1. From the Departments of Urology, Thomas Jefferson University, Philadelphia, Pennsylvania
2. Montreal General Hospital, Montreal, Quebec, Misericordia Hospital, Edmonton and Calgary General Hospital, Calgary, Alberta, Camp Hill Hospital, Halifax, Nova Scotia and East Toronto General Hospital, Toronto, Ontario, Canada
3. Louisiana State University Medical Center, New Orleans, Louisiana
4. Shepherd Spinal Center, Atlanta, Georgia
5. University of South Florida and James Haley Veterans Administration Medical Center, Tampa, Florida