Modeling esophageal protection from radiofrequency ablation via a cooling device: an analysis of the effects of ablation power and heart wall dimensions.
BACKGROUND
Esophageal thermal injury can occur after radiofrequency (RF) ablation in the left atrium to treat atrial fibrillation. Existing methods to prevent esophageal injury have various limitations in deployment and uncertainty in efficacy. A new esophageal heat transfer device currently available for whole-body cooling or warming may offer an additional option to prevent esophageal injury. We sought to develop a mathematical model of this process to guide further studies and clinical investigations and compare results to real-world clinical data.


RESULTS
The model predicts that the esophageal cooling device, even with body-temperature water flow (37 °C) provides a reduction in esophageal thermal injury compared to the case of the non-protected esophagus, with a non-linear direct relationship between lesion depth and the cooling water temperature. Ablation power and cooling water temperature have a significant influence on the peak temperature and the esophageal lesion depth, but even at high RF power up to 50 W, over durations up to 20 s, the cooling device can reduce thermal impact on the esophagus. The model concurs with recent clinical data showing an 83% reduction in transmural thermal injury when using typical operating parameters.


CONCLUSIONS
An esophageal cooling device appears effective for esophageal protection during atrial fibrillation, with model output supporting clinical data. Analysis of the impact of ablation power and heart wall dimensions suggests that cooling water temperature can be adjusted for specific ablation parameters to assure the desired myocardial tissue ablation while keeping the esophagus protected.
['Mercado|Marcela|M|http://orcid.org/0000-0002-1453-4690', 'Leung|Lisa|L|', 'Gallagher|Mark|M|', 'Shah|Shailee|S|', 'Kulstad|Erik|E|']
D001281:Atrial Fibrillation D003080:Cold Temperature D004947:Esophagus D006321:Heart D006801:Humans D008954:Models, Biological D058958:Organs at Risk D000078703:Radiofrequency Ablation D014867:Water
Esophageal protection Radiofrequency ablation Atrial fibrillation Mathematical modeling Esophageal cooling Ablation parameters Finite element model