Which medical condition may lead to the need for a nephrostomy tube?

A nephrostomy tube is used to drain urine directly from the kidney when normal urinary flow is obstructed. The condition that most commonly necessitates this intervention is obstructive uropathy. This condition can arise from various causes, such as tumors, strictures, or stones that block the urinary tract, preventing urine from flowing from the kidney to the bladder.

By placing a nephrostomy tube, healthcare providers can relieve pressure from the kidney, allowing urine to exit the body and preventing further renal damage or complications. This procedure is critical as it helps in managing potential kidney injury and enables subsequent treatment for the underlying cause of the obstruction.

In contrast, while renal calculus (kidney stones) can lead to obstructive uropathy, not all cases of renal stones require nephrostomy placement — only when there's a significant obstruction and kidney compromise. Urinary incontinence and urinary retention typically do not result in the need for nephrostomy tubes; incontinence usually involves the bladder rather than an obstruction affecting the kidney, and urinary retention can often be managed through other means, such as catheterization or medications.