1. Department of Cardiothoracic Surgery, Tanta University, Tanta, Egypt
2. Department of Thoracic Surgery, King Fahd Specialist Hospital, Buraydah, Saudi Arabia
3. Cardiac Surgery Division, Department of Surgery, University of Ottawa Heart Institute, Ottawa, Canada
4. Department of Cardiovascular Surgery, King Faisal Specialist Hospital and Research Centre, Jeddah, Saudi Arabia