Comparison of reinnervation for preservation of denervated muscle volume with motor and sensory nerve: an experimental study

Prevention of the atrophy of denervated muscles is essential for a good outcome in facial contouring and oral reconstruction. In this study, we compared the effectiveness of end-to-end and end-to-side neurorrhaphy of the motor nerve, and end-to-end neurorrhaphy of the sensory nerve, all of which are frequently used in such reconstruction for the prevention of muscle atrophy. Wistar rats were divided into four groups: group 1, motor nerve division of semi-membranosus without repair; group 2, motor nerve division and end-to-end coaptation to the saphenous nerve; group 3, motor nerve division and end-to-side coaptation to the sciatic nerve; and group 4, motor nerve division and end-to-end repair. Measurement of semi-membranosus volume, histological evaluation and staining of neuromuscular junctions that were carried out 3 months postoperatively revealed that muscle volume preservation was larger in groups 3 and 4 than in the other two groups (p<0.05), but slightly superior in group 4 (p<0.05). There was no statistical difference between groups 2 and 1; histologically, muscle architecture was better preserved in group 2 than in group 1; reactivation of the neuromuscular junctions was observed in all except group 1. End-to-side repair of motor nerves is one of the better options for the preservation of muscle volume when end-to-end nerve repair is not indicated. Sensory protection may also provide some advantages in the preservation of muscle volume.     

中枢神经提取液对失神经肌肉的作用

目的：研究中枢神经的有效物质对失神经肌肉的作用。方法：在ＳＤ大鼠失神经趾长伸肌中，应用中枢神经提取液（ｃｅｎｔｒａｌｎｅｒｖｅｅｘｔｒａｃｔ，ＣＥ），并观察肌肉萎缩的生理学指标。结果：肌肉失神经后的最大强直收缩力（ｔｅｔａｎｉｃｔｅｎｓｉｏｎ，ＰＯ）及强直收缩后动作电位（ｐｏｓｔｅｔａｎｉｃｔｗｉｔｃｈｐｏｔｅｎｔｉａｔｉｏｎ，ＰＴＰ）下降，舒张期时程（ｒｅｌａｘａｔｉｏｎｔｉｍｅ，ＲＴ）延长，肌湿重、肌肉总蛋白及肌纤维截面积（ｃｒｏｓｓ－ｓｅｃｔｉｏｎａｒｅａ，ＣＳＡ）的减少，均可被中枢神经提取液有效地缓解。结论：中枢神经提取液可减缓失神经肌肉的萎缩     

背根神经节感觉神经元延缓失神经支配肌肉萎缩作用的实验研究

通过建立臂丛节前损伤的模型,观察撕脱的背根神经节通过相连的外周神经是否对相应的骨骼肌有延缓萎缩的作用,以期寻找防止肌萎缩的方法。方法:选用雄性成年SD大鼠60只,随机分成2组。实验组:制成C_5C_6根性撕脱的模型,使拖出椎孔的背根神经节仅通过肌皮神经与完全失神经支配的肱二头肌有联系。对照组:于椎孔外切断C_5C_6神经根,并造成肱二头肌完全失神经支配。于术后1、2、3、4和5个月各时间段,分别测定肱二头肌纤颤电位波幅、肌张力、肌湿重、肌纤维截面积并观察背根神经节中感觉神经元的变化。结果:术后1～5个月背根神经节中均见到存活的感觉神经元;纤颤电位波幅实验组大于对照组;实验组肌张力于术后1、2个月时明显优于对照组;术后1、2、3个月,实验组的肌湿重、肌纤维截面积明显高于对照组。结论:在节前损伤1～3个月内,背根神经节中感觉神经元有延缓失神经支配骨骼肌萎缩的作用。     

End-to-side neurotization with the phrenic nerve in restoring the function of toe extension: an experimental study in a rat model

