Catheter-Based Left Atrial Appendage (LAA) Ligation for the Prevention of Embolic Events Arising From the LAA

Background— Surgical ligation of the left atrial appendage (LAA) has been shown to be an effective alternative to warfarin therapy in patients with atrial fibrillation. A novel catheter-based approach for LAA ligation was evaluated for safety and effectiveness in a canine model. Methods and Results— A total of 26 healthy mongrel dogs underwent ligation of the LAA through a catheter-based approach. Intracardiac echocardiography and contrast fluoroscopy were used to position a marker balloon at the origin of the LAA. An over-the-wire approach was used to guide the LARIAT snare device over the LAA to enable ligation of the LAA. Sixteen dogs were euthanized acutely. The LAA was examined to assess the placement and completeness of the ligation. The remaining 10 dogs were used for long-term follow-up. The snare delivery device was able to completely capture, advance, and close the anatomic base of the LAA in all cases. In all animals, complete LAA exclusion through this closed-chest approach was achieved without complications. Chronic follow-up revealed healthy active dogs. Examination of the LAA at 7 days, 1 month, and 3 months demonstrated completely endothelialized orifice of the LAA. Conclusions— Using a closed-chest approach in the canine model, the catheter-based snare delivery device achieved safe and reliable ligation of the entire LAA. The clinical application of this novel approach may provide an alternative to warfarin or to permanent device implants in patients with nonvalvular atrial fibrillation for the prevention of embolic events originating from the LAA.