Proactive esophageal cooling during laser cardiac ablation: A computer modeling study

Area of Science:

• Cardiovascular Medicine
• Biomedical Engineering
• Medical Physics

Background:

• Laser ablation is a growing treatment for atrial fibrillation (AF).
• Atrioesophageal injury is a serious complication of AF ablation.
• Proactive esophageal cooling (PEC) is known to reduce esophageal injury during radiofrequency ablation.

Purpose of the Study:

• To evaluate the protective effects of PEC during laser ablation for AF.
• To determine if PEC impacts therapeutic lesion formation in the atrium.
• To assess the risk of esophageal injury with varying tissue thicknesses during laser ablation.

Main Methods:

• Developed 3D mathematical models of atrial and esophageal walls.
• Simulated laser-tissue interaction using Beer-Lambert's law.
• Calculated temperature distribution with Pennes' Bioheat equation and tissue damage with the Arrhenius equation.

Main Results:

• PEC significantly lowered esophageal temperatures by ~22°C and atrial wall temperatures by ~9°C.
• Esophageal transmural lesions were absent with PEC.
• Esophageal thermal damage occurred only without PEC and with proximity ≤3.5mm.

Conclusions:

• PEC effectively mitigates esophageal injury risk during laser ablation for AF.
• PEC does not significantly degrade the quality or depth of cardiac lesions.
• Thermal latency is a factor in lesion formation and potential collateral damage.