The phrenic nerve being transferred to the posterior division of the lower trunk with end-to-end neurorrhaphy is reported to be effective in restoring the function of digit extension in literature. However, the phrenic nerve is extremely important in respiration. We designed an animal experiment to discover whether the phrenic nerve being transferred to the posterior division of the lower trunk with end-to-side neurotization was feasible and provided the theoretical basis. A sum of 36 Sprague-Dawley rats was randomly assigned to one of two groups. In Group A, the phrenic nerve was transferred to the posterior division of the lower trunk with end-to-side neurotization. In Group B, the posterior division of the lower trunk was directly sutured. The results of behavioral assessment, electrophysiology, histology and nerve fiber count and muscle weight at 12 weeks postoperatively were recorded. In Group A, none of the rats experienced tachypnea. The motion of slight toe extension was observed. The results of electrophysiology, histology and nerve fiber count and muscle weight in Group A were not as well as those of Group B, but gradually improved with time. The phrenic nerve being transferred to the posterior division of lower trunk with end-to-side neurotization can partially restore the function of toe extension in a rat model. Whether the function of digit extension can be restored by the phrenic nerve with end-to-side neurotization in humans still needs more practice in clinic.     

Effect of systemic creatine monohydrate supplementation on denervated muscle during reinnervation: experimental study in the rat

The purpose of this experimental study was to evaluate possible upgrading effects of systemic creatine monohydrate administration on the reinnervation of denervated muscle. At the same time, the protective effect of the agent on denervated muscle until ultimate reinnervation after nerve repair was quantified. The functional outcome of muscle reinnervation after creatine monohydrate application was compared with a control group. Forty adult Wistar rats weighing 180 to 220 g were used. The right sciatic nerve was dissected, exposed, and cut at the level of the midthigh in all rats. The experimental design consisted of two groups: experimental (animals were fed creatine monohydrate) and control (gavage feeding was provided by saline). Both groups were divided into two subgroups: subgroups A and B for the experimental group, and subgroups C and D for the control group. In subgroups A and C, the nerves were repaired with four 10-0 epineurial stitches. In subgroups B and D, both the proximal and distal ends of the nerves were ligated and no neural anastomosis was performed. In the experimental groups (subgroups A and B), the rats were fed by daily supplementation of oral creatine monohydrate, 300 mg/kg body weight. In the controls (subgroups C and D), oral supplementation was provided by saline. Functional recovery was evaluated using walking track analysis, pinching test, and limb circumference and toe contracture measurements at the end of 6 months, after which the rats were sacrificed and nerve specimens from both ends of the repair sites and the whole gastrocnemius muscle were obtained to document the results of the histomorphometric and histochemical studies, including light microscopic examinations and muscle weight measurements. The mean functional recovery values in subgroups A, B, C, and D were 91 percent, 80 percent, 87 percent, and 59 percent, respectively. Functional recovery improved significantly in the experimental groups (in both the surgically repaired and unrepaired subgroups), compared with the control groups (p<0.05). The pinching test revealed a statistically significant difference in nerve conduction between the experimental and control groups (p<0.05). The limb circumference ratio of the surgically treated side to the untouched side in subgroups A, B, C, and D were noted as 0.95, 0.89, 0.91, and 0.87, respectively, and the difference between the experimental and the control groups was statistically significant (p<0.05). The differences between subgroups A and B, C and D, A and C, and B and D were also significant. The surgically repaired and creatine-supplemented subgroups demonstrated the best results in toe contracture index. The muscle weight measurement results were concordant with the results of the limb circumference ratio. In both surgically repaired subgroups (subgroups A and C), there were qualitatively significant amounts of myelinated fibers in the nerve distal to the anastomotic site; there were no myelinated fibers in the distal stumps of subgroups B and D. Histochemical analyses of the contents of the muscle fiber types also revealed no significant difference. Overall, the results showed the useful effect of oral creatine supplementation on both surgically repaired and unrepaired nerve injuries. The best results were obtained from surgically repaired nerve injuries and also from the systemic creatine-supplemented subgroups. This study confirms that systemic administration of creatine monohydrate has a protective and upgrading effect on the functional properties of denervated muscle, especially in surgically reinnervated subjects.     

