1. From the Department of Surgery, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
2. From the Departments of Biostatistics, Epidemiology and Scientific Computing, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
3. From the Department of Surgery, King Abdulaziz Medical City, Riyadh, Saudi Arabia
4. From the Department of Surgery, King Khalid Hospital, Riyadh, Saudi Arabia