title: Robot-assisted prostatectomy in obese patients: how influential is obesity on operative outcomes?
abstract: OBJECTIVE
  To compare operative outcomes of robot-assisted radical prostatectomy (RARP) in obese and nonobese patients with prostate cancer.
  
  
  METHODS
  A literature search of MEDLINE, EMBASE, Google Scholar, and the Cochrane Library was performed up to March 2014. All studies that have assessed operative outcomes of RARP in obese and nonobese patients were included. Outcome measures were perioperative and functional results, including operating time, estimated blood loss (EBL), complications, length of hospital stay (LOS), positive surgical margins (PSMs), and recovery of continence and potency. Pooled odds ratios (ORs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated using fixed-effect or random-effect model. Subgroup analysis was performed for institutions with greater experience of RARP in obese cases.
  
  
  RESULTS
  Thirteen observational studies from 12 study population were included for 1821 obese patients compared with 4801 nonobese patients. Operating time (p=0.0001; WMD: 24.28; 95% CI, 11.93-36.64) and EBL (p=0.003; WMD: 38.28; 95% CI, 13.45-63.11) were significantly increased in obese patients compared with nonobese counterparts. There was no significant difference in complications, LOS, or PSM rates. Subgroup analysis for studies that have involved ≥100 obese cases showed consistent results, but the increases in operating time (9.8 minutes; 95% CI, 1.7-18 minutes) and EBL (14 mL; 95% CI, 5.0-23 mL) were much lower compared with the original analysis. As for functional outcomes, obese patients showed significantly higher probabilities of incontinence (p=0.003; OR: 1.41; 95% CI, 1.13-1.77) and impotency (p=0.02; OR: 1.29; 95% CI, 1.03-1.61) at 1 year.
  
  
  CONCLUSIONS
  Perioperative outcomes of RARP in obese patients are comparable with those in nonobese patients, except for significant but small increases in operating time and EBL. Surgeons should initiate RARP procedures in obese cases after overcoming the learning curve. Further studies should be performed to evaluate the functional outcomes for obese patients undergoing RARP.
authors.affiliation: Department of Urology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine , Shanghai, China .
authors.forename: Tianyuan
authors.initials: T
authors.lastname: Xu
authors.forename: Xianjin
authors.initials: X
authors.lastname: Wang
authors.forename: Leilei
authors.initials: L
authors.lastname: Xia
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Zhang
authors.forename: Liang
authors.initials: L
authors.lastname: Qin
authors.forename: Shan
authors.initials: S
authors.lastname: Zhong
authors.forename: Zhoujun
authors.initials: Z
authors.lastname: Shen
mesh_terms: D000328:Adult; D016063:Blood Loss, Surgical; D019317:Evidence-Based Medicine; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009765:Obesity; D061646:Operative Time; D017063:Outcome Assessment, Health Care; D011183:Postoperative Complications; D011468:Prostatectomy / Q000009:adverse effects* / Q000379:methods; D011471:Prostatic Neoplasms / Q000601:surgery; D065287:Robotic Surgical Procedures / Q000009:adverse effects* / Q000379:methods