听神经瘤显微手术面神经损伤的预防

Prevention of facial nerve injury in acoustic neuroma microsurgery

目的总结与分析听神经瘤显微手术中预防面神经损伤的方法。方法经MRI和（或）CT检查确诊的大型听神经瘤（≥4．0cm）180例（72％）及中型听神经瘤（2．4～4．0cm）70例（28％）。均采用经患侧枕下乙状窦后入路保留面神经的显微手术。注意三大解剖关系：骨性解剖、蛛网膜解剖、神经与血管的解剖。肿瘤囊内减压后，确认面神经的起始位置、面神经与肿瘤的关系、面神经变形与扭曲、面神经分离的方法、面神经的断裂端-端吻合。随访6个月～1年。结果肿瘤全切除240例（96．0％）；次全切除10例（4．0％），其中死亡1例（0．4％）。面神经功能评定：Ⅰ级214例（85．6％）；Ⅱ级25例（10．0％）；Ⅲ级5例（2．1％）；Ⅳ级5例（2．1％）。结论术中注意典型的解剖位置，正确的手术入路和显微手术技术可达到较高的肿瘤全切除率，提高面神经的功能保全率。

Objective To summarize and analyse the techniques of avoiding facial nerve injury during acoustic neuroma microsurgery. Methods One hundred and eighty patients with large acoustic neuroma （≥4 cm） and 70 patients with medium acoustic neuroma（2. 4-4.0 cm） were diagnosed by MRI/ CT scan before operation and confirmed by postoperational pathologic examination. All of patients were treated by sub-occipital retrosigmoid approach for tumor removal and facial nerve reservation during operation. The relationships among the bone, arachnoid, nerve and vascular anatomy were particularly observed during the operation. After decompression of the tumor, the origination and location of the facial nerve as well as the relationship between the tumor and the facial nerve should be identified. The patients were followed-up from 6 months to 1 year postoperatively and assessed by House-Brackmann facial nerve function grading system. Results Total tumor resection was achieved in 240 of 250 cases （96%） and subtotal in 10 cases including 1 case died because of cerebellar encephalomalacia after operation. According to the House-Brackmann facial nerve function grading, recovery of normal function （ grade Ⅰ ） was achived in 214 cases（85.6% ）, grade Ⅱ in 25 cases（10% ） , grade Ⅲ in 5 cases（2. 09% ） and grade Ⅳ in 5 cases （2. 09% ）. Conclusion Microneurosurgical techniques are helpful for total resection of acoustic neuroma and keeping facial nerve anatomic intact.