An in-vitro comparative study of magneto holmium: YAG and fiber dust thulium fiber lasers-primary effects on ablation, retropulsion, fragmentation, and temperature changes using phantom urologic stones.

OBJECTIVE

This in-vitro study compared the Magneto Holmium: YAG (Ho: YAG) laser (Standard, magneto, Virtual Basket settings) with the Fiber Dust Thulium Fiber Laser (TFL) (short and long pulse settings). The aim was to evaluate retropulsion, ablation efficiency, temperature, fragmentation time and laser efficiency in gypsum phantom stones. Tests were conducted at three energy levels (0.5 J, 1 J, 2 J) and with two fiber sizes (200 μm and 550 μm).

METHODS

Synthetic gypsum stones were prepared. A Quanta System Magneto Holmium-YAG Laser (Cyber Ho 150 W Magneto) and a Thulium Fiber Laser (Fiber Dust) were used for stone fragmentation. A high-speed camera captured stone displacement within an acrylic water bath.

RESULTS

Retropulsion was generally reduced and more consistent with TFL (especially Short pulse) and Ho: YAG Magneto settings (P < 0.001). TFL Short pulse demonstrated significantly higher ablation efficiency compared to Ho: YAG Standard and Virtual Basket modes (P < 0.001). Temperature rise was notably significantly higher with TFL Long pulse, compared to all Ho: YAG settings; whereas TFL Short pulse also induced a greater temperature increase than Ho: YAG Standard mode (P = 0.003). Both TFL Short pulse and Ho: YAG Magneto significantly reduced fragmentation time compared to Ho: YAG Standard (P = 0.001). TFL Short pulse showed significantly greater overall laser efficacy than all Ho: YAG modes (P = 0.003).

CONCLUSION

Thulium Fiber Laser (TFL) achieves rapid ablation and fragmentation, it generates significantly more heat, especially in long pulse mode. In comparison, the Ho: YAG Magneto setting delivers fast fragmentation and high ablation efficiency with minimal thermal rise. Further in vivo studies are needed to confirm these advantages in practice.