Thromboemoblism is the most feared complication of atrial fibrillation. Percutaneous left atrial appendage occlusion is a new interventional procedure for reducing thromboembolic risk in patients with atrial fibrillation. The paper reports of a post mortem analysis of the device demonstrating that one year after implantation the atrial surface of the device is completely covered by neo-endothelium and the device occludes the appendage completely.