经枕下-乙状窦后入路显微切除听神经瘤的显微解剖学研究

Microanatomic reserch of microsurgical removal of acoustic neuroma via the suboccipital retrosigmoid approach

目的通过研究经枕下-乙状窦后入路的桥小脑角区的结构,为临床经枕下-乙状窦后入路切除听神经瘤提供解剖学资料。方法在10%甲醛固定并灌有乳胶的成人头颅湿标本20例,模拟枕下-乙状窦后手术入路,逐层解剖、观察桥小脑区的三个解剖间隙的主要血管神经解剖变异和走行,并测量面神经与前庭蜗神经进入脑干处的距离。结果桥脑小脑角区的重要血管和神经之间关系存在一定变异,观察了小脑上动脉、小脑下前动脉、小脑下后动脉、岩上静脉、面听神经、三叉神经以及后组颅神经的行程、分支和变异等情况,但这些结构在桥小脑区的三个解剖间隙内层次分明,分布较恒定。面神经与前庭蜗神经进入脑干处的距离为(2.3±1.1)mm。结论通过经枕下-乙状窦后入路来解剖桥小脑角区的神经血管,具有重要意义,充分认识了各重要神经和血管结构关系,对临床手术有极其重要的指导作用。

Objective To provide clinical anatomical datas for removing acoustic neuromas via the suboccipital retrosigmoid approach,we investigated the structure of suboccipital retrosigmoid approach to the cerebellopontine angle （CPA） region. Methods Twenty adult cadaveric heads fixed in 10% formalin and purfused with emulsio were used to simulate the suboccipital retrosigmoid approach in this study. Dissections were performed gradually, the anatomy variability and travelling of neurovascular in the three anatomical interspaceal of cerebellopontine angle （CPA） region were observed. And also the distance between facial nerve and vestibular cochlear nerve （cranial nerves Ⅶ and Ⅷ） at the enterance of brain stem was measured. Results Varia tions were found in neurovascular structures of CPA. The travelling, branch and variation of superior cerebellar artery, anterior inferior cerebellar artery, posterior inferior cerebellar artery, superior petrosal vein, facial nerve, acoustic nerve, trigeminal nerves and post--group cranial nerves were studied, however, the order and distribution of these structures in the three anatomi eal interspaceal of cerebellopontine angle （CPA） region is clear and constant. The distance between cranial nerves Ⅶ and Ⅷ is（2. 3±1.1）mm. Conclusion It will be of great significance to dissecting the neurovascular in CPA via the suboccipital retrosigmoid approach. The relationships between these important neural and vascular could be well understood and it could also be of great help to guiding the clinical surgery.