Pelvi-Ureteric Junction Obstruction in a Solitary Functioning Kidney in Children: An Unfavourable Combination

Solitary functioning kidney (SFK) is linked to chronic kidney disease (CKD) in children, particularly when associated with congenital anomalies of the kidney and urinary tract (CAKUT). Pelvi-ureteric junction obstruction (PUJO) is the most frequent obstructive uropathy in SFK. This study aimed to evaluate long-term kidney function in children operated on for PUJO in an SFK.

Among a retrospective cohort study of children with an SFK, a subgroup analysis was performed: primary SFK with operated PUJO (n = 35); primary SFK without CAKUT (n = 108); primary SFK with CAKUT other than PUJO (n = 24). Markers of CKD and measured glomerular filtration rate were assessed during follow-up.

Surgery was indicated because of neonatal acute kidney injury (AKI) (n = 21), worsening renal pelvis dilation (n = 10). The median age at surgery was 15 months (1.2-30 months). At a median age of 13 years at last follow-up, the proportion of CKD was higher in primary SFK with PUJO compared to primary SFK without CAKUT (43% vs. 12%, p = 0.0008). In SFK/PUJO, neonatal AKI was predictive of subsequent CKD (OR 4.8, p = 0.04).

PUJO in an SFK is associated with a high rate of CKD during childhood, particularly when neonatal AKI is present.