Axonal regeneration from the spinal cord to peripheral nerve induced by end-to-side neurorrhaphy Evidence from acetylcholinesterase staining and Fluorogold retrograde tracing

BACKGROUND： In recent years, surgeons have advocated root or trunk repair of avulsed nerve roots for overall recovery. However, donor nerves pose a major problem, because they do not contain adequate numbers of axons. Moreover, the procedures lead to nerve deficits in the donor nerve following transplantation. OBJECTIVE： To observe whether axonal regeneration occurs by end-to-side neurorrhaphy in the peripheral nerve and spinal cord. DESIGN, TIME AND SETTING： A neuroanatomical, randomized, controlled, animal study was performed at Functional Anatomy Lab in Nagoya University School of Medicine from May 2002 to July 2003. MATERIALS： Fluorogold was purchased from Fluorochrome, LLC, USA. BX50 light microscope and fluorescent microscope were purchased from Olympus, Japan. METHODS： A total of 21 rats were randomly divided into three groups, and the posterior avulsion injury model （C6-8） of the brachial plexus was performed. In the ventral root graft group, the avulsed C7 ventral roots were reanastomosed to the small anterior lateral aspect window of the spinal cord via nerve grafts. In the dorsal root graft group, the C7 dorsal roots were reanastomosed at the small pia mater window of the posterior lateral aspect of the spinal cord via nerve grafts. In the control group, the avulsed nerve roots were not repaired. MAIN OUTCOME MEASURES： The nerve grafts were collected from the ventral and dorsal root graft groups, and the C7 proximal nerve end was collected from the control group. Acetylcholinesterase staining was performed on the tissue. Fluorogold retrograde tracing technique was applied to determine the origin of the regenerating axons. RESULTS： Results showed that acetylcholine-positive axons existed in nerve grafts of the ventral and dorsal root graft groups. However, axons were not found in the avulsed nerve roots of the control group. Fluorogold retrograde tracing confirmed the presence of fluorogold-containing neurons in the ventral and dorsal horn of the ventral and dorsal root graft groups. Fluorogold-positive neurons were not observed in the control group. CONCLUSION： End-to-side neurorrhaphy induced axonal regeneration from the spinal cord to the peripheral nervous system.

Current concepts in end-to-side neurorrhaphy

In peripheral nerve injury,end-to-side neurorrhaphy involves coaptation of the distal stump of a transected nerve to the trunk of an adjacent donor nerve.It has been proposed as an alternative technique when the proximal stump of an injured nerve is unavailable or the nerve gap is too long to be bridged by a nerve graft.Experimental and clinical data suggests that end-to-side neurorrhaphy can provide satisfactory functional recovery for the recipient nerve,without any deterioration of the donor nerve function.The most accepted mechanism of nerve regeneration following end-to-side neurorrhaphy is collateral sprouting.The source of the regenerating axons traveling in the epineurium of the donor nerve is thought to be the proximal Ranvier’s nodes at the site of end-to-side neurorrhaphy,however,histologic evidence is still lacking.Partial neurotomy of the donor nerve may enhance regeneration of motor neurons through end-to-side neurorrhaphy and reinnervation of motor targets.

Study on functions of regenerated axons in end-to-side neurorrhaphy

Objective: To probe the possibility of functional sensory endings regeneration after end-to-side neurorrhaphy. Methods: Fifteen New Zealand rabbits were used in this study. The left greater auricular nerve served as the donor nerve. A nerve ed taken from the right ear served as the receptive nerve which anastomosed to the donor nerve by means of end-to-side method and the other end implanted into the denervated skin flap. Normal skin and denervated skin flap without nerve implantation served as control groups, 5 animals in each group. The single nerve fibre recording technique was used to investigate the number, distribution and types of regenerated discharging nerve fibers 4 mouths after operation. Results: The inductive discharges of nerve fibres wave observed in all types of regenerated sensory nerves, the total discharging fibers was about 58% of that in normal skin. Few discharging fibers were observed in denervated skin flap without nerve implantation. Conclusion: End-to-side neurorrhaphy can regenerate functional axons.

