An Ex Vivo Evaluation of Air Intrusion Into Pulsed Field Ablation Sheaths During Ablation and Mapping Catheter Insertion.

INTRODUCTION: Pulsed field ablation (PFA) is the newest ablation technology, and currently, no data exist on the amount of air intrusion into new, large bore PFA sheaths during ablation or mapping catheter insertion. METHODS: An ex vivo study was performed using various combinations of commercially available PFA ablation catheters and sheaths. Common mapping catheters and a non-PFA steerable sheath were also evaluated as a reference. The siphon principle was used to create negative pressure to simulate left atrial pressure during spontaneous inspiration. Ablation and mapping catheters were advanced to the end of the sheaths under negative pressure and then removed. Air was withdrawn from the sheaths and was measured in milliliters (mL). RESULTS: A total of 55 trials were performed. The average volume of air intrusion with all sheath/catheter combinations was 9.6 + 5.2 mL. The 13 Fr (inner diameter) Faradrive sheath (Boston Scientific Inc.) entrained significantly more air (16.5 + 4.1 mL) compared with the 12 Fr FlexCath Contour sheath (Medtronic Inc.) (6.1 + 2.7 mL, p < 0.01), 13 Fr Agilis NxT sheath (Abbott Inc.) (8.7 + 1.8 mL, p < 0.01), and Vizigo sheath (Johnson & Johnson MedTech Inc.) (5.8 + 2.1 mL, p < 0.01), regardless of the catheter used. There was significantly higher volume of air intrusion with the Farawave ablation catheter through the Faradrive sheath (13.6 + 2.0 mL) than through the 13 Fr Agilis (9.4 + 2.1 mL, p = 0.03) or the PulseSelect through FlexCath Contour sheath (4.0 + 2.7 mL, p < 0.01). Mapping catheters entrained significantly more air than ablation catheters in both the Faradrive (18.0 ± 4.1 mL vs. 13.6 ± 4.1 mL, p = 0.04) and the FlexCath Contour (7.1 ± 2.2 mL vs. 4.0 ± 2.7 mL, p = 0.03). CONCLUSION: Using a model that simulates left atrial PFA in spontaneously breathing patients, a large volume of air intrusion was observed during insertion and removal of ablation and mapping catheters into new, large bore PFA sheaths. New sheath designs are needed to minimize air intrusion during catheter exchanges to avoid air embolism when performing PFA using left atrial delivery sheaths.