Which urinary diversion device is used for large kidney stones obstructing the ureter?

• A. Urinary catheter
• B. Nephrostomy
• C. Colostomy
• D. Suprapubic catheter

Answer: (B)

The use of a nephrostomy for large kidney stones obstructing the ureter is based on its specific function in managing urinary obstruction. Nephrostomy involves placing a tube into the kidney to allow urine to drain directly from the kidney into a collection bag outside the body. This is particularly useful when there are obstructions, such as large kidney stones, which can block the normal flow of urine through the ureters.

When a stone obstructs the ureter, a nephrostomy can bypass the obstruction, thereby relieving pressure on the kidney and preventing further complications, such as kidney damage or infection. This intervention helps maintain kidney function while addressing the underlying issue of the obstruction, allowing for subsequent treatment of the stones.

In contrast, other urinary diversion devices like urinary catheters, suprapubic catheters, and colostomies do not serve the same specific purpose as a nephrostomy in the case of obstructive nephropathy caused by stones. Urinary catheters typically drain urine from the bladder rather than addressing issues in the upper urinary tract, while suprapubic catheters are inserted into the bladder for similar drainage purposes. Colostomy is unrelated to the urinary system, as it diverts the colon. Thus,