神經內鏡枕下中線入路暴露第四腦室解剖研究

【摘要】 目的 通過解剖觀察內鏡下經枕下中線入路暴露第四腦室的解剖結構，探討該術式的可行性。方法 使用9例福爾馬林固定的尸頭標本，模擬神經內鏡經枕下中線入路顯露第四腦室，觀察解剖過程中的關鍵結構及暴露范圍。結果 該入路通過枕下正中直切口暴露雙側枕骨鱗部，擴大枕大孔后緣后制作雙側枕骨骨瓣。解剖枕大池蛛網膜，將小腦扁桃體外側移位，顯露第四腦室正中孔、脈絡膜、脈絡叢及四腦室下頂部等結構。通過四腦室正中孔引入內鏡即可顯露菱形窩、上髓帆、小腦上腳和中腳以及中腦導水管等結構，內鏡下單純的四腦室內解剖可視化無需打開膜髓帆結構。打開膜帆結構可擴大顯露外側隱窩，雙側打開可全程顯露第四腦室底部、頂部及側隱窩。結論 神經內鏡枕下中線入路可直接暴露第四腦室和腦干背側結構，利用內鏡技術的深入照明和寬廣視角，可在不切除寰椎后弓的情況下清晰暴露第四腦室底部結構，聯合膜髓帆切開可進一步擴展手術視角。

【關鍵詞】 神經內鏡；枕下中線入路；第四腦室；解剖研究

【中圖分類號】 R651" 【文獻標志碼】 A" 【文章編號】 1672-7770（2025）01-0026-05

Endoscopic suboccipital midline approach to the fourth ventricle： a cadaveric anatomical study

Abstract： Objective To explore the feasibility of the suboccipital midline approach for exposing relevant anatomical structures of the fourth ventricle under endoscopic observation. Methods Nine formalin-fixed cadaveric head specimens were used to simulate the endoscopic suboccipital midline approach to expose the fourth ventricle. Key anatomical structures during the dissection process and along the exposure pathway were observed under the endoscope， as well as the exposure range and anatomical characteristics of the fourth ventricle through this pathway. Results This approach exposed the bilateral occipital squama through a midline incision at the suboccipital region， creating bilateral occipital bone flaps after expanding the posterior edge of the foramen magnum. By dissecting the arachnoid of the cerebellar cistern and laterally displacing the cerebellar tonsils， structures such as foramen of magendie of the fourth ventricle， choroid plexus， and the inferior and superior parts of the fourth ventricle were exposed. Introducing the endoscope through the foramen of magendie of the fourth ventricle allows for the visualization of the rhomboid fossa， superior medullary velum， superior cerebellar peduncles， and the cerebral aqueduct. The anatomy within the fourth ventricle can be visualized without opening the velum structure. By dissecting laterally and inferiorly from the attachment of the inferior medullary velum at the nodulus， cutting the inferior medullary velum and choroid plexus could expand the exposure of the lateral recesses. Bilateral opening of the choroid plexus and inferior medullary velum and lifting them superiorly could fully expose the rhomboid fossa， the top and lateral recesses of the fourth ventricle， while unilateral opening of the velum may limit the view of the contralateral lateral side to some extent. Conclusions The endoscopic suboccipital midline approach is a vital strategy for directly exposing the fourth ventricle and the dorsal aspect of the brainstem. Utilizing the deep illumination and broad-angle imaging provided by neuroendoscopic technology， this surgical route can clearly expose the fourth ventricle without the resecting the posterior arch of the atlas. Additionally， combining with the opening of the velum and medullary velum can further expand the surgical view of the lateral and superior aspects of the fourth ventricle.

Key words： endoscopic; suboccipital midline approach; fourth ventricle; anatomy

第四腦室是一個位于小腦、延髓和腦橋之間的帳篷狀結構，對于后顱窩、腦干以及第四腦室的病變手術，對其解剖細節的全面了解是必不可少的。第四腦室的底部位于其前部，其中上三分之二為橋腦，而下三分之一則為延髓。該結構的頂部包括上部和下部，上部由上髓帆和小腦上腳組成，下部由下髓帆、脈絡膜、蚓結節和蚓垂部組成。……