Introduction. The prevalence of urolithiasis (ICD) reaches 5-20% with an annual increase. Endoscopic methods play a leading role in the surgical treatment of urolithiasis.  The aim of the surgery is the achievement of stone free status without complications. The technological progress has led to the development of computer programs for visualization before the surgery, which have been used to assess the topography, skeletotopy, anatomy of the renal cavity system, structural features and angioarchitectonics.

Aim of the study. Improving the effectiveness and safety of percutaneous interventions using the biometric planning method.

Materials and methods. We analyzed the treatment results of 120 patients who were underwent percutaneous interventions for nephrolithiasis in the period from 2019 to 2021. The main method of preoperative examination was multispiral computer tomography (MSCT) with 3D reconstruction and biometric assessment of anatomical parameters.

Results. Single kidney stones were detected in 45 patients, multiple – in 24, coral-shaped – in 51 patients. The growth of microflora in urine culture was noted in 64 cases. The average time of X-ray screening was 20.5 minutes (7-34 minutes). The average duration of surgery is 110 minutes (65-240 minutes). Complete purification of the calyx-pelvic system from concretions was achieved in 78% of patients. Complications were detected in 21 (17.5%) patients, 52% of them – grade I-II on the Clavien-Dindo scale. The optimal parameters for percutaneous nephrolithotripsy in monotherapy mode were determined: lower polar anatomy – neck length < 2 cm, width > 0,5 cm, lower cervical-pelvic angle > 70°, lower cervical-frontal angle >135°; upper polar anatomy – single calyx, calyx neck length < 2 cm, width calyx necks > 1,0 cm, upper cervical-cervical angle > 135°, upper cervical-frontal angle >135°; anatomy of the central segment – A1.

Discussion. The creation of a morphometric model makes it possible to define the stages of surgery, reduce the risks of complications, increase the efficiency and safety of the procedure.

Conclusion. Currently the use of biometric parameters before percutaneous and endoscopic intrarenal interventions is the most effective method of virtual planning, which allows to free the urinary tract from the maximum volume of stone and return the patient to a full life in the shortest possible time.