Differential Air Entrainment of Mini-Basket and Circular Mapping Catheters Through the FARADRIVE Sheath: Mitigation With a Liquid-Sealed Insertion Method.

BACKGROUND: Iatrogenic air entrainment is a preventable embolic hazard in pulsed field ablation (PFA). Mapping catheter insertion through large-bore PFA sheaths may be a vulnerable step, but the roles of catheter geometry and liquid-sealed insertion are unclear. METHODS AND RESULTS: In an ex vivo saline tank model, ORION mini-basket and SPIRAL circular mapping catheters were inserted through the FARADRIVE steerable sheath using saline infusion only, continuous manual suction, or liquid-sealed insertion with a custom Adapter Sink. The primary endpoint was macroscopic air recovered distally after each trial of 10 insertions; the trial was the unit of analysis, and 0.2 mL was the smallest quantitatively reportable volume. In 60 trials (600 insertions), mitigation strategy significantly affected air entrainment (Kruskal-Wallis p < 0.001). Under saline infusion alone, ORION generated more air than SPIRAL (23.86 ± 3.63 vs. 7.20 ± 2.09 mL per 10 insertions; 2.39 vs. 0.72 mL per insertion; adjusted p < 0.001). Manual suction reduced entrainment to 3.96 ± 1.01 and 1.02 ± 0.45 mL per 10 insertions (0.40 and 0.10 mL per insertion), but residual air persisted. With liquid-sealed insertion, no visually detectable or quantitatively measurable macroscopic air was observed in any trial. CONCLUSIONS: Air entrainment varied according to mapping-catheter geometry and mitigation strategy. Timed manual suction substantially reduced, but did not abolish, measurable air. Liquid-sealed insertion was associated with no measurable macroscopic air within this ex vivo model, warranting further evaluation under physiologic pressure conditions and in clinical PFA workflows.