; 95% CI = 1.26–9.22; p=0.016) was the only significant predictor of the combined outcome IA or LR. Discussion In the present study, after mostly laparoscopic MWA, LR was higher than the rates available in the literature for percutaneous MWA of HCC but lower than in the limited studies analyzing isolated percutaneous MWA of liver metastases. Future developments may help establish the role of each therapeutic modality per tumor, in order to improve the outcomes.