1. Division of General Surgery, Michael E. DeBakey Veterans Affairs Medical Center, Department of Surgery, Baylor College of Medicine, Houston, Texas.
2. Division of General and Trauma Surgery, Harborview Medical Center and the Department of Surgery, University of Washington, Seattle, Washington.
3. Division of General Surgery, Lyndon Baines Johnson General Hospital and the Department of Surgery, The University of Texas at Houston, Houston.
4. Division of General Surgery, St. Michael's Hospital, Department of Surgery, University of Toronto, Toronto, Ontario, Canada.