甲壳胺膜管修复不同长度神经缺损的实验研究

背景目前,将天然可降解生物材料运用于周围神经外科领域,尤其对于神经损伤程度与生物导管适应证之间的关系的研究报道较少.目的观察甲壳胺膜管桥接大鼠不同长度坐骨神经缺损,对神经再生的影响.探索此方法在不同程度神经损伤修复中的适应证.设计完全随机对照实验研究.地点和对象安徽医科大学实验外科中心.实验对象为清洁级SD大鼠,体质量220～240g,雌雄不限,由安徽医科大学实验动物中心提供.干预SD大鼠102只,按缺损长度与神经干直径之比造模分为缺损4,6,8倍组.采用相互对照,用甲壳胺膜管桥接缺损,层流室饲养4,8,12周后处死动物.主要观察指标术后4,8,12周分别作大体观察、超微结构的透射电镜观察、组织学观察和远端轴突再生率的比较.结果缺损4,6倍组,能展趾活动,有肌肉收缩现象.缺损8倍组溃疡及肌萎缩加重.桥接体周围无疤痕粘连.缺损4倍组优于缺损6,8倍组,缺损6倍组优于缺损8倍组,缺损4,6倍组髓鞘成熟良好,缺损8倍组仍有髓鞘溃变现象;3组均无胶原纤维增生.结论甲壳胺膜桥接周围神经缺损,可防止疤痕侵入,有利于轴突再生.对于神经缺损不超过其直径6倍者,用甲壳胺膜管桥接后再生轴突的质量和数量均较优.

An experimental study of repairing nerve defect indifferent lengths with chitosan membranous tube

BACKGROUND: Recently, the reports about the application of naturaldegradable biomaterial in peripheral nerve surgery field, especially the rela-tionship between the severity of nerve injury and the indication of biologicalductus, were rare.OBJECTIVE: To observe the impact of bridging the sciatic nerve defect indifferent lengths with chitosan membranous tube on nerve regeneration in therat and to explore the indication of this method in the repair of nerve injurywith different severity.DESIGN: A completely randomized controlled study.SETTING and MATERIALS: The study was completed in the Experi-mental Surgery Center of Anhui Medical University. Subjects were SD rats(grade cleanness) in either gender with a body weight from 220 g to 240 gobtained from Experimental Animal Center of Anhui Medical University.INTERVENTIONS: Totally 102 SD rats were allocated into four-time defect(4-fold defect), six-time defect(6-fold defect) and eight-time defect(8-folddefect) groups according to the ratio of the length of defect to the diameter ofnerve stem. Inter-control was introduced. Defects were bridged by chitosanmembranous tube. Animals were fed in laminar flow room and executed at 4,8 and 12 weeks.MAIN OUTCOME MEASURES: General observations, ultrastructure ob-servations under transmission electron microscope, histology observations andthe comparison in the regeneration rates of axons at distal end were assayedrespectively at 4, 8 and 12 weeks after the surgery.RESULTS: 4-fold and 6-fold defect groups had toe spread-out and musclecontraction. There was no scar adhesion around bridging. The result of4-fold-defect group was better than that of 6-fold defect and 8-fold defectgroups. 6-fold defect group was better than that of 8-fold defect group. Thematurities of myelin sheath in 4-fold and 6-fold defect groups were good, whilethere was still ulceration in myelin sheath in 8-fold defect group. There were nocollagen hyperplasias in all 3 groups.CONCLUSION: Peripheral nerve defect bridged by chitosan membranoustube could prevent the invasion of scar tissue, which is helpful to the regen-eration of axons. The quality and quantity of regenerated axons after thebridging by chitosan membranous tube were preferably good if the length ofnerve defect did not exceed 6 times as its diameter.