What is a Percutaneous Nephrostomy?
The urinary system clears the body of metabolic waste products and other molecules from the bloodstream. The kidney filters the blood and sends urine to the bladder through a long muscular tube called the ureter.
There are two kidneys and ureters, on the right and left side of the lower back. One or both ureters can become blocked for various reasons, and require an intervention to relieve the obstruction. A ureter that remains blocked endangers the health of the kidney. In the short term, blocked urine presents a risk of serious infection and in the long term, the kidney may lose its ability to make urine. If both kidneys are blocked the body has no way to be rid of urinary waste.
There are three ways that ureters can be unblocked – urologic surgery, cystoscopy (done by a urologist doctor using a tube or cystoscope placed into the bladder), or a percutaneous (through the skin) nephrostomy performed by an interventional radiology doctor. In general, a nephrostomy drainage is done when cystoscopy has been unsuccessful or is not considered appropriate.
A nephrostomy is a plastic tube placed through the skin and directly into the kidney, allowing the urine from that kidney to exit the body into a plastic collection bag. This is usually a temporary remedy, allowing the urologist to decide on the best long term solution.
How should I prepare?
Before the procedure, you will have blood tested to determine how well your blood clotting is functioning. You should inform your doctor of all medications you are taking, including any herbal supplements. Inform us of any allergies, particularly to local or general anesthetic medications or to contrast materials (sometimes called X-ray dye) or to latex gloves. Always inform your doctor if you are or may be pregnant.
Eat a light meal the evening before. You will be instructed not to eat or drink after midnight before the procedure, and if you are diabetic you should receive instructions from your doctor about adjusting medications and insulin dose on the day of the procedure. You will likely be asked to remove your clothing and wear a gown during the procedure. You will need a ride home with a friend or relative.
How is the procedure performed?
The patient will be positioned on a fluoroscopy table where real-time X-ray imaging can be done. After the skin is cleansed and local anesthetic given, ultrasound and fluoroscopy are used to place a very thin, long needle through the skin and into the kidney. Once the tip of the needle is in the kidney, the needle will be exchanged over a wire for a thin plastic catheter, which is then coiled in the urine collecting system.
Decisions about the next step of care will be made after the patient has recovered from the procedure and the anesthesia.
What will I experience during and after the procedure and when will I get my results?
The sedation will make you very drowsy and relaxed. The local anesthetic will sting at the skin entry. The placement of the catheter through the kidney into the ureter may mild discomfort. The catheter placement occasionally comes very close to a rib and can result in a pain with movement, but this generally resolves in a few days. Pain medications may be given.
The interventional radiologist will inform you whether the procedure has been a technical success.
What are the benefits and risks?
The most immediate benefit of unblocking the ureter is to decrease the risk of serious urinary infection. However, the procedure may cause an immediate wave of bloodstream infection which will be known by shaking chills and fever, and uncommonly a life-threatening illness known as sepsis. To prevent or decrease the severity of this reaction, you will be given IV antibiotics before the start of the procedure, and you will be managed in an intensive care setting after the procedure if there is any sign of infection.
When both ureters are blocked, the immediate goal is to allow recovery from acute renal failure. Uncommonly, the goal of nephrostomy is to divert urine away from a ureter or bladder that may be injured and leaking, to allow for healing.
The placement of a nephrostomy catheter is a first step and usually will be followed by other procedures or surgery. Occasionally, however, the overall situation may be that the plastic nephrostomy is left in place for a long time, and then would require specific techniques to manage the catheter.
Any procedure that requires puncturing the kidney carries a roughly 1 percent risk of serious internal bleeding requiring transfusion. Rarely, another procedure is required if such bleeding does not stop.
Radiologyinfo.org for Patients
The radiology information resource for patients. RadiologyInfo.org tells you how various X-ray, CT, MRI, ultrasound, radiation therapy and other procedures are performed. It also addresses what you may experience and how to prepare for the exams. The website contains over 200 procedure, exam and disease descriptions covering diagnostic and interventional radiology, nuclear medicine, radiation therapy and radiation safety and is updated frequently with new information. All material on the RadiologyInfo.org website is reviewed and approved by experts in the field of radiology from the ACR and RSNA, as well as other professional radiology organizations.