Presentation Authors: Laurian Dragos*, Ghiroda, Romania, Bhaskar K. Somani, Southampton, United Kingdom, Keller Etienne X., De Coninck Vincent M.J., Doizi Steeve, Paris, France, Cumpanas Alin A., Martis Sandra M., Livius C. Daminescu, Timisoara, Romania, Wiseman Oliver J., Cambridge, United Kingdom, Traxer Olivier, Paris, France
Introduction: The Moses Technology developed to enhance the High power Holmium lasers (HPH) lithotripsy is challenged by the novel Super-pulse Thulium fibre laser. The goal of our study was to evaluate in-vitro which laser has a better stone ablation effect.
Methods: An in-vitro observational study was performed using a Super-Pulse Thulium fiber (SPT) laser prototype with 200Âµm fibre and a High-Power Holmium (HPH) laser Moses Technology (Lumenis Pulse 120H) with 230Âµm fibre. A mechanical device for precisely holding the laser fibre was created (Fig.1). Fine metal sheets calibrated at different widths were used to fix the laser fibre at the required distance from the tissue. The laser was activated for ten seconds using different laser settings and at different distances from the target (0 mm, 1 mm, 2 mm), in saline. Calcium oxalate monohydrate (COM) - like artificial stones were created in a standardised manner. The ablation volumes were precisely measured using a 3D high precision computer controlled optical micro-scanner. The obtained images were processed using two Autodesk softwares.
Results: On the stone phantoms, the laser ablation volume increased with the laser power and decreased with the distance to target.Moses technology in distance mode provided bigger ablation volumes than close mode, especially at 1 mm distance from the stone, at the same laser settings The difference was not statistically significant. SPT ablation volume was similar to HPH Moses distance mode when same power and energy were used. SPT ablation volume was similar to HPH Moses close mode when same power but very low energy and very high frequency were used.Ablation volume for each machine's best capabilities for dusting settings (HPH 0.2J/80Hz, SPT 0.05J/900 Hz) was almost three times better for SPT. (Table 1)
Conclusions: At same power, HPH Moses and SPT have similar effect on stones. The big difference is when maximal dusting setting are used, SPT being more efficient than HPH Moses.