1. University of Alabama–Birmingham, Department of Surgery; Birmingham Veterans Administration Hospital, Birmingham
2. Central Texas Veterans Health Care System, Temple
3. Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
4. Veteran Affairs Boston Health Care System and Tufts University School of Medicine, Department of Surgery, Boston, Massachusetts
5. Stanford University, Department of Surgery; Veteran Affairs Palo Alto Health Care System, Palo Alto, California