Persistent polyuria after posterior urethral valves

Area of Science:

• Pediatric Nephrology
• Urology
• Renal Physiology

Background:

• Posterior urethral valves (PUV) are a common congenital anomaly in male infants.
• Valve ablation is the primary treatment, but long-term renal function and urinary handling require evaluation.

Purpose of the Study:

• To evaluate urinary concentrating ability, urine production, and glomerular filtration rates (GFR) in boys with a history of treated PUV.
• To identify potential correlations between these parameters and long-term renal health.

Main Methods:

• Assessed urinary concentrating capacity using overnight urine osmolality and stimulated maximum concentrating ability with desamino-cys-1-8-D-arginine vasopressin.
• Calculated 24-hour urine volumes from frequency/volume charts.
• Estimated glomerular filtration rate (GFR) via 51Cr-ethylenediamine tetra-acetic acid plasma clearance.

Main Results:

• 59% of boys exhibited impaired urinary concentrating capacity (< 800 mOsm/kg).
• Mean 24-hour urine volume was 1025 mL; mean GFR was 81 mL/min/1.73 m2SA.
• Significant correlations were found between GFR, maximum urine concentration, and 24-hour urine volume.

Conclusions:

• Persistent polyuria is a common sequela following posterior urethral valve ablation.
• Impaired concentrating ability and polyuria have significant implications for urinary continence and ongoing renal impairment in affected boys.