Comparison of hydrochloric acid infusion radiofrequency ablation with microwave ablation in an ex vivo liver model

Objectives To compare sizes and shapes of ablation zones resulting from hydrochloric acid infusion radiofrequency ablation (HRFA) and microwave ablation (MWA), using normal saline infusion radiofrequency ablation (NSRFA) as a control, at a variety of matched power settings and ablation durations, in an ex vivo bovine liver model.Methods A total of 90 ablation procedures were performed, using each of three modalities: NSRFA, HRFA, and MWA. For each modality, five ablation procedures were performed for each combination of power (80 W, 100 W, or 120 W) and duration (5, 10, 20, 30, 45, or 60 min). The size of ablation zones were compared using ANOVA, the Kruskal-Wallis test, or generalized linear regression.Results For ablation durations up to 30 min, mean transverse diameter (TD) after HRFA and MWA did not differ significantly (β = 0.13, p = .20). For ablation durations greater than 30 min, mean TD was significantly larger after HRFA than after MWA (β = 1.657, p < .001). The largest TD (9.46 cm) resulted from HRFA performed with 100 W power for 60 min.Conclusions Compared to MWA, monopolar HRFA with power settings of 80 W–120 W and durations of less than 30 min showed no significant difference. When duration of more than 30 min, HRFA created larger ablation zones than MWA.