Hi, this is Tom, and in this episode I'm going to be going through posterior urethral valve.

And you can find notes at zero to finals.com and in the zero to finals pediatrics book.

And you can find flashcards and questions at members.0.0 tofinals.com.

And at the end of the episode, we'll go through some questions to test you on what you just heard. So let's jump straight in. A posterior

urethral valve is where there is tissue at the proximal end of the urethra near the outlet of the bladder that obstructs the flow of urine

out of the bladder. It only occurs in males. The obstruction to the outflow of urine creates

back pressure into the bladder, the ureters, and up to the kidneys. This causes bladder distension,

visicohuretural reflux, or V-U-R, which is reflux of urine from the bladder to the ureters,

hydro ureter, which is swelling of the ureters, and hydronephrosis, which is swelling of the

renal pelvis and calices in the kidney. The restriction prevents the bladder from fully emptying,

which increases the risk of urinary tract infections.

Let's talk about the presentation.

Mild cases may be asymptomatic.

More significant cases can present with difficulty passing urine,

weak urinary stream,

chronic urinary retention, a palpable bladder on examination,

recurrent urinary tract infections, and impaired kidney function.

Severe cases can cause obstruction to the urine outflow in the developing fetus during pregnancy,

which results in bilateral hydronephrosis, with swelling of the kidneys,

and oligohydramnius, which is low amniotic fluid volume.

Oligohydramnius can lead to undeveloped fetal lungs, which is called pulmonary hypoplasia,

causing breathing difficulties after birth.

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