CVAC2 shows safety, efficacy for stone clearance in real-world study

Data from a real-world study showed that the CVAC 2.0 ureteroscope (CVAC2) demonstrated a safe and effective approach to stone clearance.¹

The data were presented by Luke Griffiths, MD, at the 40th Annual European Association of Urology (EAU) Congress in Madrid, Spain.

Luke Griffiths, MD

“The original CVAC device had no camera and was directed in calyces using fluoroscopy only. So, while early results were promising, the limitations were obvious,” Griffiths explained during the presentation. “The second generation of Calyxo CVAC dramatically improved on the original design and now functions as a disposable ureteroscope. It fits into a 12/14 fr access sheath [and] has a 7 fr lumen with simultaneous irrigation and aspiration. In this study, we wished to look at the stone clearance rates of the new CVAC version 2.”

To that end, the investigators assessed 74 patients who underwent CVAC2 from May to October 2024. Data were prospectively collected as part of the Registry for Stones of the Kidneys and Ureter (ReSKU) database performed at University of California, San Diego.

Among all patients who underwent CVAC2, 14 had post-procedure CT and 8 were able to be analyzed using the Mayo Clinic stone analysis software (qSAS). Among these 8 patients, 3 were male. The average age was 57 years. The average pre-procedure stone volume was 614 ± 469 mm³, and the average density was 576 ± 151 Hounsfield units. There was an average of 6 ± 3 weeks between ureteroscopy and follow-up CT.

Overall, patients achieved an average volume reduction of 94.2% ± 11 following CVAC2 (P = .008). The majority of patients (n = 5) achieved greater than 99% stone clearance. Two patients had stone clearance rates between 90% and 99%, and 1 patient had a stone clearance rate below 90%.

The CVAC2 system also appeared to be safe, with no major complications reported. One patient had to be readmitted due to a urinary tract infection.

Based on these findings, the authors concluded, “CVAC2 demonstrates a safe and highly effective approach to stone clearance, even for larger stone volumes. Larger sample size and more mature data will hopefully validate these findings.”

Additional data on CVAC System

Two additional studies on the CVAC system were also presented at the EAU Congress.

The first compared intrarenal pressure during ex vivo ureteroscopy with the CVAC System vs standard ureteroscopy.²

The 2 approaches showed comparable intrarenal pressure in a compliant ureter model. In the non-compliant ureter model, CVAC (either active or passive aspiration) led to significantly lower intrarenal pressure vs standard ureteroscope (P < .05). Specifically, the standard ureteroscope demonstrated a 1.7- to 2.9-fold increase in intrarenal pressure vs the CVAC System.

The second study compared the CVAC System with Direct-In-Scope Suction (DISS) in an in vitro model.³

Overall, CVAC was shown to have significantly superior aspiration rates vs DISS across all stone size groups assessed (all, P < .001). Specifically, in groups with median fragments less than 1 mm, the rates of aspiration with CVAC were 6 to 30 times greater than those with DISS. However, clogging rates were greater in the CVAC arm. In total, 6 clogs were noted in the CVAC groups vs no clogs in the DISS groups.

Brett Johnson, MD

“The data presented at EAU25 add to the growing body of evidence supporting the CVAC System as the emerging standard of care in kidney stone removal,” said lead author Brett Johnson, MD, an assistant professor of Urology at UT Southwestern Medical Center, in a news release.⁴ “Aspiration technology like the CVAC System instills renewed confidence in urologists about our ability to remove as much stone as possible and provide better patient outcomes. When compared with suction-based technologies such as DISS, the CVAC System aspiration rate is significantly superior across an array of sizes due to its purposeful design and unique mechanism of action. The robust evidence supporting the CVAC System should give physicians and patients the confidence that the system can facilitate their long-desired outcomes of maximized stone clearance.”

REFERENCES

1. Griffiths L, Girgiss J, Sheetz T, et al. Early experience using CVAC next Gen 2.0 — with quantitative computer tomography stone analysis software. Presented at 40^th Annual European Association of Urology Congress. Madrid, Spain. March 21-24, 2025. Abstract A0308

2. Eisner BH, Serge M, Jenkins T. CVAC system maintains consistently low intrarenal pressure independent of ureteropelvic junction compliance via continuous fluid outflow. Presented at 40th Annual European Association of Urology Congress. Madrid, Spain. March 21-24, 2025. Abstract A0307

3. Johnson B, Palma-Zamora I. CVAC system superior to direct-in-scope suction across range of stone sizes in a direct in vitro comparison of stone fragment aspiration. Presented at 40th Annual European Association of Urology Congress. Madrid, Spain. March 21-24, 2025. Abstract A0309

4. Calyxo announces new data demonstrating CVAC System maximizes stone clearance while maintaining safe intrarenal pressure. News release. Calyxo. March 25, 2025. Accessed April 1, 2025. https://calyxoinc.com/calyxo-news/eau-2025-new-data-cvac-system-outperforms-direct-in-scope-suction/