Saline-irrigated radiofrequency ablation electrode with external cooling

Area of Science:

• Cardiovascular Interventions
• Medical Device Engineering

Background:

• Open-flush irrigated ablation electrodes enhance radiofrequency catheter ablation safety by preventing protein aggregation.
• Left-sided procedures, such as atrial fibrillation ablation, critically require improved safety measures.
• Electrode cooling compromises temperature feedback, risking excessive tissue heating and complications.

Purpose of the Study:

• To investigate the impact of thermally insulating irrigation channels in irrigated ablation electrodes.
• To determine if insulation improves temperature feedback and lesion control during radiofrequency ablation.

Main Methods:

• Standard irrigated ablation electrodes were modified by thermally insulating internal irrigation channels.
• Lesions were created in canine thigh muscle preparations using both standard and modified catheters.
• Ablation parameters included 60-second applications, 20-50 Watts, and a 20 cc/min saline flush.

Main Results:

• Fifty-seven lesions were created; lesion dimensions were similar between standard and modified catheters.
• The modified catheter demonstrated a significantly higher maximum electrode temperature rise during ablation.
• Insulation improved the correlation between maximum electrode temperature rise and lesion volume (from 0.38 to 0.62).

Conclusions:

• Thermal insulation of irrigation channels enhances temperature feedback during radiofrequency ablation.
• This modification improves the controllability of lesion formation in irrigated ablation electrodes.
• The findings suggest a safer and more predictable ablation process.