Facts on File Encyclopedia of Health and Medicine

extracorporeal shock wave lithotripsy (ESWL)
A therapeutic procedure in which a machine
called a lithotriptor generates shock waves that
cause calcifications within the urinary tract, com-
monly called kidney stones (NEPHROLITHIASIS) or
bladder stones (UROLITHIASIS), to break apart into
smaller fragments the URINEcan carry out of the
body. Lithotripsy became available in 1980 and
has evolved into the current treatment of choice
for stones smaller than 2 centimeters (about 0.75
inch) in diameter that form in the KIDNEYS, URETER,
andBLADDER. ESWL is sometimes effective for gall-
stones (cholelithiasis) as well. Today there are sev-
eral types of lithotriptors, each of which uses a
different energy source though all apply the same
basic approach which is to focus a pulse of intense
energy (the shock wave) at the stone.

Women who are or could be pregnant

should not undergo ESWL.

Typically preparation requires having nothing
to eat or drink for six hours before the scheduled
time of the procedure. The urologist or nephrolo-
gist may recommend stopping routine use ofNON-
STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS),
aspirin, and anticoagulation medications for 7 to
10 days before the scheduled ESWL to reduce the
risk of bleeding during or after the procedure, as
these medications interfere with PLATELET AGGREGA-
TIONand prolong the length of time a BLOODclot
takes to form. ESWL takes about an hour to per-
form, with about two hours in the recovery room
afterward. The person undergoing ESWL treat-
ment will need someone to take him or her to and
from the treatment center.

Procedure
The urologist or radiologist generally gives the
person an anesthetic or sedative for comfort
before the ESWL begins. The pressure of the shock
waves coming in contact with the stones can be
uncomfortable. The lithotriptor integrates FLUO-
ROSCOPYor ULTRASOUNDto pinpoint the location of
the targeted stone and can target several stones in
one ESWL session. The person wears a hospital
gown and lies on a cushioned table. The ESWL
technician positions the lithotriptor over the per-
son to deliver the shock waves, with continual

monitoring and adjustment to maintain accurate

focus. The radiologist or urologist makes sure the

person has adequate ANESTHESIA or SEDATION to

remain comfortable for the duration of the proce-

dure.

Risks and Complications

The most common risk associated with ESWL is

bleeding from the tissues around the site of the

stone, resulting in HEMATURIA(bloody urine) and

some discomfort. Many people experience discom-

fort for up to several days after the ESWL, for

which the urologist prescribes ANALGESIC MEDICA-

TIONS(pain relief). Most people should plan on

taking it easy for a few days after ESWL. It may

take days to weeks for all of the fragments to pass,

and larger fragments may cause pain when they

pass. Sometimes fragments of the stone cluster in

the ureter or URETHRA, temporarily blocking the

flow of urine and causing considerable PAIN. Gen-

erally movement (such as walking) and drinking

lots of fluids help flush these clusters from the

body, with appropriate analgesic medication to

mitigate the pain. Some people require several

ESWL sessions to completely disperse all of the

stones and fragments.

Outlook and Lifestyle Modifications

Once the stone breaks apart and the fragments

pass from the body in the urine, no further treat-

ment for the stone is necessary. The urologist or

nephrologist may recommend dietary changes,

increased physical activity, increased water con-

sumption, and sometimes medications to help pre-

vent new stones from forming. Such factors

depend on the stone’s content and the person’s

medical history, including other health conditions.

Both kidney stones and bladder stones tend to

recur.

See alsoCYSTINURIA; GALLBLADDER DISEASE; SUR-

GERY BENEFIT AND RISK ASSESSMENT.

Fanconi’s syndrome A dysfunction of the KID-

NEYSin which the renal tubules do not function

properly, resulting in a constellation of diverse

symptoms. The renal tubule, a structure of the

kidney’s filtering mechanism within the NEPHRON,

filters many substances from the BLOODto retain

those the body needs and excrete those the body

Fanconi’s syndrome 189