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.     

Sciatic nerve regeneration through alginate with tubulation or nontubulation repair in cat

A novel material for nerve regeneration, alginate, was employed in both tubulation and nontubulation repair of a long peripheral nerve defect injury. Twelve cats underwent severing of the right sciatic nerve to generate a 50-mm gap, which was treated by tubulation repair (n = 6) or nontubulation repair (n = 6). In the tubulation group, a nerve conduit consisting of polyglycolic acid mesh tube filled with alginate sponge was implanted into the gap and the tube was sutured to both nerve stumps. In the nontubulation group, the nerve defect was repaired by a simple interpolation of two pieces of alginate sponge without any suture. The animals in both groups exhibited similar recovery of locomotor function. Three months postoperatively, successful axonal elongation and reinnervation in both the afferent and efferent systems were detected by electrophysiological examinations. Intracellular electrical activity was also recorded, which is directly indicative of continuity of the regenerated nerve and restoration of the spinal reflex circuit. Eight months after operation, many regenerated myelinated axons with fascicular organization by perineurial cells were observed within the gap, peroneal and tibial branches were found in both groups, while no alginate residue was found within the regenerated nerves. In morphometric analysis of the axon density and diameter, there were no significant differences between the two groups. These results suggest that alginate is a potent material for promoting peripheral nerve regeneration. It can also be concluded that the nontubulation method is a possible repair approach for peripheral nerve defect injury.     

兔化学去细胞神经移植修复大鼠坐骨神经缺损

目的：以化学去细胞兔神经移植修复大鼠坐骨神经缺损，从而探索化学去细胞异种神经移植修复神经缺损的可能性；方法：以30％TritonX-100和40%脱氧胆酸钠顺序处理新鲜取材的兔神经(直径15nm左右)，移植修复成年wistar大鼠l.0cm坐骨神经缺损．4个月后行电生理及组织学检查，观察神经再生情况；结果：移植神经未被宿主排斥，大量再生的神经纤维长过移植物，并恢复电传导功能；结论：化学去细胞异种神经可以作为修复周围神经缺损的一种很有前途的方法。     

去细胞异种神经复合神经生长因子修复神经缺损的实验研究

目的 应用含有神经生长因子(NGF)的去细胞异种神经基膜管作为神经移植替代物桥接大鼠坐骨神经缺损,观察其对神经再生的作用.方法 选用Wistar大鼠45只,随机分为3组,每组15只,于术制成右后肢坐骨神经长10 mm的神经缺损,取兔胫神经制成去细胞神经基膜管,电镜及HE染色观察神经基膜管超微结构,流式细胞仪检测去细胞前后神经主要组织相容性抗原Ⅱ(MHC Ⅱ)的变化情况.A组以含有NGF的去细胞异种神经基膜管桥接神经缺损,B组单纯采用去细胞异种神经基膜管桥接神经缺损,C组采用自体神经移植修复神经缺损.术后1个月行神经电生理检测即胫后肌群运动诱发电位,用HE染色、免疫组化染色、透射电镜等方法对移植体远端吻个口再生神经纤维进行形态学观察,并对再生有髓神经纤维的数量、密度、直径及雪旺细胞的密度进行量化分析.结果 移植前新鲜神经组MHC-Ⅱ检测值为72.14±19.88,去细胞组MHC-Ⅱ检测值为4.19±3.11,两组比较差异有统计学意义(t=3.817,P＜0.05);透射电镜观察显示为胶原性管道,无细胞成分.术后4周,处死前行运动诱发电位检测,神经传导速度A组为(21.16±2.31)m/s,B组为(13.37±1.89)m/s,C组为(21.43±2.18)m/s,A组与 C组比较差异无统计学意义(P＞0.05),A组与 B组比较差异有统计学意义(P＜0.05).组织学观察见3组移植体远端吻合口横切面再生神经纤维呈微束状,透射电镜观察再生神经纤维具有正常的形态和结构.A、C组再生神纤纤维数量及直径均优于B组,差异有统计学意义(P＜0.05).结论 经化学萃取的去细胞兔胫神经基膜管能够移植于大鼠,成功修复大鼠坐骨神经缺损,而且复合NGF的去细胞基膜管在神经修复质量上优于单纯的去细胞神经基膜管,更加接近自体神经移植的效果.     

