The Analysis Of Protecting The Facial Nerve Function In Acoustic Neuroma Resection And Its Influence Factors

Objectives:The dysfunction of the facial nerve is the main postoperative complication in patients with acoustic neuroma,and reducing its occurrence is our current operating principle.Therefore,the accurate nerve tracing preoperative is vital for protecting the nerve function during intraoperation,which can help the operator to make preoperative plan and protect facial nerve.Our study applied the relative relationship between the acoustic neuroma and facial nerve by using diffusion tensor imaging,combined with intraoperative electrophysiological monitoring,comparing with the other two groups after operation and electrophysiological monitoring about the difference of facial nerve function postoperation,and discussing the difference among the three groups in the protection of postoperative nerve function,and then offering a more favorable method for the facial nerve protection.Then analyse the effects of age,sex,maximum tumor diameter and specific parameters of diffusion tensor imaging of patients on postoperative neurological function.Methods:There were 143 cases were collected retrospectively,who were dignosed acoustic neuroma(vestibular schwannoma)by the clinical and pathological diagnosis in the Shanxi Province People’s Hospital from June 2012 to June 2019.According to the screening criterias,the collected cases were divided into three groups: 33 patients in the simple operation group,61 patients in the electrophysiological monitoring group and 49 patients in the diffusion tensor imaging monitoring combined with electrophysiological monitoring group.All cases were treated with Mircrosuegery via the Retrosigmoidcraniotomy approach,then we classified them into three groups by the lateral nerve function,whichⅠ~Ⅱ grade was mild,Ⅲ~Ⅳ grade was moderate,Ⅴ~Ⅵ grade wasparalysis 30 days after suegery according to the House-Brackmann(H-B)grade.The Fisher probability method was used to compare the facial nerve function among the three groups,when p<0.05 has statistical significance.Collecting the valid patients’ information which including the age,sex,tumor size,FA value and ADC with lateral nerve in the diffusion tensor imaging monitoring group.The facial nerve function was divided into 3 grades according to the House-Brackmann(H-B)grade after 1 month of follow-up patients.The multivariate Logistic regression analysis was used to analyze whether there was a linear correlation between the first five factors and postoperative nerve function of the patients.Results:1.Postoperative complications happened to one patient,then observation group were excluded.In the remaining cases,total tumor resection was performed in 17 cases(51.52%)and subtotal resection in 16 cases(48.48%).Under electrophysiological monitoring,total resection of tumor was performed in 45 cases(73.77%)and subtotal resection in 16 cases(26.23%).2.In the diffusion tensor imaging group,it was found that the facial nerve was located in the ventral superior of the tumor in 17 cases(34.69%),the ventral in 16cases(32.65%),the ventral inferior 9 cases(18.37%),the superior pole of the tumor in 5 cases(10.21%),the inferior pole of the tumor in 1 case(2.04%),and the nerve display was poor in 1 case(2.04%).Total resection was performed in 36 cases(73.47%)and subtotal resection in 13 cases(26.53%).3.Ten days after operation of facial nerve function,there were 11 patients with mild abnormality,19 patients with moderate abnormality and 3 patients with severe abnormality in the simple microsurgery group;the patients in the operation group had the most mild abnormality,39 patients with mild abnormality,21 patients with moderate abnormality and 1 patient with severe abnormality,and the neurological function of the patients in the last three years was less than that in the previous three years;42 patientswere mildly abnormal and 7 patients were moderately abnormal in the DTI localization group.4.Comparing the postoperative neurological function of the three groups through SPSS22.0,it was found that there was a statistical difference among the three groups(p <0.05).After the comparison of the three groups,it indicated that significant difference among them(p<0.0167).5.We found that for patients who with 2-4cm acoustic neuroma,the maximum diameter of the tumor was larger than 3cm,FA<0.35 and ADC>2.85 were correlated with postoperative neurological function(p<0.05),but there was no significant correlation between sex,age and postoperative neurological function(p>0.05).Conclusions:1.Diffusion tensor imaging can accurately describe the traces of facial nerve,and it can be used to describe the relationship between facial nerve and acoustic neuroma.2.There is statistical difference in the postoperative neurological function and between the application of electrophysiological monitoring and the combined group,which can assist the operator to make the operation plan and protect the facial nerve.3.The maximum diameter of the tumor,the specific parameters of diffusion tensor imaging FA and ADC value are related to the postoperative neurological function of the patients,and can be used as factors affecting the postoperative neurological function of the patients.