神经干细胞移植再支配失神经骨骼肌的实验研究

目的 探讨采用神经干细胞移植的方法使失神经骨骼肌重获神经再支配的可行性。方法 将108只SD大鼠按注射药物的不同随机分为3组，每组36只大鼠。切断右侧胫神经建立腓肠肌失神经实验模型。实验组：将神经干细胞悬液注射到切断胫神经的远端。对照组：注射等量的细胞培养液。损伤组：注射等量的生理盐水。术后8、10、12周采用免疫组织化学、HRP逆行示踪技术和神经形态学的方法，检测失神经骨骼肌是否重新获得移植神经干细胞的再支配。结果 术后8周局部即可检测到分化的神经元和神经胶质细胞，其再生的轴突与靶肌肉已经建立神经突触连接。术后10、12周时，再生的神经纤维进一步增多。结论 周围神经断伤后局部用神经干细胞移植能够使远端失神经骨骼肌重新获得神经再支配。     

化学萃取自体骨骼肌桥修复神经缺损初步研究

目的 观察化学萃取自体骨骼肌桥修复大鼠坐骨神经缺损的可行性。方法 用化学萃取方法制备自体肌骼肌的无细胞基底膜管，修复大鼠坐骨神经１５ｍｍ神经缺损，与冻融肌作骼肌桥作对照，用免疫组织化学方法及碱性磷酸酶组织化学方法观察神经及血管再生的情况。结果 化学萃取自体骨骼肌桥在修复神经缺损伤后，其物理性能，移植物血管化过程和神经再生速度与质量均优于冻融肌桥。     

Transfer of the nerve to the brachioradialis muscle to the anterior interosseous nerve for treatment for lower brachial plexus lesions: case report

In lower lesions of the brachial plexus (C8-T1) there is good function of the shoulder, elbow, and wrist, although that of the hand is impaired. Reconstruction of finger flexion is generally obtained by tendon transfer. We present a case report involving transfer of the motor nerve branch of the brachioradialis muscle to the anterior interosseous nerve to restore finger flexion in acute lower brachial plexus lesion.     

神经束植入联合甲钴胺治疗失神经骨骼肌的实验研究

目的研究神经束植入治疗失神经支配骨骼肌．并比较靶肌肉局部用药与全身性用药的疗效,探讨神经营养药物应用的最佳给药方法。方法选用雄性大鼠60只随机等分5组．每组12只,制作左侧胫神经切断动物模型。A组：神经束植入组;B纽：神经束植入＋左侧腓肠肌注射甲钴胺;C组：神经束植入＋腹腔注射甲钴胺;D组：胫神经切断：E组：胫神经切断＋左侧腓肠肌注射生理盐水。术后当日开始,B组隔日左侧腓肠肌注射甲钴胺300μg／kg;C组隔日腹腔注射甲钴胺300μg／kg;E组隔日左侧腓肠肌注射等渗盐水0．02ml。分别于术后4周和8周测量左小腿腓肠肌电生理、肌纤维横截面积和肌细胞TUNEL染色。结果术后4周及8周,A,B,C三组腓肠肌电位波幅组间比较差异均有显著性（P〈0．05）;D组与E组腓肠肌纤颤电位波幅差异无显著性（P〉0．05）。术后4周及术后8周,肌纤维横截面积和肌细胞TUNEL阳性细胞数A,B,C组间差异均有显著性（P〈0,05）,D,E组间差异无显著性（P〉0．05）,A,B,C组与D,E组差异有显著性（P〈0．05）。B组明显优于其他组。结论神经柬植入能有效防治失神经骨骼肌萎缩,靶肌肉给药效果优于全身用药。     

