SURE procedure linked with lower health care utilization vs URS

Two-year outcomes from the ASPIRE trial continued to show that steerable ureteroscopic renal evacuation (SURE) with the CVAC Aspiration System led to significantly reduced health care consumption events (HCEs) compared with ureteroscopy (URS).^1,2

The updated findings were shared during the 2025 World Congress of Endourology and Uro-Technology (WCET), building on 1-year data that were previously presented 2024 annual meeting.

“The data presented at WCET 2025 reinforce what many of us are seeing in practice—the second-generation CVAC System is a reliable, effective, and differentiated solution for stone clearance,” said Karen Stern, MD, an associate professor of urology at the Mayo Clinic College of Medicine and Endourology Fellowship Program Director in Arizona, in a news release on the findings.¹

In total, the study enrolled 101 adult patients across 11 clinical trial sites in the US. All patients had at least 1 renal stone and total stone burden of 7 to 20 mm. For the study, participants were randomly assigned to undergo the SURE procedure (n = 46) or URS (n = 55). HCEs were defined as emergency department visits, hospitalizations, and retreatment.

At 2-year follow-up, 4.3% of patients in the SURE arm vs 20% of patients in the URS arm experienced a HCE (P = .02), translating to a 73% reduction in the risk of HCE in the SURE arm. The index treatment remained a significant predictor of HCE even after adjusting for baseline stone volume (adjusted HR, 0.2, 95% CI, 0.04 to 0.90; P = .04). Overall, patients who underwent URS were 5 times more likely to experience a HCE compared with those who underwent the SURE procedure.

Further, patients who underwent the SURE procedure demonstrated a significantly longer event-free period vs those who underwent URS. Specifically, the average time to event was 701.6 days in the SURE arm compared with 608.2 days in the URS arm, yielding a mean difference of 93.4 days.

Safety was found to be comparable through 2-year follow-up.

Overall, the authors conclude that these findings link the CVAC system’s mechanism of action to long-term benefits in patients with kidney stones.

Additional Data on CVAC

Data from the prospective CLEARANCE study, evaluating the safety and efficacy of the CVAC System, were also presented at the 2025 WCET meeting. Overall, results showed that CVAC was safe and led to high stone clearance and low residual stone volume (RSV) in patients with kidney stones. The data were presented by Brian Eisner, MD, who is the chair of urology at Tulane University School of Medicine in New Orleans, Louisiana.

In total, the study included 30 patients who were treated across 10 surgeons. Of those, 26 patients had non-contrast CT available at post-operative day 30. At baseline, the mean stone volume and density was 703.6 mm³ and 1203 HU, respectively.

Data showed that the mean stone clearance increased from 93.8% on day 1 to 96.2% on day 30. Over the same time period, RSV decreased from 36.0mm³ to 14.1mm³.

The authors noted, “Stone clearance remained high, and RSV remained low at [post-operative day] 30 even with increasing baseline stone volume.”

Additionally, the stone-free rate (no residual stones) increased from 25% on post-operative day 1 to 46.4% by post-operative day 30.

No device-related injuries were reported. All adverse events were mild and resolved without issues. No patients in the study required retreatment or hospital readmission for residual fragments.

“The CLEARANCE study presented by Brian Eisner, MD, reinforces the consistency of outcomes we've seen across trials—even in more complex cases with higher-density stones,” Stern added in the news release.¹ “This is particularly meaningful given the ASPIRE 2-year findings identified residual stone volume as the strongest predictor of long-term health care consumption events. This is the first and only study to track long-term outcomes of an aspiration procedure, which showed that patients treated with SURE using the CVAC System experienced significantly fewer unplanned post-op care events compared to those treated with traditional URS. As technologies evolve, adopting standardized volumetric metrics like RSV will be key to guiding care and ensuring lasting benefits for patients.”

REFERENCES

1. Calyxo debuts reverse deflection CVAC System and reveals groundbreaking two-year ASPIRE data at WCET 2025, underscoring the technology’s role in advancing endourology. News release. Calyxo. September 11, 2025. Accessed September 11, 2025. https://www.businesswire.com/news/home/20250911893155/en/Calyxo-Debuts-Reverse-Deflection-CVAC-System-and-Reveals-Groundbreaking-Two-Year-ASPIRE-Data-at-WCET-2025-Underscoring-the-Technologys-Role-in-Advancing-Endourology

2. Stern K, Matlaga B, Mueller T, et al. Steerable Ureteroscopic Renal Evacuation Reduces the Risk of Healthcare Consumption Events at 2 Years Compared to Standard Ureteroscopy (URS). Presented at: 42nd World Congress of Endourology and Uro-Technology (WCET). Phoenix, Arizona. Abstract MP16:01. https://www.liebertpub.com/doi/10.1177/08927790251368714

3. Eisner BH, Pathak NJ, Sabnis R, et al. A Prospective Study of Steerable Ureteroscopic Renal Evacuation Using the Second-Generation CVAC Aspiration System: Results from the CLEARANCE Study. Presented at: 42nd World Congress of Endourology and Uro-Technology (WCET). Phoenix, Arizona. Abstract MP16:17. https://www.liebertpub.com/doi/10.1177/08927790251368714