title: Ureteroscopic treatment of renal calculi in morbidly obese patients: a stone-matched comparison.
abstract: OBJECTIVE
  To report a matched comparison of morbidly obese (MO) patients and normal weight (NW) patients who underwent ureteroscopic (URS) treatment of renal calculi. Shock wave lithotripsy and percutaneous nephrostolithotomy may be precluded in MO patients, and URS treatment offers a minimally invasive alternative.
  
  
  METHODS
  We retrospectively reviewed the charts of patients who underwent URS at our institution between 1997 and 2000. Fifty-four patients underwent URS treatment solely for renal calculi. Sixteen MO patients underwent 18 procedures. Thirty-eight NW patients, who underwent 39 procedures, were matched to the MO patients by stone location and size. Stones were categorized by location and size, less than 10 mm or 10 mm or greater. The factors and outcomes assessed were stone length, operative time, presence of a ureteral stent, success, and complications.
  
  
  RESULTS
  The overall success rate was 83% (15 of 18 procedures) for MO patients and 67% (26 of 39 procedures) for NW patients, but this difference was not significant (P = 0.23). The difference in the success rate for renal calculi 10 mm or greater (100% versus 38%) approached significance (P = 0.09). This may be related to other distinctions between the groups. URS treatment was often a salvage therapy in the NW group after other modalities failed. No significant differences were found between the other outcomes.
  
  
  CONCLUSIONS
  URS treatment of renal calculi when matched for location and size is as successful and no more morbid in MO than in NW patients. URS treatment of renal calculi is a safe and effective first-line treatment for renal calculi in MO patients.
mesh_terms: D015992:Body Mass Index; D001835:Body Weight; D015897:Comorbidity; D006801:Humans; D007431:Intraoperative Complications / Q000453:epidemiology; D007668:Kidney / Q000000981:diagnostic imaging; D007669:Kidney Calculi / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000601:surgery*; D009767:Obesity, Morbid / Q000453:epidemiology*; D011183:Postoperative Complications / Q000453:epidemiology; D011859:Radiography; D016896:Treatment Outcome; D018666:Ureteroscopy / Q000009:adverse effects / Q000379:methods*