1. Weill Cornell Medical College, Doha 24144, Qatar
2. Clinical Research, Trauma Surgery Section, Hamad General Hospital, Doha 3050, Qatar
3. Clinical Medicine, Weill Cornell Medical College, Doha 24144, Qatar
4. Trauma Surgery Section, Hamad General Hospital, Doha 3050, Qatar
5. Department of Surgery, Arizona University, P.O. Box 245005, Tucson, AZ, USA