title: The Risks and Benefits of Cavernous Neurovascular Bundle Sparing during Radical Prostatectomy: A Systematic Review and Meta-Analysis.
abstract: We summarize published data on associations between cavernous neurovascular bundle preservation (nerve sparing) during prostatectomy and positive surgical margins, erectile function, urinary function and other patient reported outcomes.
  
  
  
  A systematic literature search of MEDLINE®, Embase® and Cochrane Reviews databases was performed for interventional or observational studies published between 2000 and 2014. English language articles that compared clinical outcomes of patients undergoing nerve sparing and nonnerve sparing radical prostatectomy were included. Meta-analyses were performed to calculate pooled relative risk estimates for positive surgical margins, erectile dysfunction and urinary incontinence in nerve sparing and nonnerve sparing groups. Sensitivity analyses compared outcomes among unilateral and bilateral nerve sparing vs nonnerve sparing groups.
  
  
  
  Of the 1,883 articles identified, 124 studies (73,448 patients) were included in the analysis. Nerve sparing did not increase the risk of positive surgical margins in patients with pT2 (RR 0.92, 95% CI 0.75-1.13) or pT3 disease (RR 0.83, 95% CI 0.71-0.96), potentially due to appropriate patient selection. The risk of incontinence was lower in nerve sparing cases (RR 0.75, 95% CI 0.65-0.85 and RR 0.61, 95% CI 0.44-0.84) at 3 and 12 months, respectively. The relative risk of erectile dysfunction with nerve sparing was 0.77 (95% CI 0.70-0.85) at 3 months and 0.53 (95% CI 0.39-0.71) at 12 months. Subgroup analyses of unilateral and bilateral nerve sparing approaches demonstrated similar results.
  
  
  
  Among cohort studies nerve sparing was not associated with worse cancer outcomes. Nerve sparing is associated with better urinary and erectile function. These results should be interpreted with caution given the potential for selection bias and unadjusted confounding factors.
authors.affiliation: Division of Urology, Department of Surgery, The Ottawa Hospital, Ottawa, Ontario, Canada.
authors.forename: Laura N
authors.initials: LN
authors.lastname: Nguyen
authors.affiliation: Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
authors.forename: Linden
authors.initials: L
authors.lastname: Head
authors.affiliation: Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
authors.forename: Kelsey
authors.initials: K
authors.lastname: Witiuk
authors.affiliation: Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
authors.forename: Nahid
authors.initials: N
authors.lastname: Punjani
authors.affiliation: Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
authors.forename: Ranjeeta
authors.initials: R
authors.lastname: Mallick
authors.affiliation: Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
authors.forename: Sonya
authors.initials: S
authors.lastname: Cnossen
authors.affiliation: Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
authors.forename: Dean A
authors.initials: DA
authors.lastname: Fergusson
authors.affiliation: Division of Urology, Department of Surgery, The Ottawa Hospital, Ottawa, Ontario, Canada.
authors.forename: Ilias
authors.initials: I
authors.lastname: Cagiannos
authors.affiliation: Division of Urology, Department of Surgery, The Ottawa Hospital, Ottawa, Ontario, Canada; Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
authors.forename: Luke T
authors.initials: LT
authors.lastname: Lavallée
authors.affiliation: Division of Urology, Department of Surgery, The Ottawa Hospital, Ottawa, Ontario, Canada.
authors.forename: Christopher
authors.initials: C
authors.lastname: Morash
authors.affiliation: Division of Urology, Department of Surgery, The Ottawa Hospital, Ottawa, Ontario, Canada; Ottawa Hospital Research Institute, Ottawa, Ontario, Canada. Electronic address: rbreau@ottawahospital.ca.
authors.forename: Rodney H
authors.initials: RH
authors.lastname: Breau
mesh_terms: D007172:Erectile Dysfunction / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D008297:Male; D059351:Organ Sparing Treatments / Q000009:adverse effects* / Q000379:methods; D000071066:Patient Reported Outcome Measures; D010413:Penis / Q000098:blood supply / Q000294:innervation; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D011468:Prostatectomy / Q000009:adverse effects* / Q000379:methods; D011471:Prostatic Neoplasms; D011788:Quality of Life; D016896:Treatment Outcome; D014549:Urinary Incontinence / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control / Q000601:surgery*
keywords: erectile dysfunction; margins of excision; prostatectomy; urinary incontinence