多种移植体修复周围神经的比较实验研究

修复神经缺损的材料甚多，但至今尚未见各种材料的比较研究。为了比较自体神经、肌肉、静脉、肌腱及硅橡胶修复神经缺损的效果，选用ＳＤ大白鼠，切断腓总神经，制成０．６ｃｍ缺损，分别用不同移植物桥接缺损。于术后６周、１２周在电生理、胫前肌称重、远端轴突计数及组织学等方面进行综合分析评价。结果表明：自体神经移植在各方面均优于其它移植体，而静脉组又优于另外３组。对各种移植体中神经再生的特点及其成熟过程进行了讨论，并探讨了形成这种差别的有关神经再生微环境的影响。     

Inside-out versus standard artery graft to repair a sensory nerve in rats

It is known that a vein graft provides a good microenvironment for axon regeneration in motor peripheral nerves, but the use of artery graft for regeneration of sensory nerves is controversial. We sectioned the saphenous nerve and repaired it by using heterologous inside-out and standard artery graft techniques in rats. After 4, 12, and 20 weeks, the graft and the distal stump were observed under electron microscopy. In each period studied, the pattern, diameters, and thickness of the myelin sheaths of the regenerated axons were measured in the graft and distal stump. There was capillary invasion in both the graft and distal stump, especially in the inside-out artery graft group. Regenerated nerve fibers were prominent in both heterologous artery grafts 4 weeks after the surgical procedures. Conversely, in the distal stump, regenerated nerve fibers were observed only after 12 weeks. In both the inside-out artery graft and standard artery graft, no statistical difference in the diameters and thickness of the myelinated fibers after 20 weeks was observed.     

Comparing FK-506 with Basic Fibroblast Growth Factor (b-FGF) on the Repair of a Peripheral Nerve Defect Using an Autogenous Vein Bridge Model

ABSTRACT?

Objective: The limited availability of donor sites for nerve grafts and the morbidity associated with their harvesting serve as motivating factors to actively conduct research to find alternatives to the status quo. Experimental and clinical studies have shown that a vein segment used to bridge a peripheral nerve defect leads to a functional nerve repair. Both FK-506 and b-FGF have been reported to enhance peripheral nerve regeneration. This study compared the effects of FK-506 with that of b-FGF on peripheral nerve regeneration in a rat autogenous vein graft conduit model. Methods: The main trunk of the right sciatic nerve was transected and bridged by an autogenous vein in 30 rats. Small osmotic pumps were placed just proximal to the anastomoses. Groups of 10 rats were assigned to receive saline solution, b-FGF (2,000 units), or FK-506 (0.5 mg/kg/day) via the osmotic pumps for 2 weeks. Sciatic nerve regeneration was evaluated by sensory function, walking track analysis, electrophysiologic studies, and light microscopic evaluation. Results: On post-operative day 90, there was a statistically significant difference (p <.005) in nerve regeneration between the rats who received saline compared with those who received FK-506 or b-FGF. This was determined using sensory function tests, sciatic function index, and electrophysiologic studies. The number of nerve axons, as determined by histological analysis, revealed there were significantly more nerve fibers which were regenerated in both experimental groups (FK-506 and b-FGF) when compared with rats who received saline. There was no statistically significant difference in the number of nerve axons that regenerated in rats injected with FK-506 vs. rats injected with b-FGF. Conclusion: FK-506 and b-FGF promote similar nerve regeneration in rats compared with control.     

