Minimizing Esophageal Heating During Radiofrequency Catheter Ablation

Atrio-esophageal fistula is a rare but devastating complication from thermal esophageal injury during pulmonary vein isolation (PVI). Modifying ablation energy delivery and placement of esophageal temperature probes (ETPs) have been employed to mitigate the risk of thermal esophageal injury. Our study sought to compare the effects of return electrode location, insulation of the ETP, and use of high-power short-duration (HPSD) ablation on esophageal temperature, ETP temperature measurement, and thermal lesion dimensions.

A myocardial phantom gel model using thermochromic material was used to approximate the atrio-esophageal environment. Irrigated ablations were performed at 30 W/20 s (low-power long duration [LPLD]) and 50 W/5 s (HPSD) with variation of return electrode position and insulation of the ETP. Temperatures were continuously logged, and digital photography with in-house software was performed to examine lesion dimensions.

Distant placement of a return electrode compared to proximal placement decreased peak esophageal temperature (T_Peak) across LPLD (41.73°C ± 0.12°C vs. 39.23°C ± 0.15°C; p < 0.0001) and HPSD ablations (39.17°C ± 0.06°C vs. 38.13°C ± 0.06°C; p < 0.0001). Insulation of the ETP reduced T_Peak across LPLD (39.13°C ± 0.25°C vs. 41.73°C ± 0.12°C; p < 0.0001) and HPSD ablation (39.17°C ± 0.06°C vs. 38.27°C ± 0.06°C; p < 0.0001). HPSD ablation produced lower mean T_Peak than LPLD regardless of the location of the return electrode location or insulation of the ETP.

HPSD settings, insulation of the ETP, and a distant return electrode placement minimized esophageal heating. These strategies may reduce thermal injury to the esophagus during radiofrequency ablation.