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.

Laparoscopic Versus Open Thermal Ablation of Colorectal Liver Metastases: A Propensity Score-Based Analysis of Local Control of the Ablated Tumors.

BACKGROUND: Laparoscopic ablation (LA) of colorectal liver metastases (CRLMs) is frequently performed in combination with laparoscopic liver resection or as a stand-alone procedure. However, LA is technically demanding and whether the results are comparable with those of open ablation (OA) has not been determined to date. This study compared the effectiveness of LA and OA in achieving local tumor control of CRLMs. METHODS: Patients undergoing LA or OA of CRLMs at Ghent University Hospital between June 2007 and February 2018 were identified from a prospective database. Lesions treated by LA and OA were matched 1:1 using a propensity score based on lesions (liver segment, size, deepness, proximity to a vessel), patients, and procedural characteristics. Ablation sites were followed up with computed-tomography or magnetic resonance imaging to assess the completeness of the ablation and ablation-site recurrence (ASR). Analysis of ASR was performed with the Kaplan-Meier method and Cox regression. RESULTS: In this study, 163 patients underwent the surgical ablation (78 LA, 85 OA) of 333 CRLMs (143 LA, 190 OA). After matching, 220 lesions (110 LA, 110 OA) were analyzed. Ablation was complete in 93.7% (LA) and 97.3% (OA) of the sites (p = 0.195). No difference in ASR was observed (p = 0.351), with a cumulative risk of ASR at 12 months of 9.1% (LA) and 8.2% (OA). After multivariable analysis, ASR was confirmed to be independent of the surgical approach. CONCLUSION: The findings showed that LA and OA achieve a comparable local control of CRLMs. This result further supports the adoption of a laparoscopic approach for the treatment of CRLMs.