Table 2.

Prior experimental studies comparing Holmium:YAG laser and Thulium fiber laser for lithotripsy

References	Year	Aim of the study	Study settings	Laser settings		Primary outcome	Secondary outcomes
				Holmium	Thulium
Blackmon et al. [55]	2010	To compare lithotripsy efficiency between the Holmium:YAG laser and the Thulium fiber laser	100 µm core diameter fiber; lithotripsy on COM and UA stones	0.07 J 3 Hz 220 ms pulse duration	0.07 J 10 Hz 1000 µs pulse duration	5–10 times higher ablation efficiency in favor of the Thulium fiber laser	At 0.07 J, the Thulium fiber laser produces cleaner craters on stones at 1 ms compared to 20 ms pulse duration
Blackmon et al. [56]	2011	To compare ablation threshold and retropulsion between the Holmium:YAG laser and the Thulium fiber laser	200–270 µm core diameter; lithotripsy on COM, UA and PoP stones	0.03–0.55 J 10 Hz 30–500 µs pulse duration	0.005–0.035 J 10–400 Hz 500 µs pulse duration	4 times lower ablation threshold in favor of the Thulium fiber laser	Holmium: linear increase of stone retropulsion with pulse energy; Thulium: minimal retropulsion at 0.035 J and ≤ 100 Hz
Blackmon et al. [70]	2013	To compare the stone-suctioning effect of the Holmium:YAG laser with the Thulium fiber laser	272 µm core diameter fiber; lithotripsy on PoP stones	0.035–0.36 J 20 Hz 300 µs pulse duration	0.035 J 10–350 Hz 500 µs pulse duration	Stone-suctioning effect is possible	Better stone-suctioning in favor of the Thulium fiber laser
Hardy et al. [57]	2014	To compare lithotripsy efficiency and irrigation temperature between the Holmium:YAG laser and the Thulium fiber laser	Holmium: 272 µm core diameter fiber; Thulium: 100 µm core diameter fiber; lithotripsy on COM stones	0.6 J 6 Hz 350 µs pulse duration	0.035 J 150–500 Hz 500 µs pulse duration	1.5, 4.3, and 7.3 times faster lithotripsy in favor of the Thulium fiber laser at 150, 300 and 500 Hz	Mean peak irrigation temperature of 24 °C for Holmium:YAG lithotripsy and 33 °C, 33 °C and 39 °C for Thulium fiber laser lithotripsy at 150, 300 and 500 Hz
Wilson [58]	2016	To compare proximal fiber tip damage between the Holmium:YAG laser and the Thulium fiber laser	Holmium: 270 µm core diameter fiber after in vivo lithotripsy; Thulium: 105 µm core diameter fiber after firing in air	0.6 J 6 Hz 350 µs pulse duration	0.035 J 50–400 Hz 500 µs pulse duration	No damage after laser delivery with the Thulium fiber laser; micrometric damages on all fibers after Holmium lithotripsy	–

COM calcium oxalate monohydrate, UA uric acid, PoP plaster of Paris