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.     

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.     

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。     

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。     

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.     

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.     

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.     

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     

医用OB胶粘合周围神经的实验研究

目的探讨医用OB胶粘合神经后的抗牵拉强度及神经修复的效果，对其粘合神经的可行性进行评估。方法Wistar大鼠72只，以左侧坐骨神经建立修复模型，随机分为神经缝合组和粘合组，每组36只。缝合组用9-0无创尼龙线做神经外膜缝合4针，粘合组用OB胶粘合神经断端。分别于术后0d、1、2、3、4、8周进行大体观察、生物力学、电生理检测和组织学观察。结果生物力学检测，术后1周和2周粘合组与缝合组最大抗牵拉强度之间差异有统计学意义（P〈0．05）。电生理检测，术后4周和8周粘合组与缝合组运动神经潜伏期延迟比之间差异有统计学意义（P〈0．05）。组织学观察，缝合组在缝线周围可见有淋巴细胞、单核细胞等异物炎症反应；而粘合组吻合口处无明显炎症反应，再生轴突排列较缝合组更规则。结论OB胶粘合神经是一种修复周围神经损伤的有效方法。     

Reliability of sciatic function index in assessing nerve regeneration across a 1 cm gap

To evaluate the validity of sciatic function index as a reliable functional parameter in assessing regeneration of rat sciatic nerve through a 1 cm gap, we undertook the following investigation. Sixty-three adult male Sprague-Dawley rats were assigned to four groups for repair of a 1 cm gap created in the right rat sciatic nerve; 19 rats were repaired with amniotic collagen conduits, 20 with nerve autograft, and 17 with silicone tubes. In seven rats, the gap was not repaired and served as a control. Functional recovery was assessed by de-Medinaceli SFI and by clinical observations, compared with quantitative and qualitative histological results at 4, 10, and 17 weeks postoperatively. The SFI results did not correlate with the histological findings and clinical observations over the observation period in all groups.     

Functional reinnervation of the canine bladder after spinal root transection and immediate end-on-end repair

The goal of this study was to transect and immediately repair ventral roots, selected by their ability to stimulate bladder contraction, to assess the feasibility of bladder reinnervation in a canine model. Brain-derived neurotrophic factor (BDNF) was delivered via an osmotic pump (0.5 or 5 mg/mL) to a cuff surrounding the reanastomosis site to the two root bundles on one side. Electrodes were implanted bilaterally immediately proximal to the site of surgical reanastomosis. Results were compared to four root-intact, control animals that also received bilateral electrode implantation. At 6-12 months post-surgery, five of eight nerve transected and repaired animals showed increased pressure and bladder emptying during electrical stimulation of the repaired ventral roots contralateral to the BDNF delivery side. Nerve tracing studies one year postoperatively determined the repaired roots to be S1 and S2 and showed regrowth of axons from the spinal cord to nerve sites proximal to the repair site and to the bladder, and the presence of neurofilament-labeled axons growing across the ventral root repair site. In conclusion, transected ventral and dorsal roots in the sacral spine can be repaired and are capable of functionally reinnervating the urinary bladder. This feasibility study paves the way for future studies utilizing other more proximal motor nerves to bypass the transection site for bladder reinnervation.     

Effects of vascular endothelial growth factor on nerve regeneration in acellular nerve grafts

The purpose of this study was to evaluate the effects of human recombinant vascular endothelial growth factor (VEGF-165) on peripheral nerve axonal sprouting and elongation following peripheral nerve injury and repair. Two-centimeter nerve gaps were created in rat peroneal nerves and repaired with either peripheral nerve autografts, acellular peripheral nerve isografts, or VEGF-165-treated acellular peripheral nerve isografts. Four months postoperatively, the peroneal nerves were harvested and histomorphometric analysis was performed. The reinnervated extensor digitorum longus (EDL) muscles were harvested and weighed. At the proximal nerve gap coaptation site, there was a statistically significant increase in the total number of axons and percent neural tissue in the VEGF-treated acellular nerve graft group, compared with the acellular peripheral nerve isograft and autograft groups. At the distal coaptation site, however, the total number of axons and percent neural tissue was similar in the acellular and VEGF-treated groups, which was significantly less than the autograft group. VEGF-165 treatment of acellular nerve grafts resulted in greater EDL muscle masses than acellular nerve grafts alone. VEGF treatment of acellular peripheral nerve isografts enhances axonal sprouting, resulting in an increased number of axons and percent neural tissue at the proximal nerve graft coaptation site. In the absence of any cellular elements, VEGF-impregnated acellular peripheral nerve grafts do not demonstrate enhanced axonal elongation, as noted by relatively few axons at the distal nerve graft coaptation site.     

