What are Ureteral Stenting and Nephorstomy?
A ureteral stent is a thin, flexible tube threaded into the ureter. When it is not possible to insert a ureteral stent, nephorstomy is performed. During this procedure, a tube is placed through the skin on the patient’s back into the kidney. The tube is connected to an external drainage bag or from the kidney to the bladder.
How should I prepare?
You may have blood drawn prior to your procedure.
Prior to your procedure, your blood may be tested to determine how well your liver and kidneys are functioning and whether your blood clots normally.
You should report to your doctor all medications that you are taking, including herbal supplements, and if you have any allergies, especially to local anesthetic medications, general anesthesia or to contrast materials (also known as “dye” or “x-ray dye”). Your physician may advise you to stop taking aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs) or a blood thinner for a specified period of time before your procedure.
Also inform your doctor about recent illnesses or other medical conditions.
Women should always inform their physician and x-ray technologist if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to radiation. If an x-ray is necessary, precautions will be taken to minimize radiation exposure to the baby.
In general, you should not eat or drink for eight hours before your procedure. However, you may take your routine medications with sips of water. If you are diabetic and take insulin, you should talk to your doctor, as your usual insulin dose may need to be adjusted.
You will be given a gown to wear during the procedure.
You should plan to have a relative or friend drive you home after your procedure.
What does the equipment look like?
During ureteral stenting, a fluoroscope and a guide wire are used to place a stent down the ureter.
A guide wire may be inserted with the aid of a fluoroscope, an imaging device that uses x-rays to see structures on a fluorescent screen.
A stent is five to 10 inches long and less than a quarter inch thick.
During a nephorstomy, a fluoroscope, or an ultrasound, and a needle are used to place a catheter in the kidney.
A catheter is a long, thin plastic tube, about as thick as a strand of spaghetti.
Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a transducer that is used to scan the body and blood vessels. The transducer is a small hand-held device that resembles a microphone, attached to the scanner by a cord. The transducer sends out high frequency sound waves into the body and then listens for the returning echoes from the tissues in the body. The principles are similar to sonar used by boats and submarines.
The ultrasound image is immediately visible on a nearby video display screen that looks much like a computer or television monitor. The image is created based on the amplitude (strength), frequency and time it takes for the sound signal to return from the patient to the transducer and the type of body structure the sound travels through.
Other equipment that may be used during the procedure includes an intravenous line (IV) and equipment that monitors your heartbeat and blood pressure.
How are these procedures performed?
Image-guided, minimally invasive procedures such as ureteral stenting and nephrostomy are most often performed by a specially trained interventional radiologist in an interventional radiology suite or occasionally in the operating room.
This procedure is often done on an outpatient basis. However, some procedures may require admission. Please consult with your physician.
Prior to your procedure, ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) may be performed.
You may be given medications to help prevent nausea and pain, and antibiotics to help prevent infection.
You will be connected to monitors that track your heart rate, blood pressure and pulse during the procedure.
A nurse or technologist will insert an intravenous (IV) line into a vein in your hand or arm so that sedative medication can be given intravenously. You may also receive general anesthesia.
If you receive a general anesthetic, you will be unconscious for the entire procedure, and you will be monitored by an anesthesiologist.
The area of your body where the catheter is to be inserted will be shaved, sterilized and covered with a surgical drape.
Your physician will numb the area with a local anesthetic.
The interventional radiologist will use x-rays and/or ultrasound to locate your kidney and a needle will be inserted through your skin into the kidneys. Contrast dye will be injected through the needle.
During ureteral stenting, you will be positioned on your stomach. Using a fluoroscope to see inside the ureter, a guide wire is inserted into the ureter. The stent is run over the guide wire and placed in its permanent position within the ureter. Once the stent has been placed, the guide wire may be removed, or a nephrostomy catheter may be left in place for a day or two and then removed.
At the end of the procedure, the catheter will be removed and pressure will be applied to stop any bleeding. The opening in the skin is then covered with a dressing. No sutures are needed.
During nephorstomy, you will be positioned on your stomach. Using a fluoroscope to see inside the kidney a guide wire is inserted into the kidney, followed by a catheter. This will be left in place until a ureteral stent can be placed or the ureteral blockage is resolved.
Your intravenous line will be removed.
Both procedures are usually completed within one hour.
What will I experience during and after the procedure?
Devices to monitor your heart rate and blood pressure will be attached to your body.
You will feel a slight pin prick when the needle is inserted into your vein for the intravenous line (IV) and when the local anesthetic is injected.
If the case is done with sedation, the intravenous (IV) sedative will make you feel relaxed and sleepy. You may or may not remain awake, depending on how deeply you are sedated.
You may feel the catheter going into the kidney and down the ureter. During placement of a ureteral stent, you may feel the guide wire go into the bladder until the stent is placed.
You will remain in the recovery room until you are completely awake and ready to return home.
As the contrast material passes through your body, you may get a warm feeling.
You will not feel when the contrast is excreted into the urine.
You should be able to resume your normal activities within a few days.
Who interprets the results and how do I get them?
The interventional radiologist can advise you as to whether the procedure was a technical success when it is completed.