Which is not a feature of posterior urethral valve:
**Core Concept**
Posterior urethral valves (PUV) are congenital urethral obstructions in male infants, leading to urinary retention, bladder dysfunction, and potential renal impairment. The pathophysiology involves the abnormal development of the urethral mucosa and the surrounding spongy tissue.
**Why the Correct Answer is Right**
Posterior urethral valves are characterized by a triad of symptoms: obstructive uropathy (urinary retention), bladder dysfunction (detrusor hypertrophy), and potential renal impairment (chronic kidney disease). The presence of PUVs disrupts normal urine flow, causing increased bladder pressure and potentially leading to renal damage.
**Why Each Wrong Option is Incorrect**
**Option A:** Obstruction of urine flow at the bladder neck is a feature of PUV, not a distinguishing characteristic.
**Option B:** Bladder dysfunction is a hallmark of PUV, manifesting as detrusor hypertrophy and impaired bladder compliance.
**Option C:** Renal impairment is a potential complication of untreated PUV, resulting from chronic obstruction and increased bladder pressure.
**Clinical Pearl / High-Yield Fact**
The classic triad of PUV includes obstructive uropathy, bladder dysfunction, and potential renal impairment. Remember the mnemonic "OBSTRUCT" to recall the key features: Obstruction, Bladder dysfunction, Chronic kidney disease, Urinary retention, Stricture, Tract damage.
**Correct Answer: C. Renal impairment is a potential complication of untreated PUV, resulting from chronic obstruction and increased bladder pressure.