RENAL SCARRING AND LONG-TERM KIDNEY OUTCOMES IN CHILDREN WITH CONGENITAL UROLOGICAL DISORDERS: A LONGITUDINAL COHORT STUDY

Abstract

Congenital urological disorders are important causes of recurrent urinary tract infections, urinary obstruction, vesicoureteral reflux, renal parenchymal injury, and long-term kidney dysfunction in children. This longitudinal cohort study investigated the development of renal scarring and subsequent kidney outcomes among children with congenital urological disorders treated at three tertiary-care hospitals in Karachi, Pakistan. An illustrative cohort of 360 children aged 1 month to 12 years was selected using age-stratified population sampling and followed for 36 months. Participants underwent clinical assessment, renal and bladder ultrasonography, urine culture, serum creatinine measurement, estimated glomerular filtration rate assessment, and, where clinically indicated, DMSA renal scintigraphy and VCUG. The primary outcome was new or progressive renal scarring, while secondary outcomes included recurrent febrile urinary tract infection, decline in estimated glomerular filtration rate, hypertension, and chronic kidney disease. In the illustrative analysis, renal scarring developed or progressed in 82 (22.8%) children. The highest proportion was observed among children with grade IV–V vesicoureteral reflux, recurrent febrile urinary tract infections, and obstructive uropathies. Children with ≥3 febrile UTIs had substantially greater risk of renal scarring than those with fewer episodes. Higher VUR grade, recurrent infection, abnormal baseline renal imaging, and delayed corrective intervention were independently associated with adverse renal outcomes. The findings support early identification, risk-based imaging, timely management of congenital abnormalities, and long-term renal surveillance.