Purpose: Intestinal low pressure orthotopic bladder substitutes have no major coordinated contractions during micturition. Therefore, the importance and type of reflux prevention were assessed in a prospective randomized study.
Materials and methods: A total of 70 patients with an ileal low pressure bladder substitute was randomized to receive a nipple valve or an isoperistaltic afferent ileal tubular segment for reflux prevention.
Results: After median observation times of 57 and 45 months, respectively, the results regarding functional reservoir capacity, incidence of infected urine, urinary continence, voiding habits and serum electrolytes, urea and creatinine were similar in both groups. Severe upper tract dilatation due to ureteroileal or nipple stenosis occurred in 9 of 67 evaluable reno-ureteral units (13.5%) in patients with antireflux nipples and in 2 of 69 (3%) in patients with an afferent tubular segment. This difference in favor of the latter cases is significant (Fisher's exact test p < 0.03). Video urodynamics did not show reflux of contrast medium during voiding in either group. A simultaneous intravesical, intra-abdominal and intrapelvic pressure increase was noted during the Valsalva maneuver.
Conclusions: While long-term upper tract preservation by an afferent tubular ileal segment must be confirmed in larger patient series with longer followup, our results indicate that reflux prevention in patients with orthotopic low pressure bladder substitutes is not a major concern and does not justify the use of antireflux mechanisms with a high complication rate.