title: Multi-session retrograde endoscopic lithotripsy of large renal calculi in obese patients.
abstract: OBJECTIVE
  To establish the safety and efficacy of planned multi-session retrograde endoscopic lithotripsy (REL) for the treatment of large renal calculi in the morbidly obese.
  
  
  METHODS
  We retrospectively reviewed charts of patients who underwent multi-session REL procedures from 2003 to 2008. Inclusion criteria included body mass index > 35, total linear stone diameter > 2.0 cm, and patients with a preoperative plan to perform multi-session ureteroscopy. A total of nine patients (six with staghorn calculi) underwent 21 separate procedures. Stone size was measured on preoperative imaging and was defined as length in greatest diameter. Stone free was defined as the complete absence of residual stone on postoperative imaging.
  
  
  RESULTS
  Mean body mass index of the patients was 47.8 kg/m2. Mean total linear stone diameter was 3.8 cm. Three of nine patients (33%) were stone free after their final treatment. Mean decrease in stone size from preoperative imaging was 3.3 cm (83%). There were no intraoperative complications. Mean length of follow up was 0.88 years.
  
  
  CONCLUSIONS
  Multi-session REL is a safe alternative to percutaneous nephrolithotomy (PCNL) in obese patients with very large stones, including staghorn calculi. We recognize that the stone free rate in this series is lower than would be expected with REL for smaller stone burdens or with PCNL. Due to the limitations imposed by both the patient's general medical conditions as well as technical considerations, these patients are left with few options for treatment. Our experience is that management with staged ureteroscopy offers a reduction in stone burden and in some patients a stone free status that provides an acceptable patient outcome.
authors.affiliation: Department of Urology, University of Michigan Health System, Ann Arbor, Michigan 48109-5330, USA.
authors.forename: Jeffery C
authors.initials: JC
authors.lastname: Wheat
authors.forename: William W
authors.initials: WW
authors.lastname: Roberts
authors.forename: J Stuart
authors.initials: JS
authors.lastname: Wolf
mesh_terms: D000368:Aged; D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007669:Kidney Calculi / Q000150:complications / Q000175:diagnosis / Q000628:therapy*; D008096:Lithotripsy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018666:Ureteroscopy