甲壳质生物套管小间隙桥接大鼠周围神经的实验研究

目的探讨脱乙酰甲壳质生物套管小间隙桥接周围神经损伤的可行性。方法将120只SD大鼠右侧坐骨神经切断,按手术方法随机分为5组。A组:神经外膜原位缝合(n=24);B组:套管小间隙原位桥接(n=24,间隙5mm);C组:两断端相对旋转180°后外膜缝合(n=24);D组:两断端相对旋转180°后套管小间隙桥接(n=24,间隙5mm);E组:套管小间隙原位桥接(n=24,间隙5mm)后间隙内注射神经生长因子(NGF)。术后2、4、6、8周分别进行电生理学检查、组织学检查以及计算单位视野有髓神经纤维数。结果组织学检查术后4周各实验组的神经远端均见到再生的神经纤维;小间隙套管组(B,D组)运动神经传导速度在各个时间检测点上均好于相应的直接外膜缝合组(A组)和旋转后直接外膜缝合组(C组)(P<0·05)。小间隙套管组(B,D组)神经远端的有髓神经纤维计数在4、6、8周3个检测点上高于相应的直接外膜缝合组(A组)和旋转后直接外膜缝合组(C组)(P<0·01);在2周时差异没有统计学意义(P>0·05)。结论生物套管小间隙(5mm)桥接的修复周围神经的效果好于断端外膜直接缝合,具有替代直接神经外膜缝合的临床应用可行性。     

小间隙桥接周围神经损伤Gap-43表达变化的实验研究

目的 观察采用小间隙桥接法修复大鼠坐骨神经损伤时套管内Gap-43 mRNA含量的变化.方法 SD 大鼠78只,随机分为13组,每组6只.其中6组切断右侧坐骨神经并原位缝合,另6组切断右侧坐骨神经采用小间隙桥接法修复.1组为正常对照.分别于术后1 d、3 d、5 d、7 d、14 d、28 d以吻合口为中心,取上下各5 mm共1 cm坐骨神经提取总RNA,采取实时荧光定量反转录聚合酶链(Real-time RT-PCR)技术检测组织中Gap-43 mRNA含量变化.结果 鼠周围神经中Gap-43 mRNA含量在正常组织有低水平表达,在损伤后1 d即升高,在损伤后28 d降低,但仍高于正常坐骨神经内表达水平.桥接缝合组Gap-43表达高于外膜缝合组.结论 大鼠坐骨神经损伤后采用不同修复方法其Gap-43基因表趋势相似,但由套管形成的封闭空间蕴含了较高的神经再生相关因子,有利于神经再生.     

小间隙桥接周围神经对缝合口神经调节蛋白-1表达变化的影响

目的 观察采用小间隙桥接法修复大鼠坐骨神经损伤时套管内神经调节蛋白-1(NRG-1)mRNA含量的变化.方法 取SD大鼠78只,体质量200～250 g.随机分为3组,其中实验组A和实验组B各有大鼠36只,正常对照组有大鼠6只.2组实验组根据观察时间的不同再分为6组,每组有大鼠6只.实验组A:切断并原位缝合右侧坐骨神经.实验组B:切断并采用小间隙桥接法修复右侧坐骨神经.分别于术后1、3、5、7、14、28 d以缝合口为中心,取上下各5 m共1 cm坐骨神经提取总RNA,采取实时荧光定量反转录聚合酶联(Real-time RT-PCR)技术检测组织中NRG-1mRNA的含量变化.结果 大鼠周围神经中NRG-1 mRNA含量在正常组织有低水平表达,在损伤后1 d即明显升高,在损伤后14 d降低,随即恢复较高水平,持续至伤后28 d.在部分时间点高于外膜缝合组.结论 大鼠坐骨神经损伤后采用不同修复方法NRG-1基因表达变化不同步,提示套管形成的封闭空间蕴含了较高的神经再生相关因子,有利于神经再生.     

