Insurance lesions: Does a second lesion make a difference?

Area of Science:

• Electrophysiology
• Cardiovascular Ablation Technologies

Background:

• The efficacy of creating repeated radiofrequency ablation lesions at the same site, termed "insurance lesions," for cardiac arrhythmia is not well-established.
• Understanding the impact of tissue type, power, and duration on lesion geometry is crucial for optimizing ablation strategies.

Purpose of the Study:

• To assess how tissue type, power, and ablation time influence lesion geometry during repeated radiofrequency ablation procedures.
• To determine the benefit of creating "insurance lesions" in cardiac tissue.

Main Methods:

• An ex vivo ablation model using custom equipment was employed.
• Radiofrequency ablations were performed on atrial and ventricular tissue samples with varying power (30W, 50W) and time (30-50s standard, 5-15s high-power, short-duration).
• Lesion dimensions (depth, width) were measured and analyzed.

Main Results:

• Multiple ablations at the same site significantly increased lesion depth in ventricular tissue only when using 30W for 50s.
• No other tested parameters (power, time, tissue type) demonstrated a significant effect on lesion width or depth with repeated ablations.
• High-power, short-duration (HPSD) ablation parameters did not yield different results regarding lesion geometry compared to standard settings.

Conclusions:

• Creating "insurance lesions" provides no significant geometric benefit over single ablations in most cardiac tissue scenarios.
• The practice of repeated ablation at the same site should be reconsidered by electrophysiologists due to limited benefits and potential risks.
• Ventricular ablation at 30W for 50s is a specific exception where repeated application may increase lesion depth.