A novel technique for an anti-refluxing uretero-ileal reimplantation entailing creation of 2 serous lined extramural tunnels in a detubularized ileal W-bladder is presented. The operation was done on 12 patients in whom an orthotopic bladder substitute was indicated. Mean followup was 18 months. Evidence indicated that this method could provide a nonobstructed unidirectional flow of urine in all of the examined renal units.