Abstract 4106: Temperature Feedback with Open Irrigated Ablation: A Comparison Between Insulated and a Non-insulated Fluid Lumen Catheters
Background: The distal tip electrode for standard open irrigated catheters is cooled during ablation. While this allows for greater energy delivery to the myocardium relative to a nonirrigated electrode it limits the temperature feedback mechanism of the device. A 2.5mm insulated irrigated ablation catheter may provide superior temperature response during ablation. The addition of more accurate temperature feedback could increase understanding of lesion formation, assist with titration of energy delivery, and improve safety.
Methods: Twenty-two swine underwent an acute ablation procedure whereby lesions were placed in the left atrium, along the cavo-tricuspid isthmus and in right atrial tissue. The temperature response, applied power, and resulting lesion characteristics were analyzed and compared between a 2.5mm insulated open irrigated RF catheter (IOIC) and a 3.5mm open irrigated RF catheter (IC). Energy set points were within the therapeutic range: 25W and 55C for IOIC and 30W and 40C for the IC. Energy was applied for 30s at each site.
Results: Seventy-seven lesions were analyzed. The mean power applied was 18.5 ± 4.2W for the IOIC and 18.7 ± 6.8W for the IC. With these average powers, the mean temperature responses were 46.0±3.8°C and 38.7 ± 0.8°C (p<0.001) respectively. The mean values of the maximum temperatures were: 51.6 ± 5.6°C and 40.4 ± 1.0°C (p<0.001). Resulting lesion volumes were larger with the IOIC (88.7 ± 92.1mm3 vs. 76.8 ± 57.6mm3). Correlation between the maximum achieved temperature and lesion volume was present with the 2.5mm IOIC catheter r=0.43, but absent with the 3.5mm IC catheter r= 0.08.
Conclusion: A 2.5mm insulated open irrigated ablation catheter provides greater temperature feedback at the same power output levels as a non-insulated 3.5mm open irrigated ablation catheter. Lesion volumes with the smaller catheter tip are also larger with a trend toward greater percentage of transmurality per treatment.