Extracorporeal Shock Wave Lithotripsy (ESWL) for Kidney Stone Treatment
Extracorporeal Shock Wave Lithotripsy (ESWL) is a non-invasive treatment for kidney stones that uses sound waves to pulverize stones within the body. ESWL is performed in an outpatient setting and the entire procedure is performed on the outside of the body.
Extracorporeal Shock Wave Lithotripsy (ESWL) was a revolutionary technology that was introduced to the treatment of kidney stones in the 1980’s. Before its introduction, stones were removed through incisions, which were far more invasive. ESWL is the application of sound waves to pulverize stones within the body from outside the body. The original ESWL devices utilized a water bath to transmit the sound waves to the body, but now lithotripters are far smaller. Now, they are typically mobile devices that use gel pads placed against the body for shock wave transmission.
ESWL can be used for ureteral stones, but is far more efficacious for stones that reside in the kidney. Now, ureteroscopy has supplanted ESWL as the most commonly performed procedure for ureteral stones and delivers a high success rate. However, ESWL is typically performed without a ureteral stent, so some patients will still choose this approach over ureteroscopy despite a lower success rate.
ESWL is usually done in an outpatient surgical center setting, as is done by the surgeons at Urologic Surgeons of Washington. The procedure requires anesthesia, and takes approximately 45 minutes. Patients will wake up with little pain. There is often bruising over the flank/kidney that was treated. Blood in the urine almost always occurs, and should be of little concern. With a typical stone sized between 5-10 mm in the kidney one can expect an approximately 90% success rate. Occasionally the stone will not fragment, will fragment but will not move, or a fragment will become impacted in the ureter. Such patients may require a subsequent procedure to become stone free. Occasionally in the setting of a large stone a second ESWL is offered.
Risks of ESWL
Complications with a lithotripsy are rare but do occur. There can be bleeding around the kidney, especially if the patient has a history of taking blood thinners or has out of control hypertension, infection, obstruction due to a fragment, or failure of the procedure. The only situation that requires an urgent trip to the GW or Sibley Emergency Room would be fevers after an ESWL (which must be assumed to be urine infection behind an obstruction that must be drained) or abdominal distention that may signal bleeding around the kidney. Otherwise, pain after a lithotripsy typically suggests good fragmentation and stone passage. Here, as long as the pain is tolerable, one should just wait a day or two for the stones to pass. Your doctor will ask you to return at a predetermined interval with a radiographic study to determine the success or failure of the ESWL. You will be asked to bring your CD of that study to your visit.