Clinical Report: Maximum Stone Size for Successful Steerable Ureteroscopic Removal

Overview

This retrospective study evaluated the upper limit of renal stone size amenable to removal using the CVAC® Aspiration System during steerable ureteroscopic renal stone evacuation (SURE). Analysis of 50 patients (55 renal units) demonstrated that stones up to 3 cm can be effectively managed with this technology, expanding treatment options for patients ineligible for percutaneous nephrolithotomy (PCNL).

Background

Ureteroscopy is the most commonly performed procedure for renal stone removal in the U.S., with advancements such as suction-based devices improving fragment evacuation. The CVAC® Aspiration System facilitates active suctioning of stone fragments ≤ 2.5 mm during laser lithotripsy. While prior trials have shown improved stone clearance with CVAC compared to traditional ureteroscopy, the maximum stone burden suitable for this approach has not been clearly defined. This study retrospectively assessed outcomes to establish the upper stone size limit for successful SURE procedures.

Data Highlights

Key Findings

• Steerable ureteroscopic renal stone removal using CVAC devices was performed on stones with a median size of 24 mm, including stones up to 3 cm.
• 54% of patients had multiple renal stones, indicating efficacy in complex stone burdens.
• Majority of patients had significant comorbidities (82% ASA Class 3 or 4), demonstrating feasibility in high-risk populations.
• Preoperative positive urine cultures were common (48%), with culture-directed antibiotics administered prior to surgery.
• Use of both first- and second-generation CVAC devices allowed simultaneous laser lithotripsy and active suctioning of fragments ≤ 2.5 mm.
• Exclusion criteria ensured accurate assessment by removing patients without preoperative CT, follow-up data, or with renal anomalies.

Clinical Implications

The findings support the use of steerable ureteroscopic renal stone removal with CVAC systems for stones up to 3 cm, offering a minimally invasive alternative for patients unsuitable for PCNL due to comorbidities or anatomical challenges. Preoperative imaging and careful patient selection remain critical. Active fragment evacuation with CVAC may improve stone clearance rates and reduce residual fragments.

Conclusion

Steerable ureteroscopic renal stone removal using CVAC technology is effective and safe for stones up to 3 cm, expanding treatment options for complex and high-risk patients. Further prospective studies are warranted to confirm these findings and optimize patient selection.

References

1. ASPIRE Trial -- ASPiration to Improve Renal calculi removal Effectiveness
2. University of Alabama at Birmingham IRB-300014501 -- Study Approval