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[Unilateral massive vesicoureteral reflux associated with congenital mechanical obstruction of lower urinary tract]
Insights
Massive reflux in children with congenital lower urinary tract obstruction often persists after treatment, indicating a protective role in preserving renal function despite associated kidney hypodysplasia.
Area of Science:
- Pediatric Urology
- Nephrology
- Developmental Biology
Background:
- Congenital mechanical obstruction of the lower urinary tract can be associated with massive vesicoureteral reflux (VUR).
- Understanding the relationship between obstruction, VUR, and renal outcomes is crucial for pediatric urologists and nephrologists.
Observation:
- A review of 9 children with unilateral massive VUR and 4 with bilateral VUR associated with congenital lower urinary tract obstruction was conducted.
- Obstructions included posterior urethral valves, anterior urethral strictures, and mega-urethra.
- Associated anomalies like anorectal malformations were noted in some cases.
Findings:
- Massive VUR, particularly on the left side, was frequently associated with ipsilateral renal hypofunction.
- Following obstruction resolution, massive reflux often persisted, and decompression did not salvage compromised kidneys.
- Kidney dysplasia and severe hypoplasia were observed, with cranio-lateral ureteral orifice positions.
Implications:
- Massive reflux may act as a 'pop-off' mechanism, potentially preserving renal function in the presence of high pressure from obstruction.
- The findings suggest a distinct embryogenesis for this VURD syndrome, linked to renal hypodysplasia and obstruction.
- While generally excellent, prognosis can be poor in rare cases, highlighting the need for careful monitoring.
Abstract:
We reviewed 9 children with unilateral massive (III and IV, Dwoskin-Perlmutter) vesicoureteral reflux associated with congenital mechanical obstruction of the lower urinary tract. Four children with bilateral reflux with bilateral difference of severity more than 2 grades were also included. Obstruction was attributed to posterior urethral valve in 5, anterior urethral stricture in 3 and mega-urethra in 1. The chief complaints were febrile episodes and urinary infection, followed by voiding difficulty, bed wetting and/or urinary incontinence and voiding through anus. All 4 children with troubles other than posterior urethral valve had either anorectal anomaly or H-type rectourethral fistula without imperforate anus. Of the 9 children 8 had massive reflux on the left side. The majority of these left ureters with massive reflux were associated with ipsilateral severe renal hypofunction on scintigraphy. After prompt resolution of obstruction, the majority of these massive reflux did not disappear. Decompression appeared to salvage none of such kidneys. The orifice positions of such ureters were far cranio-lateral and the resected kidneys showed dysplasia or severe hypoplasia. The prognosis was generally excellent except one child with massive reflux on the right side who progressed to an end-stage renal disease. The embryogenesis of this "VURD syndrome" was discussed in its relation to the "bud theory" of renal hypo-dysplasia. It was showed that this syndrome was observable in obstructions other than the posterior urethral valve. Massive reflux appeared to serve as "pop-off" mechanism to buffer high pressure and to lead to preservation of better renal function. Reflux in children with congenital mechanical obstruction may be the result of 2 different mechanisms.(ABSTRACT TRUNCATED AT 250 WORDS)