Usman Ahmad1, Sudish C Murthy1, Siva Raja2. 1. Department of Cardiothoracic Surgery, Section of Thoracic Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio. 2. Department of Cardiothoracic Surgery, Section of Thoracic Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio. Electronic address: rajas@ccf.org.