Clinical Study On The Factors Affecting The Facial Nerve Outcome In Acoustic Neuroma Surgery

Objective(s):The protection of facial nerve function in acoustic neuroma surgery is one of the key and difficult points in neurosurgery.The factors affecting facial nerve outcome after surgery were observed and explored to provide reference for clinical treatment.Methods:Data of 52 patients who were hospitalized in the department of minimally invasive neurosurgery,the first affiliated hospital of kunming medical university,from January 2015 to March 2018 were retrospectively collected.On the basis of"Consensus of Chinese experts on multidisciplinary collaborative diagnosis and treatment of acoustic neuroma",we exclude 6 patients who were selected for follow-up observation due to tumor size(Stage 1,intracanalicular),no obvious growth of tumors and no obvious clinical symptoms,and 4 patients who were not allowed to receive surgical treatment due to systemic conditions were excluded.Finally,a total of 42 patients with acoustic neuroma confirmed by pathological results after surgical treatment were included.Their gender,age,tumor diameter,cystic degeneration,tumor side,facial nerve spatial location,intraoperative electrophysiologic monitoring and postoperative long and short-term facial nerve outcome were recorded,and their correlation was studied with statistical knowledge.Results:1.Compare the age of the postoperative facial nerve function in group A with group B,P=0.75>0.05;Gender comparison,P=0.661>0.05;tumor side comparison,P=0.763>0.05;there were no statistically significant difference.2.Compare the tumor diameter of the postoperative facial nerve function in group A with group B,group A was 2.92±0.19cm,group B was 4.900±0.26cm,the average diameter of group B is bigger than group A,P<0,0001,the difference was statistically significant.3.Whether long-term or short-term after surgery,When the tumor diameter>4 cm,the rate of a good Postoperative facial function(Grade 1 or 2)was significantly lower than the overall's,as for the tumor diameter<3 cm,the rate of a good Postoperative facial function(Grade 1 or 2)was significantly higher than the overall's.4.The rate of a good Postoperative facial function(Grade 1 or 2)for solid vestibular schwannoma is 80.6%,as for the cystic vestibular schwannoma,the rate comes to 45.5%,obviously lower than the former.P=0.026<0.05,the difference was statistically significant.5.The rate of a good Postoperative facial function in facial nerve spatial location type 1 was 86.4%;type 2,69.2%;type 3,28.6%;type 1-3 decline in turn.P=0.013<0.05,the difference was statistically significant.6.The rate of a good Postoperative facial function of using intraoperative electrophysiologic monitoring was 86.2%,significantly higher than the one who do not use(38.5%),P=0.002<0.05,the difference was statistically significant.7.Logistic multivariate regression analysis results shows that the tumor diameter,cystic degeneration,facial nerve spatial location,intraoperative electrophysiologic monitoring were closely associated with postoperative facial nerve function(P<0.05).8.Compare short-term's postoperative facial nerve function with long-term's,the good facial nerve function rate increased from 59.5%to 71.4%.Conclusion(s):1.The postoperative facial nerve function of acoustic neuroma has nothing to do with the patient's gender,age or tumor side.2.With the increase of tumor diameter,the tumor will pulling and extruding facial nerve cause its deformation,the adhesion between the facial nerve and tumor will become more tightly.The bigger the diameter,the more obviously the facial nerve disfunction will be.3.The cystic tumor can increase the adhesion with the surrounding tissue,and the rate of good postoperative facial nerve function of the cystic obviously lower than the solid.4.Facial nerve spatial location can affecte postoperative facial nerve functionthe by the way of increasing the adhesion between the facial nerve and tumor.And the rate of good postoperative facial nerve function of type 1-3 decline in turn.5.Intraoperative electrophysiologic monitoring can improve postoperative facial nerve function.6.The postoperative facial nerve function can slowly recover over a period of time,postoperative rehabilitation exercise and acupuncture therapy is important.