ESWL
(Extra Corporeal Shockwave Lithotripsy)
 |
Extra Corporeal Shockwave Lithotripsy (ESWL)
is
a procedure whereby urinary stones are broken using a special machine
without surgery. A shockwave is generated in a water bath or a gel
filled bag placed under the patient by producing a high voltage spark.
This has the same effect as throwing a pebble in a pond and producing
ripples on the water surface. As the shockwave travels through the human
tissues it does not cause any significant damage. However as it meets a
urinary stone it will break up crystals which the stone is made of.
It may take up to two thousand shockwaves, or more, to complete the fragmentation.
Sometimes, multiple stages become necessary. |
Indications
ESWL is best suited for stones in the kidney and kidney pelvis. The success
rate for stones less than one inch in size is about ninety percent . Stones in the mid
ureter and the lower ureter will break up in fifty percent of the cases.
Procedure
Before ESWL it is customary to place a ureteral stent
from the bladder
to the kidney. This is a small caliber tube about the size of the tip
of a lead
pencil made of silicone. This tube will help localize the stone during
the
procedure since X-Ray is used to find the stone and bring it to the
focus. After the procedure the stent helps the patient pass the
fragments.
This happens because the stent makes the ureter larger and the pieces
pass by
the stent more easily. The disadvantage of having the stent is that in
some
patients the tip of the stent which extends into the bladder can cause
irritation and
frequent urination. Since the stent has no valves as a normal ureter,
urine may back
up to the kidney specially during voiding and this can cause pain in
the flank.
At times the stent can cause blood in the urine. This will usually
subside after
a period of rest. Naturally the stent will have to be removed after the
stone
fragments pass. This is done by cystoscopy.
Post Op
After the patient wakes up from anesthesia he is taken to the recovery room
where he will recover for about thirty minutes . Following that he will go back
to patient holding where he can be seen by his family. Sometimes it is necessary
to dismiss the patient with a foley catheter and a leg bag to be removed the
next morning.
