颈部脊神经后根显微外科解剖学研究

Microsurgical anatomy of the cervical dorsal nerve roots

目的 :为颈部选择性脊神经后根切除术 (Selectiveposteriorrhizotomy ,SPR)提供可靠的后根分束的形态学依据。方法 :对 2 0例 (40侧 )C4 ～T1节段脊神经后根的自然分束和后根之间纤维联系进行显微外科解剖学观察。结果 :颈部各节段后根所含各级神经束的数目基本一致。一个脊神经后根有 8～ 10个神经小束组成 ,上位的 4～ 5个神经小束形成 1～ 2个神经亚束 ;下位的 4～ 5个神经小束形成 1～ 2个神经亚束。神经亚束出硬脊膜 ,在神经根袖内形成上下排列的两个神经束。颈部后根间存在着神经纤维联系 ,出现率为 72 .9%。根据神经纤维联系的形状 ,可分为“N”型或反“N”型、“Y”型、“H”型、“人”型、“X”型和复杂型 ;根据神经纤维联系的位置 ,可分为近端、中段和远端 3型 ;根据神经纤维联系的粗细 ,可分为神经小束分支、神经小束和神经亚束 3型。结论 :颈部后根神经分束位于齿状韧带外侧缘的内侧 ,一般的SPR后根分束为 4～ 6束 ,达神经亚束水平。高选择性SPR后根分束应达到神经小束水平 ,8～ 10束。同时对后根间的神经纤维联系进行了系统的形态学分类。

Objective: To provide reliable morphologic basis of the cervical dorsal root for selective posterior rhizotomy (SPR). Methods: The rootlets of the cervical dorsal roots and the conjoint nerve roots(CR) were observed under microscope in 20 dessected cervical specimens (male 14, female 6).Results: The number of the rootlets in every cervical dorsal root are almost the same. Each dorsal root has 8～10 rootlets, and every 4～5 rootlets formed 1～2 subbundles.The subbundles pierced through the dura, and formed 2 superior inferior arranged bundle in the nerve roots sleeve.Conjoint nerve root(CR) between the two cervical dosal roots were found on 77.9% of the specimens.According to the shape of CR, it could be divided into six types: “N” or reverse “N”, “Y”, “H”, “人”, “X”and complex type; according to the location of CR, it was divided into proximal type, middle type and distal type; according to the diameter of CR, it was divided into proximal type, middle type and distal type; according to the diameter of CR, it was divided into three types: branch of rootlet, rootlet and subbundle of rootlet.Conclusion: The cervical dorsal roots are divided into rootlet at the medial of the lateral free edges of denticulated ligament.The dorsal roots were divided into 4～6 subbundles in general SPR, while 8～10 rootlets in hyperselective posterior rhizotomy.Furthermore, CR of cervical dorsal roots were observed and classified and its effect on SPR was also stressed.