Impact of prenatal urinomas in patients with posterior urethral valves and postnatal renal function

Posterior urethral valves (PUV) are a common cause of lower urinary tract obstruction. Renal failure occurs in approximately one third of the cases. It is debated whether urinoma formation is a protective mechanism to reduce pressure-related impairment of renal function. The aim of our study was to determine if urinoma formation is able to preserve renal function on the side of the urinoma.

Five male patients diagnosed with posterior urethral valves and uni- or bilateral urinoma formation were reviewed. Renal function was assessed by serum creatinine level at days 4-7 and at two months, in addition to dimercaptosuccinylacid (DMSA) scintigraphy at 4-6 weeks postnatal age.

Impaired renal function occurred unilaterally in four patients, two had bilateral urinoma formation, and the other two boys presented with unilateral urinoma, one with preserved renal function ipsilateral to the urinoma and the other on the contralateral side. Urinary ascites was detected in three patients, all underwent antenatal centesis.

No association was found between renal function and urinoma formation in patients with PUV.