How is posterior urethral valve (PUV) diagnosed and treated?

From the Guidelines

Posterior urethral valve (PUV) is diagnosed through a combination of prenatal ultrasound, postnatal imaging studies, and cystoscopy, with voiding cystourethrogram (VCUG) being the key diagnostic tool, as it shows dilation of the posterior urethra and often reflux of urine into the ureters 1. The diagnosis of PUV typically begins with prenatal ultrasound screening, where hydronephrosis, dilated bladder, or oligohydramnios may be detected. After birth, VCUG is used to confirm the diagnosis, as it provides detailed images of the urethra and bladder. Renal ultrasound is also essential in assessing kidney damage, while cystoscopy allows for direct visualization of the valve leaflets. Some key points to consider in the diagnosis and treatment of PUV include:

• The importance of early diagnosis and treatment to prevent long-term kidney damage and other complications 1
• The use of VCUG as a diagnostic tool to identify VUR and other urinary tract abnormalities 1
• The need for immediate bladder drainage using a urethral or suprapubic catheter to prevent further kidney damage 1
• The role of endoscopic valve ablation as a definitive treatment for PUV, typically performed within the first few days or weeks of life 1
• The importance of long-term management and follow-up to monitor for complications and prevent progressive renal damage 1 It is essential to note that the treatment and management of PUV should be individualized based on the severity of the condition and the presence of any complications. The most recent and highest quality study 1 emphasizes the importance of early intervention and long-term follow-up in improving outcomes for children with PUV.

From the Research

Diagnosis of Posterior Urethral Valve (PUV)

• The diagnosis of PUV is typically made by a combination of voiding symptoms, ultrasonography, and confirmed by voiding cysto-urethrogram (VCUG) 2, 3, 4.
• Voiding symptoms may include poor stream, straining at voiding, dribbling of urine, fever, and urinary retention 2.
• Ultrasonography may show normal results or renal or vesical disorders, but VCUG is necessary to confirm the diagnosis 3.
• Urodynamic studies may also be performed to assess bladder function and detect any obstructive patterns 3, 5.

Treatment of Posterior Urethral Valve (PUV)

• The current gold standard therapy for PUV is endoscopic ablation of posterior urethral valves using cold knife or laser 2.
• Valve ablation is typically performed after clinical stability, and is no longer considered an emergency procedure after birth 5.
• Re-look cystoscopy is recommended at 3 months after primary fulguration to check for residual valves or urethral stricture 2.
• Long-term follow-up is necessary to monitor bladder function and prevent progressive bladder dysfunction, which can cause deterioration of the upper urinary tract 5.

Assessment of Treatment Success

• The urethral ratio on VCUG can be used as a quantitative measurement to assess success of posterior urethral valve ablation 6.
• A post-fulguration urethral ratio of 2.5-3 represents an acceptable result postoperatively 6.
• Re-look cystoscopy and VCUG can be used to evaluate the success of treatment and detect any residual obstruction or complications 2, 3.