颈总动脉周交感神经网剥脱切除术后痉挛肌肉内酶与肌纤维结构的研究

目的　探讨交感神经切断后,痉挛肌肉内酶与肌纤维结构的改变。方法　将20只wistar大白鼠作成痉挛性模型,分成两组,随机选择1组行颈总动脉周交感神经网剥脱切除术,另1组作为对照,于术后第20天切取两组大鼠部分肱三头肌组织,采用(Ellman)爱尔蒙法及AU1000检测仪测定肌组织内乙酰胆碱酯酶活性和肌酸激酶含量,在IBAS图像分析仪上观察两组肌组织内快收缩肌纤维与慢收缩肌纤维的改变情况。结果　交感神经切断后,乙酰胆碱酯酶活性和肌酸激酶含量明显下降,分别从（3.37±1.01）U/g降至（2.15±1.42）U/g（P＜0.01）;（3582.90±1561.7）IU/L降至（420.10±73.55）IU/L（P＜0.01）,快肌纤维明显减少,从（275727.31±98240.23）μm     

细胞外ATP防治失神经肌肉萎缩的实验研究

目的　探索细胞外ATP是否对失神经支配肌肉有保护作用。方法　SD大鼠 12只 ,在梨状肌下缘切断坐骨神经 ,制作腓肠肌失神经支配模型。左侧为实验组 ,术后于腓肠肌内注射ATP 0 .1mg/d ;右侧为对照组 ,腓肠肌内注射等量生理盐水。于术后 8、12周取 2组标本称肌湿重 ,检测运动终板、肌纤维横截面积及组织学变化。结果　实验侧的腓肠肌饱满有弹性、色泽好 ;对照侧肌纤维萎缩变细、色泽苍白。实验组运动终板边缘清晰 ,终板乙酰胆碱酯酶染色较深。比较两组的运动终板平均灰度值和平均光密度值 ,差异有显著性意义 (t =3 .0 5 7、4.13 8,P <0 .0 5 ) ,两组肌纤维横截面积相比 ,差异有显著性意义(t =4.191,P <0 .0 5 )。结论　ATP具有明显延缓失神经肌肉肌萎缩和减轻皮肤溃疡的作用     

外源性表皮生长因子促进鼠坐骨神经再生的实验研究

目的 评价外源性表皮生长因子（exogenous epidemal growth factor,EGF）对神经再生的影响。方法 雄性SD大鼠48只,建立成鼠坐骨神经挤压伤模型。按术后注射药物的不同成分2组,每组24只鼠。损伤对照组：在神经损伤处注射生理盐水5μl;EGF组：注射EGF／生理盐水液（10μg/5μl）。于术后2、4、6周3个时间点测定坐骨神经功能指数、CMAP的潜伏期、最大语诱发电位的恢复率、组织学检测、电镜超微结构观察。结果 坐骨神经功能指数恢复率在各时间点,EGF组无明显优于对照组（P＜0．01）。CMAP潜伏期的延迟率,EGF组明显小于对照组（P＜0．01）;诱发电位恢复率EGF组明显好于对照组（P＜0．01）。组织学检查：有髓神经纤维数在术后2、4周时EGF组明显多于对照组（P＜0．01）;各时间点有髓神经纤维直径及截面积,EGF组明显优于对照组（P＜0．01）。超微结构观察：EGF组再生神经的有髓纤维数,髓鞘厚度,髓鞘的成熟度明显好于对照组。结论 外源性EGF对神经的再生和功能恢复有一定的作用。     

