title: The Effect of Stone Composition on the Efficacy of Retrograde Intrarenal Surgery: Kidney Stones 1 - 3 cm in Diameter.
abstract: OBJECTIVE
  The goal of this study was to analyze the effect of stone composition on the efficacy of retrograde intrarenal surgery (RIRS) with kidney stones of 1-3 cm, 1-2 cm, and 2-3 cm in diameter.
  
  
  METHODS
  We undertook a retrospective analysis of 74 patients with kidney stones who underwent RIRS. The patients were divided into two groups based on stone composition: Group I (n=47) (calcium oxalate monohydrate and calcium phosphate) was the hard to fragment stone group and group II (n=27) (calcium oxalate dihydrate, magnesium ammonium phosphate, and uric acid) was the easy to fragment stone group. Forty-six patients with kidney stones 1 to 2 cm in diameter were divided into group A (n=30) (smaller than 20 mm, hard to fragment stones) and group B (n=16) (smaller than 20 mm, easy to fragment stones). Twenty-eight patients with stones 2 to 3 cm in diameter were divided into group C (n=17) (larger than 20 mm, hard to fragment stones) and group D (n=11) (larger than 20 mm, easy-to-crush stones).
  
  
  RESULTS
  The stone clearance rates of group I and group II were 66.0% and 88.9%, respectively (P<0.05). The stone clearance rates of group A and group B were 73.3% and 100% (P<0.05). The stone clearance rates of group C and group D were 52.9% and 72.7%, respectively.
  
  
  CONCLUSIONS
  Stone composition has a significant impact on the efficacy of RIRS in the management of 1 to 3 cm kidney stones. For 2-3 cm calcium oxalate dihydrate stones, uric acid stones, and magnesium ammonium phosphate stones, the outcome of RIRS treatment was relatively good, and RIRS is recommended.
authors.affiliation: Department of Urology, The Second Affiliated Hospital of Xi'an Jiaoton University , Xi'an, China .
authors.forename: Yuquan
authors.initials: Y
authors.lastname: Xue
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Yang
authors.forename: Tie
authors.initials: T
authors.lastname: Chong
mesh_terms: D000328:Adult; D002129:Calcium Oxalate; D002130:Calcium Phosphates; D005260:Female; D006801:Humans; D007668:Kidney / Q000601:surgery*; D007669:Kidney Calculi / Q000737:chemistry / Q000601:surgery*; D017616:Magnesium Compounds; D008297:Male; D008875:Middle Aged; D053040:Nephrolithiasis / Q000601:surgery; D010710:Phosphates; D012189:Retrospective Studies; D000069877:Struvite; D016896:Treatment Outcome; D018666:Ureteroscopy / Q000379:methods*; D014527:Uric Acid
chemical_list: D002130:Calcium Phosphates; D017616:Magnesium Compounds; D010710:Phosphates; D002129:Calcium Oxalate; D014527:Uric Acid; C020243:calcium phosphate; D000069877:Struvite