To evaluate the application of Mixed Reality technology in the planning of ultrasound-guided percutaneous nephrolithotomy (PCNL) for special types of complex upper urinary stones.

Clinical data of 15 patients with complex upper urinary stones undergoing ultrasound-guided PCNL were analyzed which included pelvic ectopic kidney, horseshoe kidney, spinal deformity, and transplant kidney. Based on preoperative computed tomography urography (CTU) data, digital 3-dimensional reconstruction is performed, and AI mixed reality is used to project 3-dimensional images in real space. This facilitates preoperative design and planning. The consistency rate of target calyx and channel numbers, stone-free rate, total operative time, percutaneous renal access establish time, decrease in hemoglobin level, surgical complications, and postoperative hospital stay are analyzed.

All patients underwent preoperative planning using mixed reality and successfully completed PCNL. Based on the preoperative planning, we utilized S-PCNL alone or combined with Needle-perc or antegrade/retrograde flexible ureteroscopic surgery. The consistency rate between preoperative planning and intraoperative completion was 87.6%. The stone-free rate was 80%. The average time for establishing the main tract was 2.3 ± 0.3 minutes, and the average total operative time was 61.5 ± 12.2 minutes. The mean decrease in hemoglobin level was 9.6 ± 1.2g/L, and the average postoperative hospital stay was 4.6 ± 0.5 days. There were no occurrences of Clavien-Dindo grade≥II complications.

Preoperative quantification and analysis of imaging data through mixed reality enable 3-dimensional visualization and facilitate surgical plans, and effectively avoid the risks of surrounding organ injury in these special urinary stones cases, make complex surgeries smoother and more controllable.