Laparoscopic-assisted microwave ablations for hepatic malignancies: a 10-year retrospective database review

Abstract

Presenter: Joshua Davis MD | Carolinas HealthCare System Background: Microwave ablation (MWA) is a safe and established method for achieving locoregional control of both primary and secondary hepatic malignancies. This technology has expanded the indications for liver-directed therapy for a broad range of cancers, but long-term data on oncologic outcomes are lacking. Although CT-guided microwave ablation is the most commonly used localization modality, a laparoscopic approach utilizing intraoperative ultrasound offers the additional benefit of evaluating the abdominal cavity and liver for unidentified tumors with minimal added morbidity. This study reports the 10-year use of laparoscopic-assisted microwave ablation in a high-volume hepatobiliary practice at a large tertiary care center. Methods: A prospectively maintained registry of laparoscopic-assisted MWAs performed in a single high-volume center was retrospectively queried for all patients who underwent laparoscopic MWA from January 1, 2010 through December 31, 2019. Patient demographics, intraoperative details, and postoperative outcomes were collected. Follow up imaging was analyzed to determine rates of incomplete ablation as identified on the first computed tomography scan performed postoperatively (typically within 4-6 weeks), and locoregional recurrence. Comparative statistics was performed as appropriate. Results: Overall, 777 separate ablation procedures for a total of 1317 lesions within the 10-year time interval was performed. Patients were 33% female; 76% Caucasian, and 18% African American. The majority of patients had an ASA score of III (76%, n=540) and average BMI of 29kg/m2. There was an average number of 1.7 lesions ablated per patient surgery with an average lesion diameter of 2.4 cm (range: < 0.5 to 8.0 cm). Hepatocellular carcinoma (58%, n=397) was the most frequent lesion ablated, followed by colorectal metastasis (20%, n=135). Patients had a median intraoperative blood loss of 50 mL and the majority of patients had no major 30-day morbidity or mortality (96% of patients with highest Clavien-Dindo classification < 3). Median length-of-stay was 1 hospital day (range 0 to 46 days). At postoperative follow up, 5.7% of patients had an incomplete ablation. The local recurrence rate was 18.2% with median time to local recurrence of 8.9 months (range: 0.7 to 90 months). The regional recurrence rate was 48.9% with median time to regional recurrence of 7.5 months (range: 0.5 to 103 months). Conclusion: Laparoscopic MWA is a viable treatment for locoregional control of both primary and secondary liver lesions. This surgery is performed in a minimally invasive fashion with assistance of intraoperative ultrasound to aid in visualization of subclinical lesions. This is an established safe technique with low associated morbidity and mortality and short associated length of stay. Additionally, locoregional recurrence in this study is comparable to historical controls of liver resection, suggesting comparable efficacy with this approach.