title: Low-power holmium laser for the management of urinary tract calculi, structures, and tumors.
abstract: OBJECTIVE
  Introduction of the holmium laser has provided an indispensable tool for the management of urinary tract stones, strictures, and superficial urothelial tumors. While full-power holmium lasers are required for laser resection of the prostate, lower-power devices can be utilized for all cases of stone fragmentation and stricture incision and most cases of superficial urothelial tumors. Herein, we report our initial experience in utilizing a low-power holmium laser in our endourologic practice.
  
  
  METHODS
  Over a 6-month period, we have utilized both low-power (25 W) and full-power (80 W) holmium lasers to fragment urinary tract stones, incise ureteral or urethral strictures, and ablate superficial urothelial tumors. A series of 80 consecutive patients were assessed prospectively. Laser fibers with a diameter of 200 microm and 365 microm were employed with power settings of 6.4 to 10 W. Laser fiber size and power settings were similar for the low- and full-power devices.
  
  
  RESULTS
  Overall, 95% of the stones were completely fragmented, with a stone-free rate at 3 months of 92%. All strictures were incised, with a 91% patency rate at 3 months. Complete tumor ablation was attained in 70%, with a tumor-free rate of 60% at 3 months. Results were equivalent for the low- and full-power lasers. The 200-microm laser fiber allowed adequate access throughout the upper urinary tract during flexible ureteroscopy and flexible nephroscopy. The 365-microm laser fiber was employed via rigid and semirigid endoscopes.
  
  
  CONCLUSIONS
  A low-power holmium laser supplies adequate fragmentation and incision power for virtually all endourologic cases. It also provides ablative power in most situations. The only current urologic application that cannot be performed with the low-power device is laser prostatic resection, which requires 60 to 80 W of power. The reduced-power holmium laser should be considered as a low-cost alternative for the management of urinary tract stones, strictures, and urothelial tumors, especially in centers where laser prostatic resection is not performed.
authors.affiliation: Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: J
authors.initials: J
authors.lastname: Kourambas
authors.forename: F C
authors.initials: FC
authors.lastname: Delvecchio
authors.forename: G M
authors.initials: GM
authors.lastname: Preminger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006695:Holmium; D006801:Humans; D017602:Lithotripsy, Laser; D028022:Low-Level Light Therapy; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014525:Urethral Stricture / Q000628:therapy*; D014545:Urinary Calculi / Q000628:therapy*; D014571:Urologic Neoplasms / Q000628:therapy*
chemical_list: D006695:Holmium