1. Department of Cardiothoracic Surgery, Assiut University Hospital, Faculty of Medicine, Assiut University, Assiut, Egypt
2. Department of Paediatric Cardiac Surgery, Alder Hey Children Hospital, Liverpool, United Kingdom
3. Department of General Surgery, University Hospitals Birmingham, United Kingdom
4. St George's Medical School, University of London, Cranmer Terrace, London, United Kingdom
5. Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom
6. Department of Public Health and Community Medicine, Faculty of Medicine, Assiut University, Assiut, Egypt
7. Department of Cardiothoracic Surgery, Liverpool Heart and Chest Hospital, Liverpool, United Kingdom