The performance of a new nanosecond pulsed-field ablation surgical clamp in the ablation of cardiac tissue: A chronic porcine model.

OBJECTIVE

The purpose of this chronic porcine model is to demonstrate the safety and efficacy of a new nanosecond pulsed-field ablation (nsPFA) parallel clamp in ablating different cardiac tissue.

METHODS

The Pulse Biosciences nsPFA CellFX Clamp System was tested on 6 pigs. Ablations were performed in all 4 heart chambers by delivering a sequence of very short-duration, high-amplitude electrical pulses taking 1.25 seconds per application independent of tissue thickness or type. Testing for electrical exit block was performed at the time of surgery and at study termination. At 35 days, animals were killed humanely and anonymized histopathology was performed to assess lesion width, depth, and transmurality. Lesion pattern and general safety were compared with 6 animals in which a bipolar radiofrequency clamp was used (AtriCure Synergy Isolator System).

RESULTS

There were no device-related serious adverse events in the nsPFA group. There was 1 early device-related mortality at day 24 in the RFA group from perforation of 1 of the ventricular ablation sites. There were also 2 intracardiac thrombotic events with 1 systemic thromboembolic event in the radiofrequency group. Exit block was confirmed in all animals from both groups for the pulmonary veins and the posterior wall. Histologic findings were consistent and demonstrated mature scar formation in all nsPFA ablation specimens, whereas a 7.1% rate of incomplete histopathological scar maturation was present in the RFA group.

CONCLUSIONS

In this chronic porcine model, a single 1.25-second application independent of tissue thickness with the CellFX Parallel Clamp System demonstrated promising safety and efficacy profile. All lesions produced by this technology resulted in persistent exit block around pulmonary veins and the posterior atrial wall consistent with a reliable, contiguous and transmural ablation without injury to adjacent organs.