Acoustic Neuroma Facial And Auditory Nerve Function Preservation

In recent years, our group has been focusing on the two fields that the function preservation of the facial and auditory nerve on acoustic neuroma. We have preliminarily explored on the two directions and concluded some lessons, the paper will elaborate these two aspects.This research includes the following two parts.PART 1:Acoustic neurinoma preservation of function of the facial nerveObjective To investigate the optimal treatment and prognostic factors of preserving function of the facial nerve for acoustic neuroma. Methods A cohort study was performed in 152 patients with surgical resection and observing the postoperative facial nerve function. The facial nerve function were compared after operation by three surgical approaches. The postoperative facial nerve function and prognostic factors were analyzed using the Logistic regression model. (P<0.05) Results There are 97.4% of patients with hearing loss,88.2% tinnitus,32.2% vertigo,24.3% facial numbness and paresthesias,13.2% unsteady,11.8% ear ache,3.9% diplopia and 2.6% choking cough of drinking water in 152 patients of acoustic neuroma. The average tumor diameter was about 2.34±1.14cm(0-5cm). The anatomical facial nerve integrity was preserved in 95.4%(145/152) of all the patients. There were significant difference between translabyrinthine approach and retrosigmoid approach on the seventh day after operation about postoperative facial nerve function. There were significant difference between translabyrinthine approach and middle cranial fossa approach on the seventh day after operation about postoperative facial nerve function. There were no significant difference between retrosigmoid approach and middle cranial fossa approach on the seventh day after operation about postoperative facial nerve function. There were no significant difference among the three approach on the 1 year after operation about postoperative facial nerve function. The Logistic regression analysis showed that on the seventh day after operation,there was no correlation between the postoperative facial nerve function and age, sex and tumor size and there was a correlation between the postoperative facial nerve function and surgical approach and the degree of adhesion of tumor and the facial nerve. On the other hand, on the 1 year after operation,the Logistic regression analysis showed that there was no correlation between the postoperative facial nerve function and surgical approach, sex and tumor size,there was a correlation between the postoperative facial nerve function and age and the degree of adhesion of tumor and the facial nerve. Conclusions 1.The translabyrinthine approach is superior for the preservation of facial nerve function to the retrosigmoid approach and the middle cranial fossa approach on the seventh day after operation. There were no significant difference between the retrosigmoid approach and the middle cranial fossa approach on the seventh day after operation. There were no significant difference among the three approach on the 1 year after operation about postoperative facial nerve function.2. On the seventh day after operation, there was no correlation between the postoperative facial nerve function and age, sex and tumor size, and there was a correlation between the postoperative facial nerve function and surgical approach and the degree of adhesion of tumor and the facial nerve. On the other hand, on the 1 year after operation, there was no correlation between the postoperative facial nerve function and surgical approach, sex and tumor size, and there was a correlation between the postoperative facial nerve function and the degree of adhesion of tumor and the facial nerve and age.PART 2:Acoustic neurinoma preservation of function of the auditory nerveObjective To investigate the optimal treatment and prognostic factors of preserving function of the auditory nerve for acoustic neuroma. Methods A cohort study was performed in fifty-four patients of acoustic neuroma with small size tried to retain hearing by follow-up observation, microsurgical resection, stereotactic radiotherapy. Results On the hearing reservation, there were 24(88.9%,24/27)patients who had slow or even no tumor growth among the 27 patients with follow-up observation,. Three of them had tumor overgrowth or obvious hearing decline, therefore observation was ceased. Two of them received surgical resection, and the left one received stereotactic radiotherapy (gamma knife therapy). The patient who received gamma knife therapy, which well preserved hearing and led to no tumor growth after the therapy.The overall hearing preservation rate of these 29 acoustic neuroma patients who received surgical resection(27 retrosigmoid approach,2 middle cranial fossa approach) was 55.2%(16/29), with hearing reaching Grade A+B post surgery. There were 7 patients whose hearing reaching Grade A and 9 patients whose hearing reaching Grade B in our research. Among them, the 14 patients with Grade A hearing before surgery had a preservation rate of 78.6% (50.0% at Grade A post surgery,28.6% at Grade B,14.3% at Grade C and 7.1% at Grade D), and the rate was 33.3% for patients with Grade B hearing pre-surgery (33.3% at Grade B after surgery,53.3% at Grade C and 13.3% at Grade D). Follow-up observation(three years) revealed stable hearing preservation in 14 of the 16 patients. Conclusions 1.Hearing preservation is affected by multiple factors, and is closely associated with initial hearing conditions. The initial hearing function has a direct impact on hearing preservation rate. Therefore, early detection, diagnosis and treatment of acoustic neuroma when hearing is at Grade A, is the key to preserve hearing.2. When we find that tumor volume rapidly growing or the utility hearing may be quickly lost, as long as the patient’s health condition allows, we should give the patient a surgical treatment immediately.