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Objective To identify the correlation between demographic factors and upper urinary tract stone composition in the Thai population. Method A retrospective observational study of first-time upper urinary tract stone former patients aged over 18 years who underwent stone surgery was performed in a tertiary referral university hospital from January 2013 to May 2018. Collected data included demographic information and stone composition information, which were analysed by the Fourier Transform-Infrared Spectroscopy (FTIR) method. The correlation between the demographic factors and major upper urinary tract stone composition was analysed using Fisher's exact test. Results A total of 480 patients were included in this study. The stones were 319 (66.5%) renal calculi and 161 (33.5%) ureteric calculi. There were 248 (51.7%) single composition stones and 232 (48.3%) mixed composition stones. The major stone compositions were 288 (60.0%) calcium oxalate (CaOx), 125 (26.0%) calcium phosphate (CaP), 40 (8.3%) uric acid (UA), 19 (4.0%) magnesium ammonium phosphate (MAP), five (1.0%) cystine, and three (0.6%) ammonium hydrogen urate (AHU). Gender was correlated with the major stone composition. In females, a correlation was found between the major stone composition and age, diabetes mellitus (DM), and glomerular filtration rate (GFR). The study showed no significant correlation between the major stone composition and dyslipidemia (DLP), hypertension (HT), gout, and body mass index (BMI) in both genders. Conclusion Gender, age, DM, and GFR were the factors affecting the stone composition.

Introduction Flexible ureteroscopy involves expensive equipment that is expensive to repair. This study aimed to investigate the effects of cleavage by various tools on the laser fiber tip and to determine the extent of damage incurred to the laser passing through the working channel and firing at different degrees of deflection. Materials and methods We investigated the effect of cleavage on Lumenis Slimline reusable fibers (272 and 365 μm) as performed by four cleavage tools: a scribe pen, a surgical blade, suture scissors, and ceramic scissors. Following cleavage, we recorded the pattern of light dispersion and power output. The laser fibers passed through the working channel at various. Results The ceramic scissors provided the best pattern of light dispersion and the highest power output. The suture scissors provided unacceptable levels of light dispersion. The 272 μm fiber was able to pass through the working channel at 30 and 45 degrees of deflection. The 365 μm laser fiber was only able to pass through the working channel at 30 degrees of deflection. There was no breakage of the laser fiber at any of the degrees of deflection evaluated. Conclusions Analysis showed that the ceramic scissors were the best tool for cleaving Lumenis Slimline reusable fibers and that suture scissors were unacceptable. We also found that the deflection angle that causes damage to the working channel by laser insertion is dependent on both the size of the laser fiber and the degree of bending. Firing the laser during scope deflection could be performed safely at any degree of deflection, even with a high laser power of 40 W for a duration of 30 s