Use of the escape™ nitinol stone retrieval basket facilitates fragmentation and extraction of ureteral and renal calculi:: A pilot study

Background and Purpose: Advances in ureteroscope and stone basket design have catapulted ureteroscopy to the forefront of surgical stone management; however, persistent problems such as stone migration continue to challenge urologists. The Escape (TM) nitinol stone retrieval basket ( Boston Scientific, Natick, MA) is a stone basket designed to capture calculi and facilitate simultaneous laser lithotripsy in situ. We report our initial experience with the Escape (TM) basket for the management of urinary calculi and compare the use of this device with other methods of optimizing ureteroscopic stone management. Patients and Methods: A prospective evaluation of 23 patients undergoing ureteroscopic holmium: yttrium-aluminumgarnet laser lithotripsy of urinary calculi was performed at two institutions by two surgeons ( R. M. and G. M. P). The Escape basket was used to prevent retrograde ureteral stone migration or to facilitate fragmentation and extraction of large renal calculi. Patient demographics and perioperative parameters were assessed. Results: Twenty-three patients ( 16 men, 7 women), with a mean age of 55.5 years ( range 33-74 yrs) were treated for renal ( n = 9) or ureteral ( n = 14) calculi. The mean stone diameter was 1.4 cm ( range 0.4-2.5 cm), mean fragmentation time was 44.1 minutes ( range 10-75 min), and mean energy used was 3.1 kJ ( range 0.4-10.6 kJ). No complications were encountered. Eighty-seven percent ( 20/23) of patients were rendered completely stone free after ureteroscopic laser lithotripsy using the Escape basket. Of the three patients with residual calculi, one patient with a 2.5-cm renal calculus had residual fragments larger than 3 mm, and two patients with large renal calculi had residual fragments smaller than 3 mm. Conclusions: The Escape basket appears to be safe and effective in preventing stone migration and facilitating ureteroscopic laser lithotripsy and stone extraction.