The analysis of stone fragments seperated from perioperative fluid in the flexible ureterorenoscopy laser lithotripsy procedure used in kidney stone treatment via X-ray di̇ffracti̇on (XRD) method

Introduction: The lifetime prevalence of urinary system stone disease ranges between 1-15%. Uncovering the etiology of stone disease, which has high prevalence and recurrence rates, and identifying predisposing factors is as important as its treatment. Treatment guidelines strongly recommend the collection and analysis of stones. In this study, the aim was to determine the type of stone by analyzing the stone dust and fragments obtained by filtering the perioperative fluid collected from patients undergoing F-URS laser lithotripsy using the XRD method. Method: Patients aged 18-90 years diagnosed with kidney stones who were scheduled for F-URS laser lithotripsy at the Bezmialem Vakıf University Urology Clinic between 17.01.2024 and 17.07.2024 were prospectively included in the study. Following the collection of fluid containing stone dust and fragments, the material obtained by filtration was sent to the Ankara Mineral Research and Exploration (MTA) Laboratory for analysis using the XRD method. Results: The average age of the patients included in the study was found to be 50.57 ± 14.5 years. In the group consisting of 77 patients, 41.6% were female and 58.4% were male. Of the patients, 42.9% were treated for right kidney stones, and 57.1% were treated for left kidney stones. Multiple urinary system localizations of stones were found in 25.97% of the patients. The average stone density was measured as 1173.3 ± 359.13 Hounsfield Units (HU). The average stone volume was calculated as 1282 ± 1894 mm³. Hydronephrosis was detected in 38.96% of the patients included in the study. The average operation time was 89.14 ± 36.12 minutes. The proportion of patients for whom XRD analysis could be performed using the stone collection method used in the study was 85.71%. The most common types of stones were Whewellite and Whewellite + Weddellite. The effect of different variables on the ability to collect stones and perform stone analysis using the method described in the study was examined. No significant relationship was found between the ability to perform stone analysis and the variables of gender (p = .777), operation side (p = .259), stone volume (p = .150), stone localization (p = .918), stone density (p = .269), 10 degree of hydronephrosis (p = .130), BMI (p = .084), and operation time (p = .397) (p > .05). Conclusion: Examining the stone dust and fragments obtained by filtering the fluid containing stone dust collected perioperatively from patients who underwent F-URS laser lithotripsy using XRD offers advantages in terms of ease of application, no additional cost, and feasibility in any center where this operation is performed. Stones can be collected for XRD analysis using this method in every patient who undergoes F-URS. Additionally, the inclusion of a stone collection device in the aspiration sheaths recently introduced into use allows for the analysis of stones from every patient, enabling the application of metaphylaxis to prevent stone recurrence in necessary cases. Keywords: Flexible URS, Kidney Stone, XRD Stone Analysis