RENAL STONE DISEASES
Renal stone disease is a frequent illness. In the West, it is estimated
that approximately 12% of males and 5% of females will have an episode
of renal colic during their lifetime. In countries with hot weather as in
Egypt higher incidence is expected especially in the presence of other
predisposing factors as bilharziasis.
Type of Stones:
Stones could be classified according to their radiologic and
structural features into:
- Radio opaque stones.
- Calcium oxalate which represents 60% of renal calculi.
- Calcium apatite or phosphates which represents 20% of renal
calculi.
- Radiolucent stones:
- Uric acid stones (7%)
- Magnesium ammonium phosphate (struvit or infection) stones
(7%). These are caused by infection with urea-splitting organisms,
particularly proteus and pseudomonas. - Cystine stones (3%)
- Magnesium ammonium phosphate (struvit or infection) stones
Pathogenesis of renal stones:
Always there are several factors playing together for stone
formation:
- Supersaturation of urine by salt (e.g. calcium oxalate).
- Increased urinary acidity.