Abstract 13271: Improved In-Vivo Performance of Second Generation Cryoballoon for Pulmonary Vein Isolation
Background: Cryoballoon ablation has become widely used for the treatment of Paroxysmal Atrial Fibrillation. A second generation cryoballoon with improved refrigerant distribution promises better PV isolation success rate without sacrificing the technology’s safety profile. This study aimed to compare the current Arctic Front® (AF) balloon to the new Arctic Front Advance™ (AFA).
Methods: Twenty pulmonary veins (PVs) from 10 healthy hound dogs weighing 29.8±1.1 kg were randomized to ablation with either AF or AFA, using a 23mm or 28mm balloon. A single 4 minute ablation was performed at each vessel, with no phrenic nerve monitoring. The Achieve™ mapping catheter was used to monitor PV time-to-isolation and confirm acute isolation. Animals were survived for 30 days. Histological analysis included confirmation of lesion circumferentiality and transmurality. The phrenic nerve, PVs, lungs, esophagus, kidneys and brain were harvested for evaluation of potential damage. A pre-procedural and pre-necropsy CT was performed to assess incidence of PV stenosis.
Results: All PVs were fully isolated with AFA; 6 of 10 PVs were fully isolated with AF. In all cases, lesion gaps with AF are believed to stem from inadequate cooling of the most distal balloon segment that was in contact with the unablated PV tissue. No untoward findings were reported in gross pathology examinations of the heart, esophagus, kidneys or brain. No PV strictures were noted, as confirmed by CT and pathology. One phrenic nerve suffered cross-sectional axonal degeneration following ablation with an AFA 23mm balloon. Only small, superficial and subclinical lung injuries were noted adjacent to 8 PVs; half were from AFA23.
Conclusions: In the canine model, PV isolation and lesion completeness is improved with Arctic Front Advance, as the system was designed to generate distal and more uniform balloon cooling. No unexpected findings were found related to the safety of this second generation cryoballoon catheter.
- © 2012 by American Heart Association, Inc.