Dos Santos Johnny Cesconetto, Musso Fernando, Mayer William Paganini, Baptista Josemberg Da Silva
Laboratory of Applied Morphology (LEMA), Universidade Federal Do Espirito Santo, Vitoria, Brazil.
Escola Superior de Ciencias da Santa Casa de Misericórdia de Vitoria, Vitoria, Brazil.
Anat Sci Int. 2020 Jun;95(3):374-380. doi: 10.1007/s12565-020-00531-5. Epub 2020 Feb 15.
Hearing or/and balance impairments may be caused by disorders of the labyrinthine artery (LA) and their branches. Most findings regarding the LA anatomy have been acquired through investigation of the cerebellopontine angle (CPA) in animal or adult human specimens. Eighty-eight CPAs and LAs of human fetuses were investigated using angio-techniques and microdissections. We found 15 intricate forms of distribution of LA. The LA usually originated from the extra-meatus loop in the anterior inferior cerebellar artery (AICA). The distribution of its terminal branches was 53.42% uni-arterial, 44.31% bi-arterial, and 2.27% tri-arterial systems. In the uni-arterial system, the LA described an anterior superior path to the cochlear nerve (CN) and originated its terminal branches in the gap between CN and the inferior part of the vestibular nerve. In the bi-arterial system, the anterior LA was located anterior and superior to the CN while the posterior LA appeared posterosuperior to the superior part of the vestibular nerve. In the tri-arterial system, the terminal branches originated directly from the AICA loop. Our results provide anatomical support to explain how compressions in the LA branches inside the internal acoustic meatus, as evoked by Schwannomas in the VII and VIII nerves, can lead to hearing and balance loss. The zone of the posterior vestibular nerve appeared to be a "safe area" for invasive procedures in these specimens.
听力或/和平衡障碍可能由迷路动脉（LA）及其分支的病变引起。关于LA解剖结构的大多数发现是通过对动物或成人标本的桥小脑角（CPA）进行研究获得的。我们使用血管技术和显微解剖对88例人类胎儿的CPA和LA进行了研究。我们发现了15种复杂的LA分布形式。LA通常起源于小脑下前动脉（AICA）的外耳道外环。其终末分支的分布为单动脉系统占53.42%，双动脉系统占44.31%，三动脉系统占2.27%。在单动脉系统中，LA向前上方走行至蜗神经（CN），并在CN与前庭神经下部之间的间隙发出终末分支。在双动脉系统中，前LA位于CN的前上方，而后LA出现在前庭神经上部的后上方。在三动脉系统中，终末分支直接起源于AICA环。我们的结果为解释VII和VIII神经的神经鞘瘤如何引起内耳道内LA分支受压导致听力和平衡丧失提供了解剖学支持。在这些标本中，前庭神经后部区域似乎是侵入性手术的“安全区域”。
