title: Robot-assisted approach improves surgical outcomes in obese patients undergoing partial nephrectomy.
abstract: OBJECTIVE
  To assess the impact of approach on surgical outcomes in otherwise healthy obese patients undergoing partial nephrectomy for small renal masses.
  
  
  METHODS
  Using our institutional partial nephrectomy database, we abstracted data on otherwise healthy (Charlson comorbidity score ≤1 and bilateral kidneys), obese patients (body mass index >30 kg/m2) with small renal masses (<4 cm) treated between 2011 and 2015. The primary outcomes were intra-operative transfusion, operating time, length of hospital stay (LOS), and postoperative complications. The association between approach, open (OPN) vs robot-assisted partial nephrectomy (RAPN), and outcomes was assessed by univariable and multivariable logistic regression analyses. Covariates included age, gender, obesity severity, tumour size and tumour complexity.
  
  
  RESULTS
  Of 237 obese patients undergoing partial nephrectomy, 25% underwent OPN and 75% underwent RAPN. Apart from larger tumour size in the OPN group (2.8 vs 2.5 cm; P = 0.02), there was no significant difference between groups. The rate of intra-operative blood transfusion (1.1 vs 10%; P = 0.01), the median operating time (180 vs 207 min; P < 0.01) and the median ischaemia time (19.5 vs 27 min; P < 0.01) were all greater for OPN. The LOS was significantly shorter for RAPN (3 vs 4 days; P < 0.01). While the overall complication rate was higher for OPN (15.8 vs 31.7%; P < 0.01), major complications were not significantly different (5.6 vs 1.7%; P = 0.20). On multivariable analyses, OPN independently predicted longer operating time, longer length of stay, and more overall complications.
  
  
  CONCLUSIONS
  At a high-volume centre, the robot-assisted approach offers less blood transfusion, shorter operating time, faster recovery, and fewer peri-operative complications compared with the open approach in obese patients undergoing partial nephrectomy for small renal masses. In this setting, RAPN may be a preferable treatment option.
authors.affiliation: Department of Urology, Cleveland Clinic, Glickman Urological and Kidney Institute, Cleveland, OH, USA.|Urology Department, Sultan Abdulhamid Education and Training Hospital, University of Health Science, Istanbul, Turkey.
authors.forename: Ercan
authors.initials: E
authors.lastname: Malkoc
authors.affiliation: Department of Urology, Cleveland Clinic, Glickman Urological and Kidney Institute, Cleveland, OH, USA.
authors.forename: Matthew J
authors.identifier: http://orcid.org/0000-0002-0324-8795
authors.initials: MJ
authors.lastname: Maurice
authors.affiliation: Department of Urology, Cleveland Clinic, Glickman Urological and Kidney Institute, Cleveland, OH, USA.|Urology Department, Amasya University Medical School, Amasya, Turkey.
authors.forename: Onder
authors.initials: O
authors.lastname: Kara
authors.affiliation: Department of Urology, Cleveland Clinic, Glickman Urological and Kidney Institute, Cleveland, OH, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Ramirez
authors.affiliation: Department of Urology, Cleveland Clinic, Glickman Urological and Kidney Institute, Cleveland, OH, USA.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Nelson
authors.affiliation: Department of Urology, Cleveland Clinic, Glickman Urological and Kidney Institute, Cleveland, OH, USA.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Caputo
authors.affiliation: Department of Urology, Cleveland Clinic, Glickman Urological and Kidney Institute, Cleveland, OH, USA.
authors.forename: Pascal
authors.initials: P
authors.lastname: Mouracade
authors.affiliation: Department of Urology, Cleveland Clinic, Glickman Urological and Kidney Institute, Cleveland, OH, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Stein
authors.affiliation: Department of Urology, Cleveland Clinic, Glickman Urological and Kidney Institute, Cleveland, OH, USA.
authors.forename: Jihad H
authors.initials: JH
authors.lastname: Kaouk
mesh_terms: D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000150:complications* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000379:methods*; D009765:Obesity / Q000150:complications*; D011446:Prospective Studies; D065287:Robotic Surgical Procedures; D016896:Treatment Outcome
keywords: nephrectomy; obesity; partial nephrectomy; robotic surgical procedures