Calyxo's CVAC System demonstrated impressive efficacy and safety in multiple real-world studies presented at the American Urological Association (AUA) 2025 Annual Meeting in Las Vegas, potentially establishing a new standard for kidney stone removal.
The second-generation CVAC System, which enables steerable ureteroscopic renal evacuation (SURE), showed consistent stone clearance results across diverse clinical settings, addressing a significant unmet need in kidney stone treatment.
Real-World Evidence Confirms Clinical Efficacy
A large, multi-site retrospective study from Northwell Health involving 163 patients confirmed that the CVAC System achieved stone-free rates consistent with the controlled ASPIRE trial (57% vs. 48% with zero residual fragments).
"Our initial experience with the second-generation CVAC System has been impressive, and I believe that the SURE procedure represents an important new treatment option for patients with a broad range of stone burdens," said Dr. Jared S. Winoker, Director of Endourology and the Center for Kidney Stone Disease at Lenox Hill and Assistant Professor of Urology at The Zucker School of Medicine at Hofstra/Northwell.
In another study from the University of California, San Diego, most patients achieved greater than 99% stone clearance, with a mean volume reduction of 94.2% based on Quantitative Stone Analysis Software (QSAS). Similarly, a retrospective review from the University at Buffalo found a median stone clearance rate of 96.4%.
CVAC System Outperforms FANS Technology
A prospective comparison study from Mayo Clinic, Arizona revealed that the CVAC System provides more absolute stone clearance with fewer complications compared to flexible and navigable ureteric access sheath (FANS).
The study showed that the CVAC System removed significantly more absolute stone volume (p<0.001) than FANS. Additionally, there were more device-related complications with FANS. Notably, residual stone volume was independent of baseline stone volume for the CVAC System but increased with increasing baseline stone volume for FANS.
Safety Profile Validated Through Intrarenal Pressure Studies
Multiple studies confirmed the safety of the CVAC System by demonstrating consistently low intrarenal pressure (IRP) during procedures.
An ex-vivo study from Massachusetts General Hospital compared IRP using the CVAC System versus traditional ureteroscopy (URS) in an explanted porcine kidney model. Results showed that in a non-compliant ureteropelvic junction model, IRP was 1.7-2.9 times higher for URS compared to the CVAC System (p<0.05).
"The multiple data sets presented at AUA 2025 clearly show that the SURE procedure using the second-generation CVAC System safely and effectively achieves this goal regardless of stone burden," said Dr. Brian Eisner, Co-Director of the Kidney Stone Program at Massachusetts General Hospital and lead author of one of the studies. "The combined safety and efficacy address a long-standing unmet need in kidney stone removal and brings us closer to making one-and-done treatment a reality for the vast majority of patients."
A first-of-its-kind prospective clinical study from the University of California, San Diego comparing in-vivo IRP between 111 consecutive patients undergoing traditional ureteroscopy (89) or SURE (22) found that median, maximum, and cumulative IRP was comparable between groups, indicating the CVAC System can be performed without elevating intrarenal pressure.
Advancing Stone Volume Measurement
Several studies utilizing QSAS reinforced stone volume as a clinically meaningful metric, potentially offering greater precision than traditional binary metrics for assessing treatment outcomes.
A study from Mayo Clinic, Arizona compared three stone volume assessment methods: manual calculation of cumulative max stone diameter, semi-automated QSAS, or fully automated artificial intelligence (AI) QSAS. Results from 84 scans showed that pre-operative manual cumulative maximal stone diameter best predicts stone-free status, while semi-automated and AI estimated stone volumes are strongly correlated (p<0.001).
Clinical Significance
Kidney stone disease affects approximately 10% of people in the U.S. at some point in their lives, according to the American Urological Association. The condition is not only painful but also results in significant healthcare costs, with Current Urology Reports estimating $4.1 billion in annual direct treatment costs by 2030.
"The breadth of clinical, pre-clinical, and real-world data presented at AUA 2025 reflects the increasing clinical experience with the CVAC System," said Joe Catanese, CEO of Calyxo. "This growing body of evidence supports the system's safety and efficacy across a range of stone sizes and clinical settings. With over 10,000 patients treated using the SURE procedure, the data reinforces the role of the CVAC System in helping physicians deliver effective stone clearance."
The CVAC System, which received FDA clearance in 2024, 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.
Earlier data presented at the European Association of Urology (EAU) Congress in March 2025 also supported these findings. A study led by Dr. Luke Griffiths showed that patients achieved an average volume reduction of 94.2% following CVAC2 treatment, with the majority achieving greater than 99% stone clearance.
Additionally, comparative studies at EAU demonstrated that the CVAC System maintained lower intrarenal pressure compared to standard ureteroscopy in non-compliant ureter models and showed superior aspiration rates compared to Direct-In-Scope Suction (DISS) across all stone size groups assessed.
As more urologists gain experience with the technology, the CVAC System appears poised to potentially transform the standard of care for kidney stone removal, offering patients the possibility of more complete stone clearance with fewer complications and repeat procedures.