End-to-side neurorrhaphy repairs peripheral nerve injury：sensory nerve induces motor nerve regeneration

End-to-side neurorrhaphy is an option in the treatment of the long segment defects of a nerve.It involves suturing the distal stump of the disconnected nerve（recipient nerve） to the side of the intimate adjacent nerve（donor nerve）.However,the motor-sensory specificity after end-to-side neurorrhaphy remains unclear.This study sought to evaluate whether cutaneous sensory nerve regeneration induces motor nerves after end-to-side neurorrhaphy.Thirty rats were randomized into three groups：（1） end-to-side neurorrhaphy using the ulnar nerve（mixed sensory and motor） as the donor nerve and the cutaneous antebrachii medialis nerve as the recipient nerve;（2） the sham group：ulnar nerve and cutaneous antebrachii medialis nerve were just exposed;and（3） the transected nerve group：cutaneous antebrachii medialis nerve was transected and the stumps were turned over and tied.At 5 months,acetylcholinesterase staining results showed that 34% ± 16% of the myelinated axons were stained in the end-to-side group,and none of the myelinated axons were stained in either the sham or transected nerve groups.Retrograde fluorescent tracing of spinal motor neurons and dorsal root ganglion showed the proportion of motor neurons from the cutaneous antebrachii medialis nerve of the end-to-side group was 21% ± 5%.In contrast,no motor neurons from the cutaneous antebrachii medialis nerve of the sham group and transected nerve group were found in the spinal cord segment.These results confirmed that motor neuron regeneration occurred after cutaneous nerve end-to-side neurorrhaphy.

Early muscle reinnervation by means of end-to-side neurorrhaphy in an experimental model

Aim:The aim of the study was to provide early muscular reinnervation to avoid muscle atrophy and functional loss in an experimental model.Methods:Fifty rats were divided into five groups.In group 0(control group)only nerve dissection was performed.Total peroneal nerve section was performed in the remaining groups.Immediate end-to-end neurorrhaphy(EEN)was made in group 1.In group 2,an end-to-side neurorrhaphy(ESN)was performed from the tibial nerve to the peroneal nerve.In group 3,a direct EEN,plus an ESN,were used as a nerve graft as a bridge from the donor nerve(tibial);all nerve coaptations were performed through an epineural window.In group 4,only a neurotomy was made without any type of reconstruction.Results:Neural diameters were similar in groups 0,1,and 3(38±1μm,31±6μm,32±3μm).Neural fibers in group 3 had an 18%increase in the number of axons(P<0.001)when compared to group 0.Group 2(28±1μm)and group 4(19±3μm)had diminished diameters with a lower index of muscle regeneration.Animals in group 4 presented with'clawed'lower extremities and had difficulty with ambulation.Neural graft diameters was similar in groups 2 and 3(33±4μm,31±3μm),but axon density was significantly higher in group 3(53±6μm,39±8μm)(P<0.001).Axon density was 36%higher when the combination of EEN and ESN with a neural graft through an epineural window was performed.Conclusion:This study revealed that the combination of EEN and ESN repairs with the addition of a neural graft provides a lower index of muscle fiber destruction,and can be a reliable method for reconstruction in high neural injuries.

The reasons for end-to-side coaptation:how does lateral axon sprouting work?

Nerve fibers are attracted by sutureless end-to-side nerve coaptation into the recipient nerve. Opening a window in the epineurium enhances axon attraction and myeliuation. The authors analyze the features of nerve repair by end-to-side coaptation. They highlight the known mechanisms of axon sprouting and different hypotheses of start up signals （presence or absence of an epineurial window, role of Schwann cells, signaling from the distal trunk）. The clinical literature is also presented and differences between experimental and clinical applications are pointed out. The authors propose their point of view and perspectives deriving from recent experimental and clinical experiences.

同期神经化髂骨瓣在下颌骨重建中保存下唇及颏部感觉的效果评价

目的 :评价同期神经化髂骨瓣在修复下颌骨缺损中,重建下牙槽神经,保存下唇及颏部感觉的效果。方法 :对于下颌骨连续性缺损需颌骨重建的患者,通过随机数字表将患者随机分配到神经化组和对照组,神经化组患者在颌骨重建术中吻合旋髂深动静脉与受区血管,并同期吻合支配腹内斜肌及髂骨的髂腹股沟神经与受区的颏神经、下牙槽神经残端;对照组术中只进行血管吻合而不进行神经重建。术中用神经监护仪检测髂骨瓣神经吻合后的神经电活力。术后通过两点辨别觉(two point discrimination, TPD)检查、感觉神经阈值(current perception threshold, CPT)检测及Touch test感觉测试丝(Touch test sensory evaluator, TTSE)检测记录患者下唇及颏部感觉恢复情况。采用SPSS 26.0软件包对数据进行统计学分析。结果:共纳入20例患者,每组各10例,2组髂骨瓣存活率均为100%,未发生皮瓣危象等严重并发症,供区无明显并发症。TPD检测、CPT测试及TTSE检测结果均提示,神经化组术后感觉减退程度更小(P<0.05)。结论:“环路重构”式同期神经吻合血管化髂骨瓣可有效保留下唇感觉,提升患者术后生活质量,是一种安全有效的重建方法。

