Abstract 4646: Visually-Guided Ablation of the Pulmonary Venous Antrum Using a Compliant Balloon Catheter
Introduction: During AF ablation, placing contiguous point ablations to electrically isolate the PVs can be technically challenging. While balloon ablation catheters (BACs) using various energy sources can facilitate this procedure, they are limited by the relatively distal nature of the level of isolation; the PV antra remain largely un-ablated. This report details the in vivo evaluation of a compliant BAC with 1) the capability for endoscopic real-time visualization of the target tissue, and 2) an adjustable short arc of light energy for ablation.
Methods: In 3 normal pigs, transseptal access was achieved followed by placement of a deflectable sheath and the BAC (Cardiofocus Inc). Once in position, a 30° arc of laser energy (980 nm) was manipulated to create an isolating antral lesion set. PV isolation was confirmed using a circular mapping catheter. The level of isolation was also visualized by high-density electroanatomical mapping (NavX, St Jude Medical Inc).
Results: The BAC was able to conform to the PV antra (Fig-A/B⇓); a 3D reconstruction of the BAC while in position is shown in Fig C⇓. Circumferential endoscopic contact was observed for all 4 PVs targeted for ablation (3-RSPVs, 1-LSPV). Electrical PV isolation was achieved for all 4 PVs. The level of RSPV (arrow) isolation is seen on the voltage maps at baseline (Fig D⇓), post-partial ablation (Fig E⇓) and post-isolation (Fig F⇓); shown are PA views. There was no PV stenosis, thrombus formation or atrial perforation. Pathological examination confirmed the lesions to be both transmural and antral in location.
Conclusions: The PV antra can be targeted for ablation using this visually-guided compliant balloon ablation system.