臂丛后根脊髓入区的显微外科解剖

Microsurgical anatomy of dorsal root entry zone of brachial plexus

目的:为临床应用后根入区破坏法治疗臂丛根性撕脱伤后疼痛提供基础。方法:在20例成年人尸体上充分暴露C5～T1脊髓节段和相应神经后根区需切除椎板的长度和宽度,测量各神经根根丝的数目、与脊髓的角度和相应各脊髓节段前正中沟至后外侧沟的距离,各脊髓节段的定位和相应神经后根区的精细定位。取下脊髓,在显微镜下测量各节段脊髓后脚在横截面上的长度、宽度和后角纵轴与脊髓矢状面的夹角,确定术中需要损伤后根区的范围和角度。结果:切除C4～C7的脊突和椎板可暴露C5～T1神经后根。C5～T1各神经后根的根丝平均为7.76条,C6的后根根丝最多。各神经后根最下缘的根丝与脊髓纵轴的夹角从C5的65.6°逐渐变小到T1的19.8°。脊髓后外侧沟(神经后根根丝进入脊髓处)到后正中沟的距离平均为2.95 mm。脊髓后脚底至后外侧沟的长度平均为3.47 mm,宽度平均为1.35 mm。后脚的纵轴与脊髓矢状面的夹角平均为35.9°,自C5至T1逐渐变小。结论:(1)用破坏臂丛脊髓后根入区的方法治疗臂丛根性撕脱伤后疼痛需切除C4～C7的棘突和椎板;(2)损伤时器械应与脊髓矢状面大约成30°～40°角;(3)在横截面上损伤的宽度不能超过1.2 mm,损伤的深度不能超过3.1 mm。

Objective: To study microsurgical anatomy of dorsal root entry zone of brachial plexus and provide references for treating root pain of brachial plexus avulsion by dorsal root entry zone lesion method. Methods: Twenty cervicothoracic spine specimens were used to explore the extension of laminectomy from C5 to T1 spine segments and the corresponding dorsal root entry zone. The number of rootlets, the angle from the downmost rootlet to spine and the distance from posterior median sulcus to posterolateral sulcus were measured. On transverse plane, the length and width of posterior horn and the angel of posterior horn to sagittal plane of spine were measured too. Results: After resecting the spinous process and lamina, the posterior root and rootlets of C5～T1 spine segments can be exposed. The average number of roolets of C5～T1 spine segments was about 7.76, C6 is the most. From up to down, the angle from the downmost rootlet to spine of C5～T1 spine segments diminished gradually. The average distance from posterior median sulcus to posterolateral sulcus was 2.95 mm. The average length, width and angle of posterior horn were 3.47 mm, 1.346 mm and 35.9 degree respectively. Conclusions: The spinous process and lamina of the C4 to C7 vertebrae should be excised when dorsal root entry zone lesions are employed to treat pain after brachial plexus avulsion. The lesion-making apparatus should be inserted at an angle of 30°～40°, the width of lesion should be less than 1.2 mm and the lesion depth less than 3.1 mm.