Welcome to the Kidney Stone Centre at St. Michael's.
This is a provincial
program affiliated with the University of Toronto.
The lithotripsy suite houses
one of three lithotripters in the province.
Our program, which has been in
operation since 1987, has treated more
patients than any other centre in the
world, and is renowned for its leadership role internationally.
On arrival, you will
be required to complete the registration process,
where the clerical staff and
nurses will ensure that all pretreatment
tests and x-rays have been completed.
The majority of patients will have a single
x-ray prior to treatment to ensure that
the stone location has not changed.
You will then be given an opportunity to
watch this educational video.
The procedure today is called shockwave lithotripsy
or SWL for short.
Lithos is from the Greek word for stone and
tripsy is from Trivian, to rub or break.
Shock wave energy is produced by an
electromagnetic shock head and focused
up through your body onto the stone.
The aim today is to break your stone into
small enough particles, two millimeters
or less, that can pass out through the
urinary system with minimal discomfort.
To help you understand your urinary
system, here is a diagram most patients
have two kidneys that filter urine from
their body. The urine collects in
cavities within the kidneys and drains
through tubes called ureters into the
bladder for storage. The bladder empties
via the urethra, the tube leading to the outside.
A kidney stone, or calculus, forms
within the cavity inside the kidney.
It may stay there attached to the wall, but
may pass into the ureter where it can
become stuck. Stones can be treated with
SWL in the kidney or ureter.
Before entering the lithotripsy
treatment room, you will be interviewed
by a nurse, your treating urologist and
the anesthetist.
Your history, test results and x-rays will be reviewed and
some of the questions are repetitive.
You will then be taken to the
lithotripsy treatment room. You will be
asked to remove your housecoat, but your
gown will be left on to ensure your privacy.
You will then be asked to get up
on the lithotripsy table. This is like an
x-ray table with a soft elastic membrane
in the centre to support you.
The anesthetist will then insert an
intravenous in order to give you some
medication to help keep you relaxed and comfortable.
ECG leads and a blood
pressure cuff will be applied to monitor
your heart rate and blood pressure
during the procedure. You will be given
supplemental oxygen to breathe while you
are sedated. Your position on the table
will be adjusted, and a small amount of
water will be poured onto the elastic
membrane supporting your body.
You'll feel your body lying in a small amount of water.
The shock head will then rotate
into position. The table will move, and a
C-shaped x-ray arm will rotate in to
target the stone. You will be notified
when the treatment is about to begin,
and then you will hear a clicking sound and
feel a tapping sensation on your back.
Try to remain quite still during the
treatment, as any movement may interfere
with the treatment of the stone.
The power of the shocks will gradually be
increased, and if you feel any discomfort,
remember to raise your left hand so that
more pain relieving medication can be
given by the anesthetist. The treatment
takes about half an hour, after which
time, you will be taken to the
post-anesthetic care unit, where you will be
monitored until the effects of the
sedation have largely worn off.
While in this area, your blood pressure will be taken,
and the treatment area will be checked.
An area of redness is common,
and usually disappears over the next few days.
You will be offered something to
eat and drink when you are ready.
Usually after one or two hours you will be ready
to go home,
but as you will still feel some effects
of the sedation, it is necessary for
someone to accompany you, and you should
not drive a car for 24 hours.
On discharge, you will receive written and
verbal instructions on what to expect
after your treatment.
You will also be given a strainer to
catch some stone fragments,
a requisition form
and a pre-addressed envelope for stone analysis.
If you experience any pain, you can take the prescribed pain medication.
However, you should call your
urologist or go to the nearest
emergency room if you are having severe
pain, which is not relieved by the oral
medication, or if you develop chills with
a fever higher than 38.5 degrees Celsius,
or if you develop persistent nausea or vomiting.
If you are
within the Toronto area you will be
given an appointment to the lithotripsy
clinic approximately two weeks after
your treatment to assess the results of
lithotripsy. If you live more than one
hour outside of the Toronto area, you
will be advised to make an appointment
to see your own urologist after two weeks.
Some patients with larger stones,
or stones in the ureter may not be
adequately fragmented by one treatment,
and about 15 per cent of our patients do
require a second treatment. This may be
booked immediately after treatment or
when you are seen at the two-week
follow-up visit. If you are interested in
stone prevention, please ask the staff
about the Provincial Kidney Stone Prevention Clinic.
If you have any questions,
please call the Kidney Stone Centre
at 416-864-3030
or toll-free at 1-800-263-2885.
During your time in the unit,
please feel free to ask us any questions
you may have about the treatment,
or the period following lithotripsy.
The staff is here to look after you.