Clinical Scorecard: Is a 3 cm Stone Size the Maximum for Successful Steerable Ureteroscopic Renal Stone Removal?

At a Glance

Key Highlights

• CVAC® Aspiration System removes stone fragments ≤ 2.5 mm during ureteroscopy with active suction.
• The ASPIRE trial showed higher stone clearance and lower residual volume with CVAC compared to traditional ureteroscopy.
• Upper limit of stone size amenable to CVAC treatment remains undefined; retrospective study analyzed outcomes up to 3 cm stones.

Guideline-Based Recommendations

Diagnosis

• Preoperative stone size measured by greatest length on non-contrast CT imaging with 2 mm slice thickness.
• Stone volume calculated using ellipsoid formula based on CT measurements.
• Exclude patients with renal anatomic abnormalities, nephrocalcinosis, or inadequate follow-up.

Management

• Use of CVAC 1.0 or 2.0 devices for steerable ureteroscopic renal stone removal with active suction.
• Laser lithotripsy initiated in dusting mode using Thulium fiber laser or Holmium laser as available.
• Placement of 12/14Fr ureteral access sheath in all cases and indwelling ureteral stents post-procedure.
• Selection of CVAC device based on market availability; stone basketing at surgeon discretion.

Monitoring & Follow-up

• Postoperative imaging within 3 months using CT or ultrasound plus abdominal X-ray to assess stone-free status.
• Stone-free defined by Endourological Society criteria (Grade A: truly stone-free; Grade B: ≤ 2 mm fragments; Grade C: 2 to ≤ 4 mm fragments).
• Monitor for adverse events within 30 days post-surgery related to procedure.

Risks

• Potential complications related to ureteroscopy and stone removal procedures within 30 days post-op.
• Patients with medical comorbidities (ASA Class 3 or 4, BMI > 40) may have increased procedural risk.
• Positive preoperative urine cultures require directed antibiotic therapy prior to surgery.

Patient & Prescribing Data

50 patients (55 renal units) with renal stones, including those with multiple stones and significant comorbidities

CVAC procedures demonstrated feasibility in patients with stones up to approximately 3 cm, including those unsuitable for PCNL

Clinical Best Practices

• Perform thorough preoperative imaging and stone burden assessment using CT with volumetric calculations.
• Administer culture-directed antibiotics for patients with positive urine cultures before surgery.
• Utilize ureteral access sheath and laser lithotripsy with active suction for efficient stone fragmentation and evacuation.
• Place indwelling ureteral stents post-procedure to facilitate recovery and fragment passage.
• Follow patients with appropriate imaging within 3 months to confirm stone clearance status.

References

• Ureteroscopy as common stone removal procedure in the US
• ASPIRE trial demonstrating CVAC efficacy
• Safety validation studies of CVAC devices
• Standard patient guidelines for ureteroscopic stone removal