Power-Controlled, Irrigated Radio-Frequency Ablation of Gastric Tissue: A Biophysical Analysis of Lesion Formation

Abstract

BACKGROUND: Radio-frequency ablation of gastric tissue is in its infancy compared to its extensive history and use in the cardiac field. AIMS: We employed power-controlled, irrigated radio-frequency ablation to create lesions on the serosal surface of the stomach to examine the impact of ablation power, irrigation, temperature, and impedance on lesion formation and tissue damage. METHODS: A total of 160 lesions were created in vivo in female weaner pigs (n = 5) using a combination of four power levels (10, 15, 20, 30 W) at two irrigation rates (2, 5 mL min-1) and with one temperature-controlled (65 °C) reference setting previously validated for electrophysiological intervention in the stomach. RESULTS: Power and irrigation rate combinations above 15 W resulted in lesions with significantly higher surface area and depth than the temperature-controlled setting. Irrigation resulted in significantly lower temperature (p < 0.001) and impedance (p < 0.001) compared to the temperature-controlled setting. No instances of perforation or tissue pop were recorded for any ablation sequence. CONCLUSION: Power-controlled, irrigated radio-frequency ablation of gastric tissue is effective in creating larger and deeper lesions at reduced temperatures than previously investigated temperature-controlled radio-frequency ablation, highlighting a substantial improvement. These data define the biophysical impact of ablation parameters in gastric tissue, and they will guide future translation toward clinical application and in silico gastric ablation modeling. Combination of ablation settings (10-30 W power, 2-5 mL min-1 irrigation) were used to create serosal spot lesions. Histological analysis of lesions quantified localized tissue damage.