Background: Laser lithotripsy devices utilized during ureterorenoscopy (URS) of calculi include the Frequency-doubled Double-pulse Nd:YAG (FREDDY) and Holmium:YAG lasers. The mechanism of action of these lasers differ, potentially conferring different safety and efficacy profiles. Since there are no in vivo studies in the literature comparing these two devices, we sought to report our early experience utilizing the FREDDY and HO:YAG lasers for ureteroscopic laser lithotripsy.
Methods: A retrospective review of 43 patients who underwent ureteroscopic lithotripsy utilizing either the FREDDY (n = 23) or Ho:YAG (n = 20) lasers were included in the study (January 2004 to March 2006). Demographic data, along with stone size, location and burden were recorded. Perioperative complications, including bleeding, ureteral perforation or any intraoperative event necessitating termination of the procedure were analyzed. Patients were categorized as stone-free (SF) or residual stone (RS) categories based on follow-up radiographs done at 6 weeks following URS.
Results: Of the 43 patients, 23 were treated with the FREDDY and 20 with the Ho:YAG lasers. Average stone size was 6.5 mm and 6.8 mm in the FREDDY and Ho:YAG groups, respectively. Stone free rates were higher in the Ho:YAG (90%) versus the FREDDY group (77%). Complications occurred in 5 patients (22%) in the FREDDY group, which was higher than the Ho:YAG group, 1 patient (5%). The complications included bleeding (n = 3), ureteral injury (n = 1) and retropulsion of the stone (n = 1) in the FREDDY group, and bleeding (n=1) in the Ho:YAG group.
Conclusions: Our results demonstrate a higher stone-free rate and a lower complication rate associated with the Ho:YAG compared to the FREDDY laser. As we gain more experience with these lasers, we will be able to further characterize the complication and success rates in the treatment of stone disease.