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Treating Kidney Stones: Shock Wave Lithotripsy

Shock Wave Lithotripsy

Shock Wave Lithotripsy (SWL) is a treatment for kidney stones that uses energy from sound waves to break stones into tiny pieces, which then are small enough to pass easily out of your body. It is offered by UC San Diego Health's Comprehensive Kidney Stone Center.

SWL is by far the least invasive surgical approach and can be the ideal approach, depending on stone size and location. The procedure is typically done on an outpatient basis.

The ideal SWL stone is less than 1.5 cm and located in either the kidney or upper ureter. The stone must be visible on a plain film X-ray (some stones can only be seen by CT imaging).

What to Expect From SWL

Shock Wave Lithotripsy Machine

Certain medications must be discontinued, since they can increase the risk of internal bleeding. The shock wave lithotripsy procedure is done under general anesthesia and takes approximately one hour with subsequent post-operative recovery. You can go home the same day and return to the clinic six weeks later.

Post-operative pain is variable and oral medications will be given before discharge. Some people don't experience any discomfort. Passage of sand-like particles is common as the minuscule stone fragments will pass over the six weeks of post-operative recovery. Typically, patients can return to work in two days.

Shock Wave Lithotripsy Outcomes

Stone-free rates after this minimally invasive surgery are variable and range from 67 percent to 86 percent. Although SWL is the least invasive procedure for treating kidney stones, it also has an accepted lower success rate.

It is nevertheless a reasonably successful procedure with little side effects. The non-invasive nature of SWL makes it an attractive option for patients. It traditionally carries lower stone-free rates for larger stones, though.


SWL is a very safe procedure. Nevertheless, complications can happen, and they include but are not limited to infection, bleeding, need for transfusion (<1 percent) and the risk of additional procedures to completely remove kidney stones.

Some medical literature suggests that SWL may be a risk factor for either high blood pressure and/or diabetes mellitus, though there is also medical literature that does not support this theory. No definitive conclusions have been made regarding this particular risk.

​Appointments & Referrals


Kidney Stone Specialists