Posterior urethral valve (PUV) is a congenital anomaly of the urethra (urinary tract) found only in male children. It refers to the presence of an abnormal flap-like structure inside the urethra that should not be there. This flap obstructs the normal flow of urine, blocking urine exit. It often presents with symptoms in the newborn period. If diagnosis and treatment are delayed, it can lead to serious problems involving the kidneys and bladder.

PUV is one of the most common congenital urological anomalies in male children. Its incidence in the population is approximately 1 in 5,000. Although the prevalence varies, it is more common in boys than often expected.

Types

PUV is generally classified into two main types.

• The classic type features a valve at the posterior urethra that completely obstructs urine flow. This causes urine to accumulate in the bladder, disrupting its normal structure. The pressure from the accumulated urine can damage the kidneys, potentially causing permanent loss of kidney function. About 90% of babies with PUV have this classic type.
• The less common and milder type has a thinner valve that allows some urine to pass. This type progresses more slowly and is more difficult to diagnose.

Symptoms

Most patients are diagnosed during routine prenatal ultrasound examinations. Findings such as decreased amniotic fluid (oligohydramnios) and a persistently full fetal bladder strongly suggest the diagnosis. If the condition is not diagnosed during pregnancy, initial evaluation after birth includes assessing the baby’s symptoms and physical examination findings.

Families often report decreased urine output or that the baby is unable to urinate. If the baby does urinate, it is usually in small drops, dark-colored, and foul-smelling. Babies with PUV may be irritable and have poor feeding. On physical examination, the bladder is often palpable as a swollen mass in the lower abdomen. Both kidneys may also be enlarged and palpable on the sides of the abdomen.

When PUV is suspected, the first investigations are ultrasound and urinalysis. Ultrasound findings showing enlarged kidneys, ureters (urine tubes between kidneys and bladder), and a distended, urine-filled bladder are highly indicative. If these findings are present, a voiding cystourethrogram (VCUG) is performed to confirm the diagnosis. This involves inserting a catheter into the baby’s urethra, filling the urinary tract with a contrast agent, and taking X-ray images.

Treatment

The treatment involves early cystoscopy (insertion of a camera into the urinary tract without incision) and ablation of the posterior urethral valve (cutting and removing the obstructing valve to restore urine flow). Babies suspected of having PUV during pregnancy or within the first few hours after birth should be referred to a center with obstetrics-perinatology, neonatal intensive care, and pediatric surgery services. The baby usually requires monitoring in the neonatal intensive care unit before and after surgery. Early intervention improves outcomes significantly.

Babies who undergo timely and appropriate surgery can live completely normal lives. Delayed diagnosis or inadequate treatment may result in permanent bladder and kidney damage, with risks of early loss of kidney function or lifelong treatment needs. These babies often struggle with urinary continence. Untreated PUV increases the risk of recurrent urinary tract infections and urethral strictures. If diagnosed early, all babies can be treated cystoscopically without the need for open surgery.

Rarely, PUV may recur, but experienced centers maintain very low recurrence rates. Such centers can regularly monitor the child and promptly address any complications before they cause significant problems.

Posterior urethral valve, if untreated, has the potential to cause serious health issues. Therefore, early diagnosis and appropriate surgical intervention are critical. If you suspect your child may have PUV, it is important to see a pediatric surgeon promptly.

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