title: Extrafascial versus interfascial nerve-sparing technique for robotic-assisted laparoscopic prostatectomy: comparison of functional outcomes and positive surgical margins characteristics.
abstract: OBJECTIVE
  To evaluate the pathologic and functional outcomes of patients with bilateral interfascial (IF) or extrafascial nerve-sparing (EF-NSP) techniques. It is believed that the IF-NSP technique used during robotic-assisted radical prostatectomy (RARP) spares more nerve fibers, while EF dissection may lower the risk for positive surgical margins (PSM).
  
  
  METHODS
  A prospective database was analyzed for RARP patients with bilateral IF- or EF-NSP technique. Collected parameters included age, body mass index, prostate-specific antigen, clinical and pathologic Gleason score and stage, estimated blood loss, operative time, and PSM characteristics. Functional outcomes were evaluated with the use of the University of California Los Angeles Prostate Cancer Index questionnaire. Men receiving postoperative hormonal or radiation therapy were excluded from sexual function analysis.
  
  
  RESULTS
  A total of 110 and 703 cases with bilateral EF- and IF-NSP, respectively, were analyzed. EF-NSP patients had higher prostate-specific antigen, clinical, pathologic stage, and pathologic Gleason score. PSM rate did not achieve statistically significant difference between groups. There was a trend toward lower pT3-PSM in the EF group (51% vs 28%; P = .08). Mid- and posterolateral PSM location were lower in the EF-NSP group, 11% vs 37% and 11% vs 29%, respectively (P < .001). The IF-NSP group patients achieved statistically significant better sexual function (P = .02) and potency rates (P = .03) at 12 months after RARP.
  
  
  CONCLUSIONS
  In lower risk patients, bilateral IF-NSP technique does not result in significantly higher PSM rates. EF-NSP appears to reduce posterolateral and mid-prostate PSM. Men with bilateral IF-NSP demonstrate significantly better sexual function outcomes.
authors.affiliation: Department of Surgery, University of Chicago, Chicago, IL 60637, USA. sergeyshikanov@gmail.com
authors.forename: Sergey
authors.initials: S
authors.lastname: Shikanov
authors.forename: Jason
authors.initials: J
authors.lastname: Woo
authors.forename: Hikmat
authors.initials: H
authors.lastname: Al-Ahmadie
authors.forename: Mark H
authors.initials: MH
authors.lastname: Katz
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Zagaja
authors.forename: Arieh L
authors.initials: AL
authors.lastname: Shalhav
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Zorn
mesh_terms: D000328:Adult; D000368:Aged; D000071938:Fasciotomy; D006801:Humans; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011467:Prostate / Q000294:innervation / Q000601:surgery; D011468:Prostatectomy / Q000379:methods*; D011471:Prostatic Neoplasms / Q000473:pathology / Q000601:surgery*; D012371:Robotics; D016896:Treatment Outcome