Kidney stones are created when certain substances in urine -- including calcium, oxalate, and sometimes uric acid -- crystallize. These minerals and salts form crystals, which can then join together and form a kidney stone.
Kidney stones usually form within the kidney, where urine collects before flowing into the ureter, the tube that leads to the bladder. Small kidney stones are able to pass out of the body in the urine -- and may go completely unnoticed by you. But larger stones irritate...
You lie on a water-filled cushion, and the
surgeon uses X-rays or ultrasound tests to precisely locate the stone.
High-energy sound waves pass through your body without injuring it and break
the stone into small pieces. These small pieces move through the urinary tract
and out of the body more easily than a large stone.
Your surgeon may use a
stent if you have a large stone. A stent is a
small, short tube of flexible plastic mesh that holds the
ureter open. This helps the small stone pieces to pass
without blocking the ureter.
What To Expect After Treatment
ESWL is usually an
outpatient procedure. You go home after the treatment
and do not have to spend a night in the hospital.
After ESWL, stone fragments usually
pass in the urine for a few days and cause mild pain. If you have a larger
stone, you may need more ESWL or other treatments.
Why It Is Done
ESWL may be used on people with a
kidney stone that is causing pain or blocking the urine flow. Stones that are
between 4 mm (0.16 in.) and
2 cm (0.8 in.) in diameter are
most likely to be treated with ESWL.
ESWL may work best for kidney
stones in the kidney or in the part of the ureter close to the kidney. Your
surgeon may try to push the stone back into the kidney with a small instrument
(ureteroscope) and then use ESWL.
ESWL is usually not used if
Are pregnant. The sound waves and X-rays may be
harmful to the
For 9 out of 10 patients who have kidney
stones smaller than
10 mm (0.4 in.)-either in the
kidney or in the
ureter-ESWL gets rid of all of the stone or leaves
only small fragments that don't cause any symptoms.1
Complications of ESWL include:
Pain caused by the passage of stone
Blocked urine flow as a result of stone fragments
becoming stuck in the urinary tract. The fragments may then need to be removed
with a ureteroscope.
Urinary tract infection.
around the outside of the kidney.
What To Think About
ESWL does not replace the need for the
preventive treatment of kidney stones, such as drinking enough fluids so that
you don't get
ESWL does not successfully treat
cystine kidney stones. These stones do not break up easily.
is a safe procedure and may be used on children and on individuals with only
one working kidney. ESWL should not be used if you have a pacemaker unless a
cardiologist has determined it is safe.