阻断部分臂丛神经下干分支对健侧颈7移位下干后神经再生的影响

The changes of the nerve fibers of lower trunk repaired by the contralateral C7 after its branches were cut

目的以大鼠健侧颈，直接修复臂丛神经下干为模型，探讨阻断下干分支前后，尺神经和正中神经神经纤维数量和质量的变化。方法雌性SD大鼠40只，随机分成4组。A组：健侧颈，直接修复下干，并从下干发出处阻断下干后股、胸前内侧神经、前臂内侧皮神经；B组：健侧颈，直接修复下干，并从下干发出处以远1cm处阻断下干后股、胸前内侧神经、前臂内侧皮神经；C组：健侧颈，直接修复下干，并从下干发出处切断后股；D组：对照组。术后比较尺神经、正中神经、胸前内侧神经和前臂内侧皮神经的神经纤维数量、神经纤维密度（P）、神经纤维数占下干神经纤维总数百分比、神经纤维直径、有髓神经纤维面积与相应分支神经总面积比（N Ratio）。结果尺神经和正中神经中，神经纤维数量、神经纤维密度、正中神经与尺神经分别占下干神经纤维百分比、神经纤维直径、不同直径神经纤维百分比、NRatio，A、B、C三组间差异均无统计学意义。前臂内侧皮神经和胸前内侧神经中，上述各检测指标B、C组间均无明显差异。结论健侧颈，直接移位下干后，在根部及根部以远1cm处阻断胸前内侧神经及前臂内侧皮神经后，对尺神经、正中神经、前臂内侧皮神经残端和胸前内侧神经残端中神经纤维的数量和质量无明显影响。

Objective To explore the changes of the nerve fibers from median and ulnar nerves after cutting the branches of lower trunk which was repaired by the contralateral C7. Methods Forty female SD rats were divided into A, B, C and D groups randomly. In group A,the contralateral Gr root was transferred to lower trunk directly, and the posterior division of lower think, medial anterior thoracic nerve and the medial antebrachial cutaneous nerve were severed at the beginning of them; In group B, the contralateral C7 root was trarsferred to lower tnmk directly, and the posterior division of lower mink, medial anterior thoracic nerve and the medial antebrachial cutaneous nerve were severed at the point which was 1 cm away from the beginning of above branches; In group C, the contralateral C7 root was tmnfferred to lower trunk directly, and the posterior division of lower trunk was severed at the beginning of it; In group D, control group. After the operation, myelinated fiber count, nerve fiber density, the percentage of the number of nerve fiber from branch accounting for that from lower trunk, nerve fiber diameter,the percentage of nerve fibers with different diameters and bl Ratio were carried out to evaluate the outcome of each group. Results Myelinated fiber count, nerve fiber density, the percentage of the number of nerve fiber from branch accounting for that from lower trtmk, nerve fiber diameter, the percentage of nerve fibers with different diameters and N Ratio in ulnar and median nerve, there were no difference between group A, group B and group C （ P 〉 0.05）. Condusion After the medial anterior thoracic nerve and medial antebrachial cutaneous nerve,repaired by the contralateral C7, were severed at the beginning and at the point which was 1 cm away from the beginning of above branches, the changes of the quantity and quality of the nerve fibers from median and ulnar nerves were not significant.