title: Endoscopically Determined Stone Clearance Predicts Disease Recurrence Within 5 Years After Retrograde Intrarenal Surgery.
abstract: To assess stone-related events (SREs) requiring retreatment in a series of 100 consecutive patients treated by retrograde intrarenal surgery (RIRS) for renal stones and to evaluate potential risk factors thereof.
  
  
  
  The primary outcome was incidence of SRE (medical or surgical treatment). Secondary outcomes included side of SRE, time to SRE, and late complications. Analysis of potential risk factors included high-risk stone formers (HRSFs), obesity, high stone burden, and lower pole stones. In addition, we evaluated endoscopically determined small residual fragments (SRF) of <1 mm (i.e., fragments too small for retrieval) as an independent risk factor.
  
  
  
  Eighty-five of the 99 patients were followed up for a mean of 59 months (31-69), among whom 26 (30.1%) had SRE. Thirty-four of the 85 (40%) patients were HRSFs, 22 of whom experienced SRE (both sides) during follow-up (64.7%, p < 0.001). Eight of the 17 patients (47.1%) with SRF experienced ipsilateral side SRE compared with 13 (19.1%) of the 68 without SRF (p = 0.022, hazard ratio 2.823, 95% confidence interval [95% CI] 1.16, 6.85). Risk for ipsilateral SRE was unaffected by the presence of SRF among HRSFs (p = 0.561). Of low-risk patients with SRF, 33.3% experienced ipsilateral SRE, while those without SRF experienced no ipsilateral SRE (p < 0.001).
  
  
  
  Endoscopically determined stone clearance predicts disease recurrence within 5 years after RIRS. Even SRF are an important risk factor for future stone-related (ipsilateral) events; therefore, patients with residual fragments of any size should not be labeled "stone free" and endoscopic stone treatment should aim at complete stone clearance.
authors.affiliation: 1 Department of Urology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Germany .
authors.forename: Simon
authors.initials: S
authors.lastname: Hein
authors.affiliation: 1 Department of Urology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Germany .
authors.forename: Arkadiusz
authors.initials: A
authors.lastname: Miernik
authors.affiliation: 1 Department of Urology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Germany .
authors.forename: Konrad
authors.initials: K
authors.lastname: Wilhelm
authors.affiliation: 1 Department of Urology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Germany .
authors.forename: Daniel
authors.initials: D
authors.lastname: Schlager
authors.affiliation: 1 Department of Urology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Germany .
authors.forename: Dominik Stefan
authors.initials: DS
authors.lastname: Schoeb
authors.affiliation: 1 Department of Urology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Germany .
authors.forename: Fabian
authors.initials: F
authors.lastname: Adams
authors.affiliation: 2 Center for Medical Biometry and Medical Informatics, University of Freiburg , Freiburg, Germany .
authors.forename: Werner
authors.initials: W
authors.lastname: Vach
authors.affiliation: 1 Department of Urology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Germany .
authors.forename: Martin
authors.initials: M
authors.lastname: Schoenthaler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004724:Endoscopy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007668:Kidney / Q000601:surgery; D007669:Kidney Calculi / Q000175:diagnosis* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D016016:Proportional Hazards Models; D012008:Recurrence; D019233:Retreatment; D012307:Risk Factors; D055815:Young Adult