Extracorporeal Shock Wave Lithotripsy (ESWL)

What is extracorporeal shock wave lithotripsy (ESWL)?

Extracorporeal shock wave lithotripsy (ESWL) is a common, nonsurgical procedure to treat kidney stones. It uses high-energy shock (pressure) waves to break up stones. Tiny pieces of the stones can then move through your urinary tract and out of your body more easily.

Kidney stones are rock-like masses that form when you have high levels of certain substances (like calcium) in your pee (urine). They form inside your kidneys but can move into your ureters (the tubes that carry urine to your bladder).

Many kidney stones pass on their own — they move through your urinary tract and you pee them out. But sometimes, a kidney stone becomes too big to move through (or gets stuck inside). Pain during a “kidney stone attack” is typically due to a stone getting stuck in your ureter and blocking drainage of pee from your kidney.

ESWL can dislodge the stones and allow you to pass them on your own.

When do you need extracorporeal shock wave lithotripsy?

Providers often use ESWL to treat kidney stones that:

• Are too large to pass on their own (larger than 5 millimeters in diameter — about the size of a pencil eraser).
• Block urine flow.
• Are very painful.

When recommending a procedure to treat kidney stones, healthcare providers consider:

• The size of the stone. ESWL usually works best to treat smaller stones.
• The location of the stone.
• Any health conditions you have or regular medications you take.
• Your body type. Anatomical differences can put additional distance between the stone and the shock waves. This can make ESWL less effective.

What happens before extracorporeal shock wave lithotripsy (ESWL)?

Your healthcare provider will explain how to prepare for ESWL. You may need to:

• Get blood or urine tests. You may have blood tests to check your kidney function and blood counts and urine (pee) tests to check for urinary tract infections (UTIs).
• Review your medications with your provider. Keep taking all medications unless your provider tells you otherwise. You may need to stop taking warfarin or other blood-thinning medications. These medications could increase the risk of bleeding related to the procedure.
• Stop eating and drinking several hours before your procedure.
• Arrange for someone to drive you home after the procedure.

How is extracorporeal shock wave lithotripsy (ESWL) done?

Before ESWL, a provider will give you anesthesia (pain relief) to keep you comfortable. You may be asleep or awake but drowsy during lithotripsy. Or you may have regional anesthesia, which means you’ll be awake but numb from the waist down.

During ESWL:

1. You’ll lie on a padded table on top of a water-filled cushion. Less commonly, you may sit in a large tub of water.
2. Providers will use X-rays or ultrasound to pinpoint the stone’s location. These images help providers aim shock waves as precisely as possible at the stone.
3. Your care team may move you slightly to line your body up with the energy beams.
4. A shock wave lithotripsy machine sends powerful energy waves through the water and into your body. If you’re awake for the procedure, you may hear a popping sound or feel a tapping sensation along your side.
5. Thousands of shock waves are aimed at the kidney stone, breaking the stone into many pieces.

How long does ESWL take?

ESWL usually takes about an hour. Your procedure may take more or less time, depending on the size and number of kidney stones you have and your overall health.

What happens after ESWL?

ESWL is usually an outpatient procedure (it doesn’t require a hospital stay). You should go home the same day but expect to spend a few hours in the recovery room.

How painful is ESWL?

If you have general or regional anesthesia, you shouldn’t feel pain during the ESWL procedure. Most people who have the procedure without anesthesia (they’re given pain medication beforehand instead) report feeling mild to moderate pain during ESWL (ranking it a 6 or lower on a pain scale of 0 to 10). About 30% of people who have ESWL without anesthesia experience severe pain (a 7 or higher on a scale of 0 to 10) during the procedure.

What are the advantages of extracorporeal shock wave lithotripsy?

ESWL can help you pass kidney stones on your own without needing more invasive surgery to remove them.

What are the potential risks or complications after extracorporeal shock wave lithotripsy?

Potential risks of ESWL include:

• Blockage in your ureter.
• Bleeding.
• Infection.

What if ESWL doesn’t work?

