Posterior urethral valves (or PUV) refer to an abnormality of the urethra, i.e. the tube which drains urine from the bladder to the outside of the body. The abnormality happens when narrow slits or small openings in the urethral valves, partially obstructs the outflow of urine. As a result, reverse flow takes place. This can drastically impact the various urinary tract organs including the urethra, bladder, ureters, and kidneys. These organs get over-filled with urine, resulting in inflammation and tissue and cell damage.
PUV, the most common cause of urinary tract obstruction in children, originates in the initial stages of fetal development. This abnormality impacts only male infants and happens only one in 8,000 births. Though it is a sporadic disorder, in certain cases, even twins and siblings develop this condition due to genetic reasons.
The most common symptoms of posterior urethral valves include:
- An enlarged bladder that could be detected through the abdomen as a huge mass
- Urinary tract infection, or UTI
- Pain or difficulty while urinating
- Weak stream of urine
- Frequency in Urinating
- Poor weight gain
Diagnosis of posterior urethral valves
The severity of PUV determines the diagnosis. Quite often, PUV are diagnosed using fetal ultrasound when a woman is still pregnant. Children, who have been diagnosed later with PUV, have developed urinary tract infections. So, it is always better to consult a child’s physician for diagnosis.
Some of the diagnostic tests include:
- Abdominal ultrasound – Abdominal ultrasound is a diagnostic imaging technique that makes use of high-frequency sound waves and a computer to produce images of blood vessels, tissues, and organs. Ultrasounds are primarily used to view the functioning of the internal organs, and to precisely assess the flow of blood through blood vessels.
- Voiding cystourethrogram (VCUG) – Voiding cystourethrogram is a specific x-ray that helps to examine the urinary tract. A catheter is positioned in the urethra and the bladder is filled with a liquid dye. X-ray images are produced as the bladder gets filled and empties. The images will reveal whether or not any reverse flow of urine is taking place into the ureters and kidneys.
- Endoscopy – It is a test that makes use of an endoscope to accurately examine the interior regions of the urinary tract. Tissue samples collected from inside the urinary tract are used for further testing.
- Blood test is performed to precisely assess the electrolyte of the child and to determine the function of the kidney.
Treatment for posterior urethral valves:
- Supportive care
The initial treatment may focus on relieving the symptoms of the child. In case the child has urinary tract infection, is dehydrated or has electrolyte irregularities, treatment would be prescribed to alleviate these conditions. The child may be administered antibiotic therapy and intravenous (IV) fluids.
- Endoscopic ablation
In this procedure, the urologist will insert an endoscope i.e. a small, thin, flexible tube equipped with a light and a camera lens at the end. He will then cautiously examine the obstruction and remove the valve leaflets through a minor incision.
A Vesicostomy is a small opening created in the bladder through the abdomen. This opening is usually repaired some time later when the valves can be cut in a safer manner.