The role of topically administered FK506 (tacrolimus) at the time of facial nerve repair using entubulation neurorrhaphy in a rabbit model

Peripheral facial nerve palsy is a common sequela of traumatic craniofacial injury, often resulting in dramatic and sometimes permanent functional deficits. Exogenous agents and methods of repair that accelerate axonal regeneration would be of great benefit to the multitude of patients with facial nerve injuries. The objective of this study was to evaluate the effect of FK506 at the time of facial nerve repair using entubulation neurorrhaphy, and to compare entubulation neurorrhaphy versus interposition autograft in critical facial nerve gap defects. The study design was a prospective, randomized, blinded animal study with a control group. Twenty-five New Zealand White rabbits were assigned to 4 experimental groups and a control group. The buccal branch of the facial nerve was used in all procedures. Group 1 was the control group. Rabbits in group 2 underwent sham surgery. Group 3 was an interposition autograft group in which a 6-mm segment of nerve was transacted, flipped, and followed by epineural repair. Groups 4 and 5 underwent transection followed by entubulation neurorrhaphy with topical administration of either a carrier molecule (group 4) or an FK506 carrier molecule (group 5). Outcome measures included daily subjective assessment of upper lip movement; electromyographic studies at weeks 3, 5, and 8 postoperatively; and blinded quantitative histomorphometric evaluation after 8 weeks. All rabbits in all groups were noted to have spontaneous movement after 8 weeks, with 1 rabbit in group 5 obtaining the highest functional score among all study groups. Electrophysiologic studies showed polyphasic potentials, indicating reinnervation in 1 rabbit in group 5. Histomorphometric examination of group 5 rabbits revealed a similar cross-sectional area distal to transection and remyelination. Other groups showed decreased cross-sectional area and/or incomplete remyelination distal to the transection. FK506 applied topically at the time of facial nerve repair using entubulation neurorrhaphy demonstrated superior results in nerve regeneration versus entubulation neurorrhaphy carrier protein alone, and interposition autograft.     

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.     

Comparison of collagen biomatrix and omentum effectiveness on peripheral nerve regeneration

Despite the presence of various nerve coaptation materials and techniques, achievement of the functional nerve regeneration is still inadequate. This study was aimed to compare the effectiveness of conduit composed of collagen biomatrix and omentum graft on peripheral nerve regeneration. Thirty-five male Wistar rats were divided into four groups. In the control group, the right sciatic nerve was skeletonized from the sciatic notch till the point of bifurcation. In the primary epineural repair group, the nerve was transected 1 cm proximal to the bifurcation with a sharp pair of micro scissors and then repaired with four epineural sutures. In the collagen biomatrix group, the epineural repaired nerve was wrapped with collagen biomatrix. In the collagen group, the epineural repaired nerve was wrapped with the nonpediculated omentum. Assessment of the nerve regeneration was based on functional (Walking Track Analysis, Electrophysiological Measurements), histological, and morphometric criteria. Light and electron microscopic examinations showed that collagen-biomatrix-wrapped specimens have the best regeneration. The electrophysiological study confirmed the recovery of electrical activity in the regenerated axons.     

Fascicular turnover flap in the reconstruction of facial nerve defects: an experimental study in rats

The purpose of this study was to assess the utility of a fascicular turnover flap for facial nerve repair and to investigate its possible application in the field of facial nerve repair using a rat model of facial paralysis. Twenty-four Wistar rats were used in this study. A left vibrissal muscle palsy model was established via excision of the buccal and marginal branches through a periauricular incision. In Group 1, the nerve gap was not reconstructed. In Group 2, the nerve gap of the marginal mandibular branch was reconstructed using an autograft, and in Group 3, the gap was reconstructed using a fascicular turnover flap. At 12?weeks after the operation, the nerve regeneration was assessed based on clinical, histopathological and electrophysiological evaluations. The functional recovery of the vibrissal muscle was observed with a fascicular turnover flap. The functional recovery of whisker movement was almost same between Groups 2 and 3 (p?=?.57). The histopathological examinations almost same result between Groups 2 and 3 (p?=?.17). The compound muscle action potential after reconstruction was also almost same between Groups 2 and 3 (p?=?.99). We found that the fascicular turnover flap could be applied to facial nerve gap reconstruction. However, further evaluations will be necessary to clarify its indication and mechanism in human.     

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。     

Fibrin glue: an alternative technique for nerve coaptation--Part I. Wave amplitude, conduction velocity, and plantar-length factors

The search for better surgical repair of nerve injuries should be aimed at uncovering alternatives that not only are efficient, but also enhance nerve growth. The purpose of this study was to compare functional nerve responses following repair with either a traditional microsuture technique or Quixil human fibrin sealant. Thirty female Lewis rats received transection of the right sciatic nerve. Nerve repair was achieved with either epineurial microsuture (n = 15) or Quixil fibrin glue (n = 15). Functional results were assessed at 2, 6, and 12 weeks postoperatively with walking-track analysis. Electrophysiologic nerve recordings were also performed 12 weeks postoperatively. Rats receiving Quixil nerve repair returned to baseline performance on the walking-track analysis significantly faster than those with microsuture repairs (6 and 12 weeks postoperatively; p < 0.0001). Recovery of nerve conduction velocities and wave amplitudes was also significantly better in the nerves repaired with Quixil than in those repaired with microsuture (p's < 0.0001). Quixil human fibrin sealant is a good alternative to traditional microsuture nerve repair techniques.