Prognostic Insights into Congenital Solitary Functioning Kidneys Among the Turkish Pediatric Population: A Comparative Study of Renal Agenesis and Multicystic Dysplastic Kidney Disease

Abstract

Objective: Our study aims to assess the outcomes of solitary functioning kidneys (SFKs) resulting from unilateral renal agenesis (URA) and multicystic dysplastic kidney (MCDK) in order to identify the factors influencing kidney damage in these patients and to elucidate the potential contrasts between these two conditions. Methods: The study retrospectively analyzes 154 pediatric patients (ages 0-18) with SFK treated at a tertiary center in Turkiye. Results: Among the 154 SFK patients, 91 are male, 74 were diagnosed with MCDK, and 80 with URA. The median age is one month at diagnosis and 69.5 months at the last follow-up. Most MCDK cases were identified antenatally, while URA was most commonly detected incidentally. Congenital anomalies of the kidney and urinary tract (CAKUT) in the functioning kidney were identified in 21.6% of MCDK patients and 7.5% of URA patients, with a significantly higher occurrence in MCDK patients (p = 0.012). Vesicoureteral Reflux (VUR) was the most prevalent CAKUT, occurring in 45% of patients. A low glomerular filtration rate (GFR) was observed in 12.4% of patients, and 15% exhibited signs of renal damage. No significant disparity was found in low GFR or kidney damage between MCDK and URA patients. Those with a low GFR showed increased rates of hydronephrosis, CAKUT in the functioning kidney, recurrent urinary tract infections (UTIs), renal scarring, hypoplastic kidneys, proteinuria, and hypertension (HT). Conclusions: The findings underline that CAKUT in the functioning kidney, recurrent UTIs, and renal scarring significantly influence GFR and kidney injury. VCUG is useful in select cases for identifying CAKUT, especially VUR. No significant distinction was observed between MCDK and URA concerning the eventual renal injury.