title: The influence of prophylactic vasoactive treatment on cochlear and facial nerve functions after vestibular schwannoma surgery: a prospective and open-label randomized pilot study.
abstract: OBJECTIVE
  Facial nerve paresis and hearing loss are common complications after vestibular schwannoma surgery. Experiments with facial nerves of the rat and retrospectively analyzed clinical studies showed a beneficial effect of vasoactive treatment on the preservation of facial and cochlear nerve functions. This prospective and open-label randomized pilot study is the first study of a prophylactic vasoactive treatment in vestibular schwannoma surgery.
  
  
  METHODS
  Thirty patients were randomized before surgery. One group (n = 14) received a vasoactive prophylaxis consisting of nimodipine and hydroxyethylstarch which was started the day before surgery and was continued until the seventh postoperative day. The other group (n = 16) did not receive preoperative medication. Intraoperative monitoring, including acoustic evoked potentials and continuous facial electromyelograms, was applied to all patients. However, when electrophysiological signs of a deterioration of facial or cochlear nerve function were detected in the group of patients without medication, vasoactive treatment was started immediately. Cochlear and facial nerve function were documented preoperatively, during the first 7 days postoperatively, and again after long-term observation.
  
  
  RESULTS
  Despite the limited number of patients, our results were significant using the Fisher's exact test (small no. of patients) for a better outcome after vestibular schwannoma surgery for both hearing (P = 0.041) and facial nerve (P = 0.045) preservation in the group of patients who received a prophylactic vasoactive treatment.
  
  
  CONCLUSIONS
  Prophylactic vasoactive treatment consisting of nimodipine and hydroxyethylstarch shows significantly better results concerning preservation of the facial and cochlear nerve function in vestibular schwannoma surgery. The prophylactic use is also superior to intraoperative vasoactive treatment.
authors.affiliation: Department of Neurosurgery, Bezikskrankenhaus Günzburg, University of Ulm, Ulm, Germany. christian.scheller@uni-ulm.de
authors.forename: Christian
authors.initials: C
authors.lastname: Scheller
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Richter
authors.forename: Martin
authors.initials: M
authors.lastname: Engelhardt
authors.forename: Ralph
authors.initials: R
authors.lastname: Köenig
authors.forename: Gregor
authors.initials: G
authors.lastname: Antoniadis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017024:Chemotherapy, Adjuvant / Q000379:methods; D003390:Cranial Nerve Neoplasms / Q000601:surgery; D005155:Facial Nerve Diseases / Q000209:etiology* / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000601:surgery; D019635:Neurosurgical Procedures / Q000009:adverse effects*; D009553:Nimodipine / Q000008:administration & dosage*; D010865:Pilot Projects; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000008:administration & dosage; D000160:Vestibulocochlear Nerve Diseases / Q000209:etiology* / Q000517:prevention & control* / Q000601:surgery
chemical_list: D014665:Vasodilator Agents; D009553:Nimodipine