Beneficial effect of nerve growth factor-7S on peripheral nerve regeneration through inside-out vein grafts: an experimental study

This study investigated the effect of local administration of nerve growth factor-7S (NGF-7S) on the axonal regrowth of mixed peripheral nerves through inside-out vein grafts. Sixty male Wistar rats were randomized into two groups (n = 30). A defect 12 mm long in the right sciatic nerve was created and repaired with an inside-out vein graft from the right jugular vein. NGF-7S (group A) or phosphate-buffered saline (group B; control) was locally administered daily during the first 3 weeks. Walking-track analysis and electrophysiological and histological-morphometric studies were carried out 4, 6, 8, 10, and 12 weeks postoperatively (subgroups a, b, c, d, and e, respectively, n = 6 each). Data analysis showed that 1) the recovery of motor function, as measured by walk pattern analysis and evoked muscle action potential, and 2) the orientation, number, myelin thickness, and diameter of myelinated fibers were better in the NGF-7S than in the control group. These findings present strong evidence of the beneficial effect of NGF-7S on peripheral nerve regeneration through inside-out vein grafts.     

Functional recovery of sciatic nerve through inside-out vein graft in rats

Objective: Present study aimed at further comprehensive functional, histomorphometrical and immunohistochemical assessment of peripheral nerve regeneration using rat sciatic nerve transection model.Methods: The 10-mm rat sciatic nerve gap was created in rats. In control group nerve stumps were sutured to adjacent muscle and in treatment group the gap was bridged using an inside-out vein graft. In sham-operated group the nerve was manipulated and left intact. All animals underwent walking track analysis test 4, 8, and 12 weeks after surgery.Subsequently, muscle mass measurement was performed to assess reenervation, histological examination to observe the sciatic nerve regeneration morphologically and immunohistochemistry to detect Schwann cells using anti S-100. Results were analyzed using a factorial ANOVA with two between-subjects factors. Bonferroni test for pairwise comparisons was used to examine the effect of treatments.Results: Functional analysis ofmyelinated nerve fibers showed that nerve function improved significantly in the time course in treatment group. However, quantitative morphometrical analysis of myelinated nerve fibers showed that there was no significant difference between 8 and 12 weeks in treatment group. Muscle weight ratio was bigger and weight loss of the gastrocnemius muscle was ameliorated by inside-out vein grafting. The position of positive immunohistochemical reactions further implied that regenerated axons and Schwann cell-like cells existed after vein grafting was performed, and was accompanied by the process of myelination and structural recovery of regenerated nerves.Conclusion: Functional analysis of peripheral nerve repair is far more reliable than quantitative morphometrical analysis     

Inside-outl vein graft repair compared with nerve grafting for nerve regeneration in rats

The inside-out vein graft is a vein conduit pulled through itself to invert the normal orientation and place the adventitial layer within the lumen of the conduit. Our study compares regeneration of peripheral nerves in the rat through two conduits: inside-out graft of the jugular vein and autogenous nerve graft. In 10 rats, the right jugular vein was harvested, turned inside out, and used to bridge a 10 mm defect created in the right sciatic nerve. The 10 mm nerve segment from the right was then used as a standard nerve graft to bridge a 10 mm gap created in the left sciatic nerve. Rats were sacrificed at 8 and 12 weeks. Regeneration on the inside-out vein graft side showed superior functional results (faster conduction velocities) and improved histological results (greater axon counts) compared with the nerve grafted side. We feel the adventitial surface of the wall of the vein promotes nerve regeneration by providing an environment rich with collagen, laminin, and Schwann cells and promotes increased vascularization of the new nerve. © 1995 Wiley-Liss, Inc.     

Autogenous venous graft with one-stage prepared Schwann cells as a conduit for repair of long segmental nerve defects