Autogenous standard versus inside-out vein graft to repair facial nerve in rabbits

Objective： To evaluate autogenous vein grafts and inside-out vein grafts as conduits for the defects repair in the rabbit facial nerves. Methods： The 10 nun segments of buccal division of facial nerve were transected for 48 rabbits in this study. Then the gaps were immediately repaired by autogenous vein grafts or inside-out vein grafts in different groups. All the animals underwent the whisker movement test and electrophysiologic test during the following 16 weeks at different time points postoperatively. Subsequently, the histological examination was performed to observe the facial nerve regeneration morphologically. Results： At 8 weeks after operation, the facial nerve regeneration has significant difference between the experimental group and the control group in electrophysiologic test and histological observation. However, at the end of this study, 16 weeks after operation, there was no signifi- cant difference between inside-out vein grafts and standard vein grafts in enhancing peripheral nerve regeneration. Conclusion： This study suggest that both kinds of vein grafts play positive roles in facial nerve regeneration after being repaired immediately, but the autogenous inside-out vein grafts might accelerate and facilitate axonal regeneration as compared with control.     

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     

Facial nerve repair using a collagen conduit in cats.

We evaluated facial nerve regeneration using a collagen tube as a nerve conduit in five cats. In three 5 mm of the facial nerve were resected, a collagen tube was implanted, and a 5 mm segment of the opposite facial nerve was resected, reversed 180 degrees, and sutured back as an autologous nerve graft. In one a collagen tube was implanted on one side, and in the remaining one a 5 mm nerve segment was reversed. Histological, electrophysiological, and horseradish peroxidase labelling examinations were carried out 4-24 weeks postoperatively. Histological study showed that the nerve was well vascularised and regenerated. Electrophysiological examination confirmed the recovery of evoked electromyograms through to the regenerated axons. Horseradish peroxidase examination also confirmed restoration of the whole facial nerve. The collagen tube is an efficient nerve conduit.     

FACIAL NERVE REPAIR USING A COLLAGEN CONDUIT IN CATS

We evaluated facial nerve regeneration using a collagen tube as a nerve conduit in five cats. In three 5 mm of the facial nerve were resected, a collagen tube was implanted, and a 5 mm segment of the opposite facial nerve was resected, reversed 180°, and sutured back as an autologous nerve graft. In one a collagen tube was implanted on one side, and in the remaining one a 5 mm nerve segment was reversed. Histological, electrophysiological, and horseradish peroxidase labelling examinations were carried out 4-24 weeks postoperatively. Histological study showed that the nerve was well vascularised and regenerated. Electrophysiological examination confirmed the recovery of evoked electromyograms through to the regenerated axons. Horseradish peroxidase examination also confirmed restoration of the whole facial nerve. The collagen tube is an efficient nerve conduit.     

联合运用冻融法和化学法去细胞同种异体神经修复兔面神经缺损

目的：通过对去细胞同种异体神经处理方法的改进,找出一种修复兔面神经缺损的理想替代材料。方法：取24只兔子,将兔左侧面神经上颊支切断以造成面神经缺损1.0cm的模型,根据修复方法不同,随机分成2组：实验组为联合运用冻融法和化学法去细胞同种异体神经修复组,对照组为自体面神倒置修复组,每组12只。术后3个月行大体观察、神经电生理检测、有髓神经纤维计数以及电镜观察,采用SPSS17.0软件包对数据进行t检验,对面神经恢复情况进行综合评价。结果：两组兔子均存活,切口愈合良好,兔面形基本对称;实验组与对照组左侧面神经上颊支传导速度分别为（55.74±10.56）m/s及（61.34±9.72）m/s,差异无显著性（P〉0.05）;实验组与对照组移植体远端吻合口邻近4.0mm段有髓神经纤维数量分别为（18173.62±918.38）n/mm2及（18601.21±982.31）n/mm2,差异亦无显著性（P〉0.05）;电镜检查结果相似。结论：联合运用冻融法和化学法去细胞同种异体神经能满意修复一定长度的面神经缺损,可以作为自体神经的一种有效替代物。     

