Related Experiment Video
Updated: Apr 25, 2026

Assessing Urinary Tract Junction Obstruction Defects by Methylene Blue Dye Injection
Published on: October 12, 2017
Posterior Urethral Valves with Severe Unilateral Vesicoureteral Reflux in a 3-year-old Boy
Abstract:
In patients with posterior urethral valves (PUV), severe unilateral vesicoureteral reflux (VUR) is one of the three conditions associated with preservation of renal function. Others are urinary ascites or urinoma in newborns and large congenital bladder diverticula. These conditions most likely provide a pop-off mechanism preventing the development of high intravesical pressure. Only 5% of patients with PUV and an associated pop-off mechanism will develop renal failure as opposed to 40 % of patients with PUV without a protective factor. We present a 3-year-old boy with posterior urethral valves and a severe right unilateral vesicoureteral reflux. He had PUV ablation with Mohan's valvotome and made satisfactory post operative recovery with indication on follow-up of preservation of renal function.
Related Concept Videos
Imaging Studies V: Intravenous Urography and Retrograde Pyelography
Imaging Studies VI: Voiding Cystourethrography and Cystography
Microbiota of the Urogenital Tract
Anatomy of the Genitourinary System II: Bladder and Urethra
Urinary Tract Calculi II: Pathophysiology and Clinical Manifestations
The Micturition Reflex
The process begins with bladder filling, where the bladder wall stretches as urine accumulates. This stretching activates the urine storage reflex, mediated by the sacral spinal segments and the pontine storage center. Efferent sympathetic impulses stimulate the detrusor muscle to relax and the internal urethral sphincter to contract, facilitating...

