舌下神经管解剖学与哑铃型舌下神经鞘瘤手术入路研究

Surgical anatomy of the hypoglossal canal and the research of surgical approach for dumbbell-shaped hypoglossal schwannoma

目的探讨哑铃型舌下神经鞘瘤的手术入路。方法采用20例干性颅底和15例寰椎标本及15例头颈湿性标本,对舌下神经管及相关结构进行测量和CT薄层扫描,并在湿性标本上研究暴露舌下神经管全程和内外口的手术入路。结果舌下神经管位置深在,周围结构复杂,其暴露的主要骨性障碍有寰椎横突、颈静脉孔、颈静脉结节和枕髁;以髁管和颈静脉孔为解剖标志在枕髁上方打开舌下神经管,切除寰椎横突,扩大枕髁前外侧的暴露,可在硬膜外暴露舌下神经管全程和内外口;结合硬膜下入路,可一期切除哑铃型舌下神经鞘瘤。结论远外侧经寰椎横突-髁上入路可作为哑铃型舌下神经鞘瘤一期手术切除的入路选择。

Objective To explore the surgical approach for the dumbbell-shaped hypoglossal schwannoma. Methods Bony hypoglossal canal （HC） and its associated structures were measured with thin-cut CT scan in 20 dried skull-basic bone, 15 dried atlases and 15 wet head-neck specimens of adults, and the surgical approach to expose the entire HC and its intracranial and extracranial orifices was explored in the wet head-neck specimens. Results HC was situated deeply in the anterior half of lateral margin of foramen magnum with complex adjacent structures, and transverse process of the atlas, jugular foramen, jugular tubercle and occipital condyle （OC） constitutes the main bony hindrances accessing to HC. However, the entire HC and its intracranial and extracranial orifices could be exposed extradurally when HC was opened above OC with condylar canal and jugular foramen as landmarks and the transverse process of the atlas was removed, which could improve the exposure of the region anterior and lateral to OC, and dumbbell-shaped hypoglossal schwannoma could be removed in one stage when combined with the subdural approach. Conclusion The far-lateral trans-supracondylar and atlas transverse process approach can be one choice for one-stage resection of dumbbell-shaped hypoglossal schwannoma.