A comparison of three different microwave systems for laparoscopic liver tumor ablation

Abstract

AbstractBackgroundOur aim was to perform a comparison of three current microwave ablation (MWA) systems widely used for laparoscopic liver ablations in terms of ablation kinetics and geometry of ablation zones.MethodsThis was a retrospective, institutional review board‐approved study comparing Emprint, Emprint HP, and NeuWave systems for laparoscopic liver ablation. Analyses were performed via Mann−Whitney U and χ2 tests. Continuous data are presented as median (interquartile range).ResultsFor Emprint, Emprint HP, and NeuWave groups, tumor size was 1.16 (0.8), 1.21 (0.7), and 1.27 (0.9) cm (p = 0.54). Ablation time per lesion was 7 (6), 4 (2.8), and 4 (3.3) min (p < 0.0001), yielding similar ablation zone volumes and margins. The time to first ablation bubble was 1 (0.13), 1.5 (0.85), and 0.75 (0.5) min, and total ablation times were 7 (4.4), 4 (2), and 3.5 (2.8) min (p < 0.0001). The roundness index A, B, and transverse were 0.94, 0.98, and 0.79; 0.95, 0.95, and 0.78; and 1.02, 0.95, and 0.96.ConclusionsAlthough a saline‐cooling system with Emprint system allowed for larger diameter spherical ablation zones to be created, it led to decreased efficiency compared to the CO2‐cooled NeuWave system, which exposes the active antenna directly to tissue. Increased power delivered by Emprint HP improved the efficiency of saline‐cooled design, as demonstrated by faster ablation times.