Vincent De Coninck1,2, Etienne Xavier Keller1,3, Paul Chiron1, Laurian Dragos4, Esteban Emiliani5, Steeve Doizi1, Laurent Berthe6, Olivier Traxer7. 1. Sorbonne Université, GRC n°20, Groupe de Recherche Clinique Sur La Lithiase Urinaire, AP-HP, Hôpital Tenon, 75020, Paris, France. 2. Department of Urology, AZ Klina, Brasschaat, Belgium. 3. Department of Urology, University Hospital Zurich, University of Zurich, Zurich, Switzerland. 4. Department of Urology, University of Medicine and Pharmacy "Victor Babes" Timişoara, Timisoara, Romania. 5. Fundació Puigvert, Department of Urology, Universidad Autonoma de Barcelona, Barcelona, Spain. 6. Process and Engineering in Mechanics and Materials Laboratory (PIMM), UMR CNRS/ENSAM, Paris, France. 7. Sorbonne Université, GRC n°20, Groupe de Recherche Clinique Sur La Lithiase Urinaire, AP-HP, Hôpital Tenon, 75020, Paris, France. olivier.traxer@aphp.fr.
Abstract
PURPOSE: To evaluate how variable working distances between the laser fiber and the stone influence ablation volume. METHODS: A laser fiber was fixed on a robotic arm perpendicular to an artificial stone. A single laser pulse was triggered at different working distances (0-2.0 mm in 0.2 mm increments) between the distal fiber tip and the stone. To achieve a measurable impact, pulse energy was set to 2 and 3 J, with either short or long pulse duration. Ablation volume was calculated with an optical microscope. Experiments were repeated five times for each setting. RESULTS: Highest ablation volume was observed with a long pulse of 3 J at a working distance of 0.4 mm between the laser fiber and the stone surface (p value < 0.05). At 2 J, the highest ablation volume was noticed with a short pulse in contact mode. However, ablation volume of the latter was not significantly greater than with a long pulse of 2 J at a working distance of 0.4 mm (p value > 0.05). Compared to lithotripsy in contact mode, triggering a single long pulse at 0.4 mm increased ablation volume by 81% (p value = 0.016) at 2 J and by 89% (p value = 0.034) at 3 J. CONCLUSIONS: For Ho:YAG laser lithotripsy, ablation volume may be higher in non-contact mode using long pulses, rather than in direct contact to the stone. Findings of the current study support the need of further studies of lithotripsy in non-contact mode.
PURPOSE: To evaluate how variable working distances between the laser fiber and the stone influence ablation volume. METHODS: A laser fiber was fixed on a robotic arm perpendicular to an artificial stone. A single laser pulse was triggered at different working distances (0-2.0 mm in 0.2 mm increments) between the distal fiber tip and the stone. To achieve a measurable impact, pulse energy was set to 2 and 3 J, with either short or long pulse duration. Ablation volume was calculated with an optical microscope. Experiments were repeated five times for each setting. RESULTS: Highest ablation volume was observed with a long pulse of 3 J at a working distance of 0.4 mm between the laser fiber and the stone surface (p value < 0.05). At 2 J, the highest ablation volume was noticed with a short pulse in contact mode. However, ablation volume of the latter was not significantly greater than with a long pulse of 2 J at a working distance of 0.4 mm (p value > 0.05). Compared to lithotripsy in contact mode, triggering a single long pulse at 0.4 mm increased ablation volume by 81% (p value = 0.016) at 2 J and by 89% (p value = 0.034) at 3 J. CONCLUSIONS: For Ho:YAG laser lithotripsy, ablation volume may be higher in non-contact mode using long pulses, rather than in direct contact to the stone. Findings of the current study support the need of further studies of lithotripsy in non-contact mode.
Authors: Jason Sea; Lee M Jonat; Ben H Chew; Jinze Qiu; Bingqing Wang; John Hoopman; Thomas Milner; Joel M H Teichman Journal: J Urol Date: 2012-01-20 Impact factor: 7.450
Authors: K F Chan; G J Vassar; T J Pfefer; J M Teichman; R D Glickman; S T Weintraub; A J Welch Journal: Lasers Surg Med Date: 1999 Impact factor: 4.025
Authors: Laurian B Dragos; Bhaskar K Somani; Etienne X Keller; Vincent M J De Coninck; Maria Rodriguez-Monsalve Herrero; Guido M Kamphuis; Ewa Bres-Niewada; Emre T Sener; Steeve Doizi; Oliver J Wiseman; Olivier Traxer Journal: Transl Androl Urol Date: 2019-09
Authors: Derek S Ho; Dominick Scialabba; Russell S Terry; Xiaojian Ma; Junqin Chen; Georgy N Sankin; Gaoming Xiang; Robert Qi; Glenn M Preminger; Michael E Lipkin; Pei Zhong Journal: J Endourol Date: 2021-03-18 Impact factor: 2.619