替代神经外膜缝合─小间隙套接法修复周围神经损伤

目的：在动脉套接的基础上，尝试一种海洋生物套管小间隙套接修复周围神经损伤，代替传统外膜缝合法的可行性方法：将SD大鼠坐骨神经切断后用不同的方法进行修复，进行动脉套接的早期和远期的组织学和电生理学观察，其后进行海洋生物套管桥接的组织学及电生理观察。结果：原位和旋转的动脉套接组与外膜原位缝合组取得了相似组织学和电生理学恢复效果，且明显好于旋转的外膜缝合组；此种海洋生物套管取得了与动脉套管相似的结果。结论：本实验结果提示动脉套接模型有利于神经再生，此种海洋生物套管小间隙套接的修复效果好于断端转位的外膜缝合，有可能成为替代临床外膜缝合的新方法。     

周围神经小间隙动脉桥接后的组织学观察

目的探讨动脉套管内神经间隙缝合后神经再生的机理。方法在ＳＤ大鼠腓总神经切断后，行外膜直接缝合及用２ｍｍ间隙自体动脉套接作比较。术后７、１４、２１、２８天取两组样本，采用多种染色法染色后，在光镜及电镜下观察神经的再生过程。结果动脉桥接组神经再生时间比直接缝合组慢２周，但再生速度基本相同。动脉套管内神经纤维向远端生长的有效率较直接缝合组大。结论神经缝合段留出供神经自然随机选择及化学特异选择的空隙，有益于混合神经修复后的有效再生     

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.     

螺旋式改良神经端侧缝合法修复周围神经损伤的实验研究

目的 对治疗周围神经损伤的常规端侧缝合方法进行螺旋式改良端侧缝合实验研究,观察神经再生修复效果,为周围神经损伤的治疗提供效果更好的修复方法.方法 选用60只健康SD大鼠,采用右侧腓总神经修复模型.术中根据手术方法的不同,随机分为A、B、C三组,每组20只.每组将右侧腓总神经在其坐骨神经分出后3mm处局部封闭,利刀切断.A组神经远断端切成90°断面,行腓总神经端端缝合;B组神经远断端切成45°斜面,同时供体神经干外束膜开窗行端侧缝合;C组神经远断端切成10°斜面,供体神经干外束膜开窗,以螺旋式改良端侧缝合法进行神经束膜及外膜缝合.术后第8周分别对各组大鼠进行组织学、肌湿重、神经电生理检测,有髓神经纤维计数及神经示踪法观察.结果 螺旋式改良缝合组(C组)观察指标均优于常规端侧缝合组(B组)(P＜0.05),与端端缝合组(A组)比较差异无统计学意义(P＞0.05).螺旋式改良端侧缝合法对促进神经纤维的再生明显优于常规端侧缝合法.结论 神经断端采用螺旋式改良缝合后,神经再生良好;螺旋式改良缝合法较常规端侧缝合法能获得更有效的神经再生;长入远端的神经纤维多少与受端缝合接触面积大小有关.当临床遇动力神经缺乏时,采用神经螺旋式改良端侧缝合法可获得更好的修复效果.     

生物套管小间隙桥接修复周围神经的实验研究

目的　探讨用部分脱乙酰甲壳质生物套管小间隙桥接修复周围神经损伤的可行性。方法　将SD大鼠双侧坐骨神经切断后 ,按手术方法随机分为 5组。A组 :神经外膜原位缝合 (n =10 ) ;B组 :生物套管小间隙原位桥接 (n =10 ) ;C组 :断端旋转 180°外膜缝合 (n =10 ) ;D组 :断端旋转 180°生物套管小间隙桥接 (n =10 ) ;N组 :正常对照 (n =10 )。术后 6周行电生理学检查 ,光镜下作再生有髓神经纤维计数。结果　A、B、D组的运动神经传导速度快于C组但慢于N组 ,5组间差异无显著意义 (P >0 .0 5 )。有髓神经纤维计数数目 ,A >B >D >C >N组 ,A、B、D组与C组相比 ,两者差异有显著意义 (P <0 .0 1,P<0 .0 5 ) ;但A、B、D 3组间的差异无显著意义 (P >0 .0 5 )。结论　部分脱乙酰甲壳质生物套管小间隙桥接修复周围神经的效果好于断端转位的外膜缝合 ,具有替代外膜缝合的可行性。     

