1 - Paediatric Nephrology Unit, Department of Paediatrics, Hospital Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central, Lisbon, Portugal
2 - Paediatric Urology Unit, Department of Paediatric Surgery, Hospital Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central, Lisbon, Portugal
- 54th ESPN Annual Meeting, Ljubljana, Slovenia, 22-25/06/2022, e-poster
Introduction: Posterior urethral valves (PUV) affect approximately 1:5000 live male births, with about 50% progressing to end-stage renal disease within ten years. We aimed to identify predictors of kidney outcomes for children diagnosed with PUV.
Material and methods: This retrospective single-centre cohort study included children who underwent a PUV ablation between January 1, 2015 and December 31, 2020. Patients with less than three months of follow-up were excluded. The primary outcome was a composite of glomerular filtration rate (GFR) below -2 SD of expected for age or renal replacement therapy (RRT).
Results: From a total of 34 patients in the cohort, 18 (53%) were diagnosed prenatally and 10 (29%) were referred to us from Portuguese-speaking African countries (PALOP). Prevalence of kidney hypoplasia was higher among patients born in a PALOP (100% versus 74%, p=0.04). Patients with a prenatal diagnosis were more frequently born preterm (56% versus 7%, p=0.003), were younger at first urethral cateter placement (6.0±14.4 days versus 14.2±32.4 months, p=0.03), and had higher baseline serum creatinine (1.64±1.61 versus 0.55±0.21 mg/dL; p=0.029) than patients diagnosed postnatally. Mean follow-up time was 3.3±1.2 years. At last follow-up, median age was 2.7 years [interquartile range (IQR) 0.9-3.9] and median GFR was 92.6 mL/min/1.73m2 [IQR 70.5-114.4]. Twelve patients (43%) met the primary outcome. Two patients needed (6%) peritoneal dialysis and another 10 (29%) had a low GFR for age. In the logistic regression analyses adjusted for age at last follow-up prenatal diagnosis (OR 8.4, 95% CI 1.3-53.0, p=0.023), prematurity (OR 49.8, 95% CI 3.5-70.5, p=0.04), and higher serum creatinine at baseline (OR 4.9, 95% CI 1.2-20.6, p=0.031) were significant predictors of the primary outcome.
Conclusions: Prenatal diagnosis of PUV, prematurity and higher serum creatinine before PUV ablation may predict adverse kidney outcomes (low GFR and need for RRT). Our sample size and time of follow-up may have limited our conclusions.
Keywords: CAKUT, posterior urethral valves