Title:
Intraoperative application of nimodipine to the facial and cochlear nerves during vestibular
schwannoma resection to avoid spasm-related postoperative facial paralysis and deafness - a
prospective randomized study
Background:
In patients undergoing microsurgical resection of a vestibular schwannoma, the facial and
vestibulocochlear nerves are at risk. Prior studies suggested positive effects of nimodipine
for preservation of the nerve function in these patients. A prospective, randomized, placebo
controlled double-blinded study will be conducted to evaluate the neuro-protective effect of
locally administered nimodipine during resection of vestibular schwannomas.
Investigational drug:
active group: "Nimotop® 10mg - Infusionsflasche" placebo: "Natrium chloratum physiologicum
0,9% - Medica Infusionslösung"
Rationale for the study: Nimodipine is supposed to counteract the vasoconstriction of
cerebral arteries caused by microsurgical manipulation and might thereby preserve facial and
cochlear nerve function
Aims of the study: Evaluation of the effect of intraoperative local administration of
nimodipine on the postoperative function of the facial and vestibulocochlear nerves after
microsurgical resection of vestibular schwannomas
Study design: prospective, double-blinded, single-center, randomized phase III trial
Study population: Patients undergoing microsurgical resection of a vestibularis schwannoma
with a maximum diameter of 10-25mm on MRI at the Department of Neurosurgery, Medical
university of Vienna.
Number of Patients: 30
Methods: In 15 patients, nimodipine will be administered locally to the facial and
vestibulocochlear nerves during resection of a vestibular schwannoma (= treatment group). In
another 15 patients, a placebo (sodium chloride solution) will be administered. In both
cases, a soaked gel foam pad will be used. The operating team and the patient will both be
blinded during the procedure. Facial nerve function and hearing will be assessed prior and
three months after surgery.
Outcome variables: Serviceable or non-serviceable hearing according to Gardner-Robertson
hearing scale and House-Brackmann score for the assessment of facial nerve function
Statistical analysis: For the evaluation of the postoperative function of the
vestibulocochlear nerve, the number of patients with postoperative serviceable hearing
(Gardner-Robertson I-II) and postoperative non-serviceable hearing (Gardner-Robertson III-V)
will be compared between both groups. For the evaluation of the facial nerve function, the
number of patients with favorable postoperative outcome (House-Brackmann I-III) and
non-favorable postoperative outcome (House-Brackmann IV-VI) will be compared. In both cases,
fisher's exact test will be used.
Expected risks/inconveniences: Administration of nimodipine is associated with the following
adverse effects: thrombocytopenia, allergic reactions, headache, tachycardia, hypotension,
nausea (occasionally) and bradycardia, ileus, reversibly elevated liver enzymes (seldom)
Risk/benefit assessment: Expected adverse effects of local nimodipine administration are
manageable and patients may profit from the use of nimodipine. No severe adverse events are
expected.