Candy cane syndrome:A systematic review

BACKGROUND Candy cane syndrome(CCS)is a condition that occurs following gastrectomy or gastric bypass.CCS remains underrecognized,yet its prevalence is likely to rise due to the obesity epidemic and increased use of bariatric surgery.No previous literature review on this subject has been published.AIM To collate the current knowledge on CCS.METHODS A literature search was conducted with PubMed and Google Scholar for studies from May 2007,until March 2023.The bibliographies of the retrieved articles were manually searched for additional relevant articles.RESULTS Twenty-one articles were identified(135 patients).Abdominal pain,nausea/vomiting,and reflux were the most reported symptoms.Upper gastrointestinal(GI)series and endoscopy were performed for diagnosis.Surgical resection of the blind limb was performed in 13 studies with resolution of symptoms in 73%-100%.In surgical series,9 complications were reported with no mortality.One study reported the surgical construction of a jejunal pouch with clinical success.Six studies described endoscopic approaches with 100%clinical success and no complications.In one case report,endoscopic dilation did not improve the patient’s symptoms.CONCLUSION CCS remains underrecognized due to lack of knowledge about this condition.The growth of the obesity epidemic worldwide and the increase in bariatric surgery are likely to increase its prevalence.CCS can be prevented if an elongated blind loop is avoided or if a jejunal pouch is constructed after total gastrectomy.Diagnosis should be based on symptoms,endoscopy,and upper GI series.Blind loop resection is curative but complex and associated with significant complications.Endoscopic management using different approaches to divert flow is effective and should be further explored.

端侧吻合与自体神经移植神经再生的比较研究

目的比较周围神经端侧吻合与自体神经移植后神经再生的效果,为临床提供实验依据。方法选用Wister大白鼠60只,随机分成3组。A组:切断左侧腓神经1cm,造成神经缺损,取对侧相应的腓神经桥接缺损。B组:切断左侧腓神经,在邻近的胫神经干外膜上开一1mm小窗,将腓神经远端吻合到胫神经干侧方开窗处。C组:方法同B组,但束膜开窗。各组分别于术后8、12周取材并进行大体、组织学、形态定量学和电生理检测。结果自体神经移植体修复神经缺损后,再生神经的数目、有髓神经纤维截面积、运动神经传导速度均优于端侧吻合的外膜、束膜开窗组(P<0.05);外膜开窗组与束膜开窗组之间无显著性差异(P>0.05)。结论自体神经移植修复大鼠周围神经缺损,其再生神经纤维质量优于端侧吻合法。

端侧吻合与神经移植修复周围神经缺损疗效的形态学比较

目的 :比较神经端侧吻合与神经移植修复神经缺损的疗效。方法 :Wistar大白鼠 2 0只 ,分两组 ,每组 10只。右侧手术 ,切除腓总神经 8mm。端侧吻合组近端反转结扎 ,远端与胫神经外膜开窗处行端侧吻合。神经移植组切取腓肠神经 10mm ,移植于腓总神经缺损处。两组动物左侧作正常对照。术后 3个月 ,行双侧腓总神经、胫前肌组织学检查、胫前肌肌湿重测定及运动终板检查。结果 :两组再生神经纤维数目、肌湿重、肌纤维截面积、运动终板的面积及着色均无显著性差异。结论

程序化功能性腮腺切除术的初步探讨

目的探讨改良腮腺切除术的临床应用。方法从手术切口、耳大神经保留、面神经解剖、区域性腮腺切除、凹陷性畸形整复和端侧神经吻合术的运用等多个方面对腮腺切除术进行改良。结果随访肿瘤均未见复发,无面瘫及明显味觉出汗综合征,耳周的感觉恢复正常,颌面部基本对称,无明显凹陷性畸形,瘢痕隐蔽。结论可根据患者的个性化情况,程序化地采用功能性腮腺切除术。

