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