[Are Optimal modes of laser lithotripsy optimal?]

Objective: to evaluate the effectiveness of the recommended modes of laser lithotripsy in clinical practice by analyzing the necessity of changing laser radiation parameters during percutaneous nephrolithotripsy (PCNL), ureterolithotripsy (URS) and retrograde intrarenal surgery (RIRS).

Materials and methods: a prospective non-randomized clinical study was conducted from October 2023 to December 2023. Patients who underwent surgical procedures for urinary stones using a Thulium fiber laser at the Clinic of Urology of Sechenov University were included. Data on localization, size and radiological density of the stones, initial parameters of laser radiation, presence or absence of mode change were recorded. Statistical data was processed using IBM SPSS Statistics software, version 26.0.0.0.0.

Results: 90 patients were included in the study. Laser radiation mode change was recorded in 38% of cases when performing RIRS, in 25% - during PCNL, and in 24% - during URS. A significantly higher total energy consumption at comparable volumes and radiological density of the stones was registered in the group of mode change at RIRS. In the URS group the results suggest that the laser radiation mode change depends on the volume and density of urinary stones.

Discussion: the need for intraoperative change of laser radiation modes in 31% of all observations may indicate that the existing optimal modes for stone destruction in clinical practice may be suboptimal. New studies of the structure and mechanical properties of urinary stones, assessment of their porosity, hardness, size and properties of crystals, as well as the use of Artificial Intelligence for automatic set up of laser radiation parameters for higher efficiency of lithotripsy.

Conclusion: In addition to linear size and radiologic density urinary stones have a whole complex of morphometric and physicochemical characteristics, so the laser lithotripsy parameters preset should be viewed only as a guideline, while effective settings are to be selected intraoperatively considering urologists knowledge of laser radiation physical properties.