Mid-Term Kidney Function in Boys With Posterior Urethral Valves and a Solitary Functioning Kidney

Area of Science:

• Pediatric Urology
• Nephrology
• Medical Imaging

Background:

• Posterior urethral valves (PUV) are a common congenital obstruction in male infants.
• The long-term renal function of patients with PUV and a solitary functioning kidney (SFK) is a concern.
• Previous studies suggest poorer outcomes for SFK patients compared to those with two functioning kidneys (2FK).

Purpose of the Study:

• To compare the mid-term estimated glomerular filtration rate (eGFR) in boys with PUV and SFK versus those with PUV and 2FK.
• To assess if having a solitary functioning kidney impacts renal function in the mid-term for PUV patients.

Main Methods:

• Retrospective analysis of the CIRCUP randomized controlled trial database.
• Included patients with confirmed PUV, comparing SFK (<10% differential function) to 2FK.
• Mid-term eGFR (>5 years) calculated using the updated Schwartz formula; DMSA scans used for renal unit assessment.

Main Results:

• Sixty-eight PUV patients were analyzed; 20 had SFK, 48 had 2FK.
• No significant difference in mid-term eGFR between SFK and 2FK groups (median 82.5 vs 94.5).
• Nadir creatinine was higher in patients with mid-term eGFR < 90 compared to those with eGFR > 90.

Conclusions:

• In boys with PUV, a solitary functioning kidney identified by DMSA scan alone is not sufficient to predict decreased renal reserve.
• Mid-term renal function appears comparable between PUV patients with SFK and 2FK.