Lithotripsy
Lithotripsy, a greek word that means "stone crushing", is a technique that uses focused energy waves to break apart kidney stones without damaging nearby tissue. Lithotripsy utilizes a medical device called a lithotripter to generate energy in a targeted manner to disintegrate kidney stones so that they can pass easily out of the body.
Origin
A German company called Dornier originally developed this technology for medical use in the 1970s and 1980s. The first lithotripter, the Dornier HM3, was commercially sold for the first time in 1983. In 1984, the U.S. Food and Drug Administration approved lithotripsy for shockwave fragmentation of kidney stones.
Types of Lithotripsy
It is estimated that more than 1 million patients are treated each year with shockwave lithotripsy. It has been shown that shockwaves can be generated and focused against kidney stones using many different methods including electromagnetic induction, microexplosions, focused laser and piezoelectric crystals. Lithotripsy techniques are available that generate energy waves from inside the body (intracorporeal) and outside the body (extracorporeal). The extracorporeal technique is most commonly used in clinical practice.
More Information
ESWL specifically refers to the non-invasive treatment of stones that are in your kidney. It is a safe, commonly used procedure that can be used on children and patients with only one working kidney. It works best for stones that are in the kidney.
If your stone is not in the kidney and has instead traveled down the ureter, ESWL is not the ideal treatment. One option is for your urologist to use a ureteroscope (link) to push the stone back into the kidney and then use ESWL.
Alternatively, an intracorporeal approach may also be used for stones in the ureter. Stones in the kidney that range in size from 4 mm to 2 cm and are not completely blocking the ureter or kidney are the best candidates for ESWL.
You may not be good candidate for ESWL if you meet any of the following criteria:
- You are pregnant
- You have an anatomically abnormal kidney
- Your kidneys are not working properly
- You have a urinary tract cancer or kidney cancer
- You have a bleeding disorder
- You have a cystine stone
If you are to undergo ESWL, an anesthesiologist will sedate you. The procedure is usually outpatient, meaning that you can go home the same day as the procedure. The basic principle of ESWL is that weak shockwaves are generated outside your body, are transmitted through your body, and focused to break apart your stone.
There are three categories of shockwave generators:
- Electrohydraulic or spark gap
- Electromagnetic
- Piezoelectric
Each of these generators produces shockwaves of different shapes that focus in different ways. They each have specific advantages, but all are effective in breaking apart stones.
Lithotripsy | Treatment
Next, the treatment is started. Depending on whether you are sedated or anesthetized, the power level and frequency of pulses are brought up slowly or more rapidly. The shock waves pulses create several different types of forces on the stone that combine to fragment it. The procedure usually takes an hour, but can go longer depending on the stone being fragmented. The picture on this page shows a visualization of the shockwaves converging on a kidney stone.
After the treatment, a stent may be placed to expand your ureter and make it easier for the newly fragmented stone to pass out of your body. It may take up to a week for the fragments to pass, and they may cause some mild pain and blood in the urine when they are passed. Your doctor may encourage you to drink as much water as you can to help pass the pieces, or void through a screen to capture the pieces for analysis.
There can be complications as a result of ESWL. These include damage to nearby blood vessels and kidney tissue, which in rare cases can impair function of your kidneys. The risks of the procedure should and will be discussed in detail by your urologist.
Advances in ureteroscopy have allowed better access through the ureter for kidney stone treatment. Most stones in the upper urinary tract can be treated with ESWL. However, certain stones are poor candidates for ESWL, as mentioned above, and require intracorporeal treatment.
For small stones, an endoscopic basket or grasping device can be used to remove a stone. However, larger stones require some fragmentation before they can be safely removed. To accomplish this, four techniques can be used for intracorporeal lithotripsy.
Types of Lithotripsy
It is estimated that more than 1 million patients are treated each year with shockwave lithotripsy. It has been shown that shockwaves can be generated and focused against kidney stones using many different methods including electromagnetic induction, microexplosions, focused laser and piezoelectric crystals. Lithotripsy techniques are available that generate energy waves from inside the body (intracorporeal) and outside the body (extracorporeal). The extracorporeal technique is most commonly used in clinical practice.
More Information
ESWL specifically refers to the non-invasive treatment of stones that are in your kidney. It is a safe, commonly used procedure that can be used on children and patients with only one working kidney. It works best for stones that are in the kidney.
If your stone is not in the kidney and has instead traveled down the ureter, ESWL is not the ideal treatment. One option is for your urologist to use a ureteroscope (link) to push the stone back into the kidney and then use ESWL.
Alternatively, an intracorporeal approach may also be used for stones in the ureter. Stones in the kidney that range in size from 4 mm to 2 cm and are not completely blocking the ureter or kidney are the best candidates for ESWL.
You may not be good candidate for ESWL if you meet any of the following criteria:
- You are pregnant
- You have an anatomically abnormal kidney
- Your kidneys are not working properly
- You have a urinary tract cancer or kidney cancer
- You have a bleeding disorder
- You have a cystine stone
If you are to undergo ESWL, an anesthesiologist will sedate you. The procedure is usually outpatient, meaning that you can go home the same day as the procedure. The basic principle of ESWL is that weak shockwaves are generated outside your body, are transmitted through your body, and focused to break apart your stone.
There are three categories of shockwave generators:
- Electrohydraulic or spark gap
- Electromagnetic
- Piezoelectric
Each of these generators produces shockwaves of different shapes that focus in different ways. They each have specific advantages, but all are effective in breaking apart stones.
Lithotripsy | Treatment
Next, the treatment is started. Depending on whether you are sedated or anesthetized, the power level and frequency of pulses are brought up slowly or more rapidly. The shock waves pulses create several different types of forces on the stone that combine to fragment it. The procedure usually takes an hour, but can go longer depending on the stone being fragmented. The picture on this page shows a visualization of the shockwaves converging on a kidney stone.
After the treatment, a stent may be placed to expand your ureter and make it easier for the newly fragmented stone to pass out of your body. It may take up to a week for the fragments to pass, and they may cause some mild pain and blood in the urine when they are passed. Your doctor may encourage you to drink as much water as you can to help pass the pieces, or void through a screen to capture the pieces for analysis.
There can be complications as a result of ESWL. These include damage to nearby blood vessels and kidney tissue, which in rare cases can impair function of your kidneys. The risks of the procedure should and will be discussed in detail by your urologist.
Advances in ureteroscopy have allowed better access through the ureter for kidney stone treatment. Most stones in the upper urinary tract can be treated with ESWL. However, certain stones are poor candidates for ESWL, as mentioned above, and require intracorporeal treatment.
For small stones, an endoscopic basket or grasping device can be used to remove a stone. However, larger stones require some fragmentation before they can be safely removed. To accomplish this, four techniques can be used for intracorporeal lithotripsy.