Mathew D Sorensen et al., 2024: Randomized Controlled Trial of Ultrasonic Propulsion-Facilitated Clearance of Residual Kidney Stone Fragments vs Observation
Mathew D Sorensen 1 2, Barbrina Dunmire 3, Jeff Thiel 3, Bryan W Cunitz 3, Barbara H Burke 4, Branda J Levchak 5, Christina Popchoi 3, Arturo E Holmes 1, John C Kucewicz 3, M Kennedy Hall 6, Manjiri Dighe 7, Jessica C Dai 8, Fionnuala C Cormack 9, Ziyue Liu 10, Michael R Bailey 1 3, Michael P Porter 1 2, Jonathan D Harper 1
1Department of Urology, University of Washington School of Medicine, Seattle, Washington.
2Division of Urology, Veterans Affairs Puget Sound Health Care System, Seattle, Washington.
3Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington.
4Institute of Translational Health Sciences, University of Washington, Seattle, Washington.
5Seattle Institute for Biomedical and Clinical Research, Veterans Affairs Puget Sound Health Care System, Seattle, Washington.
6Department of Emergency Medicine, University of Washington School of Medicine, Seattle, Washington.
7Department of Radiology, University of Washington School of Medicine, Seattle, Washington.
8EvergreenHealth Urology Care, Kirkland, Washington.
9Division of Nephrology, Department of Medicine, University of Washington, Seattle, Washington.
10Department of Biostatistics and Health Data Science, Indiana University School of Medicine, Indianapolis, Indiana.
Abstract
Purpose: Ultrasonic propulsion is an investigational procedure for awake patients. Our purpose was to evaluate whether ultrasonic propulsion to facilitate residual kidney stone fragment clearance reduced relapse.
Materials and methods: This multicenter, prospective, open-label, randomized, controlled trial used single block randomization (1:1) without masking. Adults with residual fragments (individually ≤5 mm) were enrolled. Primary outcome was relapse as measured by stone growth, a stone-related urgent medical visit, or surgery by 5 years or study end. Secondary outcomes were fragment passage within 3 weeks and adverse events within 90 days. Cumulative incidence of relapse was estimated using the Kaplan-Meier method. Log-rank test was used to compare the treatment (ultrasonic propulsion) and control (observation) groups.
Results: The trial was conducted from May 9, 2015, through April 6, 2024. Median follow-up (interquartile range) was 3.0 (1.8-3.2) years. The treatment group (n = 40) had longer time to relapse than the control group (n = 42; P < .003). The restricted mean time-to-relapse was 52% longer in the treatment group than in the control group (1530 ± 92 days vs 1009 ± 118 days), and the risk of relapse was lower (hazard ratio 0.30, 95% CI 0.13-0.68) with 8 of 40 and 21 of 42 participants, respectively, experiencing relapse. Omitting 3 participants not asked about passage, 24 treatment (63%) and 2 control (5%) participants passed fragments within 3 weeks of treatment. adverse events were mild, transient, and self-resolving, and were reported in 25 treated participants (63%) and 17 controls (40%).
Conclusions: Ultrasonic propulsion reduced relapse and added minimal risk.
J Urol. 2024 Aug 15:101097JU0000000000004186. doi: 10.1097/JU.0000000000004186. Online ahead of print. PMID: 39146526
Comments 1
The most important message is : IT WORKS! There might be hidden information between the lines and outside statistics however , there is a positive effect on the long-time course and consequences of residual fragment that have become a nearly accepted fact only by the sheer frequency. The number of patients is very small in relation to the fact that it is a multicentre study,
a) run in at least 3 urological departments according to the affiliations of the 17 authors,
b) was conducted during a long time from May 9, 2015, through April 6, 2024 and
c) with treatments performed by 9 operators including 5 urologists.
So besides the fact that 12 of 118 patients primary selected were excluded due to obstructed view for the ultrasound waves by ribs or fragments to deep - > 10 cm - there are probably other bias that lead to the small case numbers.
At the end it will be money that counts, when the equipment will be available and praised in advertisements to attract patients or when the balance between treatment costs and money saved by omitting secondary procedures allows its general use with the health system. This may take some time.
Peter Alken