Evaluation of renal function and upper urinary tract morphology in the ileal orthotopic neobladder with no antireflux mechanism

Abstract PURPOSE: Long-term renal function is crucial in orthotopic bladder substitutions, and can be influenced by several factors including ureteral obstruction, urinary infection and reflux. In this study we investigated the prevalence of renal functional impairment and the incidence of morphological alterations of the upper urinary tract in patients who had a low pressure ileal neobladder constructed with no antireflux mechanism. MATERIALS AND METHODS: From 1996 to 2002, 70 men received a W-shaped neobladder using refluxing ureterointestinal anastomoses and short afferent limb. Final evaluation of patient status was in November 2003. A total of 20 patients died during followup and mean followup of the remaining 50 patients was 50 months (range 21 to 89). Kidney morphology was evaluated using technetium diethylenetetraminepentaacetic acid nuclear renography and ultrasonography. Total and separate renal function were evaluated by measuring plasma creatinine and glomerular filtration rate (GFR), the latter measured as the renal clearance of technetium diethylenetetraminepentaacetic acid. Measured values of GFR were compared with the results from a group of healthy subjects of the same age. RESULTS: The anastomotic stricture rate was 4%, 2 severe strictures occurred 2 and 4 months after surgery, while 2 moderate strictures were detected with renal scans during the study. Renal scintigraphy revealed an excretory phase within the normal range in 67 of 99 renoureteral units (68%), a short delay in collecting system drainage associated with mild and transient pelvicaliceal dilatation in 23 (23%), and dilatation of the upper urinary tract in the remaining 9 (9%) including obstructive in 2 (2%) and not obstructive in 7 (7%). Mean (+SD) total GFR of the patients was 89.7 (19.6) ml per minute per 1.73 m. Mean total GFR of the control group was 90.6 (11.4) ml per minute per 1.73 m. The comparison between measured GFR of patients and the control group showed no statistically significant difference. CONCLUSIONS: Our medium-term data support the assumption that the lack of any antireflux mechanism in orthotopic neobladder, per se, has no detrimental effect on renal function.