Robert Wood Johnson University Hospital



(Extracorporeal Shockwave Lithotripsy, ESWL, Shock Wave Lithotripsy)

Procedure overview

What is lithotripsy?

Lithotripsy is a noninvasive (the skin is not pierced) procedure used to treat kidney stones that are too large to pass through the urinary tract. Lithotripsy treats kidney stones by sending focused ultrasonic energy or shock waves directly to the stone first located with fluoroscopy (a type of X-ray “movie”) or ultrasound (high frequency sound waves). The shock waves break a large stone into smaller stones that will pass through the urinary system. Lithotripsy allows persons with certain types of stones in the urinary system to avoid an invasive surgical procedure for stone removal. In order to aim the waves, your doctor must be able to see the stones under X-ray or ultrasound.

There are two types of shock wave technology. The original lithotripsy machines sent the shock waves through water in a tub in which the person being treated was placed. This technology remains in use today. More recently, machines have been developed that send shock waves through padded cushions on a table, so the procedure does not involve immersing a person in water.

Other procedures that may be used to treat kidney stones include:

About kidney stones

When substances that are normally excreted through the kidneys remain in the urinary tract, they may crystallize and harden into a kidney stone. If the stones break free of the kidney, they can travel through, and get lodged in, the narrower passages of the urinary tract. Some kidney stones are small or smooth enough to pass easily through the urinary tract without discomfort. Other stones may have rough edges or grow as large as a pea causing extreme pain as they travel through or become lodged in the urinary tract. The areas most prone to trapping kidney stones are the bladder, ureters, and urethra.

Most kidney stones that develop are small enough to pass without intervention. However, in about 20 percent of cases the stone is greater than 2 centimeters (about one inch) and may require treatment. Most kidney stones are composed of calcium; however, there are other types of kidney stones that can develop. Types of kidney stones include:

How does the urinary system work?

Illustration of the anatomy of the urinary system, front view
Click Image to Enlarge

The body takes nutrients from food and converts them to energy. After the body has taken the food that it needs, waste products are left behind in the bowel and in the blood.

The urinary system keeps chemicals, such as potassium and sodium, and water in balance, and removes a type of waste, called urea, from the blood. Urea is produced when foods containing protein, such as meat, poultry, and certain vegetables, are broken down in the body. Urea is carried in the bloodstream to the kidneys.

Urinary system parts and their functions:

Reasons for the procedure

When kidney stones become too large to pass through the urinary tract, they may cause severe pain and may also block the flow of urine. An infection may develop. Lithotripsy may be performed to treat certain types of kidney stones in certain locations within the urinary tract.

There may be other reasons for your doctor to recommend lithotripsy.

Risks of the procedure

You may want to ask your doctor about the amount of radiation used during the procedure and the risks related to your particular situation. It is a good idea to keep a record of your past history of radiation exposure, such as previous scans and other types of X-rays, so that you can inform your doctor. Risks associated with radiation exposure may be related to the cumulative number of X-ray examinations and/or treatments over a long period of time.

Complications of lithotripsy may include, but are not limited to, the following:

Contraindications for lithotripsy include, but are not limited to, the following:

Patients with cardiac pacemakers should notify their doctor. Lithotripsy may be performed on patients with pacemakers with the approval of a cardiologist and using certain precautions. Rate-responsive pacemakers that are implanted in the abdomen may be damaged during lithotripsy.

There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your doctor prior to the procedure.

Obesity and intestinal gas may interfere with a lithotripsy procedure.

Before the procedure

During the procedure

Illustration of lithotripsy
Click Image to Enlarge

Lithotripsy may be performed on an outpatient basis or as part of your stay in the hospital. Procedures may vary depending on your condition and your and your doctor’s practices.

Generally, lithotripsy follows this process:

  1. You will be asked to remove any clothing, jewelry, or other objects that may interfere with the procedure.
  2. If you are asked to remove clothing, you will be given a gown to wear.
  3. An intravenous (IV) line will be inserted in your arm or hand.
  4. You may receive a sedative or anesthetic agent to ensure that you remain still and pain-free during the procedure.
  5. After the sedation has taken effect, you will be positioned on a water-filled cushion or immersed in a water-filled tub.
  6. After the stone(s) has been located with fluoroscopy or ultrasound, you will be positioned for the most direct access to the stone.
  7. If you are awake during the procedure, you may experience a light tapping feeling on your skin.
  8. A sequence of shock waves will be created to shatter the kidney stone(s).
  9. The stone(s) will be monitored by fluoroscopy or ultrasound during the procedure.
  10. A stent may be placed in the ureter to help the stone fragments (gravel) pass.
  11. Once the stone fragments are small enough to pass through the urinary system, the procedure will end.

After the procedure

After the surgery you will be taken to the recovery room for observation. Once your blood pressure, pulse, and breathing are stable and you are alert, you will be taken to your hospital room or discharged home.

You may resume your usual diet and activities unless your doctor advises you differently.

You will be encouraged to drink extra fluids to dilute the urine and reduce the discomfort of passing stone fragments.

You may notice blood in your urine for a few days or longer after the procedure. This is normal.

You may notice bruising on the back or abdomen.

Take a pain reliever for soreness as recommended by your doctor. Aspirin or certain other pain medications may increase the chance of bleeding. Be sure to take only recommended medications.

You may be given antibiotics after the procedure. Be sure to take the medication exactly as prescribed.

You may be asked to strain your urine so that remaining stones or stone fragments can be sent to the lab for examination.

A follow-up appointment will be scheduled within a few weeks after the procedure. If a stent was placed during the procedure, it may be removed at this time.

Notify your doctor to report any of the following:

Your doctor may give you additional or alternate instructions after the procedure, depending on your particular situation.

Online resources

The content provided here is for informational purposes only, and was not designed to diagnose or treat a health problem or disease, or replace the professional medical advice you receive from your doctor. Please consult your health care provider with any questions or concerns you may have regarding your condition.

This page contains links to other websites with information about this procedure and related health conditions. We hope you find these sites helpful, but please remember we do not control or endorse the information presented on these websites, nor do these sites endorse the information contained here.

American Urological Association

National Institute of Diabetes and Digestive and Kidney Diseases

National Institutes of Health (NIH)

National Kidney Foundation

National Library of Medicine


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