Real-world data demonstrate the efficacy of the CVAC System across varied clinical settings, showing significant reductions in absolute stone volume and fewer complications compared to the flexible and navigable ureteric access sheath (FANS). Clinical studies further validate the safety profile of the CVAC System.
Studies based on QSAS (Quantitative Stone Analysis Software) —a software system used for analyzing kidney stones— underscore the clinical relevance of stone volume as a more precise and clinically meaningful measure for assessing kidney stone volume, supporting the move beyond binary metrics.
PLEASANTON, Calif.--(BUSINESS WIRE)--Calyxo, Inc., a medical device company advancing innovative solutions for kidney stone treatment, today announced the results of multiple real-world, clinical, and pre-clinical studies demonstrating the safety, efficacy, and clinical utility of the steerable ureteroscopic renal evacuation (SURE) procedure using the Company’s CVAC System. The data were presented at the American Urological Association (AUA) 2025 Annual Meeting, which took place April 26-29 in Las Vegas. In addition to the abstracts presented at the conference, Calyxo hosted a series of events aimed at educating physicians on the CVAC System, its distinctive mechanism of action, and best practices to build confidence, ensure procedural safety, and optimize outcomes.
"It is well understood in the urology community that increasing stone-clearance rates are essential to achieving improved patient outcomes and reducing the need for repeat procedures,” said Brian Eisner, M.D., Co-Director of the Kidney Stone Program at the Massachusetts General Hospital in Boston, and lead author of abstract IP08-05. “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. Two studies, including one of my own, further enhance our understanding of the CVAC System’s safety profile by demonstrating that it consistently maintains low IRP comparable to commonly used ureteroscopes. 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.”
Real-World Evidence Demonstrates Effectiveness and Safety of the CVAC System
These studies collectively demonstrate that the CVAC System provides consistent results in multiple real-world clinical settings, giving physicians confidence that the SURE procedure can achieve optimal stone clearance outcomes.
Real-World Experience with CVAC 2.0 for Steerable Ureteroscopic Renal Evaluation in a Large, Multi-Site Academic Institution (Northwell)1
- Stone-free rates (SFR) in this large, multi-site, real-world retrospective study (N=163) were consistent with and confirmed the results of the controlled ASPIRE trial (57% vs. 48%2 SFR with zero residual fragments)
Early Experience of Steerable Ureteroscopic Evacuation (S.U.R.E) with CVAC System Next Gen 2.0 — with Quantitative Computer Tomography (University of California, San Diego)3
- Most patients achieved >99% stone clearance (94.2% mean volume reduction) based on QSAS.
A Retrospective Analysis of the 2nd Generation CVAC Ureteroscope’s Stone Clearance: Our Initial Experience (University at Buffalo, Buffalo)4
- A retrospective review of initial experience data from two hospitals found a median stone clearance rate of 96.4%.
"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 Jared S. Winoker, MD, Director of Endourology and the Center for Kidney Stone Disease at Lenox Hill, Assistant Professor of Urology at The Zucker School of Medicine at Hofstra/Northwell, and senior author on abstract PD01-06. “The data from our study, along with other real-world evidence presented at AUA 2025, demonstrate that the CVAC System delivers consistent and excellent outcomes across diverse clinical sites and operators. These findings further support the SURE procedure with the CVAC System as a leading option for kidney stone removal.”
Study Reveals Distinctions Between CVAC System and FANS
This prospective study, using QSAS, of patients undergoing SURE with the CVAC System (n=26) or FANS (n=53) at the Mayo Clinic, Arizona in 2024, shows that the CVAC System provides more absolute stone clearance with fewer complications compared with FANS, supporting real-world advantages.
Prospective Comparison of Flexible and Navigable Ureteric Access Sheath (FANS) and CVAC 2.0 In-Scope Aspiration System for High-Volume Stone Disease (Mayo Clinic, Arizona)5
- CVAC System removed significantly more absolute stone volume (p<0.001) than FANS.
- There were more complications with FANS, all of which were device related.
- RSV was independent of baseline stone volume for CVAC System but increased with increasing baseline stone volume for FANS.
CVAC System Maintains Low Intrarenal Pressure
Clinical and ex vivo studies show that the CVAC System maintains consistently low intrarenal pressure (IRP), demonstrating the safety of the SURE procedure.
