The introduction of extracorporeal shock wave lithotripsy (ESWL) in the early 1980s revolutionized the treatment of patients with kidney stone disease. Patients who once required major surgery to remove their stones could be treated with ESWL, and not even require an incision. As such, ESWL is the only non-invasive treatment for kidney stones, meaning no incision or internal telescopic device is required.
ESWL involves the administration of a series of shock waves to the targeted stone. The shock waves, which are generated by a machine called a lithotripter, are focused by x-ray onto the kidney stone. The shock waves travel into the body, through skin and tissue, reaching the stone where they break it into small fragments. For several weeks following treatment, those small fragments are passed out of the body in the urine.
In the two-plus decades since ESWL was first performed in the United States, we have learned a great deal about how different patients respond to this technology. It turns out that we can identify some patients who will be unlikely to experience a successful outcome following ESWL, whereas we may predict that other patients will be more likely to clear their stones. Although many of these parameters are beyond anyone’s control, such as the stone size and location in the kidney, there are other maneuvers that can be done during ESWL treatment that may positively influence the outcome of the procedure. At the Brady Urological Institute, our surgeons have researched techniques to make lithotripsy safer and more effective, and we incorporate our own findings as well as those of other leading groups to provide a truly state of the art treatment.
Advantages of ESWL
The primary advantage of ESWL is that it is completely non-invasive.
Who should be treated with ESWL?
ESWL is well suited to patients with small kidney stones that can be easily seen by x-ray.
ESWL is NOT a particularly good treatment for:
- Pregnant patients
- Patients on “blood thinners” or patients with bleeding disorders. Aspirin or other blood thinners must be discontinued for at least 1 week prior to ESWL.
- Patients with chronic kidney infection, as some fragments may not pass, so the bacteria will not be completely eliminated from the kidney.
- Patients with obstruction or scar tissue in the ureter, which may prevent stone fragments from passing.
- Patients who require immediate and/or complete clearance of stone material.
- Patients with stones composed of cystine and certain types of calcium, as these stones do not fragment well with ESWL
Because ESWL is a completely non-invasive therapy, most ESWL treatments are performed on an outpatient basis.
Although the use of anesthesia does depend on patient and physician preference, recent data suggest that the results of ESWL may be improved with the administration of a mild anesthetic.
When the patient has been adequately anesthetized, a computerized x-ray machine is used to pinpoint the location of the stone within the kidney. A series of shock waves (several hundred to two thousand) is administered to the stone. Our treatment protocols incorporate the latest research findings which suggest that adjustments of both the shock wave power and the rate at which the shock waves are delivered can affect treatment outcome.
Our goal when performing ESWL is to maximize the breakage of a patient’s kidney stone while minimizing injury that the shock waves can cause to the kidney and surrounding organs.
Typically, an ESWL procedure lasts for approximately one hour.