title: Flexible ureterorenoscopy (URS): technique and results.
abstract: OBJECTIVE
  This paper has two main objectives: First, to expose the URS technique used in our Department because there are important differences with respect to others centres published, explaining same aspect that can benefit to the better development of the technique. Second, we present the results of a series of 100 cases. Flexible ureterorenoscopy (Flex URS) has been little used to date, mainly because of the technical difficulties created by the deficient quality of the instruments used, such as ureteroscopes offering scant visibility, poor illumination, a small working channel, deficient quality of the forceps and baskets, etc.
  
  
  METHODS
  We present our recent series of flexible URS for the treatment of renal lithiasis. We performes a retrospective analysis of this treatment corresponding to the period between January 2007 and March 2010. In this period we have treated 100 patients. The medium size of the stone treated is 1.5cm (0.5-6cm) and we used ureteroscopic protector sheath in all cases. The lithotripter system used in all cases was Ho:YAG Laser with 200 and 365 micras fibers
  
  
  RESULTS
  The stone-free rate (SFR) in the immediate postoperative period was 77% (77/100 patients). Residual stones, defined as stone fragments visualized in the operating room via fluoroscopy and directly with the flexible ureteroscope. Three months after surgery, the SFR was 92.7% (89/96 patients) confirmed by intravenous urography. Regarding complications, we had 5 patients with ureteral lesions during protector sheath pass and 9 patients that presented at the emergency room with pain secondary to the double J catheter.
  
  
  CONCLUSIONS
  Flexible URS for of renal lithiasis can be defended in stones measuring up to 2 cm in diameter, based on our treatment algorithm.
authors.affiliation: Urology Department, Hospital Universitario La Paz, Madrid, Spain.
authors.forename: José Ramón
authors.initials: JR
authors.lastname: Cansino Alcaide
authors.forename: Javier
authors.initials: J
authors.lastname: Reinoso Elbers
authors.forename: David
authors.initials: D
authors.lastname: López Sánchez
authors.forename: Sonia
authors.initials: S
authors.lastname: Pérez González
authors.lastname: Rodriguez
authors.forename: Alfredo
authors.initials: A
authors.lastname: Aguilera Bazán
authors.forename: Alberto
authors.initials: A
authors.lastname: Rando Tous
authors.forename: Luís
authors.initials: L
authors.lastname: Hidalgo Togores
authors.forename: Javier
authors.initials: J
authors.lastname: De La Peña Barthel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018666:Ureteroscopy; D055815:Young Adult