title: Retroperitoneoscopic renal biopsy in extremely obese patients.
abstract: OBJECTIVE
  Retroperitoneoscopic renal biopsy can be technically challenging in extremely obese patients because of loss of surgical landmarks and difficulty in identifying the kidney within retroperitoneal adipose tissue. We present our experience with retroperitoneoscopic renal biopsy in extremely obese patients and describe our surgical technique.
  
  
  METHODS
  We performed retroperitoneoscopic renal biopsies on 8 extremely obese patients (body mass index greater than 40). Mean patient weight was 144.3 kg. Three patients presented with acute renal failure and 5 presented with nephrotic range proteinuria. Retroperitoneoscopic renal biopsy was indicated based on extreme obesity alone in 3 patients, 2 patients had failed previous attempts at percutaneous biopsy, 1 patient had a solitary kidney, 1 patient required chronic anticoagulation, and 1 patient was a Jehovah's Witness. Intraoperative ultrasonography and an anatomic approach facilitated the dissection and identification of the kidney.
  
  
  RESULTS
  All eight retroperitoneoscopic renal biopsies were completed successfully without complication and all patients were discharged within 24 hours of the procedure. Sufficient tissue for pathologic diagnosis was obtained in all cases. Mean operating room time was 153 minutes and mean estimated blood loss was 71 mL. The patients returned to normal activity at a mean of 1.8 weeks.
  
  
  CONCLUSIONS
  With the use of intraoperative ultrasonography and a systematic, anatomic approach, retroperitoneoscopic renal biopsy can be successfully completed in extremely obese patients. This procedure can be reliably performed on an outpatient basis with minimal morbidity and should be considered a viable alternative to open renal biopsy.
authors.affiliation: James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.
authors.forename: R N
authors.initials: RN
authors.lastname: Chen
authors.forename: R G
authors.initials: RG
authors.lastname: Moore
authors.forename: S
authors.initials: S
authors.lastname: Micali
authors.forename: L R
authors.initials: LR
authors.lastname: Kavoussi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000295:instrumentation / Q000379:methods*; D004724:Endoscopy; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000150:complications / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000150:complications; D012187:Retroperitoneal Space