CVAC 2.0 demonstrates efficacy for clearing stones less than 2 cm

The CVAC 2.0 system showed efficacy for treating kidney stones less than 2 cm in size, researchers reported at the 2025 American Urological Association Annual Meeting in Las Vegas, Nevada.¹

“CVAC Ureteroscopy appears to have effective stone clearance for renal stones less than 2 cm," wrote the investigators.

For the study, the authors, led by Bryson Cook, MD, a urology resident at the State University of Buffalo in New York, conducted a retrospective review that included 42 patients who had preoperative and postoperative CT imaging between March 2024 and June 2024. The patients were from 2 hospitals and were treated by 14 attending urologists. The primary outcome was stone clearance. Patients were included in the review if they were older than 18 years of age, were treated with CVAC 2.0, and had received preoperative CT scans within 1 year as well as a postoperative CT scan. Patients were excluded if they had other recent stone surgery or preoperative CT imaging older than 1 year. A radiologist independently reviewed and measured stone volume, and also evaluated stone location and Hounsfield units. The investigators also evaluated gender, race, prestented status, and fluoroscopy time.

Mean (± standard deviation [SD]) patient age was 63.67 ± 13.38 years. Fourteen (33.33%) patients were male and 28 (66.66%) were women. Seventy-four percent were White, 21% were Black, and 0.05% were unspecified. Mean change in glomerular filtration rate was 1.29 ± 13.06, mean total operative time was 39.31 ± 16.8 minutes, and mean fluoroscopy time was 35.02 ± 27.37 seconds.

In terms of stone characteristics, mean (± SD) Hounsfield units was 981.21 ± 346.84, and the mean pre-operative largest stone size was 11.09 ± 4.98 Hounsfield units. Stone composition was calcium phosphate in 14.88% ± 29.27%, calcium oxalate monohydrate in 63.5% ± 40.67%, calcium oxalate dihyrdate in 7.5% ± 15.48%, uric acid in 12% ± 31.07%, and other in 1% ± 6.32%.

The investigators reported a median stone clearance of 96.44% (interquartile range, 80.39%-99.15%). In addition, there was “no correlation between stone clearance and stone location, Hounsfield units, prestented status, or stone composition,” according to the investigators.

“CVAC Ureteroscopy appears to have effective stone clearance for renal stones less than 2 cm. More research is needed to identify which patients benefit the most from CVAC compared to other stone treatment modalities as well as complications,” the investigators wrote in their poster.

In a news release regarding CVAC 2.0 presentations at AUA, Calyxo founder Jee Shin said, “Kidney stones are a painful condition that all too often results in multiple procedures leading to more pain, costs, and the risk of complications for patients. The rapid adoption of the CVAC System in the past year reflects the urology community’s growing commitment to achieving stone-free outcomes for patients—and our own commitment to generating robust clinical evidence to support that goal. The data being presented at AUA2025 will be the first on the second-generation CVAC System and an important step in expanding the body of evidence around aspiration-based stone clearance. We look forward to engaging with urologic surgeons at AUA who share our passion for advancing kidney stone treatment.”²

REFERENCES

1. Cook B, Heitanen C, Bodkin JJ, et al. A retrospective analysis of the 2nd generation CVAC ureteroscope’s stone clearance: our initial experience. J Urol. 2025;213(5S):e424. doi:10.1097/01.JU.0001109856.11315.1d.19

2. Calyxo celebrates one year anniversary of the launch of 2nd generation CVAC System at American Urological Association 2025 Meeting. News release. Calyxo. April 23, 2025. Accessed April 28, 2025. https://calyxoinc.com/calyxo-news/aua-2025-cvac-system-1-year-anniversary-new-data-and-demos/