Facial nerve repair accomplished by the interposition of a collagen nerve guide

OBJECT: Facial nerve paralysis due to a surgical procedure or trauma is a frequently observed complication. The authors evaluated facial nerve repair achieved by the interposition of a collagen nerve guide. METHODS: Ten cats were divided into three groups. Group 1 consisted of six animals in which a 5-mm facial nerve segment on one side was resected and replaced by a collagen tube that was sutured to bridge both nerve stumps. On the opposite side a 5-mm segment of facial nerve was resected, reversed 180 degrees, and sutured to the stumps as an autograft nerve. Group 2 consisted of two cats in which the collagen nerve guide was interposed on one side and the nerve on the other side was left intact. Group 3 consisted of two cats in which a reversed autograft nerve was placed on one side and the nerve on the other side was left intact. Histological, electrophysiological, and horseradish peroxidase labeling examinations were performed starting 3 weeks after surgery. Light and electron microscopic examinations of collagen tube-implanted specimens revealed a well-vascularized regenerated nerve. The electrophysiological study confirmed the recovery of electrical activity in regenerated axons. Horseradish peroxidase labeling also confirmed restoration of the whole facial nerve tract. CONCLUSIONS: The collagen nerve guide shows great promise as a nerve conduit.     

犬化学去细胞神经同种异体移植的实验研究

目的以化学去细胞同种坐骨神经移植修复犬坐骨神经的长段缺损，观察其功能恢复及神经再生。方法15犬分成去细胞同种神经组(实验组)6犬、自体神经组(对照组Ⅰ)6犬、新鲜同种神经组(对照组Ⅱ)3犬。右侧坐骨神经造成5．0cm长缺损，以上述三种移植物桥接修复。术后6个月行步态分析、神经电生理及神经再生观察。结果实验组和对照组Ⅰ在运动功能恢复，踝关节运动步态，小腿二头肌运动诱发电位、感觉诱发电位，移植段内新生轴突、血管及雪旺细胞，远端胫神经内有髓神经纤维及靶肌肉运动终板等方面非常相似。对照组Ⅱ神经功能始终无恢复，移植段被吸收。结论化学去细胞同种神经移植物修复犬粗大长段神经缺损时不会被宿主排斥和吸收，其近期功能恢复及神经再生与自体神经移植无明显差别。     

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。     

大鼠正中神经修复后不同时段的电生理变化与神经再生的相关性分析

目的 探讨大鼠正中神经切断缝合后的不同时段,其复合神经动作电位(CNAP)与形态学方面的特点及其相关性分析.方法 在大鼠上臂正中神经中段切断缝合后的不同时间点(2、3、4、6、8和12周)进行CNAP检测,随后取正中神经组织进行形态学检查.结果 术后第2周可以记录到CNAP.术后再生神经记录的CNAP幅度比对照组显著减低(P<0.01),波幅下面积(Area)也显著低于对照组(P<0.01),传导速度(CV)显著慢于对照组(P<0.01).术后2～6周的潜伏期(Lat)均比对照组明显延长(P<0.05);术后2～8周刺激强度,即阈强度(THI)和超大刺激强度(SSI)显著低于对照组.CNAP的第一峰波幅(FPA)、峰-峰波幅(PPA)、Area、CV变化趋势为随时间增加而逐渐增高,而其参数Lat、THI、SSI随时间增加而逐渐降低.神经修复后2周缝合口远端已有少量的新生轴突,随着再生时间延长,越来越多的再生轴突延伸至远端.远端记录的CNAP波幅与其有髓神经纤维计数之间有强的正相关(相关系数为0.953).线性回归分析表明,存在线性关系.术后8周髓鞘趋向于成熟.结论 CNAP是早期诊断和评价损伤神经再生程度的良好指标.正常正中神经的CNAP波幅可能与有髓神经纤维的计数呈线性关系.术后第8周,CNAP参数趋向于稳定,神经髓鞘渐趋向于成熟.

