Urinomas protect renal function in posterior urethral valves--a population based study.

BACKGROUND/PURPOSE: Urinomas have been thought to protect renal function in boys with posterior urethral valves (PUVs), although recent reports have disputed this. This study tested the hypothesis that urinomas protect global renal function in boys with PUV. METHODS: A retrospective analysis of all boys with PUV presenting to a tertiary unit derived from a region with an estimated population of 5.5 million was performed. Comparisons of the initial nadir creatinine, current creatinine, and renal status score (RSS) were made between those with and without urinomas. The RSS was derived from nephrology assessment of current renal status (0 = normal to 4 = end-stage renal failure or transplantation). Results were given as median (range), except for RSS, which was given as mean +/- SEM. P < or = .05 was regarded as significant. RESULTS: During 1989-2009, 9 of 89 PUV boys were diagnosed with urinomas. Initial nadir creatinine was statistically lower in boys with urinomas (31 [18-44] vs 45 [20-574] mumol/L, P < .01). Length of follow-up was similar (5.1 [2.2-17.3] vs 5.9 [1.8-19.7] years, P = .59). Follow-up creatinine was significantly lower in urinoma boys (44 [25-77] vs 61 [29-1227] micromol/L, P < .05), as was the RSS (0.14 +/- 0.14 vs 0.91 +/- 0.14, P < .01). No urinoma boys progressed to end-stage renal failure or required transplant. CONCLUSION: This population-based study of PUV boys demonstrates that urinomas reduce nadir creatinine and significantly protect long-term global renal function.

Urinomas associated with posterior urethral valves.

PURPOSE: We evaluated the incidence and clinical implications of urinomas in boys with posterior urethral valves. Our secondary aim was to evaluate the treatment modalities of urinomas. MATERIALS AND METHODS: We retrospectively reviewed the hospital data of 200 patients with posterior urethral valves treated between 1953 and 2003. Documentation was sufficient in 196 cases to evaluate the presence of urinomas. A group of 69 patients with posterior urethral valves without urinoma served as controls. RESULTS: Of 196 patients 17 (9%) had urinoma. However, the incidence of urinoma increased to 15% after ultrasonography came into standard clinical use. Nine patients had perirenal urine collection, 6 had urinary ascites and 2 had urinothorax. At presentation median serum creatinine values were similar in patients with urinoma (145 mumol/l, range 54 to 431) and controls (126 mumol/l, 19 to 593, p = 0.547). Creatinine decreased similarly in patients with and without urinoma after the obstruction was relieved. Vesicoureteral reflux was detected in 69% of the patients with urinoma and in 76% of the controls. Median split function on the side of the urinoma was 51% (range 38% to 70%) on (99m)technetium diethylenetetramine pentaacetic acid scintigraphy. During childhood end-stage renal failure developed in 4 of the 16 patients (25%) with urinoma and in 16 of the 69 controls (23%). CONCLUSIONS: The true incidence of urinomas is probably close to 15% in patients with posterior urethral valves. Renal function is similar in patients with posterior urethral valves with and without urinoma. In asymptomatic cases urinomas apparently do not require any specific treatment.