Chemical, Chromatographic and Electron Microscopic Analysis of the Bubbles Emerging During Holmium:YAG Laser Lithotripsy of Cystine Stone

Abstract

Abstract The primary aim of the present in vitro study is to analyze the chemical content of the bubbles occurring during the fragmentation of cystine stone with high-power and low-power Ho:YAG laser. The secondary aim of our study is to discuss their clinical importance. Human renal calculi (calcium oxalate monohydrate (COM), cystine, and uric acid) were fragmanted with low-power and high-power Ho:YAG laser in separate experimental setups at room temprature, and it was observed whether the gas production during this time. After laser lithotripsy, a cloudy colored gas was obtained only fragmentation of cystine stone. Qualitative gas content analysed performed with Gas chromatography–mass spectrometry device. In addition, the fragments in the aqueous cystine calculi setup were dried and taken to the laboratory to be examined with scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and X-ray diffraction analysis. No gas production was observed after fragmentation in the COM and uric acid stone. Free cystine, sulfur, thiophene, and hydrogen sulfide gas were produced by low-power and high-power Ho:YAG laser lithotripsy of cystine stone. In SEM-EDX mapping analysis, free cystine molecule containing 42.8% sulfur (S), 21% oxygen (O), 14.9% carbon (C), 21% nitrogen (N) atom was detected in the cystine stone experimental setup. The evidence obtained that hydrogen sulfide emerges in the gaseous environment during Ho:YAG laser fragmentation of cystine stone requires caution against the risk of in vivo production and toxicity.