In some cases, shock wave lithotripsy doesn’t break up a stone enough for all the pieces to pass on their own. If that happens, you may need another procedure.

Depending on your situation, your provider may recommend a second ESWL or a ureteroscopy, a minimally invasive way to clear remaining stones. Talk to your healthcare provider about the different types of kidney stone treatments.

How long does it take to recover from extracorporeal shock wave lithotripsy?

Most people get back to their usual routines within a few days of ESWL. But you may have lingering side effects until your body has passed the last of the stone fragments. As you recover from ESWL, you may experience side effects like:

• Soreness. You may feel sore or stiff near the treatment area. Some people notice slight bruising along their side.
• Blood in your pee. It’s common to see small amounts of blood in your pee (pink-tinged pee).
• Painful urination.

These symptoms usually go away after a few days.

How long does it take to pass stones after ESWL?

You can expect to pass kidney stone fragments in your pee for several days to weeks after the procedure. Stone pieces may look like sand, gravel or dust.

Expect to feel some discomfort as stone fragments pass. Pain may come and go until all the kidney stone pieces have worked their way out of your body.

To help move the stone out and manage pain, your provider may prescribe:

• Tamsulosin (Flomax®). This relaxes your bladder and helps you pee the stone out.
• Ketorolac (Toradol®). This is a prescription pain reliever.

Take any medications as prescribed. You may also be able to take over-the-counter (OTC) pain medication to keep you comfortable until you’ve passed all the stone fragments. Ask your provider what medications are safe to take.

Does it hurt to pee after lithotripsy?

Yes, it can hurt to pee for a few days after shock wave lithotripsy. And passing stone fragments (even tiny ones) can hurt — sometimes a lot. Ask your provider what to expect and when to let them know about painful urination.

How effective is shock wave lithotripsy at treating kidney stones?

Success rates for ESWL vary widely (from 30% to 90%). The success rate can depend on:

• The size of the stone.
• The stone’s location.
• The type of stone.
• Your body type.

You have a higher chance of success if the kidney stone is inside certain parts of your kidney or the upper part of your ureter.

How can I take care of myself after ESWL?

Your provider will give you instructions on how to take care of yourself after ESWL. They may ask you to:

• Drink plenty of water. Staying hydrated helps stone fragments move through your body and avoid constipation.
• Collect stone pieces that you pass. Testing the stone can tell your provider what caused it (and how to prevent new stones). They’ll give you a urine strainer to collect fragments when you pee.
• Drop off the stone sample for testing. You can store the stone fragments you collect in a specimen cup your provider gives you or a plastic bag. Follow your provider’s instructions. You may need to take it to your next follow-up visit or drop the sample off at a lab.

When should I call my healthcare provider?

Contact your provider if you have any questions before or after the procedure. This includes questions about how the procedure works, how to take your medications and any concerns about symptoms you have after the procedure.

Go to the emergency room if you have:

• Sudden, severe belly (abdomen) or back pain.
• Persistent nausea or vomiting.
• Dizziness or lightheadedness.
• Pain that gets worse, even after taking pain medication.
• Fever.
• Chills.
• Blood clots in your pee.

Who is ineligible for shock wave lithotripsy?

Some medical conditions could make shock wave lithotripsy less effective or riskier for certain people. Your healthcare provider may recommend against shock wave lithotripsy if you’re pregnant or have:

• Abdominal aortic aneurysm.
• Bleeding disorders like hemophilia.
• Conditions that require blood thinner medications.
• Obesity.
• Kidney infection or other type of urinary tract infection.
• Kidney cancer.
• Decreased kidney function.
• Spinal deformities like scoliosis.
• High blood pressure not managed by medication.

A note from Cleveland Clinic

ESWL is a safe, noninvasive treatment for breaking up kidney stones. It’s an option for many people that allows stones to pass on their own, without surgical procedures. But many factors, such as stone size and location, can impact its effectiveness. Certain health conditions can also increase your risk of complications from ESWL. Talk with your provider about what to expect and whether shock wave lithotripsy is the right kidney stone treatment for you.