Surgical Treatment Of Large Acoustic Neuroma

OBJECTIVE: To investigate the degree of resection and facial nerve function of large acoustic neuroma,and to summarize the experience to improve the surgical effect of large acoustic neuromaMETHODS: The clinical data of 45 patients with acoustic neuroma treated in the ninth ward of neurosurgery department of Tianjian Huanhu hospital from January 2014 to December 2018 were analyzed retrospectively.All the operations were performed by the same operator(Dr.Wang Hong)through the retrosigmoid approach.Head CT,TLC-scanning of temporal bone,cranial plain and enhanced MRI,hearing test and electrophysiological examination were performed on admission to hospital.Neuroelectrophysiological monitoring was routinely used during the operation.According to the House-Brackmann grading system,evaluating the functions of facial nerve preoperative,postoperative and during follow-up for all patients.The patients with tumor recurrence or regrowth were treated with radiotherapy during the follow-up period.The related factors affecting the postoperative facial nerve function of patients with large acoustic neuroma were statistically analyzed,and the relationship between the degree of tumor resection and facial nerve function,as well as the relationship between the degree of tumor resection and tumor recurrence were compared and analyzed.The results were statistically analyzed by SPSS25.0 software.RESULTS: Of the 45 patients with large acoustic neuroma,women accounted for 52.0%,the age was 48.00±11.59 years.Right acoustic neuroma accounted for 56.0%,the diameter of tumor was 38.91±7.31 mm and the maximum diameter was 58 mm.Follow-up period ranged from 4 months to 5 years,forty patients were followed up for more than one year.There were no perioperative deaths.Of the 40 patients who were followed up for more than one year,the gross total resection rate was 12.5%(5/40),the near-total resection rate was 55.0%(22/40),and the subtotal resection rate was 32.5%(13/40).Anatomic preservation rate of facial nerve 100%,the good rates of early postoperative(at discharge)and long-term(latest follow-up)facial nerve function were 62.5%(25/40)and 82.5%(33/40),respectively.The good rates of facial nerve function in the early and long term after operation were 20.0% and 60.0% in the gross total resection group,77.3% and 86.4% in the near-total resection group,and 76.9% and 84.6% in the subtotal resection group,respectively.Statistical analysis showed that early postoperative facial nerve function is related to the degree of tumor resection(P < 0.05).The recurrence rates of gross total resection group,subtotal resection group and subtotal resection group were 0%,13.6% and 15.4% respectively.The average follow-up period after gamma knife radiosurgery was 34.3 months,the control rate was 100%.CONCLUSION: Large acoustic neuroma can be completely resected by retrosigmoid approach,when facial nerve and brainstem adhere closely to the tumor,subtotal resection or subtotal resection can be selected with auxiliary radiotherapy or follow-up observation,good preservation of facial nerve function and good tumor control can be obtained,this strategy can be used as a feasible method to improve the quality of life of patients with large acoustic neuroma after operation.