人发角蛋白桥接周围神经缺损的形态学观察

目的 :了解人发角蛋白在神经再生中的作用 ,为临床桥接周围神经缺损寻求新的替代材料。方法 :将 18只新西兰兔的双侧坐骨神经切断 ,造成 10mm缺损 ,一侧用人发角蛋白桥接 (实验组 ) ,另一侧用空硅胶管桥接 (对照组 ) ,术后 1、 2、 3个月通过肉眼观察 ,光镜、电镜和有髓神经密度测定 ,观察、分析神经再生情况。结果 :实验组再生神经均通过 10mm缺损 ,对照组有 2例无神经生长 ;实验组再生神经排列较紧密、有序 ,髓鞘形成早于对照组 ;神经纤维密度明显高于对照组 (P <0 0 1)。结论 :人发角蛋白可促进周围神经再生 ,是桥接周围神经缺损的理想材料。     

骨骼肌包埋自体神经片段修复周围神经缺损的实验研究

作者设计用骨骼肌包埋自体神经片段修复周围神经缺损，试图克服单纯骨骼肌修复神经缺损中缺乏雪旺氏细胞的不足．选实验用大白鼠４０只．随机分成Ａ、Ｂ两组，每组２０只．造成坐骨神经缺损２ｃｍ，分别用骨骼肌包埋自体神经片段及单纯骨骼肌桥接．经２个月大体观察、镜下观察及电生理测定，证实骨骼肌包埋自体神经片段修复周围神经缺损所再生的神经纤维在直径、髓鞘厚度、数量及运动神经传导速度等方面均优于单纯骨骼肌桥接．     

Quantification of nerve tension after nerve repair: correlations with nerve defects and nerve regeneration

This study tested the validity of a quantitative in vitro nerve-tension-measuring technique, by correlating the tension measurements with functional and morphologic assessments of nerve regeneration. Initially, harvested nerves were used in vitro to determine a K value for lateral displacement in this tissue. Next, this value was used to calculate the tension of nerve repair, following 0-, 3-, 6-, and 9-mm resections of nerves in groups of rats. After quantifying the nerve tensions following excision and repair, the authors determined a sciatic function index to evaluate functional recovery and axon diameter in the animals. Functional recovery was significantly impaired in animals with elevated measurable tension (9.04 +/- 0.74 g in a 6-mm defect, 27.76 +/- 8.86 g in a 9-mm defect), compared to animals with no or 3-mm excision and measured tension of 3.3 +/- 1.09 g or less. Increased tension was also associated with a significant decrease in axon diameter. This study succeeded, therefore, in quantitatively relating the elements of measured nerve tension, nerve gaps, functional nerve recovery, and morphologic regeneration. Quantification of nerve tension by lateral displacement in vivo offers a possible solution to clinical management of nerve gaps, when the choice between primary repair and nerve grafting is not a clear one.     

