title: Endoscopic lithotripsy and the FREDDY laser: initial experience.
abstract: OBJECTIVE
  The frequency-doubled double-pulse neodymium:YAG (FREDDY) laser has been developed for endoscopic lithotripsy and combines the characteristics of solid and dye lasers with a thin flexible optical fiber enabling it to be used with flexible ureterorenoscopy. Furthermore, it is less expensive and easier to maintain than other lasers. Our goal was to evaluate its efficacy and role in the ureteroscopic treatment of urinary stones.
  
  
  METHODS
  We used a FREDDY laser in 26 patients (29 stones). For 4 stone cases, this was the first line of treatment; for the remaining cases, this was the second line of treatment, following SWL in 23 cases and nephrolithotomy in 2 cases. The mean stone size was 9 mm, with a range of 6 to 15 mm. There were 13 renal and 16 ureteral stones. The absence of residual fragments at 3-month postoperative radiography was considered to reflect successful treatment.
  
  
  RESULTS
  Twenty-six stones were treated with satisfactory results. Within 3 months, 18 patients were stone free (69%), and 72.4% of the stones (21/29) had been treated completely. Fragments of 8 stones still remained in 8 patients. Of these stones, 5 were >10 mm and persisted at 3 months. Fragmentation was ineffective for 2 cystine stones and poor for 1 calcium oxalate monohydrate stone. Hospitalization, on average, was 1.5 days with a range of 1 to 3 days. A ureteral perforation was observed in the case of an impacted ureteral stone.
  
  
  CONCLUSIONS
  Because of the wavelengths used, endoscopic FREDDY laser lithotripsy is an effective and harmless method. This laser can be used as a therapeutic tool because of its moderate cost and ability to be used with flexible ureterorenoscopy. However, it is important to be aware of the FREDDY laser's limited fragmentation capabilities for cystine stones and its inability to treat tissue lesions such as urinary-tract stenosis and tumors.
authors.affiliation: Urology Department, Tenon Hospital, Paris, France.
authors.forename: Francis
authors.initials: F
authors.lastname: Dubosq
authors.forename: Federico
authors.initials: F
authors.lastname: Pasqui
authors.forename: Frédéric
authors.initials: F
authors.lastname: Girard
authors.forename: Sébastien
authors.initials: S
authors.lastname: Beley
authors.forename: Nicolas
authors.initials: N
authors.lastname: Lesaux
authors.forename: Bernard
authors.initials: B
authors.lastname: Gattegno
authors.forename: Philippe
authors.initials: P
authors.lastname: Thibault
authors.forename: Olivier
authors.initials: O
authors.lastname: Traxer
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000628:therapy*; D017602:Lithotripsy, Laser / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D014514:Ureteral Calculi / Q000628:therapy*; D020709:Ureteroscopes; D018666:Ureteroscopy