CVAC System Maintains Consistently Low Intrarenal Pressure Independent of Ureteropelvic Junction Compliance Via Continuous Fluid Outflow (Massachusetts General Hospital, Boston)6
The ex-vivo study compared IRP using the CVAC System or ureteroscopy (URS) in an explanted porcine (pig) kidney model with compliant and non-compliant ureteropelvic junctions (UPJ). The study evaluated both the passive and active irrigation modes for the CVAC System. Results showed:
- In the non-compliant UPJ model, IRP was 1.7-2.9x higher for URS compared to CVAC System (CVAC IRP significantly lower than URS IRP, p<0.05).
- Significantly lower IRP for CVAC System active mode compared with CVAC System passive mode (p<0.05) in the non-compliant UPJ model.
Impact of Steerable Ureteroscopic Renal Evacuation (SURE) Using CVAC on Intrarenal Pressure (University of California, San Diego)7
- First prospective clinical study comparing in-vivo IRP between 111 consecutive patients undergoing traditional ureteroscopy (89) or SURE (22).
- Median, maximum and cumulative IRP was comparable between groups.
- Results indicate the CVAC System can be performed without elevating intrarenal pressure.
The Case for Volumetric Analysis in Kidney Stone Studies
Multiple studies utilizing Quantitative Stone Analysis Software (QSAS) collectively reinforce stone volume as a clinically meaningful metric, potentially offering greater precision than traditional binary metrics.
Comparing Performance of Automated and Semi-Automated Methods for Measuring Kidney Stone Volumes: Can Pre-op Volumes Predict Stone-Free Outcomes After Ureteroscopy? (Mayo Clinic, Arizona)8
This study compared three stone volume assessment methods: manual calculation of cumulative max stone diameter, semi-automated QSAS, or fully automated artificial intelligence (AI) QSAS to determine the best method to assess stone-free rate. Results from 84 scans (46 pre-op and 38 post-op) showed:
- Pre-operative manual cumulative maximal stone diameter best predicts stone-free status.
- Semi-automated and AI estimated stone volumes are strongly correlated (p<0.001).
“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. Our goal has always been to provide a solution that aligns with both physician needs and patient outcomes—and the data presented at AUA highlights that progress.”
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 lives9. Kidney stone disease is a painful condition that can result in significant healthcare costs (Current Urology Reports estimates $4.1 billion in annual direct treatment costs by 2030)10.
About the CVAC System
The 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.
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.
- Klyde et. al. PD01-06: Real-World Experience with CVAC 2.0 for Steerable Ureteroscopic Renal Evaluation in a Large, Multi-Site Academic Institution, Conference Presentation, AUA 2025
- Matlaga, BR. J. Endourology. 2024
- Griffiths et. al. IP11-10: Early Experience of Steerable Ureteroscopic Evacuation (S.U.R.E) with CVAC System Next Gen 2.0 — with Quantitative Computer Tomography, Conference Presentation, AUA 2025
- Cook et. al. IP08-19: A Retrospective Analysis of the 2nd Generation CVAC Ureteroscope’s Stone Clearance: Our Initial Experience, Conference Presentation, AUA 2025
- Cabo et. al. MP29-04: Prospective Comparison of Flexible and Navigable Ureteric Access Sheath (FANS) and CVAC 2.0 In-Scope Aspiration System for High-Volume Stone Disease, Conference Presentation, AUA 2025
- Eisner, B, IP08-05: CVAC System Maintains Consistently Low Intrarenal Pressure Independent of Ureteropelvic Junction Compliance Via Continuous Fluid Outflow, Conference Presentation, AUA 2025
- Berrios et. al. PD01-09: Impact of Steerable Ureteroscopic Renal Evacuation (SURE) Using CVAC on Intrarenal Pressure, Conference Presentation, AUA 2025
- Cabo et. al. IP22-21: Comparing Performance of Automated and Semi-Automated Methods for Measuring Kidney Stone Volumes: Can Pre-op Volumes Predict Stone-Free Outcomes After Ureteroscopy?, Conference Presentation, AUA 2025
- AUA Guidelines: Medical Management of Kidney Stones 2019
- Roberson, Curr Urol Rep 2020; 21:18
Contacts
Media Contact
Alyssa Paldo
Alyssa.paldo@finnpartners.com
M: +1 847 791 8085
