Lithotripsy is a non-invasive and commonly used alternative to surgery for the treatment of kidney stones. The procedure works by focusing high-energy shock waves to disintegrate kidney stones. Once disintegrated the sand-like fragments pass out of the body in the urine. Large stones may require more than one lithotripsy treatment.
The full medical term is extracorporeal shock wave lithotripsy (ESWL), meaning that the shock wave is generated outside of the body.
Lithotripsy treatment for kidney stones is arranged through a urologist after tests are carried out to determine suitability for the treatment.
Who is lithotripsy appropriate for?
Lithotripsy may be recommended when a kidney stone
is too large to pass on its own, or when a stone becomes stuck in the ureter (the tubes that connect the kidneys and bladder).
Lithotripsy is usually not recommended when the kidney stone is greater than approximately 2cm in diameter, is particularly dense or is a struvite type stone. These stones may need to be surgically removed.
Lithotripsy may not be appropriate if a patient has one of the following conditions:
- Aortic aneurysm
- Bleeding disorders
- Significant obesity
- Severe skeletal abnormalities
The lithotripsy procedure
Lithotripsy is usually a day stay procedure. It is usual for an ultrasound scan or x-ray of the kidney to be performed as part of this preparation to check the position of the kidney stone.
Prior to the procedure the patient is not allowed anything to eat or drink for a period of time (usually at least six hours). To ensure the patient remains still during the lithotripsy procedure an anaesthetic is given. This is usually in the form of intravenous sedation (given through a drip into the hand or arm) though in some cases a general anaesthetic may be recommended.
To allow the shock waves to be transmitted through the skin a rubber pad covered with a special gel is placed against the skin. Using ultrasound or x-ray guidance, the shock waves are focused on the kidney stone and the lithotripsy machine is activated.
The procedure takes approximately one hour, depending on the size and number of kidney stones. Throughout the procedure the patient is constantly monitored by the urologist and an anaesthetist.
If the kidney stone or stone fragments are large, a small tube (stent) may need to be inserted into the ureter prior to lithotripsy. This is positioned via the urethra (the body's tube through which urine is carried from the bladder to the outside) using a telescopic instrument called an endoscope. The stent allows the fragments to pass from the kidney without blocking the ureter. It will be removed in an outpatient clinic at a later date.
After the procedure
Once fully awake, the patient is transferred back to the ward for recovery. Intravenous fluids may be administered during and immediately after the procedure to help flush out the kidney stone fragments. Once able, the patient will be encouraged to drink plenty of fluid to assist in this process.
Often there is slight bruising around the area where the shock waves have entered the body, causing discomfort. Some discomfort may be also be experienced as the stone fragments pass through the urinary tract. If a stent was inserted there may be some urinary frequency (needing to pass urine frequently) and/or discomfort due to the stent irritating the ureter and bladder.
The degree of discomfort experienced following the procedure will vary between individuals and can be influenced by the size of the residual stone fragments and the duration of the procedure. Pain-relieving medications can help to alleviate any discomfort experienced.
Prior to being discharged from hospital, clear recovery and activity guidelines should be given. In some cases a course of antibiotics may be prescribed to help prevent infection.
It is usual for blood to be present in the urine for a few days after the procedure. It is important to inform the urologist promptly if the blood in the urine does not resolve or worsens, if a fever develops, if difficulty with urination is experienced, or there is increasing pain.
Usually work and other normal activities may be resumed the following day, if the person is feeling able. If a stent has been inserted, a return to work will need to be discussed with the urologist.
A follow up appointment with the urologist is usually arranged for four to six weeks after the lithotripsy procedure. An x-ray or ultrasound scan may be taken prior to this appointment to see if the procedure has been successful in clearing the kidney stone.
Clinical Reference Systems (2006) Lithotripsy for kidney stones. (Disease/Disorder overview). McKesson Health Solutions LLC. Farmington Hills, MI. Thompson Gale
Extra-Corporeal Shock Wave Lithotripsy (ESWL) (2005) Pamphlet. Promed Urology Ltd.
Healthpoint (2013) Kidney Stones. Auckland Regional Urology Service. Auckland District Health Board.
Knight, J. (2006) Lithotripsy. The Gale Encyclopedia of Medicine. Third Edition. J. L. Longe, (Editor). 5 vols. Farmington Hills, MI. Thompson Gale
Last Reviewed – 23 May 2013