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Kidney Stone Centre

Shockwave Lithotripsy: About Shockwave Lithotripsy

Shockwave lithotripsy (SWL), also know as extracorporeal shockwave lithotripsy, is the most non-invasive common surgical treatment for kidney stones. It generates shock waves outside the body and then, using X-rays, focuses them on a kidney stone to break up the stone. Since most SWL machines rely on X-rays to see and localize the kidney stone, it can be difficult or impossible to treat stones that cannot be seen with X-rays.
SWL can treat stones anywhere in the urinary tract: in the kidney, ureter or bladder. It is an effective treatment, but can be less effective for certain types of kidney stones, and so your urologist may recommend other treatments, such as ureteroscopy or percutaneous nephrolithotomy.

SWL is generally performed with a light sedative given intravenously by an anesthetist. The treatment generally takes about 30-60 minutes. Patients usually have their treatment and go home on the same day.

Following lithotripsy, it is common to experience some blood in the urine and some mild pain in the side for a few days after treatment. You will be given a strainer to filter your urine in order to catch stone fragments that may be analyzed at a later date.

SWL Machine

The lithotripter at the St. Michael’s Hospital Kidney Stone Centre is a third-generation machine (the Dornier MFL 5000). With first-generation machines, patients were immersed in a water bath; with this machine, a water cushion is applied to the patient’s back over the kidney. This machine generates shock waves using spark gap electrohydraulic technology and uses X-rays to see and target kidney stones. The machine has been carefully reviewed in a number of medical studies, which have found it to be safe and effective.

Potential Complications

Although SWL is safe, there are some potential complications that can occur with it:

  • Bleeding that becomes worse with the use of aspirin, aspirin-like drugs and blood thinners.
  • Urinary infections, which may lead to a fever or more complicated infection if left untreated.
  • Renal colic, which is severe kidney pain due to blockage of the kidney by stone fragments.
  • Failure to break the stone, as more than one treatment may be necessary to break the stone completely. Hard stones that may not fragment with SWL, and an alternative treatment may be necessary.

Other complications are extremely rare.