摘要
目的评价臂丛神经根椎孔外断裂后神经根直接吻合的可行性。方法取4～6月龄SD大鼠48只,雌雄不限,体重250～300g。手术分离左侧C5～7神经根至臂丛神经干部,于椎孔外根干交界部位切断C5～7神经根,切断后即刻吻合(实验侧);右侧不作处理(对照侧)。术后观察大鼠一般情况,于术后3周,3、6个月取材,行大体、组织学观察及BDA神经示踪技术,观察肱二头肌湿重变化,脊髓前角α运动神经元和神经元内尼氏体数目及形态的改变,周围神经纤维再生数目、距离,轴索和髓鞘发育情况。结果大鼠术后存活良好。实验侧术后呈跛行步态,出现展爪反射;3个月后展爪反射消失;对照侧正常。大体观察,实验侧术后6个月内神经粘连加重,吻合口两侧神经干干瘪,无光泽;对照侧正常。术后3周和3个月实验侧及对照侧肱二头肌湿重分别为(0.28±0.12)、(1.37±0.33)g和(0.58±0.10)、(1.36±0.35)g,差异有统计学意义(P<0.05);6个月时分别为(1.39±0.31)、(1.37±0.38)g,差异无统计学意义(P>0.05)。实验侧脊髓和上干改良Marsland与LFB双重染色后观察脊髓内神经元数目减少,胞体由肿大到皱缩,细胞核和尼氏体减少;上干内染色完整的神经纤维逐渐增多,神经轴索较细,髓鞘淡染。术后3周、3个月、6个月实验侧脊髓前角α运动神经元数目分别为对照侧的84.5%±3.2%、74.4%±4.5%、73.7%±3.8%。实验侧肱二头肌HE染色观察术后3个月内变性明显,之后逐渐恢复;对照侧无明显变性。术后6个月神经纤维BDA染色观察:神经越靠近近端,髓鞘着色越明显,轴突越粗大;越靠近远端时情况相反,并可见到轴突中断。肌皮神经入肌点处偶见阳性标记的神经髓鞘和轴突。结论臂丛神经根椎孔外断裂即刻吻合后,脊髓前角α运动神经元坏死比率为20%～30%,残存神经元多为受损神经元,再生神经纤维表现为动力不足和发育不全,对终末器官功能恢复无意义。肱二头肌恢复机制有待进一步研究。
Objective To evaluate the feasibility of direct anastomosis in the rat model of the brachial plexus extravertebral foramen nerve root division of C5-7. Methods Forty-eight SD rats （male or female） aging 4-6 months and weighing 250-300 g were selected to make the model of extravertebral foramen nerve root division of C5-7. The left C5-7 nerve roots, as the experimental sides, were separated to the brachial plexus nerve trunk and the transected roots were sutured to the proximal stump immediately after cutting off the brachial plexus extravertebral foramen nerve root division. The right C5-7 nerve roots, as the control sides, received no operation. The general condition of rats after operation was observed. The gross observation, the histological observation and BDA nerve tracing technology were adopted to observe the wet weight of musculus biceps brachii, the cross section of biceps brachii and the spinal cord and distal nerve trunk at 3 weeks, 3 months and 6 months after operation. Results All rats survived well after operation. Claudication and unfold claw reflex were observed in the experimental sides, and the unfold claw reflex disappeared 3 months later. Comparatively, the control sides were normal. Nerve adhesion aggravated gradually and the neural stems were shriveled within 6 months after operation in the experimental sides. Comparatively, the control sides were normal. The wet weight of biceps brachii in the experimental sides and the control sides at 3 weeks, 3 months and 6 months after operation was （0.28 ± 0.12）, （1.37 ± 0.33）, （0.58 ± 0.10）, （1.36 ± 0.35）, （1.39 ± 0.31）, （1.37 ± 0.38） g, respectively, indicating significant differences between two sides at 3 weeks and 3 months （P 〈 0.05）, but no significant difference at 6 months （P 〉 0.05）. The modified Marsland and the LFB staining of spinal cord and superior trunk of brachial plexus showed that the number of neurons, cell nuclear and Nissl body decreased and cell bodies changed from swelling to shrinkage, dyeing nerve fibers increased, neural axone was thin and myelin sheath was slightly stained at each time point in experimental side. The number of motor neurons in cornu anterius medullae spinalis in the experimental side was 84.5% ± 3.2%, 74.4% ± 4.5%, 73.7% ± 3.8% of that in the control side at each time point, respectively. HE staining of biceps brachii detected that the muscle denaturation was very serious at 3 months after operation and then recovered. Neural tracing used BDA showed that the closer to the proximal of nerve trunk, the more obviously stained it was of myelin sheath and the more massive of axon at 6 months after operation. And there was almost no myelin and axon stained in musculocutaneous nerve. Conclusion In the rat model ofbrachial plexus extravertebral foramen nerve root division, the motoneuron in cornu anterius medullae spinalis necrosis rate reaches 20%-30%, and most of the residual neurons are pathologic. The regenerated fibers manifest as insufficient dynamic power and incomplete development, making no sense for the recovery of end organ function. Therefore, the exact mechanism of the recovery of biceps brachial muscle demands further study.
出处
《中国修复重建外科杂志》
CAS
CSCD
北大核心
2008年第9期1077-1081,共5页
Chinese Journal of Reparative and Reconstructive Surgery
基金
吉林省科技厅资助项目(200505232)~~
关键词
臂丛神经损伤
脊髓前角运动神经元
神经再生
神经示踪
Brachial plexus injury Motor neuron in cornu anterius medullae spinal is Nerve regeneration Nerve tracing
