A Prospective Study of Steerable Ureteroscopic Renal Evacuation Using the Second-Generation CVAC® Aspiration System: Results from the CLEARANCE Study

Purpose: To evaluate the safety and effectiveness of the second-generation Calyxo Vacuum Aspiration and Control System (CVAC®) Aspiration System. Methods: A prospective study of steerable ureteroscopic renal evacuation using the second-generation CVAC was performed. Stone clearance (percent stone volume removed), residual stone volume (RSV), and stone-free rate (SFR) at postoperative day 30 were assessed using noncontrast CT (NCCT). Adverse events were recorded. Results: Twenty-six out of 30 subjects had POD 30 NCCT. Mean baseline stone volume and density were 703.6 mm 3 and 1203 HU, respectively. Mean stone clearance was 96.2%; average RSV was 14.1 mm 3 , and SFR (zero residual fragments) was 46.4%. Stone clearance remained high, and RSV remained low with increasing baseline stone volume. There were two instances of urinary tract infection (Clavien-Dindo grade II) and no subjects requiring intervention or retreatment. Conclusions: The CVAC Aspiration System safely delivers high stone clearance and low RSV.