title: Percutaneous Nephrolithotomy in Patients With BMI >50: Single Surgeon Outcomes and Feasibility.
abstract: OBJECTIVE
  To evaluate the use of percutaneous nephrolithotomy (PNL) and technical approach in the super obese population (body mass index [BMI] ≥ 50).
  
  
  METHODS
  We performed a retrospective review of 31 consecutive PNL cases with a BMI > 50 from a single surgeon (SYN) from 1995 to 2013. Procedures were performed in the prone position, and upper pole access was used. Operative time, length of hospital stay, stone burden, complication rates, and stone-free rates were measured.
  
  
  RESULTS
  Of the 31 patients who underwent PNL (age 51.2 ± 12; 71% female), the mean BMI was 59.1 ± 6 kg/m(2) (range 50.4-71.7 kg/m(2)). Mean stone burden was 3.8 cm ± 2. The majority of patients (90.3%) had an upper pole puncture site for access with an operative time of 122.1 ± 75 minutes. The technique was similar to non-obese patients; however, there was a need for extra-long instrumentation. The overall stone-free rate was 71%, with utilization of a second-look PNL in 11 cases. The complication rate, Clavien grade 3 or higher, was 9.7% (3 of 31).
  
  
  CONCLUSIONS
  PNL is technically feasible, safe, and effective in patients with a BMI ≥ 50. The complication rate, length of hospital stay, and stone-free rate with use of second-look PNL in super obese patients are comparable to severely obese patients. Intervention should not be automatically ruled out or delayed based on the patient's BMI alone.
authors.affiliation: Department of Urology, University of Wisconsin School of Medicine and Public Health, Madison, WI. Electronic address: streeper@urology.wisc.edu.
authors.forename: Necole M
authors.initials: NM
authors.lastname: Streeper
authors.affiliation: Department of Urology, University of Wisconsin School of Medicine and Public Health, Madison, WI.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Radtke
authors.affiliation: Department of Urology, University of Wisconsin School of Medicine and Public Health, Madison, WI.
authors.forename: Kristina L
authors.initials: KL
authors.lastname: Penniston
authors.affiliation: Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI.
authors.forename: John C
authors.initials: JC
authors.lastname: McDermott
authors.affiliation: Department of Urology, University of Wisconsin School of Medicine and Public Health, Madison, WI.
authors.forename: Stephen Y
authors.initials: SY
authors.lastname: Nakada
mesh_terms: D015992:Body Mass Index; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007669:Kidney Calculi / Q000150:complications / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous / Q000379:methods*; D009767:Obesity, Morbid / Q000150:complications*; D061646:Operative Time; D011183:Postoperative Complications / Q000453:epidemiology; D012189:Retrospective Studies; D066231:Surgeons; D016896:Treatment Outcome; D014922:Wisconsin / Q000453:epidemiology