Pain scores dropped significantly, procedure is ‘nearly painless’
Assessment of pain scores by each patient before and after treatment showed overall significant decreases in both mean and median scores, with 10 patients reporting decreased pain and two reporting increased pain.
When discomfort occurred during the procedure it was described by patients as either similar to a pinprick or as a referred sensation to pass urine and the stone. These effects occurred during 18 of 820 (2%) total propulsive bursts of ultrasound administered.
“It’s nearly painless, and you can do it while the patient is awake, and without sedation, which is critical,” said Dr. Hall in a statement from the University of Washington School of Medicine. He envisions eventually performing the procedure in a clinic or emergency department setting.
All three patients with a proximal stone and three patients with a distal stone who did not pass their stone after treatment underwent surgical stone removal.
The researchers acknowledge that a lack of a control group was a study limitation. They cite a historical, spontaneous stone passage rate of 54% included in a 2016 guideline from the American Urological Association and based on a meta-analysis of 27 studies with 1,205 total patients.
The study was funded by the United States National Aeronautics and Space Administration, which is interested in having a technology available to treat ureteral stones that may develop during prolonged space travel.
The study received no commercial funding. Four of the study’s 23 authors, including Dr. Sorensen, are consultants to and hold equity in SonoMotion, a company that has licensed the tested technology from the University of Washington for commercial development. The report did not identify a specific manufacturer of the ultrasound equipment used for treatment.
A version of this article first appeared on Medscape.com.
*Correction, 10/21/22: An earlier version of this article misstated the location of the stones. They were in the ureter.