title: Ureteroscopic management of recurrent renal cystine calculi.
abstract: OBJECTIVE
  Patients with recurrent cystine nephrolithiasis oftentimes require multiple procedures for stone removal. As the majority of cystine stones are resistant to the effects of shockwave lithotripsy, repeat percutaneous surgery is often required and may cause renal damage. Moreover, repeat percutaneous access may become more difficult as perinephric fibrosis develops. Small-caliber ureteroscopes along with the holmium laser now enable routine intrarenal ureteroscopic access to symptomatic renal stones. Herein, we present our experience in managing recurrent renal cystine calculi using flexible ureterorenoscopy and assess whether such an approach may be used as an alternative to percutaneous surgery in selected patients.
  
  
  METHODS
  Three patients with large-volume (mean diameter 22 mm) renal cystine stones were managed with a 7.5F flexible ureterorenoscope combined with holmium laser lithotripsy to fragment the stones completely.
  
  
  RESULTS
  The mean treatment time was 97 minutes, with successful fragmentation in all cases. Two of the three patients were completely stone free on follow-up intravenous urography, with the third patient having only small-volume residual fragments in a lower pole calix. All patients are currently asymptomatic and are being maintained on high oral fluid intake, urinary alkalization with potassium citrate, and alpha-mercaptopropionylglycine to reduce urinary cystine excretion.
  
  
  CONCLUSIONS
  Flexible ureterorenoscopy with holmium laser lithotripsy provides a reasonable alternative for the management for recurrent cystine calculi in patients who are not candidates for repeat percutaneous procedures. Although it is time consuming, complete stone fragmentation, along with clearance of fragments, can be achieved in the majority of patients.
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: R
authors.initials: R
authors.lastname: Munver
authors.forename: G M
authors.initials: GM
authors.lastname: Preminger
mesh_terms: D003553:Cystine; D006695:Holmium; D006801:Humans; D007669:Kidney Calculi / Q000601:surgery / Q000628:therapy*; D017602:Lithotripsy, Laser / Q000379:methods*; D012008:Recurrence; D016896:Treatment Outcome; D020709:Ureteroscopes
chemical_list: D003553:Cystine; D006695:Holmium