Introduction: The thulium fiber laser (TFL) is becoming of interest to Urologists due to its unique properties. The TFL pulse profile consists of rectangular pulses, designed for enhancing photothermal ablation. Energy for each pulse may be modified by altering pulse duration or peak power. Our aim for this study is to compare short pulse (SP) versus long pulse (LP) for common 10W dusting settings using the TFL platform. Methods: All tests were conducted using an IPG Photonics TLR-50W TFL system and a 200µm fiber on “soft” (5:2) Begostone phantoms. The most popular 10W dusting settings (Figure 1) among endourologists familiar with TFL were evaluated.[1] Four different standoff distances (0.2mm, 0.5mm 1mm, 2mm), and a clinically significant scanning speed of 1mm/sec was used. The pulse profiles were altered for each energy setting to produce a short pulse (SP) and a long pulse (LP) design. The laser fiber was scanned in a 15mm straight line with a 3D positioning system across a polished and submerged Begostone surface. Ablation volumes were quantified by optical coherence tomography (OCT). [1] Sierra A, Corrales M, Piñero A, Traxer O. Thulium fiber laser pre-settings during ureterorenoscopy: Twitter's experts' recommendations. World J Urol. 2022;40(6):1529-1535. doi:10.1007/s00345-022-03966-9 Results: Overall, SP provided greater ablation volume when compared to LP. The greatest difference observed between SP and LP was at 1J/10Hz and SD of 0.2mm (2.51mm3 vs. 0.35mm3) and this difference was statistically significant (p < 0.005). Out of the 20 performed trials there were only two instances in which LP outperformed SP in terms of ablation volume: 0.4J/25Hz at SD of 2mm (0mm3 vs. 0.15mm3) and 0.2J/50Hz at SD of 0.2mm (0.79mm3 vs 0.81mm3). In the latter case, however, the difference was not found to be statistically significant (p=0.7). Conclusions: TFL short pulse profile offers superior trough ablation volumes than long pulse during dusting under clinically relevant scanning speed of 1 mm/s with a time average power of 10W. SOURCE OF Funding: N/A
