Calyxo Announces New Data Demonstrating CVAC System Maximizes Stone Clearance While Maintaining Safe Intrarenal Pressure
Three new abstracts presented at the European Association of Urology 2025 Annual Meeting (EAU25) underscore the design and resulting efficacy of the CVAC System, outperforming direct-in-scope suction (DISS) in an ex-vivo setting and consistently achieving high stone clearance in a real-world setting.
PLEASANTON, CA — March 25, 2025 — Calyxo, Inc., a medical device company developing innovative solutions for patients with kidney stones, today announced new data presented at EAU25 that further prove the safety, efficacy, and effectiveness of performing steerable ureteroscopic renal evacuation (SURE) using the CVAC System. An all-in-one kidney stone clearance solution, the CVAC System integrates three unique design features – microjet irrigation, simultaneous flow, and a large outflow lumen – that work in tandem to maximize fragment aspiration. The data from two ex-vivo studies1,2, and one real-world study3 collectively highlight the CVAC System’s unique mechanism of action and its ability to provide superior stone clearance while maintaining safe intra-renal pressures.
In his presentation titled CVAC System Superior to Direct-In-Scope Suction Across Range of Stone Sizes in a Direct In Vitro Comparison of Stone Fragment Aspiration1, Johnson utilized stone analogs to compare the aspiration efficiency of the CVAC System and DISS in an in vitro model. The stones were sorted into size groups, and multiple aspiration runs were performed. The CVAC System demonstrated significantly superior aspiration rates compared to DISS across all five size groups (p < 0.001). For groups with median fragment widths < 1mm, the CVAC System aspirated 6-30 times faster than DISS. For groups with median fragment widths > 1 mm, DISS was unable to aspirate fragments, while the CVAC System aspirated fragments at 0.5 – 1.6 g/min. Based on the in vitro aspiration performance reported in this study, the expected in vivo time to clear a 15 mm spherical stone broken into 0.6 mm fragments would be 1.2 min for the CVAC System and 34.9 min for DISS, thereby demonstrating the effectiveness of the CVAC System mechanism of action in maximizing stone clearance.
Brian Eisner, M.D., and Co-Director of the Kidney Stone Program at the Massachusetts General Hospital in Boston, presented results from CVAC System Maintains Consistently Low Intrarenal Pressure Independent of Ureteropelvic Junction Compliance Via Continuous Fluid Outflow2, an ex-vivo study that compared intra-renal pressure (IRP) using the CVAC System or standard ureteroscopy (URS) in an explanted porcine (pig) kidney model. Results showed that while there were no statistically significant differences in IRP when the CVAC System was compared to the standard ureteroscope for the compliant ureter model, the IRP with the standard ureteroscope was 1.7 – 2.9-fold greater than IRP with the CVAC System for the non-compliant ureter model. This study underscores the benefits of the CVAC System’s mechanism of action in helping maintain low IRP irrespective of anatomical variations by providing outflow through the device instead of relying on outflow through a ureteral access sheath.
Luke Griffiths, M.D. at the University of California San Diego (UCSD), discussed results from a real-world study Using CVAC next Gen 2.0 with Quantitative Computer Tomography Stone Analysis Software3 that reported the initial experience with the next-generation CVAC System at UCSD. Residual stone volumes were analyzed using quantitative stone analysis software (qSAS), which generates standardized 3D volumetric measures. Of 74 patients treated with the redesigned CVAC System, eight patients had preoperative CT amenable to qSAS analysis. Most patients in the study achieved >99% clearance.
“At Calyxo, we are committed to generating evidence that allows physicians and patients to make informed decisions about their kidney stone removal options, and the findings presented at EAU25 continue to support the superior safety and efficacy of the CVAC System,” said Jacqueline Welch, MD, PhD, Vice President, Medical and Clinical Affairs at Calyxo. “We believe a truly effective, standard-of-care solution for kidney stone removal must deliver across all critical dimensions: safety, efficacy, and healthcare utilization. CVAC System is designed to meet this standard—and this latest evidence supports just that.”
About Kidney Stones
According to the American Urological Association, approximately 10% of people in the U.S. will have a kidney stone at some point in their lives. Kidney stone disease is a painful condition that brings significant healthcare costs (Current Urology Reports estimates $4.1 billion in annual direct treatment costs by 2030).
About the CVAC System
The new CVAC System was FDA-cleared in 2024 and enables a minimally invasive approach for kidney stone clearance. It is an all-in-one solution designed to efficiently and effectively remove kidney stones. It uses irrigation and vacuum aspiration to continuously clear stone fragments during and after laser lithotripsy, enabling physicians to achieve a stone-free outcome. The efficacy of the CVAC System has been demonstrated in the ASPIRE clinical trial, published in December 2024, which showed that the SURE procedure using the CVAC System achieves superior stone clearance regardless of baseline stone volume compared with standard ureteroscopy4.
About Calyxo, Inc.
Calyxo, Inc. is an innovation-driven medical device company focused on improving care for patients with kidney stones by delivering paradigm-shifting solutions that enable urologists to safely, effectively, and efficiently achieve unrivaled clinical outcomes. Learn more at calyxoinc.com.
“CVAC” and “Calyxo” are registered trademarks of Calyxo, Inc.
Alyssa Paldo
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M: +1 847 791 8085
- Johnson, Brett A., et al. CVAC System Superior to Direct-In-Scope Suction Across Range of Stone Sizes in a Direct In Vitro Comparison of Stone Fragment Aspiration, Conference Presentation, March 2025
- Eisner, Brian., CVAC System Maintains Consistently Low Intrarenal Pressure Independent of Ureteropelvic Junction Compliance Via Continuous Fluid Outflow, Conference Presentation, March 2025
- Griffiths, Luke. Using CVAC next Gen 2.0 — with Quantitative Computer Tomography Stone Analysis Software, Conference Presentation, March 2025
- Matlaga, BR, J. Endourology, 2024
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