Lithotripsy is a technique used to break up stones that form in the kidney, bladder, ureters, or gallbladder. There are several ways of doing this, although the most common is extracorporeal shock wave lithotripsy. The shock waves are focused on the kidney stone and break the stone into tiny pieces, which are passed out of the body naturally during urination.
Extracorporeal shock wave lithotripsy (ESWL) is used to treat a wide range of patients with stones in the kidney or the ureter.
ESWL uses shock waves (sound waves) to break the stones into small pieces. The pieces then leave your body naturally during urination, so no incisions are needed. ESWL is an outpatient procedure, but anesthesia is required. You may be given a light sedative or a full general anesthetic, if necessary.
To be a good candidate for ESWL, you must be in reasonably good health, not have infected urine or a bleeding disorder and be able to take some type of anesthesia. It is also necessary that the stone being removed be no larger than two centimeters and that you have a direct flow of urine to the bladder.
This treatment option is not used if the stone is larger than two centimeters, or very hard, if there is a narrowing of the urinary tract below the stone, or if the patient is very overweight or has certain medical conditions. More than 550 ESWL were performed at ESWL division of IURTC with Dornie MPL 9000 lithotripter machine.
How does lithotripsy work?
- The stones are located using C-arm fluoroscopy and/or ultrasound. The patient, lying on a radioluscent treatment table, is positioned so that the stones can be targeted precisely.
- The doctor will determine what kind of anesthesia or sedation the patient needs in order to reduce any discomfort.
- After the first series of shock waves, progress is assessed, the patient may be repositioned and the treatment continues as necessary.
- After the treatment, patients can move about almost at once. Usually treatments are on an outpatient basis. After one or two days most patients are able to resume daily activities.
- It may take about 90 days for the stone fragments to pass out of the body. You will be asked to start out with a liquid diet and to drink lots of water since this helps the passing of stone fragments. For a few days patients' urine may have some blood. The passing of stone fragments through the urinary tract may cause discomfort.
You will usually be asked not to drink or eat anything for several hours before the test. Before the test is scheduled, tell your health care provider about any medicines you take. You may be asked to stop taking aspirin, ibuprofen, coumadin, and any other drugs that interfere with blood clotting several days before. You should tell your doctor if you are pregnant, because lithotripsy must not be performed during pregnancy.
The health care provider will use x-ray or ultrasound images to see where the stones are. High-energy shock waves, also called sound waves, pass through your body to the area on the kidney stones. You may feel a tapping sensation when this starts. The waves break the stones into tiny pieces. It is easier for smaller pieces to pass out of the body during urination. The procedure generally takes from 45 minutes to 1 hour. You will be asked to visit your doctor for a follow-up appointment in the weeks following the lithotripsy. (For example, this might include a kidney x-ray to determine if kidney stones are still present.)
ESWL is an alternative to surgery that is sometimes needed to remove stones from the kidney or ureter. Because ESWL requires no cutting, you have less pain and a quicker recovery. An overnight hospital stay is usually not needed. This procedure prevents you from having to undergo surgery to have the stones removed, which reduces discomfort, complications, hospital stay, costs, and recovery time.
Is this treatment method suitable for everyone?
Your physician will decide if lithotripsy is the right treatment method for you. Some medical conditions prohibit the use of the ESWL. The size, number, location, and composition of the stones have to be considered when choosing the lithotripsy treatment method.
How successful is lithotripsy?
About 70 to 80% of patients are found to be free of stones within three month of treatment. After treatment some patients may still have stone fragments that are too big to be passed and have to be retreated.
Complications of lithotripsy are rare, but include the following:
- Bleeding of the kidneys
- Bruising of the kidneys or skin
- Obstruction of the ureter (the passageway from the kidney to the bladder)
- Failure of the stone to fragment
Extracorporeal shock wave lithotripsy is a very safe procedure with few complications. However, minor complications do occur:
An excessive urge to urinate, excessive blood in the urine, extreme pain, or other unusual symptoms, may indicate an infection or a blockage, and if any of these symptoms occur, you must contact your doctor immediately.
Passing the Stone
It may take anywhere form a day to several weeks for the stone particles to leave your body. During this time, drink plenty of liquids. It's normal for your urine to be cloudy or slightly blood for a few weeks. You may even see small pieces of stone in your urine. A slight fever and some pain are also normal. Your doctor may ask you to strain your urine to collect some stone particles for chemical analysis.
When to Call Your Doctor?
Call your doctor if you have any of the following:
- Fever over 100.4 degrees F
- Heavy bleeding
- Pain not relieved by pain medications
- Nausea and vomiting
- Difficulty urinating
Results - The results of ESWL depend on the size of the stone, stone burden, type of stone, and location. In general ESWL is used for stones less than 1 to 2 centimeters in size. Most stones fracture well with ESWL treatment. Hard stones such as calcium oxalate monohydrate and cystine stones are more difficult to break with ESWL and therefore often require percutaneous nephrostolithotomy. Fragments from stones located higher within the collecting system are more likely to pass spontaneously than stones in the lower portion of the kidney, simply due to gravitational effect. Stones larger than 1 to 2 centimeters or hard stones will often require multiple ESWL treatments to entirely rid the kidney of all stone fragments.
Prevent Future Stones
After your kidney stone has been treated, takes these steps to prevent future stones:
- Drink lots of water, about 8 to 12 eight-ounce glasses every day.
- Follow the diet your doctor recommends.
- Take your prescribed medications.
- See your doctor regularly for checkups.