To compare intraoperative as well as postoperative outcomes of SOLTIVE Thulium laser compared to Ho:YAG laser for the treatment of urolithiasis.

The hypothesis is that utilizing the SOLTIVE Thulium laser for the treatment of urolithiasis will result in a more efficient procedure, with comparable stone free rate to that of Holmium laser and subjective improvement in physician satisfaction.

Urologists utilize several different laser technologies which continue to rapidly advance and improve. The Holmium:YAG laser (Hm:YAG), Thulium:YAG (Tm:YAG) laser and most recently, the thulium fiber are essential tools used in endourology. The holmium:YAG laser fiber is a 2120nm which has been the primary workhorse for many endoscopic procedures as it is broadly available with many versions and upgrades. The thulium:YAG laser has also shown its own set of advantages such as being lighter weight, having high frequency capability, generating less degradation, and consuming less energy.

The natural progression of lasers has continued with the development of the thulium fiber laser (TFL), which is a distinct technology from the previous Thulium:YAG lasers. This remains an important separation as prior studies with Tm:YAG the cannot be directly applied to this new technology. TFL's have a wavelength of 1940nm, different from the Hm:YAG laser of 2120nm and Tm:YAG at 2010nm, which is absorbed nearly five times more in water further allowing for improved efficiency and has less penetration of a depth of 0.15mm. In preclinical studies, the TFL demonstrated two to threefold higher comparison to holmium:YAG as well as four times less retropulsion.

The thulium fiber laser has been studied and applied in several different Urological procedures and the initial clinical data on these has been promising. Based on the temporal pulse shape, the TFL resulted in a two-fold ablation power in comparison to holmium as well as greater versitility. More specifically, the TFL has been effective in several studies during laser lithotripsy. In a comparison study of the TFL and high-powered holmium laser in ureteral stones, the procedures were faster, required fewer stents and no residual stones were seen at 30 days.

Specifically, Olympus's super-pulsed SOLTIVE thulium laser fiber was FDA approved for use in numerous urological indications including lithotripsy. This SOLTIVE thulium laser fiber is a super pulsed laser with numerous benefits including high frequency capabilities of 2,200 Hertz (Hz) compared to Ho:YAG capabilities of 80-100 Hz, decreased fiber degradation, continuous laser mode resulting in smoother cut, shallower tissue penetration (0.15 mm) which results in less surrounding tissue damage, 50 mm diameter laser fiber versus 200 mm allowing for increased maneuverability, visibility, and decreased energy consumption. The SOLTIVE laser allows for greater power through a smaller fiber decreasing fiber failure and endoscope damage. This greater tissue ablation capacity also results in improved hemostasis if identified during endoscopy. Finally, this laser is much smaller and compact in size in comparison to Holium lasers. It allows for a less crowded operating room and has the ability to be utilized in any operating room outlet in comparison to the 220 Volt outlet required by Holium.

In addition, as the prevalence of stones continues to rise, the economic burden of stone disease is also increasing. Despite this upward trend, there are very few studies that have looked at this economic impact of specific stone treatments based on particular laser subtypes. Perez-Ardavin et al looked at comparison between extracorporeal shockwave lithotripsy and ureteroscopy for stones smaller than 2cm which showed higher cost and increased perceived affection. The TFL may address some of this disparity with improved efficacy, less OR time and potential reduced need for ureteral stenting. Furthermore, the TFL may lead to decreased patient costs and allow for more procedures to be completed in turn providing benefit to both patients and hospitals.

Despite the favorable data and qualities in other TFL studies, there remains an insufficient data on clinical performance of the SOLTIVE Thulium laser fibers for treatment of urolithiasis, particularly in the United States. Additionally, there has been limited comparison of economic utility of the TFL to the widely utilized holmium laser fibers.

Inclusion Criteria:

1. Patients must be 18 years of age or older
2. Patients must be diagnosed with single stone burden <2.0 cm
3. Patients must opt for definitive treatment with ureteroscopy with lase lithotripsy and stone basket extraction

Exclusion Criteria:

1. Patients with multiple stones or stones bilaterally
2. Patient with stones >2.0cm
3. Patient who wish to continue with trial of passage