BACKGROUND: Posterior urethral valves (PUV) represent the most common cause of lower urinary tract obstruction in male infants (~1/4000 live births). Long-term kidney outcomes of PUV remain uncertain. We aimed to determine the time-varying risk of major adverse kidney events (MAKE) following children with PUV into adulthood.
METHODS: A population-based retrospective cohort study of all males (<2 years) diagnosed with PUV between 1991-2021 in Ontario, Canada. Comparator cohorts were: 1) male general population and 2) male pyeloplasty patients (both <2 years, without PUV). The primary outcome was MAKE (death, chronic kidney replacement therapy [dialysis or kidney transplant], or chronic kidney disease). Time-varying hazard ratios were calculated using Cox proportional hazards models with restricted cubic splines. We censored for death, provincial emigration, or administrative censoring (March 31, 2022).
RESULTS: We included 727 children with PUV, 855 pyeloplasty comparators, and 1,013,052 general population comparators. The median age at PUV diagnosis was 40 days (Q1-3 10-196). Median follow-up time was 16.6 years (Q1-3 8.6-24.5) overall. Throughout follow-up, 32.3% of children with PUV developed MAKE vs. 0.8% of the general population and 5.8% of pyeloplasty comparators. The adjusted hazard ratio for MAKE was 36.6 (95%CI 31.6-42.4) among children with PUV vs. the general population. The risk of developing MAKE decreased over the first 5 years after PUV diagnosis, but remained elevated for >30-year follow-up (Figure).
CONCLUSIONS:
Children with PUV are at increased risk of adverse long-term kidney outcomes well into adulthood. These findings justify close kidney health surveillance among those with a PUV history, with special consideration around the transition to adult urologic care.
