High-intensity ultrasound epicardial ablation produced significantly deeper lesions (11.6±3.2 mm vs 4.7±1.6 mm) and greater epicardial sparing compared to radiofrequency ablation (P<0.0001).
Does epicardial high-intensity ultrasound ablation improve lesion depth and epicardial sparing compared to radiofrequency ablation in an in vivo swine model?
High-intensity ultrasound ablation creates significantly deeper lesions with greater epicardial sparing compared to radiofrequency ablation in a swine model, offering a potential alternative for epicardial VT ablation.
Absolute Event Rate: 11.6% vs 4.7%
p-value: p=<0.0001
BACKGROUND: Epicardial radiofrequency catheter ablation of ventricular tachycardia remains challenging because of the presence of deep myocardial scar and adjacent cardiac structures, such as the coronary arteries, phrenic nerve, and epicardial fat that limit delivery of radiofrequency energy. High-intensity ultrasound (HIU) is an acoustic energy source able to deliver deep lesions through fat, while sparing superficial structures. We developed and tested an epicardial HIU ablation catheter in a closed chest, in vivo swine model. METHODS AND RESULTS: The HIU catheter is an internally cooled, 14-French, side-facing catheter, integrated with A-mode ultrasound guidance. Swine underwent percutaneous subxyphoid epicardial access and ablation with HIU (n=10 swine) at 15, 20, and 30 W. Compared with irrigated radiofrequency lesions in control swine (n = 5), HIU demonstrated increased lesion depth (HIU 11.6±3.2 mm versus radiofrequency 4.7±1.6 mm; mean±SD) and epicardial sparing (HIU 2.9±2.1 mm versus radiofrequency 0.1±0.2 mm) at all HIU powers, and increased lesion volume at HIU 20 and 30 W (P<0.0001 for all comparisons). HIU ablation over coronary arteries and surrounding epicardial fat resulted in deep lesions with normal angiographic flow. Histological disruption of coronary adventitia, but not media or intima, was noted in 44% of lesions. CONCLUSIONS: Compared with radiofrequency, HIU ablation in vivo demonstrates significantly deeper and larger lesions with greater epicardial sparing in a dose-dependent manner. Further development of this catheter may lead to a promising alternative to epicardial radiofrequency ablation.
Nazer et al. (Sat,) conducted a other in In vivo swine model (n=15). High-intensity ultrasound (HIU) epicardial ablation vs. Irrigated radiofrequency (RF) ablation was evaluated on Lesion depth (mm) (p=<0.0001). High-intensity ultrasound epicardial ablation produced significantly deeper lesions (11.6±3.2 mm vs 4.7±1.6 mm) and greater epicardial sparing compared to radiofrequency ablation (P<0.0001).