title: Improved Postoperative Facial Nerve and Hearing Function in Retrosigmoid Vestibular Schwannoma Surgery Significantly Associated with Semisitting Position.
abstract: OBJECTIVE
  The pros and cons of semisitting positioning (SSP) versus lateral, horizontal positioning (LP) during retrosigmoid vestibular schwannoma (VS) surgery, especially concerning postoperative cranial nerve and brain stem preservation, are under continuous discussion.
  
  
  METHODS
  In a single-center retrospective cohort study, 30 VSs operated on in SSP compared with 30 operated on in LP with comparable demography were analyzed. During SSP surgery, transesophageal echocardiographic monitoring for venous air embolism was used continuously. Electrophysiologic cranial nerve monitoring was used in both groups.
  
  
  RESULTS
  Length of surgery was significantly different between both groups: 183 minutes mean in SSP surgery versus 365 minutes mean in LP surgery (P = 0.0001). Postoperative rates of facial palsy and hearing loss were also significantly different. Six months postoperatively, 63% had normal facial nerve function after SSP surgery, whereas in LP surgery, 40% had no facial palsy (P = 0.02). Hearing preservation rate was also significantly different: 44% in SSP surgery compared with 14% in LP surgery who had preserved hearing (P = 0.006). Because of cerebrospinal fluid leaks, there were 3 operative revisions in the LP group (10%) and 1 (3.3%) in the SSP group. A clinically insignificant venous air embolism rate was found in 3.3% of patients (1/30) during SSP surgery. The neurologic outcome after 6 months was 1.2 on the Rankin Scale in the LP group and 1.0 in the SSP group, with zero mortality.
  
  
  CONCLUSIONS
  SSP compared with LP surgery was associated with significantly shorter operation time and better facial and cochlear nerve function in VS surgery postoperatively, without differences in complication rates.
authors.affiliation: Department of Neurosurgery, University Hospital Erlangen, Erlangen, Germany. Electronic address: karl.roessler@uk-erlangen.de.
authors.forename: Karl
authors.initials: K
authors.lastname: Roessler
authors.affiliation: Department of Neurosurgery, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Krawagna
authors.affiliation: Department of Neurosurgery, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Bischoff
authors.affiliation: Department of Neurosurgery, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Rampp
authors.affiliation: Department of Neurosurgery, Katharinen Hospital Stuttgart, Stuttgart, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Ganslandt
authors.affiliation: Department of ENT, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Iro
authors.affiliation: Department of Anesthesiology, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Hubert
authors.initials: H
authors.lastname: Schmitt
authors.affiliation: Department of Neurosurgery, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Buchfelder
mesh_terms: D065634:Cerebrospinal Fluid Leak / Q000601:surgery; D015331:Cohort Studies; D017548:Echocardiography, Transesophageal; D004618:Embolism, Air / Q000175:diagnosis / Q000209:etiology; D020220:Facial Nerve Injuries / Q000209:etiology* / Q000628:therapy*; D005260:Female; D034381:Hearing Loss / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000009:adverse effects* / Q000379:methods*; D056888:Patient Positioning; D011183:Postoperative Complications / Q000453:epidemiology* / Q000503:physiopathology*; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
keywords: Facial nerve preservation; Hearing preservation; Lateral position; Semisitting position; Vestibular schwannoma surgery