(UroToday.com) During the third day of the 2026 American Urological Association (AUA) Annual Meeting, Dr. Jackson Cabo of Mayo Clinic and colleagues presented a large multicenter comparison evaluating stone clearance outcomes between the CVAC 2.0 aspiration ureteroscope system and Flexible and Navigable Ureteral Access Sheaths (FANS) during ureteroscopy (URS) for renal stones. The study explored whether aspiration-assisted technology may offer advantages for patients with larger stone burdens.
As endourology increasingly shifts toward maximizing stone clearance while minimizing retreatment, suction-assisted technologies have rapidly gained traction. Both FANS and steerable ureteroscopic renal evacuation (SURE) technologies have independently demonstrated improved stone clearance compared to conventional URS alone, including reductions in downstream clinical recurrence. However, both technologies require specialized disposable equipment and carry substantial procedural costs, raising important questions regarding which patients may derive the greatest benefit from each platform. Direct multicenter comparative data between these aspiration-based systems have remained limited.
To address this gap, Dr. Cabo and his team performed a real-world, retrospective multicenter analysis of adult patients undergoing flexible URS for renal stones across six North American institutions between March 2024 and June 2025.
The study compared demographic variables, operative characteristics, volumetric stone clearance on thin-slice postoperative non-contrast CT imaging, stone-free rates using Endourological Society criteria, and complication outcomes between patients treated with either the CVAC 2.0 aspiration system or FANS. Pearson correlation analysis was additionally used to evaluate the relationship between preoperative stone volume and postoperative residual stone burden.
A total of 504 procedures were included in the overall cohort for safety analysis, while 250 patients were eligible for detailed volumetric stone clearance analysis based on availability of complete postoperative CT imaging.
Among these, 110 patients underwent CVAC procedures and 140 underwent FANS-assisted URS. Notably, patients undergoing CVAC procedures had substantially larger preoperative stone burdens compared to those treated with FANS (713 mm³ vs. 430 mm³, respectively), reflecting a notable baseline difference between the cohorts.
Importantly, despite substantially larger baseline stone burdens in the CVAC cohort, postoperative residual stone volumes remained low and comparable between groups, with both technologies achieving greater than 95% volumetric stone clearance overall.
Absolute stone clearance volumes were greater in the CVAC cohort, reflecting the larger initial stone burdens treated with aspiration-assisted URS. These findings highlight an important distinction between traditional binary stone-free definitions and volumetric clearance analysis. Although complete stone-free rates remained relatively modest in both cohorts using Endourological Society criteria, postoperative residual stone volumes were minimal and nearly identical, suggesting that volumetric assessment may better capture clinically meaningful procedural success.
When evaluating stone-free rates specifically, no significant differences were observed between groups. Complete stone-free status was achieved in 19% of CVAC cases and 28% of FANS cases, while approximately three-quarters of patients in both groups demonstrated residual fragments less than 100 mm³. Operative times were longer overall in the CVAC cohort, likely reflecting treatment of larger and more complex stone burdens; however, no operative-time differences were observed in the subgroup analysis of patients with stones greater than 2 cm.
Dr. Cabo’s team then focused specifically on patients with larger stone burdens greater than 2 cm. Within this subgroup, relative stone clearance continued to favor CVAC aspiration technology despite significantly larger starting stone burdens. Dr. Cabo suggested that active in-scope aspiration may help maintain procedural efficiency during larger-volume cases by continuously evacuating fragments and reducing intrarenal fragment accumulation throughout lithotripsy.
Dr. Cabo specifically highlighted the residual stone volume correlation analysis as the presentation’s most important finding. As demonstrated in the correlation analysis, increasing preoperative stone volume was significantly associated with greater residual stone volume following FANS procedures. In contrast, no significant relationship was observed for CVAC aspiration-assisted URS. This finding suggests that aspiration-assisted URS may partially decouple increasing stone burden from residual fragment accumulation, allowing stone clearance efficiency to remain more stable even in patients with larger renal stone volumes.
Complication rates were low overall and largely comparable between groups. Infectious complications were rare and did not differ significantly between cohorts. However, minor ureteral injuries were observed more frequently in the FANS cohort, although most represented low-grade mucosal injuries without major clinical sequelae.
During the discussion period, audience members raised several practical questions regarding implementation of aspiration-assisted URS in contemporary stone practice. One attendee asked about the relative costs of CVAC versus FANS technologies, to which Dr. Cabo responded that pricing structures have evolved over time and may vary considerably between institutions. Additional discussion, prompted by a question from Dr. Bird of UF Health, focused on procedural workflow considerations, including pre-stenting practices and access sheath utilization. Dr. Cabo noted that pre-stenting was more commonly observed in the CVAC cohort and that 12/14 access sheaths were utilized in the majority of aspiration-assisted cases. Another audience member questioned whether CVAC procedures may require more extensive stone dusting to facilitate aspiration through the evacuation lumen, potentially increasing operative time. In response, Dr. Cabo acknowledged that operative times were longer overall in the broader cohort but emphasized that no significant operative-time differences were observed in the subgroup analysis of patients with stones greater than 2 cm.
Dr. Cabo concluded that both FANS and CVAC aspiration technology achieved excellent overall volumetric stone clearance exceeding 95%. However, unlike FANS, residual stone burden following CVAC procedures did not appear to rise substantially with increasing preoperative stone volume, supporting a potential role for aspiration-assisted URS in the management of larger renal stones. Dr. Cabo acknowledged that the multicenter retrospective design remains inherently non-randomized and noted that future adequately powered prospective studies will be necessary to further define the comparative role of aspiration technologies during URS. The presentation additionally generated significant discussion regarding the evolving role of volumetric stone clearance metrics and whether minimizing residual stone volume, rather than simply achieving traditional binary “stone-free” status, may better predict downstream patient outcomes and healthcare utilization. As endourology continues shifting toward volumetric outcome assessment and maximal fragment clearance, aspiration-assisted URS may represent an important step toward extending the effectiveness of flexible URS in patients with increasingly complex stone burdens.
Presented by: Jackson Cabo, MD, Mayo Clinic, during the 2026 American Urological Association (AUA) Annual Meeting, May 15-18, 2026, Washington DC
Co-Authors: Christopher Ballantyne, Victoria Edmonds, Stephen Harrington, Levi Bowers, William Peterson, Connor Hoffman, Halle Foss, Daniel Turin, Garrett Ungerer, Runhan Ren, Vernon Pais, David Tzou, Jack Hannallah, Kevin Koo, Aaron Potretzke, Kevin Wymer, Connor Forbes, Ben Chew, Ryan Hsi, Nicole Miller, Mitchell R. Humphreys, and Karen L. Stern
Moderated by: Bodo Knudsen (Ohio State University), Karthik Tanneru (Medical University of South Carolina (MUSC)), Amir Patel (Oregon Health and Science University)
Written by: Seyed Amiryaghoub M. Lavasani, B.A., University of California, Irvine, @amirlavasani_ on Twitter during the American Urological Association (AUA) 2026 Annual Meeting, Washington, DC, Fri, May 15 – Mon, May 18, 2026.