成人菱形唇：9+2纤毛超微结构及桥小脑角手术解剖

文献信息

中文摘要

目的： 菱形唇（RL）是一种神经上皮结构，从第四脑室外侧隐窝延伸至桥小脑角（CPA）。尽管其表面已描述有纤毛，但成人纤毛的超微结构特征仍不清楚。我们表征了成人RL的组织学和超微结构构筑，并评估其在CPA手术中的解剖学相关性。
方法： RL标本取自两名接受前庭神经鞘瘤手术的患者。两例均进行了组织学和免疫染色分析，包括乙酰化α-微管蛋白和AQP4的双重免疫荧光，而其中一例进行了扫描电子显微镜（SEM）和透射电子显微镜（TEM）检查。检查了两具福尔马林灌注的尸体头，以评估RL与CPA结构的解剖关系。
结果： 组织学显示，室管膜样细胞的脑室单层覆盖在富含胶质细胞的层之上。免疫荧光显示，RL顶端表面沿分布有乙酰化α-微管蛋白阳性纤毛。SEM显示密集的纤毛覆盖，而TEM显示特征性的9+2轴丝排列，与运动纤毛的超微结构特征一致。尸体解剖显示了RL与脉络丛、Luschka孔及下组颅神经，尤其是CN IX的空间关系。
结论： 成人人RL保留了有组织的神经上皮构筑。在超微结构检查的标本中，纤毛表现出特征性的9+2轴丝排列。尽管未直接评估纤毛运动及其对CSF动力学的影响，这些发现为外侧隐窝显微解剖提供了新见解。RL可作为CPA手术中显微外科定位的有用解剖参考。

英文摘要

OBJECTIVE: The rhomboid lip (RL) is a neuroepithelial structure extending from the lateral recess of the fourth ventricle into the cerebellopontine angle (CPA). Although cilia have been described on its surface, their ultrastructural characteristics in adults remain unclear. We characterized the histological and ultrastructural architecture of the adult RL and evaluated its anatomical relevance in CPA surgery.
METHODS: RL specimens were obtained from two patients undergoing surgery for vestibular schwannoma. Histological and immunostaining analyses were performed in both cases, including double immunofluorescence for acetylated α-tubulin and AQP4, whereas scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were performed in one case. Two formalin-perfused cadaveric heads were examined to assess the anatomical relationships of the RL with CPA structures.
RESULTS: Histology demonstrated a ventricular monolayer of ependymal-like cells overlying a glial-rich layer. Immunofluorescence demonstrated acetylated α-tubulin-positive cilia along the apical surface of the RL. SEM revealed dense ciliary coverage, whereas TEM demonstrated a characteristic 9+2 axonemal arrangement consistent with the ultrastructural features of motile cilia. Cadaveric dissection demonstrated the spatial relationship of the RL with the choroid plexus, foramen of Luschka, and lower cranial nerves, particularly CN IX.
CONCLUSIONS: The adult human RL retains an organized neuroepithelial architecture. In the ultrastructurally examined specimen, cilia exhibited a characteristic 9+2 axonemal arrangement. Although ciliary motility and its effects on CSF dynamics were not directly assessed, these findings provide new insight into lateral recess microanatomy. The RL may serve as a useful anatomical reference for microsurgical orientation in CPA surgery.