颈交感神经网切除对肢体痉挛骨骼肌肌电图、酶及肌纤维结构的影响

目的　探讨交感神经切除后 ,痉挛肌肉内肌电图、酶及肌纤维结构的改变。方法　将2 0只Wistar大白鼠作成痉挛性模型 ,分成两组 ,随机选择 1组行颈总动脉周交感神经网剥脱切除及颈上节交感神经切除术 ,另 1组作为对照 ,于术后第 8天用Dantec肌电图仪观察肱三头肌F波幅度。术后第 2 0天切取两组大鼠部分肱三头肌组织 ,采用 (Ellman)爱尔蒙法测定肌组织内乙酰胆碱酯酶活性 ,在IBAS图像分析仪上观察两组肌组织内快收缩肌纤维与慢收缩肌纤维的改变情况。结果　交感神经切除后 ,F波幅度及乙酰胆碱酯酶活性明显下降 ,分别从 (0 .3 778± 0 .160 0 )mm降至 (0 .15 5 2± 0 .0 80 0 )mm (P <0 .0 1) ;(3 .3 7± 1.0 1)U / g降至(0 .84± 0 .65 )U / g(P <0 .0 1) ,快肌纤维明显减少 ,从 (2 75 72 7.3 1± 982 40 .2 3 )U/m2 降至 (8814 8.2 2± 3 5 111.18)U /m2 (P <0 .0 1) ,慢肌纤维显著增加 ,由 (4 2 710 .78± 2 885 8.3 7)U/m2 增至 (179184.73± 870 44 .5 9)U/m2(P <0 .0 1)。结论　交感神经切除后痉挛肌肉兴奋性下降     

神经损伤(移位)时近侧分支保留对神经再生肌肉功能恢复影响的比较实验研究

目的探讨神经移位时保留神经干近侧分支对神经再生和肌肉功能恢复的影响.方法SD大鼠36只,随机分两组,实验组(分支保留组):在右侧副神经发出2个进入斜方肌肌支后3mm处,用特制的损伤钳,以相同挤压力度及相同时间将副神经夹成2mm的损伤段;对照组(分支切断组):副神经远侧段的处理与实验组相同,并将副神经近侧的两个分支切断.术后2、4、6周分别进行电生理、组织学和图像分析检测,比较近侧分支保留与否对神经再生、肌肉功能恢复的影响.结果神经干电位传导速度(NCV)恢复率、有髓神经纤维通过率、神经纤维轴突截面积恢复率的检测结果显示实验组恢复优于对照组,差异有统计学意义(P＜0.05).结论神经损伤(移位)时保留近侧分支有利于神经损伤修复(移位)术后神经再生和肌肉功能恢复.     

Muscle flap mass preservation by sensory reinnervation with end-to-side neurorrhaphy: an experimental study in rats

The purpose of this study was to determine whether sensory reinnervation with end-to-side neurorrhaphy preserves muscle mass in pedicled muscle flaps. A new muscle flap model innervated by the common peroneal nerve (CPN) was tested in rats. Animals were divided into group 1 (CPN transected without repair), group 2 (CPN transected and immediately repaired by end-to-end neurorrhaphy), and groups 3A and 3B (CPN transected and repaired with the sural nerve, by end-to-end and end-to-side neurorrhaphy, respectively). We evaluated the muscle-preserving effect by measuring muscle weight and performed histological and morphometric analyses 3 months after the procedure. Sensory reinnervation significantly preserved the muscle mass, although less than motor reinnervation. There was no significant difference between the end-to-end and end-to-side procedures. Results of morphometric analysis in each group paralleled those of mean muscle weight. Sensory reinnervation with end-to-side neurorrhaphy appears to be useful in the preservation of muscle flap mass.     

Use of an intact sensory nerve to bridge a motor nerve defect: an experimental study

OBJECT: End-to-side neurorrhaphy has recently became popular for peripheral nerve repair. Although this method is mainly indicated in nerve defects in which there is an absent proximal nerve stump, bridging a motor nerve defect by coapting the proximal and distal ends of the defect to a neighboring mixed nerve in an end-to-side fashion has been another experimental use of this method. In this situation, however, the source of the regenerating axons is unclear because the axons in both the proximal end of the defect and the bridging intact nerve have the capacity for regeneration. The goal of this study was to identify the source of the regenerating axons. METHODS: In this experimental study, the authors used a sensory nerve to bridge a motor nerve defect so that they could elucidate the source of the regenerating motor axons in the distal part of the motor nerve. One advantage of using a sensory nerve was that it eradicated the risk of damaging another motor nerve. Tests used in the analysis included gait evaluation, electrophysiological tests, and histological assessment. CONCLUSIONS: Results of this study showed that, in the rat model, a sensory nerve can be used to bridge a motor nerve defect, thereby eliminating the need for nerve grafting.