do stones form?
cause of urinary stone formation remains the subject
of major research. To put it briefly the urine
is made up of a number of compounds (solutes)
in solution and there is always a tendency for
these solutes to crystallize out forming stones.
Various agents act as promoters and inhibitors
of crystallization. Stone formation is influenced
by dietary factors, nature and amount of fluid
intake, age, sex, climate, geography, hygiene,
do stones form?
all stones are formed in the kidneys, initially
as small particles. These particles grow within
the kidney to varying sizes, often filling up
the whole kidney as a branched stone (the staghorn
calculus). Sometimes they move out of the kidney
when relatively small, and then migrate down the
ureter into the bladder. As they migrate down
the ureter they may block the ureter causing obstruction
to the flow of urine: this results in pain which
may be very severe (colic). Some reach the bladder,
and lodge there, growing larger and larger. Rarely
they block the urethra causing a painful retention
are the symptoms of urinary stones?
days silent urinary stones are often diagnosed
incidentally in the course of routine health check
ups. These stones are usually small, though rarely
even large stones may be symptom-free. Stones
cause symptoms depending on their location. Thus
stones in the kidney may cause a dull ache, a
violent colic, an urinary infection or the passage
of blood in the urine.
are stones diagnosed?
ultrasound examination picks up most urinary tract
stones. However a special X-ray called an IVU
is usually considered essential in the treatment
of urinary tract stones. The urologist will also
request urine tests, blood tests, and occasionally
more specialised tests like renography/ CT scan/
is an IVU?
it a dangerous and painful test? The IVU test
refers to an intravenous urogram or pyelogram.
In this test an iodine containing dye is injected
intravenously, usually into a forearm vein. The
kidneys excrete this dye, and if X-rays are now
performed the structure and function of the kidneys
can be assessed. The whole of the urinary drainage
system: the calyces, pelvis and ureters are demonstrated
on the X-rays. In patients with stones the exact
position of the stone can be assessed, and proper
test may mean spending a minimum of an hour and
sometimes several hours in the X-ray department
where repeated X-rays are taken. Otherwise this
is quite a simple test.
is a rare incidence of serious allergy to the
injected dye, but the modern agents used these
days are very safe. The radiologist will discuss
the test with you. Please also inform the radiologist
if you have history of allergy or asthma.
the urologist the IVU provides unparalleled information
and is often essential.
Do all urinary stones need treatment?
stones less than 5 mm in size pass out spontaneously,
and the urologist may advise "expectant"
treatment. The patient is encouraged to drink
plenty of fluids, and is asked to report for follow-up
periodically, and surgical intervention considered
only if the stone causes symptoms, or remains
stationary at a particular location, or enlarges
progressively in size.
there a medicine for stones?
is no known medicine that dissolves stones consistently
and predictably. One should drink plenty of fluids,
and the doctor will advise you about a specific
diet if indicated.
are the treatments available for stones?
various options available are: lithotripsy, percutaneous
nephrolithotomy, open surgery.
many centuries surgery was the only option in
treating stones that would not pass spontaneously.
About 22 years ago the German aeronautics company
Dornier, through ground-breaking research, developed
the means for focusing external energy to treat
Kidney stones and pulverize them to small fragments
that are voided naturally with the urine. This
was a major advancement, perhaps one of the most
significant medical advancements of the last century.
the last 20 years lithotripter applications for
renal stone therapy have been perfected, and these
days lithotripsy is performed as a day procedure
in a painless fashion. For this treatment the
patient lies on a special couch. X-ray and/or
ultrasound are used to target the stone, and by
a computerised system the stone is placed at the
focal point of the energy source of the lithotripter.
Treatment usually lasts about 45 minutes. After
treatment the patient rests for a while and then
is allowed to return home. Sometimes a "stent"
is placed in the ureter if it is anticipated that
the stone fragments may block the ureter after
lithotripsy. Repeat sessions of lithotripsy may
be required, usually not earlier than 5-7 days.
all urologists realize that lithotripsy is, sadly
not an answer to many of the stones seen in day
to day practice. The reason is that for stones
that are more than 3 cms in size, branched stones
and various other complicated situations lithotripsy
is either not effective or is slow to work with
patients needing multiple procedures and hospital
these patients, surgery still remains a valid
option. In an average practice in India, where
patients present with advanced and neglected disease,
at least 40% of kidney stones fall into this category.
These larger stones are removed by a new technique
called PCNL or percutaneous nephrolithotomy.
kidney stones be treated by "microsurgery"?
What is PCNL?
kidney stones can be treated by what is popularly
known as "microsurgery" though the correct
medical term would be percutaneous nephrolithotomy
(PCNL). In this technique the stone is removed
by making a small tunnel into the kidney from
the back. A fine needle is used to puncture the
renal collecting system with the aid of X-ray
and/or ultrasonography, and a guide wire is led
into the kidney through the needle. This guide
wire is dilated and a nephroscope (kidney telescope)
is inserted into the pelvis of the kidney. The
stones are visualized, fragmented, and extracted,
allowing the kidney to be rendered free of stones
at the end of the operation in the vast majority
patients. This is of course an operation, needing
full general anesthesia, average 90 minutes of
operation time, 3 -4 day hospitalization and an
occasional need for blood transfusion. Patient
returns to light work in 7 days time. Nevertheless
the operation is safe, for both the patients and
the kidney. This operation has really reduced
the need for open surgery (cutting surgery), which
is now reserved for exceptional indications.
seem to be many ways of treatment? What is right
now there is a choice of treatment options for
Kidney stones, both to the patients and to the
surgeon. Lithotripsy is reserved for the smaller
stones. For stones larger than 3 cms in size PCNL
is the preferred modality of treatment. The major
advantages of PCNL over lithotripsy would be :
procedure complete stone clearance applicable
for most types of kidney stones.
for therapy of large stones, branched stones,
stones in multiple locations of the Kidney.
of repeated hospital visits and less loss of
more cost effective option.
morbidity, and early return to normal life and
are stones in the ureter treated?
depends on the size of the stone, and the location
of the stone. Small stones, less than 5 mm, often
pass spontaneously and may be treated expectantly.
If treatment is considered essential most ureteric
stones are treated by ureteroscopy. In this technique
a fine instrument called the ureteroscope is passed
under anaesthesia to the ureter until the stone
is reached. Once reached the stone is fragmented
with a energy probe. The most common form of energy
probe used is the pneumo-ballistic lithotripter
which works on the principal of the pneumatic
drill. Other energy sources for lithotripsy within
the ureter include ultrasonic, electrohydraulic
and laser devices. After pulverisation the stone
fragments are washed out or extracted, and a fine
tube (stent) is left in the ureter (usually) for
a few weeks. Very large ureteric stones may be
removed by open operation or by laparoscopy.
stones form again after complete removal?
answer unfortunately is yes, even if the stone
has been completely removed. This is because the
factors that cause stone formation persist. The
doctor will probably investigate you thoroughly
for biochemical abnormalities that cause stone
formation and then advise you about the any diet
changes that you may have to make. A high fluid
intake is routinely advised. You will also need
to be followed up closely.