Results of 5,035 stone analyses: a contribution to epidemiology of urinary stone disease

Between 1978 and 1988 5,035 urinary calculi have been analysed by X-ray diffractometry. 1,615 of these stones have additionally been investigated by scanning electron microscopy (SEM). The overall sex-ratio was 1.86 (m/f). Ca-stones and uric acid containing stones are more frequent in male patients (m/f = 2.08 and 3.86, respectively) whereas infection stones and cystine stones show a higher rate of appearance in female patients (m/f = 0.6 and 0.88, respectively). The percentage of open surgery ranged about 30% in the first few years but decreased to 5-7% in the last few years due to the new methods of stone removal. The rate of occurrence of the crystalline phases does not differ remarkably from other statistics except for a higher incidence of apatite because of the high sensitivity of detection of this phase by SEM. The recurrence rate of brushite stones amounting to 66.7% is very high and exceeds even that of cystine stones (60.7%).