【作者】 王瑜；

【导师】 肖传国；

【作者基本信息】 华中科技大学 ， 外科学， 2006， 博士

【摘要】 目前通过大量的动物实验和临床应用研究已经证实:人工体神经-内脏神经反射弧理论和技术能够安全有效的解决脊髓损伤(SCI)患者以及先天性脊柱裂脊膜膨出(Spina Bifida,SB)患者大小便失禁这一医学和社会学难题。然而对于脊膜膨出患者,该手术需要牺牲一根功能正常的下肢运动神经来再生支配膀胱、直肠,理论上可能会对下肢正常的运动功能有一定影响。这在以往的动物实验和临床应用中也得到了证实。尽管衡量手术利弊,相对于能够获得膀胱控制和排尿功能,手术产生的下肢并发症还是可以接受的,但我们仍应努力通过完善手术方法尽量减少手术对下肢运动功能的损伤。为了能够在不影响获得膀胱控制这一主要目标的前提下,尽可能的降低手术副作用,我们通过动物实验来探讨切断大鼠脊神经后对其下肢运动功能有无影响以及影响大小;并试图寻找到能够尽量减少脊神经切断导致的所支配肌肉功能损伤的方法,为临床应用提供新的思路。实验一大鼠脊神经损伤后所支配骨骼肌及其运动终板的退变观察目的研究大鼠脊神经运动根损伤后所支配骨骼肌组织形态学变化,为临床提供理论基础。方法选用SPF级成年雄性SD大鼠32只,随机分为2组:一组单纯切断左侧的L4脊神经前根,另一组同时切断左侧的L4和L5脊神经前根,以各大鼠的左侧为实验侧,右侧为自身对照侧。分别于手术后6周和16周时每组各取8只测定双侧趾长伸肌的肌湿重和肌细胞截面积,并观察骨骼肌运动终板的形态。结果术后6周:单纯L4神经根切断组和L4,5神经根切断组的实验侧肢体功能较正常对照侧均有明显损伤(P<0.01),运动终板崩解变性。术后16周:单纯L4神经根切断组的实验侧肢体功能接近正常(P>0.05),再生运动终板结构接近正常;L4,5神经根切断组的实验侧肢体功能与对照侧相比,有极显著性差异(P<0.01),未见再生的运动终板。结论单纯L4神经根切断近期可造成肢体功能损伤,随时间推移,损害逐渐减轻,甚至消失;但若合并L5神经根损伤将可能造成肢体功能的永久性损害。实验二利用端侧神经吻合方法建立人工体神经-内脏神经反射弧的实验研究目的探讨利用端侧神经吻合方法建立人工反射弧来重建膀胱功能的可行性。方法取SPF级雄性SD大鼠20只,分为2组:(1)正常手术组:在椎管内分别离断左侧L4(LL4)前根和L6(LL6)前根,将LL4前根中枢段断端与LL6前根外周段断端行端端吻合,共10只;(2)端侧吻合组:在椎管内离断左侧L6前根,将LL6前根外周段断端与LL4前根行端侧吻合,共10只;手术6个月后电刺激吻合口近端测定各组大鼠的最大膀胱收缩压力,并对再生有髓神经纤维计数进行比较。结果端侧吻合组大鼠的膀胱最大收缩压力与再生有髓神经纤维计数均明显低于正常手术组(P<0.01)。结论实验证实,利用端侧神经吻合方法建立人工反射弧来重建膀胱功能效果不佳,不能替代原手术方法。实验三在原反射弧手术基础上,比较各吻合方法对防治术后失神经肌萎缩作用的实验研究目的在人工体神经-内脏神经反射弧手术的基础上,比较各种吻合方法对防治术中失神经支配骨骼肌萎缩的作用,试图为临床减少手术副作用提供新的思路。方法取SPF级雄性SD大鼠40只,随机分为4组:A组(端侧吻合组):建立反射弧后,将残余的左侧L4前根外周段断端与左侧L3前根行端侧吻合;B组(易位吻合组):建立反射弧后,将残余的LL4前根外周段断端与LL6前根中枢段断端行端端吻合;C组(失神经组):建立反射弧后,将残余的LL4前根外周段断端与LL6前根中枢段断端翻转固定;D组(对照组):不作其他特殊处理;每组10只。各组均切断LL5,并将LL5两断端翻转固定。于手术6月后取实验侧趾长伸肌测量肌湿重和肌细胞截面积,并比较A组和B组的再生有髓神经纤维数目。结果A、B组与失神经组相比,肌湿重和肌细胞截面积有非常显著性差别(P<0.01)。A组的失神经肌肉恢复和神经再生情况明显好于B组,其差异有非常显著性意义(P<0.01)。结论实验证实,易位吻合和端侧吻合能够恢复所损的L4VR支配的下肢运动的部分功能,且端侧神经吻合其神经再生效果要优于易位神经吻合更多还原

