Percutaneous urinary procedures are used to drain urine and remove kidney stones that are too large to pass from your body by way of the urinary tract (ureters, bladder, and urethra). There are two such procedures: percutaneous nephrostomy and percutaneous nephrostolithotomy or nephrolithotomy. “Percutaneous” means through the skin.
To perform these procedures, your doctor will insert a needle through a small incision in your back and then into your kidney. After the needle is in place, either a flexible tube (a catheter) or a specialized instrument will be threaded through the needle and into the kidney. When a catheter is used, the procedure is called percutaneous nephrostomy. When an instrument is used, the procedure is called percutaneous nephrostolithotomy or nephrolithotomy. Your doctor can insert an instrument called a nephroscope to view the stones in your kidney and break them into smaller pieces.
Your doctor may recommend one of these procedures for any of the following reasons:
- to relieve pain after treatment for kidney stones
- to help urine drain from the kidney if the flow is blocked by a stone
- to treat a kidney stone that is too large to pass out of the body through the normal passage of urine
- to treat kidney stones that are causing infection or leakage of urine into your body
- to treat kidney damage
These procedures are typically performed in a hospital. You will be asked to fast (stop eating and drinking) for at least six to twelve hours before your procedure is scheduled. Upon arrival at the hospital, you will change into a hospital gown. You may be given medication to help you relax. You will be asked to lie down on an exam table on your stomach. Your doctor will inject a topical anesthetic, such as Lidocaine or Xylocaine, into a small area of your back. This is similar to the injections a dentist might give you to numb your gums before a dental procedure.
Once the area is numb, the doctor will make a small incision and insert a sterile needle into your back. If you are having a percutaneous nephrostomy, your surgeon will guide a flexible tube (catheter) directly into your kidney through this needle. The other end of the catheter will be connected to a bag that will collect urine and any debris from kidney stones that drains from your kidney. You may feel some discomfort while the tube is being inserted into the kidney. An X-ray will be taken to ensure that the tube is in the right place.
If you are having a percutaneous nephrostolithotomy (or nephrolithotomy), your surgeon will thread special instruments through the needle and into your kidney. These instruments will be used to break apart any kidney stones you have and remove the pieces. Your surgeon might use ultrasound, lasers, or a type of water drill to break the stones apart in your kidney. You will probably be given general anesthesia during a nephrolithotomy, which is a three to four hour procedure.
Your doctor may use intravenous pyelography to visualize urinary tract structures. For this, a dye is injected into one of your veins, and X-rays are taken as the dye travels through your kidneys to your bladder.
A tube will be left in your kidney temporarily to help the kidney continue to drain after the procedure. Another small tube called a stent may be inserted into your ureter. Ureters are tubes that carry urine from the kidneys to the bladder. This stent will help maintain the flow of urine from your kidney. When urine builds up in your bladder, it is drained from the body through the urethra during normal urination.
These procedures are generally safe. However, every surgical procedure carries the risk of infection, bleeding, and blood clots. Studies suggest that the risk of infection is slightly higher for patients who are diabetic. Risks are also higher for people with ongoing urinary tract infections.
Other risks include:
- fragments of a stone could remain and the procedure would need to be repeated
- bleeding around the kidney
- kidney infection
- fragments of kidney stones may block the ureters
- your kidney function could deteriorate or even stop completely
Before your procedure, your doctor will speak with you about the procedure you will undergo and ask questions about your medical history and what medications you are taking. Tell your doctor about all the medications you take—both prescription and over-the-counter. Also, tell your doctor about any herbal preparations or supplements you are taking. You should alert your doctor if you are pregnant or could be pregnant. Be sure to let your doctor know if you have ever had an allergic reaction to the contrast dye used with X-rays.
Your doctor or nurse will tell you when to arrive at the hospital and how many hours before the procedure you should stop eating and drinking. If you are given medications, take them with small sips of water.
After the procedure you will go to the recovery room, where your vital signs will be closely monitored. You may be able to eat soon after the procedure.
X-rays will be taken to ensure that the kidney stones are gone and your kidney is healed. You may be able to go home within one to two days.
Most people will experience relief from pain and removal of all stones after undergoing percutaneous nephrostomy and/or nephrostolithotomy. Some people may need to undergo the procedure more than once to remove all their kidney stones.