Abstract：

Objective To explore the characteristics of compound nerve action potential (CNAP) after rat median nerve transection and repair,and their correlation with neuromorphometry at various time points. Methods The median nerve was transected and sutured at mid-arm level. At various time points from 2 to 12 weeks postoperatively,CNAP recording was performed and the median nerve was harvested for morphological examination. Results CNAP could be recorded at 2 weeks after nerve repair. The CNAP amplitude,the area below the curve (Area) and conduction velocity (CV) of regenerated nerve were significantly lower than those of control group (P＜0.01). From 2 weeks to 6 weeks postoperatively,CNAP latency (Lat) was obviously longer than normal (P＜0.05). From 2 weeks to 8 weeks postoperatively,CNAP stimulus intensity (threshold intensity and the supramaximal stimulation intensity,THI and SSI) was significantly lower than that of the control group (P＜0.01). First peak amplitude (FPA),peak-peak amplitude (PPA),Area and CV of CNAP increased with time,while parameters such as Lat,THI and SSI decreased over time in regenerated median nerve. Regenerated axons could be seen at 2 weeks after nerve transection and repair. More and more regenerated axons were seen with the lapse of time. There was a strong positive correlation between CNAP amplitude and the number of myelinated nerve fibers,with a 0.953 correlation coefficient. Linear regression analysis revealed the existence of a linear relationship. The maturity of regenerated nerve at 8 weeks reflected by myelin sheath thickness was close to that of a normal median nerve. Conclusion CNAP recording is a valuable tool to evaluate the extent of early nerve regeneration after nerve suture repair. There might exist a linear relationship between CNAP amplitude of normal median nerve and the number of myelinated nerve fibers. CNAP parameters are inclined to stabilize and nerve myelin sheath maturation is close to normal 8 weeks postoperatively.     

静电纺纳米聚乳酸己内酮共聚物导管修复周围神经缺损的实验研究

目的 探讨应用同轴静电纺丝技术制备的聚乳酸己内酮共聚物[Poly(1-lactide-co-epsilon-caprolactone),P(LLA-CL)]导管,移植修复大鼠周围神经缺损的效果.方法 选取健康SD大鼠54只,随机分成3组,每组18只.先造成坐骨神经1.5cm缺损段,然后分别采用P(LLA-CL)导管桥接(A组)、硅胶管桥接(B组)、自体神经逆行原位移植(C组).分别在术后4、8、12周对大鼠进行大体观察、坐骨神经功能指数检查、神经电生理检查、肌肉湿重、再生有髓神经纤维计数、电镜观察,评价各组神经再生.结果 术后4周时A组再生神经已部分生长到导管的中部;8周时再生神经已通过神经导管,但再生的神经纤细;12周时再生神经粘连较轻,直径较粗.A组的坐骨神经功能指数、神经电生理、肌肉湿重和组织学观察等各项指标均略差于C组,但明显优于B组.结论 纳米聚乳酸己内酮神经导管具有促进神经轴突再生的作用,有望成为自体神经移植的替代材料应用于周围神经缺损的修复.     

Long-term result of guided nerve regeneration with an inert microporous polytetrafluoroethylene conduit

Thedevelopmentinmicrosurgicaltechniqueshasgreatlyimprovednervefunctionalrecovery .However ,owingtotheinabilitytocoaptateandsuturethousandsofnervefiberstotheirfunctionallysimilarnervefibersandinaccuratesutureofthenervestumps ,regeneratednervefiberspartiallylosethechancetoselectivelyregrowintotheirtargetendoneurialtubes,1 4whichresultsinaninevitablemismatchofmotorandsensorynervefibers .Thus,thecontact guidance basedmicrosurgicalnerverepairhasfailedtoachieveconsistentsatisfactoryfunctionalrecover…     

Repair of the facial nerve in the cerebellopontine angle using freeze-thawed skeletal muscle autografts. An experimental surgical study in the sheep

Summary Six adult blackface sheep underwent repair of the transected facial nerve in the cerebellopontine angle using short freezethawed muscle autografts. A typical facial palsy was observed on the side of the intervention immediately after operation. The sheep were allowed to recover for one year by which time clinical observation showed a complete recovery of the facial palsy in 5 sheep and a partial recovery in the remaining sheep. Under general anaesthesia function of the repaired VIIth nerve and the normal contralateral facial nerve were assessed using electrophysiological stimulating and recording techniques. These studies showed restoration of facial nerve continuity to have taken place with functional reinnervation of target facial muscles. Electrophysiological indices of nerve function were consistent with those expected after repair of any peripheral nerve. Morphometric study of the nerves after their removal showed structural changes which though quantitatively different from those of normal nerve were consistent with those seen in other sites and studies where nerves have been repaired. This technique is discussed as a possible treatment for facial nerves whose continuity is disrupted during the removal of cerebellopontine angle tumours.     

