ESWL or Extracorporeal Shock Wave Lithotripsy is a non-invasive technique for treating stones in the kidney or ureter using high-energy shock waves. Stones are broken into "stone dust" or fragments that are small enough to pass in urine.
ESWL works better with some stones than others. The size and shape of stone, the predicted
hardness of the stone, the location of the stone in your urinary tract, your health, and your
kidneys' health will be part of the decision to decide the best treatment for your stone.
Kidney stones that are smaller than 2 cm in diameter are the best size for ESWL. Larger stones can be treated by PCNL or RIRS. However, larger kidney stones can be treated in experienced hands with multiple sessions and a ureteric stent.
Ureteral stones that occur in the upper third of the ureter near the kidney can be treated by SWL. Ureteral stones that occur lower (near the bladder) are more difficult to treat with ESWL, but can be successfully treated by experienced operators.
ESWL is more appropriate for some people than others. Because x-rays and shock waves are needed in ESWL, pregnant women with stones are not treated this way. People with bleeding disorders, infections, severe skeletal abnormalities, or who are morbidly obese also not usually good candidates for ESWL. lf your kidneys have other abnormalities, your doctor may decide you should have a different treatment. lf you have a cardiac pacemaker, your cardiologist will be involved in the decision on whether you can have ESWL.
You will be positioned on an operating table. A soft, water-filled cushion may be placed on your abdomen
or behind your kidney. The body is positioned so that the stone can be targeted precisely with the shock
ESWL is delivered with sedation and pain relief medication to help the patient remain still, reduce any discomfort, and this improves the breaking of the stone.
About 3-4 thousand shock waves are needed to crush the stones. The complete treatment takes about 50 to 70 minutes.
Sometimes, a ureteral stent is inserted prior to ESWL. Ureteral stents are soft plastic tubes which are introduced into the bladder and threaded up to the kidney. They have ensure good drainage of urine from the kidney to the bladder. They are used when the ureter is blocked, when there is a risk of infection and in patients with intolerable pain or reduced kidney function.
After the procedure, you will usually stay for about an hour then be allowed to return home if all is well. You will be asked to drink plenty of fluids, strain your urine through a filter to capture the stone pieces for testing, and you will be given painkillers to bring home. Alpha blockers which are drugs that relax the ureter may be given to help passage of the stone fragments after ESWL.
Dr Robert Tan is a practicing consultant urologist with over 35 years of experience. He graduated from the medical school at the University of New South Wales, Australia, and has cared for thousands of patients over the decades.View Profile
Dr Lincoln Tan is a consultant urologist and accredited robotic surgeon. Dr Tan is trained in all aspects of open and endoscopic urology and specialises in the minimally invasive treatment of urologic cancers.View Profile