The use of autogenous venous graft with intraluminal injection of Schwann cells to enhance nerve regeneration of long segmental nerve defects was evaluated in a rabbit tibial nerve-repair model. Schwann cells were isolated from the excised rabbit tibial nerve by using the polylysine differential adhesion method. The cultured cells were identified by immunocytochemical labeling for S-100 protein. Tibial nerve defects in 4-cm segments were created in 24 animals, which were then divided into three groups. In Group 1, the tibial nerve defect was repaired with interposition vein graft alone; in Group 2, the nerve defect was repaired with a vein graft with intraluminal injection of Schwann-cell suspension; in Group 3, the nerve defect was repaired by autogenous nerve graft alone. At 2 months postoperatively, electrophysiologic evaluation showed that an evoked muscle action potential was recorded for the animals in Group 2, with vein grafting plus Schwann cells, and for those in Group 3, with autogenous nerve grafting, but not for those in Group 1, where vein grafting alone was used. The average motor nerve conduction velocity in the group with vein grafting and Schwann cells was 3.4 +/- 1.5 m/sec, which was slower than the nerve grafting group (7.8 +/- 1.8 m/sec). Histologic analysis confirmed there was formation of new nerve fascicles with myelination in the vein graft filled with Schwann cells. No nerve regrowth was found in the vein grafts without Schwann cells. These results suggested that isolated Schwann cells are able to survive in a vein graft, and that the vein graft with intraluminal seeded Schwann cells could be an alternative for repairing injured nerves with long gaps.     

REPAIR OF FACIAL NERVE WITH ALGINATE SPONGE WITHOUT SUTURING: AN EXPERIMENTAL STUDY IN CATS

A bioabsorbable material, alginate, was used to repair a defect in the facial nerve. In five cats a 5-mm gap was created in the dorsal ramus of the facial nerve on one side selected at random, which was repaired by implantation of alginate sponge without suturing. In the control group, two cats had a similar nerve injury but without implantation of alginate. Behavioural, electrophysiological, and histological examinations were made over a period of 16 weeks postoperatively. Movement of the upper eyelids and electrophysiological function were restored 12 weeks postoperatively, and many myelinated axons were observed both in the gap of facial nerve and its branches 16 weeks after operation, whereas no alginate residue was detected remaining within gap. In the control group, no movement or electrophysiological restoration was recorded, and there were few regenerated axons accompanied by a large amount of scar tissue. The nerve repaired with alginate showed remarkable regeneration. These results suggest that alginate is a promising material for facial nerve repair, and sutureless repair with alginate is a possible option for treating defects in the facial nerve.     

Comparison of regeneration results of prefabricated nerve graft, autogenous nerve graft, and vein graft in repair of nerve defects

The purpose of this study was to evaluate the effectivity of prefabricated nerve grafts in the repairing nerve defect and to compare them with the autogenous nerve graft and vein graft. Four groups were created, each containing 10 rats. First, nerve prefabrication was carried out in groups I and II during 8 weeks. For this purpose, jugular vein graft was sutured to the epineural windows on the peroneal and tibial nerve at the right side in an end-to-side fashion. To create neurotrophic stimulus, partial incision was performed on the nerves in group I, and gene therapy was performed by plasmid injecting to the adjacent muscles in group II. At the end of the eighth week, prefabricated nerve grafts, jugular vein, and the axons passing through it were taken. Then, gap was created on the left peroneal nerve in all groups. Defect on the peroneal nerve was repaired by using the prefabricated nerve grafts in groups I and II, the autogenous nerve graft in group III, and the vein in group IV. Assessment of nerve regeneration was performed by using electromyography. Morphological assessment was performed after follow-up period. According to electrophysiological and morphological results, the results of first three groups were similar. There was no statistically significant difference between three groups. Prefabricated nerve graft is as effective as autogenous nerve graft, and it can be used in the repair of nerve defects as autogenous nerve graft as an alternative.     

Repair of facial nerve with alginate sponge without suturing: an experimental study in cats.

A bioabsorbable material, alginate, was used to repair a defect in the facial nerve. In five cats a 5-mm gap was created in the dorsal ramus of the facial nerve on one side selected at random, which was repaired by implantation of alginate sponge without suturing. In the control group, two cats had a similar nerve injury but without implantation of alginate. Behavioural, electrophysiological, and histological examinations were made over a period of 16 weeks postoperatively. Movement of the upper eyelids and electrophysiological function were restored 12 weeks postoperatively, and many myelinated axons were observed both in the gap of facial nerve and its branches 16 weeks after operation, whereas no alginate residue was detected remaining within gap. In the control group, no movement or electrophysiological restoration was recorded, and there were few regenerated axons accompanied by a large amount of scar tissue. The nerve repaired with alginate showed remarkable regeneration. These results suggest that alginate is a promising material for facial nerve repair, and sutureless repair with alginate is a possible option for treating defects in the facial nerve.     

