P1861Influence of thermal conductivity on esophageal protection with a cooling device during high-power short-duration radiofrequency ablation

Abstract

Introduction Recent clinical data show that high-power, short-duration (HPSD) radiofrequency (RF) ablation can result in a similar esophageal injury rate as traditional low-power, long-duration (LPLD) ablation. Existing methods to prevent esophageal injury have yielded mixed results and can result in prolonged procedure time, potentially increasing the incidence of post-operative cognitive dysfunction. A new esophageal cooling device currently available for whole-body temperature modulation is being studied for the prevention of esophageal injury during LPLD RF ablation and cryoablation. We sought to develop a mathematical model of HPSD ablation in order to quantify the capability of this new esophageal cooling device to protect from esophageal injury under high-power conditions. Methods Using a model we developed of HPSD RF ablation in the left atrium, we measured the change in esophageal lesion formation and the depth of lesions (measured as percent transmurality) with the esophageal cooling device in place and operating at a temperature from 5°C to 37°C. Tissue parameters, including thermal conductivity, were set to average values obtained from existing literature, and energy settings were evaluated at 50W for between 5 and 10 seconds, and at 90W for a duration of 4 seconds. Results Esophageal injury as measured by percent transmurality was considerably higher at 50W and 10s duration than at 90W of power with 4s duration, although both settings showed potential for esophageal injury. The protective effect of the esophageal cooling device was evident for both cases, with a greater effect when using 50W for 10s (Figure 1). At the coldest device settings, using a 5 min pre-cooling period also reduced the transmurality of the intended atrial lesions. Esophageal protection in HPSD ablation Conclusions Esophageal cooling with a new patient temperature management device shows protective effects against thermal injury during RF ablation across a range of tissue thermal conductivity, using a variety of high-power settings, including 90W applied for 4 seconds. Adjusting the cooling power by adjusting the circulating water temperature in the device allows for a tailoring of the protective effects to operating conditions. Acknowledgement/Funding Attune Medical

Multicenter analysis of atrioesophageal fistula rates before and after adoption of active esophageal cooling during atrial fibrillation ablation

“…[21][22][23] Active esophageal cooling using a dedicated esophageal cooling device is a newer technique that has shown benefits in preclinical studies, mathematical modeling, and clinical studies. [24][25][26][27][28][29][30][31][32][33][34] An international multicenter randomized controlled trial is currently underway (NCT04577859), but this study relies on the surrogate endpoint of endoscopically detected esophageal lesion (EDEL) reduction. Because an event rate of <1% requires an extremely large sample size, no study to date has evaluated the effectiveness of any strategy in reducing AEFs.…”

Esophageal Cooling During Radiofrequency Ablation: Can Opposite (Strategies) Attract?

“…This has not been systematically evaluated in a large group of patients with available data only from mathematical modeling studies and smaller clinical trials. [9] The authors' findings suggest that active esophageal cooling does not significantly impact atrial tissue lesion formation in a clinically significant way. The authors appropriately recognize that their findings are inherently limited by the single-center study design.…”

Esophageal cooling during radiofrequency ablation: Can opposite (strategies) attract?

“…This has not been systematically evaluated in a large group of patients with available data only from mathematical modeling studies and smaller clinical trials. 9 The authors' findings suggest that active esophageal cooling does not significantly impact atrial tissue lesion formation in a clinically significant way. The authors appropriately recognize that their findings are inherently limited by the singlecenter study design.…”

“…While active esophageal cooling has been proposed as a potential strategy to reduce esophageal thermal injury during RF ablation, it has been unclear whether esophageal cooling can adversely impact posterior RF lesion formation. This has not been systematically evaluated in a large group of patients with available data only from mathematical modeling studies and smaller clinical trials 9 . The authors' findings suggest that active esophageal cooling does not significantly impact atrial tissue lesion formation in a clinically significant way.…”