犬化学去细胞神经同种异体移植的早期观察

目的：以化学去细胞同种异体神经，移植修复犬粗大神经的长段缺损，观察早期功能恢复及神经再生。方法：去细胞神经移植组和自体神经移植组各3犬，分别桥接坐骨神经5.0cm缺损。术后3个月观察其运动功能及神经再生。结果：实验组和对照组在术后功能恢复；移植段内新生神经纤维、新生血管及许旺细胞；吻合口远端有髓神经纤维等方面非常相似。结论：化学去细胞神经作为同种异体神经移植物，在修复粗大和长段神经缺损时不会被宿主排斥和吸收，其早期功能恢复及神经再生与自体神经移植无明显差别。     

壳聚糖管与聚乙醇酸纤维复合移植修复大鼠坐骨神经缺损研究

目的：动态观察壳聚糖管与聚乙醇酸纤维复合移植修复大鼠坐骨神经缺损的过程及结果。方法：用复合移植物辅加“神经再生素”桥接大鼠坐骨神经10mm的缺损，分别于术后不同时间行足迹实验及再生神经的免疫组化、光电镜观察。结果：术后1周移植物表面即可见纤维膜性组织和微血管形成，第4周再生神经到达缺损的远段，第8周部分神经再生通过缺损，随时间延长，有髓神经纤维比例增多，髓鞘增厚。第16周，移植物基本降解，被再生神经组织替代。足迹试验显示术后第8周坐骨神经功能开始恢复，第16周达正常的60％左右。结论：复合移植物可诱导许旺细胞的迁移和再生轴索的生长，有利于神经同再生时各种膜性结构及微血管形成，并在发挥“桥梁”作用后逐渐降解。     

Highly Permeable Genipin‐Cross‐linked Gelatin Conduits Enhance Peripheral Nerve Regeneration

Here we have evaluated peripheral nerve regeneration with a porous biodegradable nerve conduit (PGGC), which was made from genipin‐cross‐linked gelatin. To examine the effect of pores, nonporous genipin‐cross‐linked gelatin conduit (GGC) was considered as the control. Both the PGGC and the GGC were dark blue in appearance with a concentric and round lumina. The PGGC featured an outer surface with pores of variable size homogeneously traversing, and a partially fenestrated inner surface connected by an open trabecular meshwork. The GGC had a rough outer surface whereas its inner lumen was smooth. Both PGGCs and GGCs had similar hydrophilicity on condition of the same material and cross‐linking degree. The porosity of PGGCs and GGCs was 90.8 ± 0.9% and 24.3 ± 2.9%, respectively. The maximum tensile force of the GGCs (0.12 ± 0.06 kN) exceeded that of the PGGCs (0.03 ± 0.01 kN), but the PGGCs had a higher swelling ratio than GGCs at 0.5, 1, 3, 6, 12, 24, 48, 60, 72, and 84 h after soaking in deionized water. Cytotoxic testing revealed the soaking solutions of both of the tube composites would not produce cytotoxicity to cocultured Schwann cells. After subcutaneous implantation on the dorsal side of the rat, the PGGC was degraded completely after 12 weeks of implantation whereas a thin tissue capsule was formed encapsulating the partially degraded GGC. Biodegradability of both of the tube groups and their effectiveness as a guidance channel were examined as they were used to repair a 10 mm gap in the rat sciatic nerve. As a result, fragmentation of the GGC was still seen after 12 weeks of implantation, yet the PGGC had been completely degraded. Histological observation showed that numerous myelinated axons had crossed over the gap region in the PGGCs after 8 weeks of implantation despite only few myelinated axons and unmyelinated axons mostly surrounded by Schwann cells seen in the GGCs. In addition, the regenerated nerves in the PGGCs presented a significantly higher nerve conductive velocity than those in the GGCs (P < 0.05). Thus, the PGGCs can not only offer effective aids for regenerating nerves but also accelerate favorable nerve functional recovery compared with the GGCs.     

去细胞异体神经基膜管桥接神经缺损的实验研究

目的 探索修复周围神经缺损的新的有效替代材料。方法 将异体的预变性神经和正常神经经溶血卵磷脂裂解液处理后,得到一种没有细胞及细胞碎片的、空的神经基膜管,将其用来修复大鼠15mm坐骨神经缺损,通过一般观察、肌萎缩测量、电生理检测、连续切片组织学观察和计算机图像为评价神经再生。结果 化学抽提的预变性神经和正常神经桥接物组均获得了密集的神经再生和良好的神经功能恢复,其中前者效果更为优越。结论 这种材料极有可能成为自体神经的替代材料应用于临床较短的神经缺损的修复。