【Abstract】 It is well established that the artificial somatic-automatics reflex arc procedure is an effective and safe treatment for spina cord injury (SCI) and spina bifida (SB) patients to gain bladder and bowel control and continence. A healthy lumbar ventral root (VR) is required to reinnervate the lower urinary tract for the somatic-autonomic reflex pathway and it would damage the original motor function of the lumbar VR. Moreover, many patients with spina bifida have preexisting lower extremity neural malfunction. We believe the lower extremity complications are acceptable in order to gain bladder control and continence. Nevertheless, efforts should be made to minimize the motor deficit of the lumbar VR.In our experiment, we studied the influence of the single and combined section of L4, 5 roots on the hind limb function and tried to find the best way to minimize the lose of the motor function of the lumbar VR. Part ⅠThe morphological investigation of partially denervatedmouse muscle after lumbar nerve root injury.Objective To study the influence of the single and combined section of L4, 5 ventral roots (VR) on the hind limb function.Methods 32 young adult male Sprague-Dawley rats were randomized into 2 groups: L4 denervated (L4) and L4, 5 denervated (L4, 5). Left L4 VR or L4, 5 VR transections produced partial denervation, the extensor digitorum longus (EDL) muscle on the right side was used as normal control. The EDL muscle wet weight, fiber cross-sectional area and motor endplate (MEP) were examined 6 weeks and 16 weeks following denervation (6 rats for each group).Results In L4 groups, it does show a harmful influence on the hind limb at 6 weeks, but the damage to the hind limb got relieved gradually as postoperative time went on, and most of them recovered to normal at 16 weeks. In L4, 5 groups, the hind limb function showed a persistent damage even at postoperative 16 weeks.Conclusions Section of L4 VR alone does show a harmful influence on the hind limb in the early stage, but it might recover to normal in the long run. But section of L4, 5 VR can cause an irrecoverable damage to the hind limb function. Part ⅡStudy on end-to-side neurorrhaphy connecting autonomicnerve to somatic nerve for restoring bladder function in rats.Objective To investigate the feasibility of establish an artificial somatic-autonomic reflex arc with end-to-side (ETS) neurorrhaphy for restoring bladder function in rats.Methods 20 SD rats were randomly divided into 2 groups: group A and group B. In group A of 10 rats, the artificial somatic-autonomic reflex pathway was established by microanastomosis of left L4 ventral root (VR) to L6 VR; in group B of 10 rats, the left L6 VR was sectioned and the distal end was sutured laterally to the intact left L4 VR. Electrophysiological and histological assessments for nerve regeneration were performed 6 months postoperatively.Results The bladder detrusor contraction of group A was very weaker, and the counts of regenerated nerve axons also showed that a significant difference existed between the two groups (P<0.01).Conclusions End-to-side neurorrhaphy is not satisfactory to establish an artificial somatic-autonomic reflex arc for restoring bladder function in rats. Part ⅢNeurorrhaphy for minimizing the neural deficit and muscular atrophy caused by partial denervation after an artificial somatic-autonomic reflex arc procedure.Objective To study the effect of different neurorrhaphy for minimizing the neural deficit and muscular atrophy caused by partial denervation after establishing an artificial somatic-autonomic reflex arc.Methods 40 young adult male Sprague-Dawley rats were randomized into 4 groups of 10 each. In group A, the distal end of the left L4 VR was sutured in an end-to-side (ETS) fashion to the intact left L3 VR after establishing an artificial somatic-autonomic reflex arc. In group B, the distal end of the left L4 VR was anastomosed to the proximal end of the left L6 VR by end-to-end (ETE) neurorrhaphy after establishing an artificial somatic-autonomic reflex arc. In group C, the artificial somatic-autonomic reflex pathway was established by microanastomosis of left L4 VR to L6 VR. In group D, the left L4 VR was left intact as control. The extensor digitorum longus (EDL) muscle on the left side was partially denervated by transecting the left L5 VR in all rats. The EDL muscle wet weight, fiber cross-sectional area and regenerated nerve axons were calculated 6 months postoperatively.Results There was significant difference of between the two groups of neurorrhaphy (group A and group B) and denervated group (group C) in muscle wet weight and fiber cross-sectional area. And the counts of regenerated nerve axons showed that group A was superior to group B. Conclusions The two neurorrhaphies all could partially recovery the motor function of the lumbar4 VR. The end-to-side neurorrhaphy is superior, though it is still not possible to restore the motor function of the L4 VR completely.更多还原