Presentation Authors: Vincent De Coninck*, Brasschaat, Belgium, Etienne Xavier Keller, Paris, France, Anastasiya Kovalenko, Viktoriya Vinnichenko, Moscow, Russian Federation, Olivier Traxer, Paris, France
Introduction: At present, the Ho:YAG laser is the most commonly used laser for treating urolithiasis. A new technology of the Ho:YAG laser â€“ Moses technology â€“ was designed to increase ablation efficiency and to reduce stone retropulsion. Recently, a thulium fiber laser (TFL) has been suggested as an alternative laser source, with a potential for higher ablative efficiency and lower retropulsion. The aim of this study was to compare the efficiency of stone dusting between a Ho:YAG laser with Moses technology and a SuperPulse TFL.
Methods: A SuperPulse TFL generator was compared to a Ho:YAG laser generator with Moses technology. 200 Âµm fibers were used in all experiments. Laser lithotripsy was performed with a flexible ureteroscope (Pusen) for direct vision and fiber control. Uric acid stones were used in this study. Irrigation pressure was 40 cm H2O. Lithotripsy was performed in a specially constructed vessel of 13 mm in diameter, with 2 mm holes drilled in the walls at a height of 40 mm to allow collection of stone dust from irrigation overflow (Figure 1). The laser parameters for both systems were 0.2 J and 80 Hz (16 W). Lithotripsy was performed during 2â€™30â€™â€™. After lithotripsy, the solution from the outer cuvette was filtered through filter paper with a pore size of 2 Âµm allowing stone dust collection. The weight of stone dust was calculated as the difference between weight of the dried filter with the stone dust and the initial weight of the filter. Experiments were repeated 5 times.
Results: Initial stone mass was 210Â±24 mg. The weight of stone dust after lithotripsy was 69Â±32 mg for Ho:YAG laser lithotripsy with Moses technology and 138Â±25 mg for the SuperPulse TFL (Figure 2).
Conclusions: The SuperPulse TFL produced twice as much stone dust as the Ho:YAG laser with Moses technology. When these promising results are confirmed in future studies, the SuperPulse TFL may be able to significantly reduce operating times.