Outcomes after Surgical Microwave Ablation for the Treatment of Colorectal Liver Metastasis

BACKGROUND: Colorectal cancer (CRC) is the third most common cause of cancer mortality worldwide. Of these, approximately 25% will have liver metastasis. We performed 394 microwave ablations (MWAs) and analyzed outcomes for survival and ablation failure. STUDY DESIGN: We conducted a retrospective review of patients who underwent a surgical MWA at a single-center high-volume institution from October 2006 to September 2022 using a prospectively maintained database. The primary outcome was overall survival. RESULTS: A total of 394 operations were performed on 328 patients with 842 tumors undergoing MWA. Median tumor size was 1.5 cm (range 0.4 to 7.0 cm), with the median number of tumors ablated per operation being 1 (range 1 to 11). A laparoscopic approach was used 77.9% of the time. Concomitant procedures were performed 63% of the time, most commonly hepatectomy (22.3%), cholecystectomy (17.5%), and colectomy (6.6%). Clavien-Dindo grade III or IV complication occurred in 12 patients (3.6%), and all of these patients had undergone concomitant procedures. Mortality within 30 days occurred in 4 patients (1.2%). The rate of incomplete ablation was 1.5% per tumor. Local recurrence occurred at a rate of 6.3% per tumor. Black patients were found to have a higher incidence of incomplete ablation and local recurrence. One-year survival probability was 91% (95% CI 87.9 to 94.3), with a mean overall survival of 57.6 months (95% CI 49.9 to 65.4 months). CONCLUSIONS: Surgical MWA offers a low-morbidity approach to treatment of colorectal liver metastasis, with low rate of failure. This large series reviews the outcomes of MWA as definitive treatment for colorectal liver metastasis. (c) 2024 by the American College of Surgeons. Published by Wolters Kluwer Health, Inc. All rights reserved.