内耳门及周围结构的显微解剖及神经内镜解剖研究

Microanatomical and neuroendoscopic studies of the internal auditory meatus and its surroun-ding structures

目的研究国人内耳门及周围结构的形态及毗邻关系,为乙状窦后入路手术提供显微解剖学依据.方法在5个新鲜国人头颅标本上模拟枕下乙状窦后手术入路,通过神经内镜和手术显微镜观察内耳门及周围结构的形态和毗邻关系.测量内耳门后下缘到乙状窦后缘中点和后、半规管后缘中点的距离.结果内耳门位于岩骨内侧面中央,面神经多位于内耳门的前上,听神经位于其后下,小脑前下动脉在内耳门处形成动脉袢,发出1～3条内听动脉.内耳门后下缘到乙状窦后缘中点的距离左侧为(32.15±1.76)mm,右侧为(33.34±1.57)mm;内耳门后下缘到后半规管后缘中点的距离左侧为(12.51±2.15)mm,右侧为(13.26±2.44)mm.结论熟悉内耳门及周围结构的显微解剖,有助于手术中保护重要结构,为听神经瘤手术中保留面、听神经功能提供了解剖学基础.

Objective To observe the morphology of the internal auditory meatus in relation with its surrounding structures in Chinese people, for the purpose of providing microanatomical reference for surgeries adopting retro-sigmoid approach. Methods The retro-sigmoid surgical approach was simulated on 5 fresh specimens of human head, in which the internal auditory meatus and its surrounding structures were observed through a neuroendoscope and a surgical microscope. The distances from the posterior inferior edge of the internal auditory meatus to the central point of the posterior edge of the sigmoid sinus and to the posterior edge of the posterior semicircular canal were measured. Results The internal auditory meatus was located at the center of the medial surface of the petrous bone, and the cranial nerve Ⅶran through its anterior-superior part while the cranial nerve Ⅷthrough its posterior-inferior part. After forming an arterial loop at the internal auditory meatus, the anterior-inferior cerebellar artery branched into 1 to 3 internal auditory arteries. The distance from the posterior-inferior edge of the internal auditory meatus to the central point of the posterior edge of the sigmoid sinus was 32.15±1.76 mm on the left side, and 33.34±1.57 mm on the right, and the distance to the posterior edge of the posterior semicircular canal was 12.51±2.15 mm on the left side, and 13.26±2.44 mm on the right. Conclusion Thorough knowledge of the microanatomy of the internal auditory meatus and its surrounding structures is of crucial importance to preserve the functions of the cranial nerves Ⅶand Ⅷin the surgical removal of acoustic neuroma.