Presentation Authors: Olivier Traxer*, Vincent De Coninck, Etienne Xavier Keller, Steeve Doizi, Paris, France
Introduction: Ho:YAG laser is the &[Prime]gold standard&[Prime] in the treatment of lower and upper urinary tract stones. Ho:YAG laser with Moses Technology is new technology to reduce retropulsion effect and increase efficiency. Recently, the SuperPulse Thulium fiber laser (SP TFL) has been suggested as an alternative laser source because it has a lower retropulsion and a higher efficiency. The aim of this study was comparing retropulsion and ablation efficiency on BegoStone of Ho:YAG laser for Short Pulse (MP), Long Pulse (LP), and Moses technology (MP) vs SuperPulse Thulium Fiber laser.
Methods: In this study, a SP TFL with pulse energy up to 6 J, repetition rate up to 1600 Hz, and average power up to 40 W was compared to Ho:YAG laser at equal settings of pulse energy and repetition rate: 0.2 Jx80 Hz, 0.5 Jx35 Hz, 0.8 Jx20 Hz, 1 Jx15 Hz, 1.5 Jx10 Hz, and 2 Jx8 Hz, with the average power ~16 W. 200Âµm fibers were used in all experiments. The high-speed camera recorded the stone movement (retropulsion) along the ruler during the first second of laser operation. The measurements were taken while the laser was firing with the desired repetition rate. Cubes with sizes 5 mm, weight about 250mg, made of the material BegoStone were used as samples for the evaluation of retropulsion. The distal end of the fiber was brought in contact with the stone and positioned at the center of the stone face. Each experiment was repeated five times. The initial speed of the displacement, tThe cumulative displacement after 1 sec of firing, and the ablation volume of the crater were evaluated
Results: The results are summarized in Table 1.
Conclusions: The retropulsion effect evaluated by the initial speed and 1 second displacement for SP TFL was ~4 times lower than for Ho:YAG laser in SP mode, and ~1.8 times lower than for LP and MP modes. The retropulsion effect was similar for LP and MP modes of Ho:YAG laser. The average ablation volume for SP TFL was 2.2, 2.0, and 1.6 times higher than for Ho:YAG laser in SP, LP and MP modes, respectively. Thus, a small retropulsion and high efficiency of SP TFL may decrease the operating time compared to the Ho:YAG laser with Moses Technology in all modes of operationh.