Syslematic classification of gallbladder stones

Objective To develop a classification of gallbladder stones,to analyze the clinical characteristics of each type of stone and to provide a theoretical basis for the formation of different types of gallbladder stones.Method 925 consecutive patients with gallbladder stones were enrolled and their gallstones were studied.The material composition of the gallbladder stones was analyzed using fourier transform infrared spectroscopy and the distribution and microstructure of the material components were observed using scanning electron microscopy.The composition and distribution of the elements were analyzed by an X-ray energy spectrometer.Gallbladder stones were classified accordingly.Results The gallbladder stones were classified into 8 types and more than ten subtypes,including cholesterol stones (n =334),pigment stones (n =246),calcium carbonate stones (n =167),phosphate stones (n =14),calcium stearate stones (n =11),protein stones (n =3),cystine stones (n =1) and mixed stones (n =149).Mixed stones were those stones with two or more than two kinds of material components and the content of each component was similar.A total of 11 subtypes of mixed stones were found in this study.Conclusion The systematic classification of gallbladder stones indicated that different types of stones had different characteristics in terms of infrared spectrogram,microstructure,elemental composition and distribution,thus providing an important basis for the mechanistic study of gallbladder stones. Key words: Gallbladder stones;  Stone type;  Spectral analysis;  Scanning electronic microscopy;  X-ray energy spectrometer