Translabyrinthine vestibular schwannoma surgery: postoperative tinnitus and cochlear nerve integrity.

Cochlear neurectomy as a surgical treatment for tinnitus is known to be only partially successful in many conditions. Translabyrinthine surgery for acoustic neuromas may be performed using a dissection technique which preserves an 'anterior curtain' which helps to protect the facial nerve. The cochlear nerve may be retained within this tissue though it can be cut during the dissection. To assess whether its integrity affects tinnitus the video recordings of 117 patients undergoing this operation were reviewed to grade the likelihood of the cochlear nerve having been retained intact. A postal questionnaire, with a response rate of 83%, was used to assess tinnitus. Patients who had a probable or definite nerve section had significantly lower postoperative tinnitus severity. The same relationship was found when patients were matched for tumour size and preoperative tinnitus. This procedure could act as a model for the effect of cochlear neurectomy on tinnitus associated with acoustic neuromas in a prospective trial.