BDNF对端侧吻合面神经再生作用的研究

目的:探讨脑源性神经营养因子(BDNF)对面神经端侧吻合后促进神经再生的作用。方法:30只家兔随机分2组,将双侧离断的面神经上颊支远端与同侧外膜开窗的下颊支行端侧吻合。术后给予BDNF的为实验组,给予生理盐水的为对照组。分别于术后2、4、8周取材,采用电生理,光镜,透射电镜等检测方法。结果:实验组神经传导速度、动作电位、组织学形态学定量分析等指标明显优于对照组。结论:BDNF对面神经端侧吻合后神经再生有明显促进作用。

周围神经端侧吻合再生纤维来源的实验研究

目的 :探索周围神经端—侧吻合后再生纤维 (侧芽 )的来源。方法 :将Wistar大鼠左侧腓总神经切断后端—侧吻合到外膜开窗的胫神经干上。术后 1 5周对胫神经和腓总神经分别用快兰和核黄作神经干注射标记 ,取背根神经节 (DRG)荧光显微镜下观察被标记细胞 ;取吻合口附近的胫、腓神经段经锇酸染色后在光镜下观察腓总神经内轴突与胫神经轴突的关系。结果 :实验组背根节内未发现双标细胞。光镜下 ,可清晰地见到左侧腓总神经内的再生纤维从胫神经近侧端下行而至。结论 :周围神经端—侧吻合腓总神经内的再生纤维来自于胫神经的侧芽缺乏依据 ,因无法排除来自腓总神经近端生长锥和受损胫神经纤维生长锥的可能。

兔耳大神经端侧吻合后神经元胞体和神经干内cAMP的水平

目的：观察神经端侧吻合后供神经的神经节和神经干内ｃＡＭＰ水平变化，为探索神经再生机制提供实验依据．方法：新西兰兔５２只，随机分为Ａ，Ｂ，Ｃ组，Ａ组为两耳大神经端侧吻合实验组，Ｂ组为未吻合对照组，Ｃ组为正常耳大神经对照组，Ａ，Ｂ２组各按术后２，４，７，１４，３０，６０ｄ分为６个观察组，每组动物４只．观察到期后，用放射免疫分析技术检测供神经节、神经干和吻合口部位的ｃＡＭＰ含量．结果：在正常耳大神经的神经节、神经干和相当于吻合口部位标本中，ｃＡＭＰ含量分别为（１．６２±０．１２），（１．５５±０．１７）和（１．５５±０．１７）ｎｍｏｌ／ｇ；Ａ，Ｂ２组在以上３个部位的ｃＡＭＰ含量呈现相同的变化趋势，即术后早期（２ｄ）下降到正常水平以下，４ｄ陡然上升，７ｄ达到峰值，分别在６０ｄ和３０ｄ缓慢下降至正常．Ａ组的ｃＡＭＰ含量在术后４ｄ～３０ｄ各时间点均显著高于Ｂ组．结论：兔耳大神经端侧吻合后，供神经的神经节和神经干内ｃＡＭＰ含量显著高于不作神经端侧吻合的对照组，恢复到正常水平的时间也明显延迟．

端侧神经吻合后再生轴突计数和截面积测定

目的 :研究端侧神经吻合后再生轴突的成熟情况。方法 :以耳大神经制成端侧吻合的神经模型。将 16只新西兰兔按手术后的时间分为 1、4、7、14、2 8、42、5 6、84d 8个观察组 ,每组 2只动物。利用HE染色及电子计算机图像分析实验结果。结果 :再生轴突的横截面积逐渐增加。再生轴突的通过率随吻合手术时间的延长不断增加 ,2 8d时 ,少量再生的轴突长入受神经 ,其再生轴突横截面积恢复率是 2 7.7%、42d为 38.4%、5 6d时达 6 1.2 %和 84d的 6 3.3%。结论 :端侧神经吻合后再生的纤维逐步成熟 。

采用神经纤维梳理技术显示神经端侧缝合后侧支再生的研究

目的探讨一种可直接显示神经端侧缝合后神经纤维侧支再生的方法。方法取5只成年Wistar大鼠,将右侧腓总神经切断,远端与外膜开窗的胫神经作端侧缝合。术后3个月切取缝合部位神经和对侧正常胫神经,福尔马林、锇酸和甘油处理后,于手术显微镜下剥离结缔组织,将神经纤维梳理出,并在光学显微镜下观察其形态。另切取缝合口及其远端的腓总神经作组织学检查。结果神经端侧缝合口分离出的神经纤维,可见在郎飞结附近发出细小侧芽,而正常胫神经则未发现。缝合口纵切片见神经纤维从胫神经进入腓总神经,缝合口远端腓总神经横切片见大量再生纤维。结论采用神经纤维梳理技术可直观地显示神经端侧缝合后神经纤维侧支再生的现象。

