Extracorporeal shock wave lithotripsy (ESWL) is a technique for treating stones in the kidney and ureter that does not require invasive surgery. High-energy shock waves are passed through the body and used to break stones into pieces as small as grains of sand. Because of their small size, these pieces can pass from the body along with the urine. ESWL treatment is recommended when a kidney stone becomes too large or painful to pass on its own.
The patient lies on a soft cushion or membrane through which the waves pass. About 3,000 shock waves are needed to crush the stones over a period of 30 minutes.
The main advantage of this treatment is that many patients may be treated for kidney stones without invasive surgery. This disadvantage is that the patient has to pass the small fragments of the original stone. It is common to have some pain in the kidney and ureter as the small stone fragments pass.
After treatment is complete, the patient can move about almost at once. Many people can fully resume daily activities within one to two days. Special diets are not required, but drinking plenty of water helps the stone fragments pass. Usually a lithotripsy patient is asked to strain his or her urine afterward to collect pieces for analysis and to determine what the stones are made of. The passage of stone fragments may take a few days or a week and may cause mild pain.
Not all kidney stones are candidates for this type of treatment. The size, number, location and composition of the stones are factors that must be taken into account when exploring treatment options. Also the stones must be clearly viewed by the x-ray monitor so the shock waves can be targeted accurately. If anatomical abnormalities prevent this, other methods of stone removal may have to be considered.
Through examination, x-ray and other tests, the doctor can decide whether this is the best treatment for the patient. In those patients who are thought to be good candidates for this treatment, about 70 to 90 percent are found to be free of stones within three months of treatment.
Parminder Sethi, MD is a urologist with Pacific Urology. The urology group has developed a Kidney Stone Center and in partnership with John Muir Health, provides a dedicated, on-site Storz lithotripter machine at the John Muir Medical Center, Concord Campus. Kidney stone patients can often undergo ESWL within 24-48 hours. For more information, please call 925-937-7740.