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Prevention of Stone Disease
Most patients will have a further stone
episode within 10 years. After the stone has been analyzed and the patient
is asymptomatic, and provided that no other significant risk factors have
been identified, most patients are advised regarding adequate fluid intake
and dietary moderation. Fluid intake is usually adequate once the urine is
almost as clear as the water they drink. Further metabolic evaluation is
usually not undertaken until the patient has had more than two stone
episodes. Patients with uric acid stones need to moderate foods with high
purine content such as shellfish and lobster and also maintain a liberal
fluid intake.
Treatment of Symptomatic Stones
A. Conservative.
A conservative trial can be followed in those whose pain is controlled
and have no septic episodes and in those that have two functioning kidneys. Most patients
present with a stone in the end of the ureter, and at least 50% of these will pass
spontaneously.
B. Surgical.
i. Ureteroscopic stone extraction.
Patients who have a stone in the lower ureter and who fail a trial of
conservative care can benefit from outpatient laser ureteroscopic stone extraction. As an
outpatient under a general anesthetic, a specialized telescope is advanced up the affected
ureter and a laser probe used to break the stone. A flexible ureteroscope may be used to
visualize stones in the kidney.
Fragments can then be removed with a special wire basket and a double-J
stent left in place in the ureter that can be removed in the office a day
or two later. This stent allows urine to pass from the kidney to the
bladder; otherwise, swelling of the ureter from the instrumentation would
obstruct the ureter and cause intense pain.
ii. Extracorporeal shock wave
lithotripsy (ESWL).
Renal and some ureteral stones can be fragmented
through a process whereby shock waves are delivered through the body onto
the stone using x-ray control. This applies usually only to stones that
can be seen under x-rays. Stents may or may not be used. The stone
fragments will usually pass within a 2-week period.
iii. Percutaneous nephrolithotomy.
Needle puncture of the kidney under a general anesthetic,
subsequent tract dilatation and use of a specialized rigid or flexible
nephroscope with or without the use of laser fibers may allow direct
visualization and destruction of renal calculi. Remaining calculi may be
retrieved through various alternative and additional procedures if dealing
with complicated kidney anatomy and very large stones. For example, additional percutaneous puncture access,
ESWL, flexible ureteroscopes and/or irrigations through the nephrostomy
tract may be reasonable.
iv. Open Surgery Procedures for Stones.
Because of the foregoing, it is very unusual to have to resort to
any of the open procedures that were at one time standard approaches to those with stone
disease.
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