A nephrostomy tube is a medical device designed to drain urine directly from a kidney. This thin, flexible catheter is inserted through the skin into the kidney, providing an alternative pathway for urine flow. It serves as a temporary measure to manage conditions that obstruct the normal urinary drainage system. The tube connects the kidney to an external collection bag.
Why a Nephrostomy Tube is Needed
A nephrostomy tube becomes necessary when the normal flow of urine from a kidney is blocked or impaired, preventing it from reaching the bladder. This obstruction can lead to urine backing up into the kidney, causing swelling, pain, and potentially damaging the kidney function over time. The primary goal of placing a nephrostomy tube is to relieve this pressure and allow the kidney to function properly, preventing infection.
Kidney stones (nephrolithiasis) are a common cause, as they can block the ureter, the tube connecting the kidney to the bladder. Tumors, such as those arising from the bladder, prostate, or kidneys, can also compress or invade the ureters, impeding urine flow. Other causes include strictures (narrowing) in the ureters, blood clots, or swelling following kidney surgery. Infections that cause obstruction, like pyonephrosis, also require drainage.
How a Nephrostomy Tube Works
The placement of a nephrostomy tube involves a minimally invasive procedure, typically performed by a radiologist using imaging guidance. The patient usually lies face down, and the skin on the lower back is numbed with a local anesthetic. An interventional radiologist then uses imaging techniques, such as ultrasound or fluoroscopy (a type of X-ray), to precisely locate the kidney and guide the insertion of a fine needle.
Once the needle is accurately positioned within the kidney’s urine-collecting system, a guidewire is advanced through it. The needle is then removed, and the nephrostomy tube, a catheter, is threaded over the guidewire into the kidney. The tube is secured to the skin, often with stitches or an adhesive dressing, and its external end is connected to a drainage bag. This setup allows urine to bypass the obstruction.
Caring for a Nephrostomy Tube
Caring for a nephrostomy tube involves daily routines. Keeping the insertion site clean and dry is important to prevent infection. Dressings around the tube typically need to be changed regularly, often at least once a week, or more frequently if they become wet or soiled.
The drainage bag should be emptied when it is about half full to prevent excessive weight from pulling on the tube and to avoid urine backing up. Ensure the drainage bag remains below the level of the kidney to promote continuous urine flow. Patients are generally advised to drink plenty of fluids to help maintain urine production and reduce the risk of tube blockage.
Common Concerns and Removal
Minor discomfort or pain at the insertion site, along with some bruising, is common in the days following placement and usually improves with time and pain medication. Pink or blood-tinged urine is normal for up to 48 hours after the procedure. More serious complications include infection, tube dislodgement, or leakage around the site.
Signs of infection include fever, chills, increased pain, redness, swelling, or foul-smelling drainage from the site or in the urine. If the tube accidentally comes out or if there is a significant decrease in urine output, immediate medical attention is necessary.
A nephrostomy tube is a temporary solution, removed once the underlying blockage is resolved. The removal process is straightforward; a healthcare provider numbs the area with a local anesthetic and gently withdraws the tube. A dressing is then applied to the site, which usually heals quickly, though minor leakage may occur for a short period.