In vitro performance of the Vortex Intelligent Stone Optimized Removal (VISOR) system versus the flexible and navigable suction ureteral access sheath (FANS) on stone clearance efficiency and intrarenal pressure control

INTRODUCTION: Flexible and navigable suction ureteral access sheath (FANS) ureteroscopy has been recognized as an important development in the suction era of endourology. The Vortex Intelligent Stone Optimized Removal (VISOR) system has recently been introduced as an alternative to FANS, featuring an integrated irrigation-suction dual-channel and IRP control design. This study aimed to evaluate the efficacy of VISOR system in comparison with FANS in vitro. METHODS: 3D-printed renal models were used, and 3 g of human calcium phosphate stones were treated via VISOR system versus FANS ureteroscopy. All procedures were performed by a single experienced urologist with a holmium laser. Primary outcome was stone clearance efficiency (SCE), calculated as: SCE (%) = [(Initial stone mass - Residual stone mass) / Initial stone mass] × 100%. Secondary outcomes included operative time, total laser energy use, residual stone mass and total stone mass removed. Accuracy of IRP measurements was also tested for the VISOR system. RESULTS: The VISOR system demonstrated comparable SCE to FANS (95.1 ± 0.6% vs. 94.8 ± 0.7%, p = 0.78). The mean operative time in the VISOR group was significantly lower by 26.2% compared with FANS (55.1 ± 2.2 vs. 74.7 ± 2.3 min, p = 0.003). We found no difference in total laser energy use (33.6 ± 1.4 vs. 33.3 ± 5.3 kJ, p = 0.96), residual stone mass (0.15 ± 0.03 vs. 0.15 ± 0.04 g, p = 0.99) and total removed stone mass (1.86 ± 0.13 vs. 1.81 ± 0.12 g, p = 0.79). The VISOR system's pressure sensor showed good correlation with an external reference pressure meter (Spearman R = 0.99, p < 0.0001). CONCLUSIONS: Based on these in vitro findings, the VISOR integrated dual-channel system demonstrated SCE comparable to FANS, with significantly shorter operative time and reliable real-time IRP control. These results suggest that the VISOR system represents a promising candidate for further clinical evaluation; whether these performance advantages translate to improved patient outcomes in vivo requires confirmation in prospective clinical studies.