Long-segment ureteral replacement with expanded polytetrafluoroethylene grafts.

OBJECTIVES: Traumatic loss of significant lengths of ureter all too often results in nephrectomy when vascularized pedicles of bowel or bladder fail or are not available for substitution. Historically, alloplastic replacement of ureters has failed due to obstruction, bioincompatibility, or graft migration. This study was undertaken to test the performance of ringed expanded polytetrafluoroethylene (PTFE) tube grafts as ureteral replacements in a canine model. METHODS: Eight female dogs underwent partial ureteral replacement with ringed PTFE tube grafts. An involuting anastomosis was used to anchor the graft to the bladder. The dogs were followed with intravenous urograms and Whitaker infusion pressure tests for up to 12 months. RESULTS: Six of 8 animals (75%) had preservation of excellent renal function with normal intravenous urograms and low Whitaker infusion pressures. One animal had mild hydronephrosis with an elevated infusion pressure. One animal died of spontaneous renal rupture secondary to obstruction at the ureteral-graft anastomosis. All other grafts were patent by histologic examination without encrustation or infection. CONCLUSIONS: Although not suggested as first-line therapy after ureteral loss, expanded PTFE may have a use as a prosthetic ureteral replacement in situations where conventional surgical therapies are unsuccessful. This material appears to be biocompatible, and the technique of bladder anastomosis described here prevented migration of the prosthesis.

Should renal ultrasound be performed in the patient with microscopic hematuria and a normal excretory urogram?

PURPOSE: We determine what additional information would be detected by renal ultrasonography that was not identified by a normal excretory urogram (IVP) performed for the evaluation of microscopic hematuria. MATERIALS AND METHODS: A retrospective review was done of 101 patients with microscopic hematuria and a normal IVP who underwent renal ultrasonography. RESULTS: Of the 101 patients with microscopic hematuria and a normal IVP, renal ultrasonography was abnormal in 20%. All findings were ultimately proved to be of no clinical significance, although 6 of 21 patients required a total of 10 additional studies, including 9 computerized tomography scans and 1 renal arteriogram. CONCLUSIONS: These data demonstrate that renal ultrasonography is unnecessary in a patient with microscopic hematuria and a normal IVP.