This is a simple non invasive technique by which stone is powdered inside the kidney. Our modern
machine does not require general anesthesia as it produces, very little pain. Hence this is an outpatient
procedure, not requiring admission.
A mechanical shock wave is generated under water and focused on the stone by
special machines. The shock wave cause cracks to form in the stone. Urine gets in to
these cracks and cause fragmentation. This fragmentation may take from 1 to 14 days.
Stones in the kidney and upper ureter less than about 1cm size and not
obstructing the kidney completely, can often be treated by ESWL. Such
stones can also be treated by other techniques such as RIRS – Retrograde Intra Renal Surgery. The
advantage of ESWL, is that it avoids any wound on the skin, and is an outpatient procedure, not
requiring anesthesia (in our hospital).
However there are a few disadvantages. The fragmented stones take a few days to clear from the
urinary passage. During their transit the fragments may cause discomfort in spite of the medicines the
doctor prescribes to prevent this. If the stone has not fragmented completely in the first session, further
sessions will be required at 3 weekly intervals. ESWL is successful in 80% of cases. In 20%, when
ESWL falls, RIRS is required.
Under anaesthesia a 3 mm diameter flexible telescope is passed into the kidney via the Urethra
(water passage from bladder) Bladder and up the Ureter (the tube connecting the bladder and Kidney).
The stone in the kidney can then be fragmented using laser fibre passed through this flexible telescope
called flexible Ureteroscope.
- You can have a light diet - non gas forming - regular meal before the procedure.
- You should have had plenty of fluids as stones break better if there is a good urine output.
- No anaesthesia is required as the procedure produces little pain.
- You will be sedated to prevent you from moving. Movement causes the focus of the shock waves to
shift from the stone. Though this will not produce any damage to surrounding structures, stone
fragmentation will not be effective.
- The machine produces a very loud noise as each mechanical shock wave is produced. To decrease
the sound an ear muff will be placed over your ears to muffle the sound.
- You will be kept in hospital for another 2 to 3 hours or until you are free of sedation and safe
enough to travel.
- You cannot drive home - you can travel as a passenger, but not on a 2 wheeler.
- A list of medicines will be given to help pass the stone fragments. Medicine for any pain during
passage of the stone fragments will also be given.
- You should sieve urine and bring all the fragments for stone analysis. Suitable sieve is available in
- Complete fragmentation may take up to 2 weeks. Therefore, next outpatient review is usually afer
- You should take an X-ray on an empty stomach in the morning before seeing the doctor in the
outpatient clinic at the time of outpatient review. Therefore 2 types of tablets given to you at discharge
for decreasing the gas content in the intestines , should be taken the day before X-ray. This will be
written in the discharge summary.