# Post‐pubertal stability of split renal function after pyeloplasty performed in childhood

## TL;DR

This study finds that some children who had successful kidney surgery may experience a decline in kidney function later in life, especially if certain factors are present.

## Contribution

The study identifies factors associated with late deterioration of split renal function after childhood pyeloplasty.

## Key findings

- Renal pelvis reduction and persistent hydronephrosis at 1 year are strong predictors of late deterioration.
- Younger age at surgery increases the risk of deterioration, while older age and higher final SRF reduce it.
- Late deterioration occurs in 20.4% of patients despite initial post-operative stability.

## Abstract

While early outcomes after pyeloplasty are well‐documented, long‐term split renal function (SRF) stability, particularly beyond puberty, remains unclear. This study evaluates SRF after prepubertal pyeloplasty and identifies factors associated with late deterioration.

A retrospective review included paediatric patients who underwent pyeloplasty between 2000 and 2025. Exclusion criteria were solitary kidney, missing imaging, congenital anomalies or prior pyeloplasty. Patients were categorised into two groups: Group 1 (no deterioration) and Group 2 (late deterioration after puberty), based on ≥5% decrease in SRF. Clinical, surgical and imaging parameters were compared among groups using Chi‐square, Fisher's exact and Mann–Whitney U tests, with multivariate logistic regression to identify predictors of late deterioration.

Out of 1493 patients, 191 were included: 152 (79.6%) in Group 1 and 39 (20.4%) in Group 2. Group 2 patients were younger at surgery, had more frequent renal pelvis reduction and persistent hydronephrosis at 1‐year follow‐up (p < 0.001). Multivariate analysis identified renal pelvis reduction (odds ratio [OR] = 9.82, 95% confidence interval [CI]: 3.551–37.799, p < 0.001) and non‐resolution of hydronephrosis (OR = 4.811, 95% CI: 1.766–13.1, p = 0.002), as late deterioration predictors. Older age at surgery (OR = 0.958, 95% CI: 0.942–0.975, p < 0.001) and higher final SRF (OR = 0.905, 95% CI: 0.855–0.958, p < 0.001) were protective against deterioration.

SRF may deteriorate after puberty despite initial post‐operative stability. Renal pelvis reduction, persistent hydronephrosis at 1 year and younger age at surgery are associated with increased risk of deterioration.