Urology - Posterior Urethral Valve

Question 1

What is a posterior urethral valve?

Answer 1

Where tissue at proximal urethra causes obstruction of urine output

Occurs in new-born boys

Question 2

What does a posterior urethral valve lead to?

Answer 2

Obstruction of the urine outflow causes back pressure into the bladder, ureters and up to the kidneys - causing hydronephrosis

Restriction in urine outflow prevents that bladder emptying fully

Increases UTI risk

Question 3

How does a posterior urethral valve present?

Answer 3

• Difficulty urinating
• Weaking stream
• Chronic retention
• Palpable bladder
• Recurrent UTIs
• Impaired kidney function

Question 4

What do severe cases of PUV lead to?

Answer 4

Obstruction to outflow in developing foetus causing bilateral hydronephrosis and oligohydramnios

Oligohydramnios leads to pulmonary hypoplasia

Question 5

What investigations are used for PUV?

Answer 5

Severe cases can be picked up on antenatal scans as oligohydramnios and hydronephrosis

• Abdominal USS - enlarged, thickened bladder and bilateral hydronephrosis
• MCUG- shows location of extra urethral tissue and reflux of urine back into bladder
• Cystoscopy- ablate or remove extra tissue

Question 6

How is PUV managed?

Answer 6

Mild can be observed and monitored

Catheter can be used to bypass while waiting for definitive management

Definitive management- ablation or removal of extra urethral tissue during cystoscopy