Retrograde intrarenal surgery technique without using fluoroscopy and access sheet in the treatment of kidney stones

Personalized Prediction of Patient Radiation Exposure for Therapy of Urolithiasis: An Application and Comparison of Six Machine Learning Algorithms

The prediction of radiation exposure is an important tool for the choice of therapy modality and becomes, as a component of patient-informed consent, increasingly important for both surgeon and patient. The final goal is the implementation of a trained and tested machine learning model in a real-time computer system allowing the surgeon and patient to better assess patient's personal radiation risk. In summary, 995 patients with ureterorenoscopy over a period from May 2016 to December 2019 were included. According to the suggestions based on actual literature evidence, dose area product (DAP) was categorized into 'low doses' ≤ 2.8 Gy·cm² and 'high doses' > 2.8 Gy·cm² for ureterorenoscopy (URS). To forecast the level of radiation exposure during treatment, six different machine learning models were trained, and 10-fold crossvalidated and their model performances evaluated in training and independent test samples. The negative predictive value for low DAP during ureterorenoscopy was 94% (95% CI: 92-96%). Factors influencing the radiation exposure were: age (p = 0.0002), gender (p = 0.011), weight (p < 0.0001), stone size (p < 0.000001), surgeon experience (p = 0.039), number of stones (p = 0.0007), stone density (p = 0.023), use of flexible endoscope (p < 0.0001) and preoperative stone position (p < 0.00001). The machine learning algorithm identified a subgroup of patients of 81% of the total sample, for which highly accurate predictions (94%) were possible allowing the surgeon to assess patient's personal radiation risk. Patients without prediction (19%), the medical expert can make decisions as usual. Next step will be the implementation of the trained model in real-time computer systems for clinical decision processes in daily practice.

Systematic Review and Meta-Analysis Comparing Fluoroless Ureteroscopy and Conventional Ureteroscopy in the Management of Ureteral and Renal Stones

Context: Stone recurrence is frequent in stone formers, and repeated diagnostic and therapeutic procedures in recurrent stone formers place patients and urologists at a significant risk of radiation-related effects. Objective: To assess the efficacy and safety of fluoroless ureteroscopy (fURS) compared with conventional ureteroscopy (cURS) in the management of ureteral and renal stones. Evidence Acquisition: A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies providing data on the stone-free rate (SFR), secondary procedures, operative time (OT), and complication rate for fURS and cURS were included. An overall analysis and a subgroup analysis based on the stone target (ureteral stones, renal stones, or a combination thereof) were performed. Evidence Synthesis: A total of 23 studies were included, recruiting 4029 patients. Pooled data showed that in comparison with cURS, fURS exhibited a similar SFR (odds ratio [OR]: 0.99; 95% confidence interval [CI]: 0.92 to 1.06; p = 0.709), without significant differences in overall intraoperative complication rate (OR: 0.73; 95% CI: 0.33 to 1.63; p = 0.446), overall postoperative complication rate (OR: 0.98; 95% CI: 0.59 to 1.63; p = 0.949), major postoperative complication rate (Clavien ≥3; OR: 0.46; 95% CI: 0.14 to 1.53; p = 0.205), OT (standardized mean difference [SMD]: 0.07; 95% CI: -0.15 to 0.29; p = 0.537), hospital stay (SMD: -0.12; 95% CI: -0.26 to 0.02; p = 0.084), or secondary procedures (OR: 1.20; 95% CI: 0.58 to 2.49; p = 0.616). The subgroup analysis revealed no differences in outcomes according to the stone target. We also identified a rate of conversion to the conventional technique of 5% (95% CI: 3% to 7%). Conclusions: The available data suggest that for the treatment of ureteral and renal stones, fURS offers a similar SFR to that provided by the cURS without any increase in complication rate, OT, hospital stay, or secondary procedures. Critical review of the dogmatic routine use of fluoroscopy during ureteroscopy may be warranted.