Tubulation repair of peripheral nerves in the rat using an inside-out intestine sleeve

This study compared the regeneration of peripheral nerves in the Sprague-Dawley rat through a nerve guide prepared from rat small intestine to nerve regeneration using a standard autogenous nerve-graft repair strategy. In one experimental group (n = 15), inside-out rat intestine sleeves were used as nerve guides to bridge a 10-mm defect created in the right sciatic nerve. These nerve guides were prepared by harvesting 14-mm segments of small intestine from Sprague-Dawley rats not otherwise used in the study. The segments were turned inside-out to expose the serosa as the lumen of the guide, and transected nerve stumps were secured 2 mm into the guide on each end with an epineural-to-guide stitch. The control group (n = 15) had an identical gap repaired with a standard autologous nerve graft. Five animals from each group were sacrificed at 4, 8, and 12 weeks. The extent of axonal regeneration was assessed by axon-counting, retrograde tracer analysis, electromyography, and qualitative histologic assessment. The inside-out intestine sleeve group exhibited faster conduction velocities and greater axon counts when compared to the autologous nerve-graft controls. These novel nerve guides proved simple to manufacture and were completely absorbed by 12 weeks.     

Inside-out vein graft promotes improved nerve regeneration in rats

Vein grafts have been used both experimentally and clinically to bridge gaps in peripheral nerves. This study describes a modification of the vein graft technique in which vein graft conduits are pulled inside-out before anastomosis with proximal and distal nerve stumps. This technique creates an autogenous vein conduit with the collagen-rich adventitial surface exposed to the regenerating axons. The inside-out technique is a fast and simple modification of the standard vein graft technique and produces an accelerated rate of nerve regeneration and significantly earlier myelination compared with the results obtained from the use of polyethylene nerve guides and standard vein graft conduits. © 1993 Wiley-Liss Inc.     

己丁糖处理神经吻合口促进神经再生的实验研究

目的:神经离断伤经显微手术修复后,神经吻合口粘连常可阻碍神经再生。本研究利用己丁糖防止粘连的作用并与其他方法进行对比,探索促进神经再生的办法。方法:将48只兔随机分为4组:己丁糖组、强的松龙组、静脉包裹组及单纯缝合组。将兔的胫神经切断后吻合,吻合口分别用己丁糖、强的松龙处理、静脉包裹及不作处理。于术后2、4、10、16周行肉眼观察及光镜检查,第16周行电镜、电生理检查及作轴突图像分析。结果:己丁糖在瘢痕床上的使用可有效防止瘢痕对修复段神经的压迫、粘连和固定,强的松龙也有防止神经粘连的作用,二者优于静脉包裹和单纯缝合组。经统计学处理,差异有显著性意义(P<0.01)。结论:术中使用己丁糖、强的松龙处理神经吻合口,能有效地防止周围神经粘连,促进周围神经再生,最大限度地恢复周围神经的功能。     

含神经生长因子的羊膜基质管桥接修复神经缺损的实验研究

目的研究含神经生长因子的人羊膜基质微孔管(NGF·HAMM)、桥接修复周围神经缺损的效果。方法分别用含神经生长因子的人羊膜基质微孔管(NGF·HAMM)、人羊膜基质微孔管(HAMM)、自体神经移植修复60只Wistar大鼠坐骨神经1.2cm缺损;同时将大鼠按手术方法分为3组,每组20只。术后进行组织形态学、电生理学、伤肢功能恢复等检测。结果近端神经再生轴突生长通过1.2cm长的NGF·HAMM移植体,重新支配终末骨骼肌,其再生神经纤维生长速度、数量明显快(多)于单纯HAMM移植体,术后3个月时坐骨神经功能恢复良好。结论NGF和HAMM联合使用可促进轴突再生及其髓鞘化,对损伤神经及伤肢的功能恢复有明显协同促进作用;NGF·HAMM是一种很有希望的神经移植替代材料。     

