THERMAL ANALYSIS OF UPPER URINARY TRACT STONES WHICH WERE PASSED

Abstract

102 passed stones which had been analysed by X-ray diffraction and infrared spectroscopy and found to be composed of calcium oxalate and apatite were studied by thermal analysis to determine the contents of weddellite, whewellite, apatite and organic matrix. The results are as follows:
1) There was a statistical correlation between the ratio of weddellite to weddellite plus whewellite determined by thermal analysis and that determined by X-ray diffraction (r=0.954).
2) There was a statistical correlation between the apatite content determined by thermal analysis and that determined by infrared spectroscopy (r=0.807).
3) The content of organic matrix was 3.8±2.2% (mean±S. D.), with a range of 1.1 to 17.2%. The content of organic matrix was correlated with the whewellite content (r=0.708) and with the apatite content (r=0.517).
The stones then were divided into 3 groups according to the principal constituent: weddellite, whewellite and apatite groups.
4) The stones of the weddellite group were significantly heavier than those of the whewellite group (p<0.01) and also seemed to be heavier than those of the apatite group.
5) The apatite content was correlated with the ratio of weddellite to weddellite plus whewellite in the weddellite and whewellite groups (r=0.528) and in the apatite group (r=0.742).
Thus, it is considered that the weddellite-apatite and whewellite-organic matrix associations have important roles in the development and growth of weddellite and whewellite calculi, respectively.