Kidney Stone Calculator

Urolithiasis is a frequent pathology, for which flexible ureteroscopy with endocorporeal laser lithotripsy has become the most frequently used surgical treatment. This procedure is limited to 90 minutes and will depend mainly on the total lithiasis volume. Knowing the duration of lithotripsy before the operation would allow to foresee situations of iterative procedures and to improve the patient's path (ambulatory or conventional surgery, work stoppage, optimization of operating times and operating room occupation times). "Kidney Stone Calculator" is a free tool capable of providing a calculi volumetry and predicting the duration of endocorporeal laser lithotripsy.The main objective of this study would be to evaluate the performance of the Kidney Stone Calculator in estimating the duration of laser lithotripsy during flexible ureteroscopy for renal calculi, by analyzing the agreement between the estimated and actual lithotripsy durations, evaluated by an intraclass correlation coefficient and its 95% confidence interval Eligible patients will be those scheduled for flexible ureteroscopy for renal calculi described on a non-injected abdominopelvic scan. A total of 240 patients over a 15-month inclusion period is planned, with a follow-up time of 3 months.

Inclusion Criteria:Age ≥ 18 yearsOne or more kidney stones documented on a preoperative non-injected abdominopelvic CT scanscheduled for flexible ureteroscopy with endocorporeal laser lithotripsyusing a reference laser (Holmium:YAG or Thulium Fiber)no opposition to the reuse of care data for researchExclusion Criteria:Ureteral calculiEncrusted JJ stentPercutaneous surgical stone managementPlanned monobloc extraction of the stoneSuspicion of struvite type stone (phosphasto-amoniacal-magnesium)