A PCN tube, short for percutaneous nephrostomy tube, is a small flexible catheter placed through your skin and into your kidney to drain urine. It bypasses the normal path urine takes from the kidney through the ureter and into the bladder, instead routing it directly out of your body into an external drainage bag. The tube is inserted through your back or side, typically under imaging guidance, and can stay in place for days, weeks, or longer depending on the underlying problem.
Why a PCN Tube Is Needed
The most common reason for a PCN tube is a blocked urinary tract. When urine can’t drain from the kidney normally, pressure builds and can damage the kidney or lead to dangerous infections. Relief of urinary obstruction accounts for 85 to 90% of all PCN placements. The three most frequent causes of that blockage in adults are kidney stones, cancer, and scar tissue from previous surgery or procedures. In large studies, about 61% of nephrostomy tubes were placed because of a malignancy blocking the urinary tract, and 26% because of kidney stones.
An infected, obstructed kidney is treated as an emergency. Trapped infected urine creates a high risk of sepsis and can permanently damage kidney function in a short time. In these cases, a PCN tube provides immediate drainage while the underlying cause is addressed.
Beyond obstruction, PCN tubes serve several other purposes:
- Urinary diversion: When urine needs to be rerouted away from the bladder, such as after a ureteral injury during pelvic surgery, a urinary fistula, or severe bladder bleeding caused by chemotherapy or radiation.
- Access for procedures: The tube tract can be used as a pathway to remove kidney stones, place stents, dilate narrowed ureters, retrieve broken stent fragments, or deliver medications directly to the kidney.
- Diagnostic testing: When imaging alone can’t confirm whether a blockage exists, doctors can inject contrast dye through the tube to visualize the urinary tract or run pressure tests to measure flow.
How the Tube Is Placed
You’ll lie face down or on your side for the procedure. A radiologist uses ultrasound to locate the kidney and find the best entry point on your back, then checks with a separate type of imaging called fluoroscopy (real-time X-ray) to make sure the puncture site avoids the ribs and surrounding structures. A thin needle is guided into the kidney’s collecting system under ultrasound, and a small amount of urine is drawn out to confirm correct positioning.
A contrast dye is then injected so the radiologist can see the kidney’s internal anatomy on X-ray. A fine guidewire is threaded through the needle and into the ureter, the needle is removed, and the tract is gradually widened to accommodate the catheter. The tube itself has a curved “pigtail” tip that coils inside the kidney to keep it from slipping out. The outer end connects to a drainage bag strapped to your leg or hung at your bedside. The whole process is done under local anesthesia with sedation, and typically takes under an hour.
Most PCN tubes range from 8 to 14 French in diameter (roughly 2.7 to 4.7 millimeters) and are about 25 centimeters long.
What Recovery Looks Like
Hospital stays after PCN placement vary. If the tube is placed as part of a stone removal procedure, you can expect 1 to 2 days in the hospital. For simpler drainage-only placements, the stay may be shorter. Some soreness at the insertion site is normal for the first few days. You’ll typically need to avoid heavy lifting, pushing, or pulling for 2 to 4 weeks, and many people return to work within about a week.
Blood-tinged urine is common right after placement and usually clears within a day or two. If you have significant pain that doesn’t respond to medication, that’s a reason to contact your care team promptly.
Caring for a PCN Tube at Home
Living with a PCN tube takes some adjustment, but most people manage daily routines well once they learn the basics. The key priorities are keeping the site clean, securing the tube, and monitoring drainage.
Empty the drainage bag when it’s half to three-quarters full, or at least once a day if it doesn’t fill that much. A bag that gets too heavy can pull on the tube and cause discomfort. Wash your hands thoroughly with soap and water before and after handling the bag or site. Leave the original hospital dressing in place until a nurse checks and replaces it, and plan on weekly site checks to confirm the skin around the tube stays clean, dry, and free of infection.
Showering is fine after the first 48 hours, but you’ll need to change the dressing immediately afterward. Baths and swimming are off limits because submerging the site raises infection risk. A securement device or support belt helps keep the tube from catching on clothing or shifting during movement. Some people find that placing a hand over the tube site when climbing stairs or bending down reduces discomfort. Vigorous exercise, rough physical activity, and sudden movements should be avoided for at least several days, and often longer depending on your situation.
Possible Complications
PCN tubes are generally safe, but complications can occur both during placement and while the tube is in place. Procedural risks include bleeding, infection, and urine leaking around the tube. After placement, the most common ongoing issues are tube blockage and dislodgement. Catheter dislodgement rates in published studies range from about 1% to as high as 37%, depending on the patient population and how long the tube stays in. One large analysis of 742 procedures found a dislodgement rate of 5.1%.
Tubes are periodically replaced on a schedule to prevent blockage from buildup and to reduce the risk of kidney infection. Your care team will set a replacement timeline based on how long the tube is expected to stay in.
Signs that something needs attention include fever or chills, cloudy or foul-smelling urine, increasing pain around the tube site, redness or swelling at the skin entry point, urine leaking around the tube rather than draining into the bag, or a sudden stop in drainage. If the tube falls out or gets pulled significantly out of position, that needs prompt medical evaluation since the tract can close quickly.
How a PCN Tube Is Removed
When the underlying problem has been resolved, your doctor will test whether urine can flow normally again before taking the tube out. This involves clamping the tube shut for 24 to 36 hours so urine is forced back through the natural route, from kidney to ureter to bladder. During this trial, you’re monitored for pain, fever, or any sign that urine is backing up. If you tolerate the clamping well and an X-ray confirms the urinary tract is draining properly, the tube is pulled out. Removal itself is quick and done at the bedside or in a clinic. The small skin tract typically closes on its own within a day or two, and you’ll be advised to avoid strenuous activity, baths, and swimming for at least a few days afterward.
For people whose obstruction can’t be fully resolved, such as those with advanced cancer pressing on the ureter, the PCN tube may remain long-term and be exchanged on a regular schedule to keep it functioning.