title: Risk assessment of stone formation in stapled orthotopic ileal neobladder.
abstract: OBJECTIVE
  The increasing trend of performing radical cystectomy with a minimally invasive approach has made stapled neobladders an attractive alternative to hand-sewn pouches. To date, data on the incidence and clinical impact of stone formation in long surviving neobladder cases are scarce. We report a long-term, single-center experience of stapled orthotopic ileal neobladder and identify predictors of stone formation.
  
  
  METHODS
  From May 2001 to October 2012, 445 consecutive patients (388 male, 57 female) underwent radical cystectomy and stapled orthotopic ileal neobladder. Univariable and multivariable analyses were performed to identify independent predictors of an increased risk of stone formation.
  
  
  RESULTS
  At a median followup of 41 months (IQR 16-58) neobladder stone formation occurred in 41 patients (9.2%). All of these patients successfully underwent endoscopic stone lithotripsy with 34 as outpatient procedures. On univariable Cox analysis only female gender (p = 0.001, HR 3.29, 95% CI 1.59-6.83) and intermittent self-catheterization (p <0.001, HR 15.2, 95% CI 5.87-39.5) were associated with an increased risk of stone formation. On multivariable analysis the only independent predictor of stone formation was intermittent self-catheterization (p = 0.001, HR 8.98, 95% CI 2.59-31.1).
  
  
  CONCLUSIONS
  In our series of stapled orthotopic ileal neobladders the rate of stone formation was comparable to that reported in the literature for completely hand-sewn ileal reservoirs. The only variable independently predictive of stone formation was intermittent self-catheterization.
authors.affiliation: Department of Urology, Regina Elena National Cancer Institute of Rome, Rome, Italy. Electronic address: marilia.ferriero@gmail.com.
authors.forename: Mariaconsiglia
authors.initials: M
authors.lastname: Ferriero
authors.affiliation: Department of Urology, Regina Elena National Cancer Institute of Rome, Rome, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Guaglianone
authors.affiliation: Department of Urology, Regina Elena National Cancer Institute of Rome, Rome, Italy.
authors.forename: Rocco
authors.initials: R
authors.lastname: Papalia
authors.affiliation: Campus Bio-Medico University of Rome, Rome, Italy.
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Muto
authors.affiliation: Department of Urology, Regina Elena National Cancer Institute of Rome, Rome, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Gallucci
authors.affiliation: Department of Urology, Regina Elena National Cancer Institute of Rome, Rome, Italy; Department of Urology, San Giovanni Bosco Hospital, Turin, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Simone
mesh_terms: D015653:Cystectomy; D005260:Female; D006801:Humans; D007082:Ileum / Q000637:transplantation*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018570:Risk Assessment; D017792:Surgical Stapling; D001743:Urinary Bladder / Q000601:surgery*; D014545:Urinary Calculi / Q000453:epidemiology*; D014547:Urinary Diversion
keywords: cystectomy; risk; surgical staplers; urinary calculi; urinary diversion