乙状窦后入路显微外科切除巨大听神经瘤32例分析

Microsurgical removal of large acoustic neurinomas through a retrosigmoid approach and analysis of the relevant topography

目的 探讨巨大听神经瘤的显微外科切除技术和有关的局部解剖,以及术后处理措施。方法 本组对32例病人进行了分析总结。采取乙状窦后入路暴露肿瘤,穿刺侧脑室后角充分引流脑室液,减低颅内压。在显微镜下保留外层蛛网膜,自上极囊内逐步切除肿瘤,最后分离内听道部分,术中记载重要结构的分布。结果 肿瘤全切除27例(85％),次全切除5例(15％),无死亡。面神经保留27例(85％)。受压面神经术中观察:位于肿瘤前上壁30例,上极2例,无后壁者。肿瘤由小脑前上动脉供血(AICA)17例,双重供血7例。结论 采取显微外科技术,掌握听神经瘤的局部解剖关系,加强手术后的观察处理是提高听神经瘤疗效,减少损伤的关键。

Objective To study the microsurgical skills, the topography relevant to CPA and postoperative management of acoustic neurinomas. Methods A series of thirty-two patients with large acoustic neurinomas were analyed. The retrosigmoid approach was introduced to expose the lesions and the cerebral fluid drained by puncturing the posterior horn of the ventricles to adequately reduce the intracranial pressure. With microsurgical technique the outmost layer of the arachnoid membrane was preserved in order to avoid damaging to the surrounding vital structures. The tumors were resected intracapsularly from the superior pole and the internal auditory meatus was finally opened. The topographic features were recorded simultaneously. Results The total removal of acoustic neurinoma was achieved in twenty seven patients (85% ), and subtotal in five cases (15%) without mortality. The anatomical preservation of the facial nerves was gained in twenty-seven patients. The facial nerves were located antero - superiorly to the capsule in thirty cases and were found transpositioned to the superior pole of the tumor in two cases. Of the supplying blood vessels to the tumors, AICA was foun in seventeen patients, and double supply by AICA and PICA or SPCA was observed in seven cases. Conclusion For the purpose of good postoperative results and little side injury, it is important to improve microsurgical skills, to get familiar with the topography of CPA and to stress postoperative management.