端侧神经吻合后再生神经纤维轴浆流恢复的形态学依据

目的 观察神经轴浆流恢复情况 ,进一步证实端侧神经吻合后纤维再生的可能性 .方法 用新西兰兔进行研究 ,随机分为 A,B两组 . A组 :实验组将左侧耳大神经切断吻合于右侧耳大神经干上 ;B组 :对照组仅切断神经 .术后 2 ,4 ,6 ,8和 12 wk,将 HRP注入吻合口远端的受神经内 ,动物再存活 4 d,免疫组化法观察 C1 - C3背根神经节内的标记阳性细胞 .结果 供神经的新生轴突能通过吻合口长入受神经 ,随时间的延长 ,神经节内的阳性细胞的数量不断增加 .结论 端侧神经吻合后侧支发芽再生 。

周围神经端侧吻合再生纤维来源的实验研究

目的:探索周围神经端-侧吻合后再生纤维(侧芽)的来源。方法:将Wistar大鼠左侧腓总神经切断后端-侧吻合到外膜开窗的胫神经干上,术后8周对胫神经和腓总神经分别用快兰和核黄作神经干注射标记,取脊髓背根神经节(DRG)荧光显微镜下观察被标记细胞;取吻合口附近的胫、腓神经段经锇酸染色后在光镜下观察腓总神经内轴突与胫神经轴突的关系。结果:实验组背根节内未发现双标细胞。光镜下,可清晰地见到左侧腓总神经内的再生纤维来自于胫神经近侧端。结论:周围神经端-侧吻合腓总神经内的再生纤维来自于胫神经的侧芽缺乏依据,因而无法排除来自腓总神经近端生长锥和受损胫神经纤维生长锥的可能。

反式端侧缝合寄养对大鼠失神经骨骼肌的保护作用

目的:感觉神经寄养可以延缓失神经骨骼肌的萎缩,但传统的端端缝合寄养方式需切断供体神经远端而影响再生神经长入。本研究探讨反式端侧缝合寄养对大鼠失神经骨骼肌的保护作用。方法:雌性SD大鼠12只,随机分为反式端侧缝合组(n=6)和对照组(n=6)。切断胫神经,缝扎近端、远端断端。反式端侧缝合组切断腓肠神经,在靠近胫神经进入腓肠肌的胫神经外膜上开窗,腓肠神经近断端以反式端侧缝合于胫神经开窗处。对照组只结扎胫神经近、远端断端。术后12周测量腓肠肌湿重、肌纤维横截面积、运动终板周径。结果:反式端侧缝合组腓肠肌湿重恢复率(39.2%±6.8%)明显优于对照组(19.5%±4.3%),差异有统计学意义(P<0.05)。光镜下对照组腓肠肌大面积萎缩,周围明显纤维化;反式端侧缝合组腓肠肌萎缩不明显,肌纤维结构排列紧密完整,周围少量纤维化。反式端侧缝合组腓肠肌的平均横截面积、运动终板平均周径均显著大于对照组[(1 148.85±547.18)μm2vs.(575.05±140.51)μm2,(102.84±53.29)μm vs.(59.60±26.71)μm],两组差异有统计学意义(P<0.05)。结论:感觉神经反式端侧缝合寄养可以保护大鼠失神经骨骼肌的结构。

面神经端侧吻合与游离移植修复对比实验研究

目的 :为了比较面神经端侧吻合与耳大神经移植的效果。方法 :选用体重 2 .0～ 2 .5kg大白兔 ,右侧切掉面神经上颊支 2cm ,远心端吻合到外膜开窗的下颊支上。左侧同样切掉面神经上颊支 2cm ,取耳大神经行端 -端神经游离移植修复。结果 :3个月后运动神经传导速度分别为 2 3.5 6± 4 .4 6m/s ,2 2 .86± 5 .2m/s(P >0 .0 5 ) ,两组均可见大量神经纤维和髓鞘 ,有髓神经纤维计数分别为 6 4 .6 6± 2 .4 8,6 3.84± 2 .78个 /每高倍视野 (P >0 .0 5 )。结论 :正常神经发出侧芽能通过端侧缝合口长入远端神经 ,使变性神经再神经化 ,面神经端侧吻合能取得与神经移植相近的结果。