大型听神经瘤的手术与病理解剖

Operative microsurgical anatomy of large acoustic neuromas

目的探讨大型听神经瘤显微手术解剖形态及与毗邻神经、血管结构的解剖关系。方法回顾性分析经显微外科手术的大型听神经瘤63例,对肿瘤的供血来源,与脑神经及血管、重要结构的解剖关系等进行分析。结果肿瘤均由小脑前下动脉分支参与供血,15例小脑上动脉参与肿瘤上极供血,22例小脑后下动脉参与肿瘤下极供血。主要经岩静脉回流至岩上窦,15例同时回流至天幕。面神经位于听神经瘤前方53例(前上方13例,正前方31例,前下方9例),肿瘤上极5例,肿瘤下极4例,肿瘤后方1例,无面神经穿过肿瘤者。结论正确认识听神经瘤病理显微解剖和与毗邻组织结构的解剖关系,对全切除肿瘤和脑神经功能保护具有重要意义。

Objective To surgically explore the microanatomical variations of large acoustic neuromas and its relationship with adjacent neurovascular structures. Methods 63 cases of large acoustic neuromas operated using microsurgery were analyzed retrospectively, to define the blood supply of tumors, as well as the topographic relationship between tumors and peripheral vital neurovascular structures. Results The blood supply of acoustic neuromas mainly originated from the branches of the anterior inferior cerebellar artery in all cases, the branches of posterior inferior cerebellar artery in 22 cases and superior cerebellar artery in 15 cases were also involved in the blood supply. The venous outflow of tumors were mainly drained into petrosal vein in 54 cases, and into superior petrosal sinus, or directly into tentorium. In the majority of cases, the facial nerves located in the ventral side of tumors of 53 cases, anterior-superior side in 13cases, anterior side in 31cases, and anterior inferior side in 9 cases. In 5 cases the nerves were displaced to the superior pole of tumor, 4 cases to the inferior pole, and in 1 case the nerve was found at the dorsal aspect of tumor. Conclusions This study demonstrate that a good understanding of pathological microanatomy of tumor, as well as its relationship with adjacent neurovascular structures, will play an important role in achieving total removal meanwhile preserving nerve function for large acoustic neuroma.