Feasibility of Closed-chest Ligation of the Left Atrial Appendage in Humans

Background: Atrial fibrillation is associated with an increased risk of embolic events. The left atrial appendage (LAA) is believed to be an incubator for thrombus formation. LAA exclusion has been advocated to potentially reduce embolic events arising from the LAA.

Objective: The aim of the study was to determine the feasibility of a closed-chest surgical suture ligation of the LAA in man.

Methods: Thirteen patients undergoing either mitral valve surgery (n = 2) or electrophysiological study and radiofrequency catheter ablation for atrial fibrillation (n = 11) underwent ligation of the LAA with the LARIAT snare device. In patients having an ablation procedure, pericardial access was obtained prior to the patients undergoing radiofrequency catheter ablation. After transseptal catheterization, endocardial and epicaridal magnet-tipped guide wires were positioned under fluoroscopic guidance to stabilize the LAA. Transesophageal echocardiography (TEE) was used as guidance for positioning a marker balloon at the ostium of the LAA. An over-the-wire approach was used to guide the LARIAT snare device over the LAA to allow closure and suture ligation of the LAA. TEE and contrast fluoroscopy were used to confirm acute closure of the LAA.

Results: Both mitral valve replacement (MVR) patients had complete closure of the LAA determined by visual inspection. Ten of 11 patients having ablation underwent a successful closed-chest LAA ligation procedure with TEE and contrast fluoroscopy verification of closure of the LAA. Only one of 11 procedures was terminated owing to the lack of echocardiography guidance of the snare over the marker balloon. One patient with pectus excavatum did have ligation of his LAA; however, a thorascopic procedure was required to remove the snare from the LAA owing to compression of the LARIAT by the concave sternum. There were no other significant complications.

Conclusions: Catheter-based surgical suture ligation of the LAA is feasible in humans. This novel catheter approach may be appropriate for patients with atrial fibrillation who are ineligible for anticoagulation therapy. Further investigation is needed to demonstrate the long-term safety and efficacy of LAA closure.