What is a key feature of a nephroureteral drain?

A nephroureteral drain is specifically designed to manage urinary tract obstruction by providing both drainage from the kidney and the ureter. One of its defining characteristics is the double J configuration, also known as a ureteral stent configuration. This design includes two curves, one at the renal pelvic end and one at the bladder end, which helps to maintain position without causing injury to the ureter.

The double J configuration is critical for ensuring that the drain remains in place while allowing for adequate drainage of urine from the renal system through the ureter and into the bladder. This is particularly important in cases where normal urinary flow is disrupted due to factors such as stones, strictures, or swelling.

The other options do not accurately describe the nephroureteral drain's characteristics. For example, it is not limited to pediatric patients; it is used in a wide range of adult patients as well. Additionally, it does not emerge solely from the skin, as it is designed to fit within the urinary tract, and while it may facilitate bladder irrigation indirectly, that is not its primary function. Therefore, the defining feature of the nephroureteral drain is indeed its double J configuration.