Cavernous nerve regeneration using acellular nerve grafts

INTRODUCTION: The restoration of erectile function following complete transection of nerve tissue during surgery remains challenging. Recently, graft procedures using sural nerve grafts during radical prostatectomy have had favorable outcomes, and this has rekindled interest in the applications of neural repair in a urologic setting. Although nerve repair using autologous donor graft is the gold standard of treatment currently, donor nerve availability and the associated donor site morbidity remain a problem. In this study, we investigated whether an "off-the-shelf" acellular nerve graft would serve as a viable substitute. We examined the capacity of acellular nerve scaffolds to facilitate the regeneration of cavernous nerve in a rodent model. MATERIALS AND METHODS: Acellular nerve matrices, processed from donor rat corporal nerves, were interposed across nerve gaps. A total of 80 adult male Sprague-Dawley rats were divided into four groups. A 0.5-cm segment of cavernosal nerve was excised bilaterally in three of the four groups. In the first group, acellular nerve segments were inserted bilaterally at the defect site. The second group underwent autologous genitofemoral nerve grafts at the same site, and the third group had no repair. The fourth group underwent a sham procedure. Serial cavernosal nerve function assessment was performed using electromyography (EMG) at 1 and 3 months following initial surgery. Histological and immunocytochemical analyses were performed to identify the extent of nerve regeneration. RESULTS: Animals implanted with acellular nerve grafts demonstrated a significant recovery in erectile function when compared with the group that received no repair, both at 1 and 3 months. EMG of the acellular nerve grafts demonstrated adequate intracavernosal pressures by 3 months (87.6% of the normal non-injured nerves). Histologically, the retrieved regenerated nerve grafts demonstrated the presence of host cell infiltration within the nerve sheaths. Immunohistochemically, antibodies specific to axons and Schwann cells demonstrated an increase in nerve regeneration across the grafts over time. No organized nerve regeneration was observed when the cavernous nerve was not repaired. CONCLUSION: These findings show that the use of nerve guidance channel systems allow for accelerated and precise cavernosal nerve regeneration. Acellular nerve grafts represent a viable alternative to fresh autologous grafts in a rodent model of erectile dysfunction.     

内脏神经-体神经端侧吻合后神经纤维再生研究

目的 观察大鼠内脏神经-体神经端侧吻合后神经纤维的再生.方法 24只成年SD大鼠随机分为实验组(n=12)和正常对照组(n=12),实验组大鼠通过内脏神经-体神经端侧吻合建立人工体神经-内脏神经反射弧6个月后,在吻合口近端和远端分别截取10 mm的供体神经(L4VR)和受体神经(L6VR),在L6VR延续的盆副交感神经(PPN)和阴部神经(PN)分别截取10 mm的神经.正常对照组大鼠分别取相应节段的L4VR、L6VR、PPN和PN神经.标本经石蜡包埋切片并行甲苯胺蓝染色,比较实验组和对照组大鼠L6VR、PPN、PN神经纤维数量.结果 实验组大鼠横断面可见新生的有髓神经纤维,L4VR、L6VR、PPN和PN的神经纤维数量分别为1602.2±75.7、1037.9±123.6、817.0 ±52.2、510.4±29.1,吻合口远近端神经纤维通过率为64.8%,实验组和对照组大鼠相应的L6VR、PPN、PN神经纤维数目比率分别为70.2%、68.9%和62.2%.结论 大鼠内脏神经-体神经端侧吻合后体神经能够长入并替代内脏神经.     

End-to-side nerve repair in peripheral nerve injury

In peripheral nerve injury, end-to-side neurorrhaphy has been reported as an alternative in cases that the proximal nerve stump is not accessible. Several hypotheses have been proposed to explain peripheral nerve regeneration after end-to-side neurorrhaphy. Recent evidence suggests that nerve regeneration occurs by collateral sprouting. Although a great number of humoral factors have been identified, molecular mechanism of nerve regeneration after end-to-side neurorrhaphy has not been completely clarified yet. The goal of this technique is to provide satisfactory functional recovery for the recipient nerve, without any deterioration of the donor nerve function. End-to-side technique has been investigated in detail in both experimental and clinical studies. Only a limited number of reported cases in clinical practice, until today, can reveal that end-to-side technique may become a viable means of repairing peripheral nerves in certain clinical situations.     

End-to-side nerve graft for facial nerve reconstruction

Reconstruction of multiple branches of the facial nerve by sural nerve graft using end-to-side nerve suture was performed successfully on a patient with advanced parotid tumor. In this technique, one end of the grafted nerve is sutured with the stump of the facial nerve trunk in an end-to-end manner. Epineural windows are made on the nerve graft, and the distal stumps of the facial nerve branches (temporal, zygomatic, and buccal branches) are sutured with the graft in an end-to-side manner. Functional recovery of all branches and satisfactory facial expression were obtained within 2 years postoperatively. Axonal regeneration through the graft was confirmed by electrodiagnosis. Regeneration through the anastomosis at the stump of the facial nerve trunk using this technique is more efficient than conventional cable grafting, and the length of the nerve required is minimal. This technique may be a useful option for facial nerve reconstruction managing multiple branches.