异体神经段皮下包埋对坐骨神经再生影响的研究

目的　探讨异体周围神经段皮下包埋对坐骨神经再生的影响。　方法　 Wistar大鼠 30只 ,雄性。 6只为供体 (C组 ) ,余随机分为两组。实验组 (A组 ) 12只 ,于右大腿后侧皮下行异体坐骨神经 (15 mm)包埋 ,2周后取出 ,修整为 10 mm的片段移植于左侧新鲜的坐骨神经缺损处 (10 m m)。对照组 (B组 ) 12只 ,于右腿相应部位皮肤切口直接缝合 ,左侧新鲜坐骨神经 (10 mm)原位吻合。术后 2、4、8和 14周行组织学观察 ,14周作电生理测定和电镜观察。　结果　术后 2周 ,A组炎性反应稍重于 B组 ;至 4周时两组的炎性反应程度相似 ,近端少许胶原纤维增生 ;8周时两组的炎性反应基本停止 ,胶原纤维增生稍明显 ;14周时两组神经外膜构成完整 ,束膜、内膜结构无明显差异。再生大量的有髓神经纤维及少量的无髓神经纤维。髓鞘结构完整。再生轴突数目、面积差异无统计学意义 ,束膜厚度、分布及范围相似。运动神经传导速度、峰值及潜伏期差异无统计学意义 (P>0 .0 5 )。　结论　皮下包埋的异体周围神经段虽有一定的炎性反应 ,但仍具有与自体神经移植相似的神经再生引导作用。     

碱性成纤维细胞生长因子结合静脉套接法修复周围神经缺损的实验研究

目的 探讨碱性成纤维细胞生长因子（ｂＦＧＦ）与静脉套接法修复神经缺损的作用。方法 新西兰大白兔５４只,分成三组,切断兔一侧坐骨神经,用自体静脉桥接。Ａ组于静脉段内注入ｂＦＧＦ溶液０．２ｍｌ（浓度４０００Ｕ／ｍｌ）,Ｂ组注入等量的生理盐水,Ｃ组不注入任何物质。分别于术后１０、３０及１００天取标本行ＨＥ染色,光镜检查。其中１００天组先做传导速度测定,远端再生神经做髓鞘染色,轴突断面做图像分析并与健侧比     

含神经生长因子的几丁质管桥接兔面神经缺损的实验研究

目的 探讨含神经生长因子（ＮＧＦ）的几丁质管在修复兔面神经缺损中的作用。方法 将１６只新西兰兔的两侧面神经上颊支分别造成８ｍｍ的缺损,左侧用管腔内注入ＮＧＦ的几丁质管修复,右侧用自体神经移植修复作对照。术后８、１６周,分别取８只兔进行电生理和超微结构研究。结果 实验侧术后８周,再生神经中有髓和无髓神经纤维排列整齐,有髓神经的髓鞘厚,板层结构清晰;术后１６周,再生神经中有髓和无髓神经纤维数量增加,形     

