Are Pressure Pop-Offs Beneficial To The Bladder In Boys With Posterior Urethral Valves?

Extended Summary Background Pressure pop-offs, such as high-grade vesicoureteral reflux with renal dysplasia, have historically been considered beneficial for renal and bladder outcomes in boys with posterior urethral valves (PUV). Recent longer-term studies have called into question the beneficial effects of pop-offs on renal function. Objective To evaluate how pop-offs affect bladder outcomes in boys with PUV. Study Design At a single-center, the electronic medical records of boys with PUV who underwent valve ablation from 2000-2014 were retrospectively reviewed for bladder and continence outcomes. Patients were excluded due to presentation after one year of age, age at last follow-up Results 48 patients met inclusion criteria, of whom 31 (65%) had pop-offs and 17 (35%) did not. Median age at last follow-up was 5.9 years (range: 1.0-12.2 years). Patients with pop-offs were more likely to have unsafe initial UDS (26% vs. 12%, p=0.15) but less likely to have high voiding pressures at their latest UDS (15% vs. 50%, p=0.03). Patients with pop-offs were more likely to have used clean-intermittent catheterization (26% vs. 0%, p=0.04) and were less likely to be toilet-trained by age 4 (76% vs. 100%, p=0.15) or dry during the day at last follow-up (56% vs. 92%, p=0.06). Toilet-trained patients with pop-offs were toilet trained by an earlier age than patients without pop-offs (3 vs 4 years, p=0.04). Discussion The results of the present retrospective study show that patients with pop-offs required more extensive interventions to achieve continence, and achieved continence and toilet-training less frequently than patients without pop-offs. Additionally, our results demonstrated that patients with pop-offs had worse bladder dynamics initially, which may suggest that pop-offs are a manifestation of more excessive pressure build-up prior to valve ablation. Conclusions Among boys with posterior urethral valves who present in the first year of life, pop-offs do not appear to impart significant benefit to bladder outcomes and may indicate more severe bladder dysfunction.