Nephrostomy tube

A nephrostomy tube is a thin, flexible plastic drain, about the width of a pencil lead to a drinking straw. One end sits inside the part of the kidney where urine collects. The other end comes out through the skin of your back and connects to a drainage bag. The tip inside the kidney curls into a small loop so it stays in place.

Doctors often call it a percutaneous nephrostomy, or PCN. Percutaneous means through the skin. The tube gives urine a way out when its normal path, the ureter, is blocked. You can read more about blocked kidneys on our interventional urology page.

What we see

A urologist can sometimes place a ureteral stent from below, through the bladder, using a small camera. That leaves nothing outside your body, but it usually needs general anesthesia, and it may not work when a tumor or scar blocks the way. A nephrostomy tube works in almost every case, and it drains infection quickly.

Many people start with a nephrostomy tube and later switch to a nephroureteral stent or a fully internal stent once the kidney has settled.

If your kidney is infected, there may be little time to prepare. In that case the tube is often placed urgently, sometimes within hours. Our before your procedure and sedation pages explain the general steps.

1. 1
   Getting ready

   You lie on your stomach or side on the X-ray table. A nurse gives you sedation through your IV and connects monitors for your heart, blood pressure and oxygen.

2. 2
   Numbing and finding the kidney

   We clean the skin of your back and numb it with local anesthetic. Using ultrasound and X-ray, we guide a thin needle into the part of the kidney where urine collects.

3. 3
   Placing the tube

   A soft guidewire goes through the needle, and the tube slides over the wire into the kidney. We inject a little contrast dye to check its position. Urine usually starts to drain right away.

4. 4
   Securing it

   The tube is held with a small stitch or an adhesive holder and covered with a dressing. It is connected to a drainage bag, and you go to recovery.

The whole procedure usually takes 20 to 30 minutes. You may feel pressure and a brief deep ache as the tube goes in. Afterward, you rest for about an hour while nurses watch you. You can eat and drink once you are awake.

1. First day
   Rest at home. No driving, alcohol or big decisions after sedation. Light meals if you feel queasy.
2. First week
   Pink urine, like rosé wine or cranberry juice, is normal. The site is sore for 2 to 3 days. Acetaminophen (Tylenol) usually helps.
3. After 24 hours
   Most normal activities, including driving, are fine. Avoid heavy lifting and hard exercise for the first day or two.
4. Every day
   Keep the bag below the kidney, check that the tubing is not kinked, and empty the bag when it is half full.
5. Every 8 to 12 weeks
   The tube is changed over a wire in a short visit, usually without a new needle stick.

You can shower from the first night. It is fine if the tube gets wet. Afterward, dry the area and put on a fresh dressing. Do not soak in a bath, hot tub, pool or the ocean while the tube is in. A leg bag or belly holder can make the tube easier to hide under clothes. See home supplies and our general guide to managing your drain.

Most people do not need to flush the tube. If the urine is very bloody or clotted, or drainage suddenly stops, we may teach you to flush it with 5 to 10 mL of sterile saline using a syringe and a three-way valve called a stopcock. Only flush if we have shown you how.

The tube stays until the cause of the blockage is fixed, for example after a stone is removed or an infection clears. For some people, especially with cancer, it may stay for months or longer. In that case we change it every 8 to 12 weeks, because minerals and debris slowly clog the tube.

When it is time to remove it, we usually do this under X-ray. We inject dye to be sure urine now flows freely to the bladder. Removal takes a few minutes and feels like a brief tug. The small hole usually seals within a day or two.

When someone comes in with a fever and a blocked kidney, I tell the family that this small tube is often the most important thing we do that day. Once the kidney is drained and the antibiotics can work, most people feel much better within a day or two. Then we sit down together and plan how to get you to the least tubing you need.

Fabio Komlos, MD, interventional radiologist · About Dr. Fabio Komlos

A nephrostomy is a common and generally safe procedure. Serious problems are uncommon, but you should know about them.