甲壳素涂层PGLA神经导管修复兔面神经缺损的实验研究

目的:探讨甲壳素涂层PGLA神经导管修复兔面神经缺损的效果。方法:成年雄性新西兰兔24只,无菌条件下切断双侧面神经下颊支,制成15mm的兔面神经下颊支缺损模型。左侧用甲壳素涂层聚丙交脂-乙交脂共聚物[poly(L-lactide-co-glycolide),PGLA]神经导管修复;右侧用翻转自体神经修复作为对照。术后5周、10周和14周行大体观察、电生理检查、组织学、电镜观察评价修复效果。结果:术后5周观察到神经导管中有新生轴索通过,再生神经发育不成熟;右侧自体神经修复近段有髓神经纤维均匀疏散分布,远段未见明显再生神经束形成。术后14周左侧再生神经已通过神经导管长入远端,电生理检查结果表明自体神经修复侧再生神经质量优于神经导管修复侧,差异有统计学意义(P<0.01)。自体神经修复再生纤维密度优于神经导管修复侧,差异有统计学意义(P<0.01),但自体神经修复侧近段神经髓鞘部分空泡样变性及脱髓鞘改变,远段再生神经纤维束形成少,面肌联带运动程度较导管修复侧严重。结论:甲壳素涂层PGLA神经导管能有效修复周围神经缺损,有望替代自体神经移植。     

不同时段异体神经片段皮下包埋对周围神经再生影响的实验研究

目的 探讨异体神经片段经皮下包埋不同时段后对周围神经再生的影响。方法 Wistar大鼠55只，雌雄不限，随机分为5组，A、B、C组（实验组）和D组（对照组）每组各10只，E组（供体组）15只。E组动物在出骨盆口以远5mm处切断双侧坐骨神经，向远端游离约15mm，切断作为移植物。A、B、C组动物均行左侧大腿切口，皮下钝性分离，埋入供体神经片段。术后1周（A组）、2周（B组）、3周（C组）显露右侧坐骨神经，距骨盆出口约5mm处切断，向远端游离约10mm再切断，取出对侧包埋的神经片段，修剪远近端保留长度约10mm，移植于右侧神经缺损处。D组显露右侧坐骨神经后，在距骨盆出口约5mm处切断，向远端游离约10mm后再切断，原位缝合。术后2、4、6、8、10及12周监测坐骨神经功能指数（sciatic functional index，SFI），术后12周行电生理检查测试运动神经诱发电位的传导速度及潜伏期，组织学检测移植神经再生轴突数目和面积，以及移植神经的超微结构变化。结果术后各组SFI逐渐下降，12周时A组和D组的SFI最小，两组间差异无统计学意义，但分别与B组和C组比较差异有统计学意义（P〈0．05）。术后12周A组和D组再生大量有髓神经纤维及少量无髓神经纤维，再生神经的数量和结构与正常神经相似，图像分析显示两组间无明显差别，与B组和C组比较差异有统计学意义（P〈0．05）。A组和D组的运动神经传导速度及潜伏期结果无差异，优于B组和C组，且差异有统计学意义（P〈0．05）。结论 异体神经片断皮下包埋后有促进周围神经再生的作用，皮下包埋1周组促神经再生作用优于皮下包埋2、3周组。     

Neurotrophins and their receptors in early axonal regeneration along muscle-vein-combined grafts

Experimental and clinical studies have shown that a vein segment filled with skeletal muscle used to bridge a peripheral nerve defect (muscle-vein-combined graft) leads to good nerve repair. However, the molecular basis of the nerve fiber regeneration process along this type of graft still remains to be elucidated. The aim of this study was to verify the expression of two neurotrophins, nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), as well as their receptors, trkA and p75, in an early stage of axonal regeneration in muscle-vein-combined grafts. Severed rat sciatic nerves were repaired by means of 1-cm-long muscle-vein-combined grafts and withdrawn immediately after surgery (control grafts) and 5 days after surgery. Longitudinal sections of grafts were immunostained by means of the following antibodies: anti-NGF, anti-BDNF, anti-trkA, and anti-p75. An anti-glial fibrillar acid protein (anti-GFAP) antibody was used to recognize Schwann cells. Results showed the presence of a number of GFAP-positive Schwann cells inside the muscle-vein grafts. Many of these cells reacted for NGF, BDNF, and p75, but not trkA. In control grafts, i.e., immediately after surgery, no immunostaining was detected for any of the antibodies used in this study. These observations suggest that, very early after surgery, the muscle-vein-combined graft offers to growing axons an environment particularly favorable for regeneration, providing us with a possible explanation for the efficacy of this grafting technique for peripheral nerve repair.