游离股薄肌移植在臂丛损伤治疗中的显微组织学及定量研究

The microhistological and quantification study of free gracilis muscle transplantation in treatment of the brachial plexus injury

目的观察股薄肌移植在臂丛损伤治疗中显微组织学变化及神经纤维数量变化。方法新鲜尸体下肢标本6具（成年男性），显微镜下分离观察股薄肌肌支神经，标记方位后在不同平面取材．4％甲醛溶液固定后冰冻切片，行改良Karnovsky-Roots法AchE组织化学染色，观察神经组织染色结果及不同断面上的神经束分布情况；石蜡包埋切片，行Loyez髓鞘染色法染色，应用图像分析系统对组织切片进行定量分析：测算各神经断面有髓神经纤维数目、神经束截面积和神经干截面积，计算神经柬和结缔组织所占比例并采用配对样本t检验。结果低倍镜下股薄肌肌支神经束大多数神经纤维呈现酶活性反应，有少量稀疏的块状酶染区。高倍镜下神经纤维形态清晰可见，轴突染色，髓鞘及周围结缔组织不染色。应用Loyez髓鞘染色法显示断面有髓神经纤维，通过图像分析系统，能够测算神经分支及各断面的神经纤维数目和结缔组织面积等指标。股薄肌神经有髓神经纤维数为（1958±375）根。前、后支有髓神经纤维数，前、后支截面积差异均有统计学意义，P〈0．05，后支的神经纤维数和截面积大于前支。股薄肌神经于上各个平面之间结缔组织面积差异均有统计学意义（P〈0．05），结缔组织所占比例向远端逐渐增加，而神经束所占比例的变化趋势和结缔组织相反。结论应用AchE组织化学染色方法，股薄肌神经运动束的特征清晰可辨，结合显微解剖结果，能够明确股薄肌神经束的走行及分布情况。应用Loyez髓鞘染色法通过定量分析可明确神经纤维数，有助于选择合适的供体神经，保证两吻合神经之间达到相互匹配。

Objective To provide histology base for the microsurgical repair of the free gracilis muscle transplantation after brachial plexus. Methods Totally 6 fresh male adult cadaveric inferior extremities were obtained. The gracilis muscle nerve were exposed and divided with the microdissection. Specimens were got from different segment after marked direction. All specimens was faced in 4% formaldehyde solution and then crossing sections were cut by cryouhramicrotome. All slides were stained use the technique of Kamovsky-Roots AchE histochemical. The result of never tissue staining and the distribution of individual functional fascicular group were observed on each cross-section.According to the result of staining combined with the microdissection and the order of different branches branching off the nerve trunk, the distribution of individual functional fascicular group were observed on each cross-section. The 5 μm-thick routine waxed crossing sections were made and stained according to the myelin technique of Loyez. These histological sections were analyzed by using image analysis system. For each histological section, the number of the medullated nerve fibers and the section areas of the each nerve tracts and trunks were measured and calculated. Then the proportion of nerve tracts and connective tissue were calculated. The proportion of each connective tissue was adopting paired - samples t test. Results Under low power lens most of the gracilis muscle nerve were positive reaction, only a few sparse block - shape enzyme staining regions were shown. Under high power lens, the gracilis muscle nerve have clear outline, enzyme staining limited at neuraxis, no staining at myelin sheath and connective tissue. Quantitative analysis shows that the total myelinated fiberscilis nerve was about （1958 ± 375） radix. The branches arising from the posterior subdivision were more than that from the anterior （P = 0.000）. There were statistical difference between the number of the medullated nerve fibers and the section areas of the anterior and posterior subdivisions,the posterior subdivision were more than that of the anterior （P 〈 0.05）. There also had statistical difference between different section areas of the connective tissue in the gracilis nerve trunk （P 〈 0.05）, the section areas of the connective tissue of the distal were more than that of proximate. Conclusions The motor fascicles characteristic of the gracilis muscle nerve can be distinguished clearly by using AchE histochemical staining, combin with the microanato- my results, we can gain the distribution of the fascicular groups on each crossing sections. Using Loyez stain- ing and quantitative analysis, we can ensure the number of the medullated nerve fibers. It is helpful to select the suitable donor nerve and ensure the dialyneury matching each other.