Wong VK, et al. Investig Clin Urol. 2020 Sep;61(5):455-463. https://doi.org/10.4111/icu.20200278

This study reports on a prospective, multicenter, single-arm, clinical trial utilizing the SonoMotion (San Mateo, California) Break Wave lithotripsy (BWL) device to fragment urinary stones. Patients with a urinary stone underwent a single treatment of 30 minutes and peak negative pressure of 4.5 to 8 MPa. Subjects were contacted and outcomes assessed at 7, 14, and 35 days after treatment, with clinical follow-up and CT imaging 70 ± 14 days postprocedure. The primary objectives were to assess the safety (hematomas, complications, etc) and effectiveness of BWL (any fragmentation, residual fragments ≤4 mm or ≤2 mm, and completely stone-free rate) as assessed via noncontrast CT-kidneys, ureters, and bladder. Forty-four patients with a ureteral (43%) or renal (57%) stone were treated across 5 centers. Stone fragmentation occurred in 88% of cases; 70% had fragments ≤ 4 and 51% ≤ 2 mm, while 49% were completely stone free on CT; no serious adverse events were reported. Eighty-six percent of patients received either no analgesic medication at all (50%) or minor analgesia (36%). After determining optimal therapy settings, 36 patients were treated and the effectiveness improved exhibiting fragmentation in 92% (33/36), residual fragments ≤ 4 mm in 75% and 58% with fragments ≤ 2 mm with 58% completely stone free. Effectiveness was less in subjects with lower pole stones with 81% fragmentation, 71% having fragments ≤ 4 mm, 29% with fragments ≤ 2 mm, and 29% completely stone free; of distal ureteral stone patients, 89% were completely stone free. BWL offered safe and effective noninvasive stone therapy requiring little to no anesthesia and was carried out successfully in nonoperative environments. ClinicalTrials.gov identifier: NCT03811171.

Chan JY, et al. Investig Clin Urol. 2020 Aug;62:e24. https://doi.org/10.4111/icu.20200319

Purpose: Urolithiasis, a condition affecting approximately 10% of the global population, is primarily treated with Shock Wave Lithotripsy (SWL) and endoscopic methods. However, SWL’s high-pressure pulses can cause tissue injury, often necessitates some level of anaesthesia, and may require repeated sessions or ancillary treatment to achieve stone free status. Burst Wave Lithotripsy (BWL) emerges as a promising alternative, utilizing multi-cycle, ultrasound bursts at lower pressure amplitude to fragment stones, while minimizing cavitation under real-time imaging in a portable manner. Methods: This scoping review evaluated BWL’s efficacy, safety, and clinical potential. A systematic search identified 19 eligible studies, including in vitro experiments, preclinical trials, and human clinical trials. Results: In vitro studies demonstrated BWL’s capability to fragment urinary stones of diverse compositions with high comminution rates. Higher ultrasound frequencies produced smaller fragments (< 1 mm), while lower frequencies resulted in larger fragments (3–4 mm), allowing for controlled fragmentation tailored to clinical needs. Preclinical trials in porcine models showed lower pressure and reduced cavitation, which account for BWL’s safety, causing less associated tissue injury even in anticoagulated subjects. Human trials reported BWL as well tolerated in awake patients with high fragmentation success rates (88–91%) and low complication rates. BWL offers distinct advantages, including lower cavitation and tissue injury risks, portability, and anaesthesia-free application. Ongoing trials aim to validate BWL’s efficacy and explore its combined use with ultrasonic propulsion. Conclusion: BWL represents a paradigm shift in lithotripsy, offering controlled fragmentation, reduced tissue injury, fragment propulsion and portability for office-based or ambulatory care. Early clinical evidence underscores its safety and efficacy, even in anticoagulated patients. While large-scale trials are needed to solidify its role, BWL’s procedural flexibility positions it as a transformative alternative to SWL, poised to redefine urolithiasis management.

The Thulium fiber laser (TFL) is a relatively new tool for endoscopic laser lithotripsy. The Endourological Society’s T.O.W.E.R. registry sought to evaluate the stone-free rate (SFR) at 3 months following URS. A subset of the study sought to determine the association between cumulative TFL energy and SFRs. 423 patients with planned ureteroscopic lithotripsy using TFL (SOLTIVE^™, Gyrus ACMI, Inc. d/b/a Olympus Surgical Technologies America) were prospectively enrolled between December 2020 and May 2023 at nine international sites. Baseline clinical characteristics and SFR data for kidney and ureteral stones were separately analyzed according to quartile cumulative TFL energy ranges. Median patient age was 58.0 (IQR: 44–67) years and maximal stone diameters were 9.9 (IQR: 7–12.9) mm and 7.4 (IQR 6.1–9.4) mm for kidney and ureteral stones, respectively. Overall SFR (no fragments) for renal and ureteral stones were 73.0% and 85.7% at 3-months. Cumulative energy levels were divided into quartiles and lower SFRs were observed with the highest quartile for kidney stones (p = 0.001), but not in ureteral stones. This correlated with kidney stone size as larger stones required more energy. The rate of adverse events related to the procedure was 1.9% (8/423). Higher stone burdens had lower stone free rates and required more cumulative laser energy. The TFL is effective in endoscopic lithotripsy. This post-marketing survey demonstrates that TFL is a safe and effective tool for endoscopic laser lithotripsy.