Experimental Studies on the Reinnervation of Posterior Cricoarytenoid Muscle by the Upper Branch of Phrenic Nerve

The purpose of this work was to reestablish the respiratory abduction of theparalyzed vocal cord through reinnervation of the posterior cricoarytenoid(PCA)mus-cle by part of phrenic fibres.In fifteen adult cats the adductor branch of the recurrentlaryngeal nerve(RLN)of the right side was cut and its distal end ligated,while the pro -ximal end was implanted into the PCA muscle belly.The whole RLN was then transectedin the tracheoesophageal groove and its distal stump anastomosed to the upper branchof the phrenic nerve.Various techniques for observation were used on day 40,80 and 150after operation.Direct laryngoscopy showed that the inspiratory abduction of the para-lyzed vocal cord recovered within 40 d in all cats.Eighty days later,a larger abducentmotion of the glottis was observed on the reinnervated side.Abduction was caused byreinnervation of the PCA muscle from phrenic motoneurons,as demonstrated by laryn-geal electromyogram,and the function of diaphragm maintained as revealed by monito-ring of the intrathoracic pressure.

Key changes in denervated muscles and their impact on regeneration and reinnervation

The neuromuscular junction becomes progressively less receptive to regenerating axons if nerve repair is delayed for a long period of time. It is difficult to ascertain the denervated muscle＇s residual receptivity by time alone. Other sensitive markers that closely correlate with the extent of denervation should be found. After a denervated muscle develops a fibrillation potential, muscle fiber conduction velocity, muscle fiber diameter, muscle wet weight, and maximal isometric force all decrease; remodeling increases neuromuscular junction fragmentation and plantar area, and expression of myogenesis-related genes is initially up-regulated and then down-regulated. All these changes correlate with both the time course and degree of denervation. The nature and time course of these denervation changes in muscle are reviewed from the literature to explore their roles in assessing both the degree of detrimental changes and the potential success of a nerve repair. Fibrillation potential amplitude, muscle fiber conduction velocity, muscle fiber diameter, mRNA expression levels of myogenic regulatory factors and nicotinic acetylcholine receptor could all reflect the severity and length of denervation and the receptiveness of denervated muscle to regenerating axons, which could possibly offer an important clue for surgical choices and predict the outcomes of delayed nerve repair.

Effects of targeted muscle reinnervation on spinal cord motor neurons in rats following tibial nerve transection

Targeted muscle reinnervation(TMR)is a surgical procedure used to transfer residual peripheral nerves from amputated limbs to targeted muscles,which allows the target muscles to become sources of motor control information for function reconstruction.However,the effect of TMR on injured motor neurons is still unclear.In this study,we aimed to explore the effect of hind limb TMR surgery on injured motor neurons in the spinal cord of rats after tibial nerve transection.We found that the reduction in hind limb motor function and atrophy in mice caused by tibial nerve transection improved after TMR.TMR enhanced nerve regeneration by increasing the number of axons and myelin sheath thickness in the tibial nerve,increasing the number of anterior horn motor neurons,and increasing the number of choline acetyltransferase-positive cells and immunofluorescence intensity of synaptophysin in rat spinal cord.Our findings suggest that TMR may enable the reconnection of residual nerve fibers to target muscles,thus restoring hind limb motor function on the injured side.

Autonomic reinnervation and functional regeneration in autologous transplanted submandibular glands in patients with severe keratoconjunctivitis sicca

Autologous submandibular gland（SMG） transplantation has been proved to ameliorate the discomforts in patients with severe keratoconjunctivitis sicca. The transplanted glands underwent a hypofunctional period and then restored secretion spontaneously.This study aims to investigate whether autonomic nerves reinnervate the grafts and contribute to the functional recovery, and further determine the origin of these nerves. Parts of the transplanted SMGs were collected from the epiphora patients, and a rabbit SMG transplantation model was established to fulfill the serial observation on the transplanted glands with time. The results showed that autonomic nerves distributed in the transplanted SMGs and parasympathetic ganglionic cells were observed in the stroma of the glands. Low-dense and unevenly distributed cholinergic axons, severe acinar atrophy and fibrosis were visible in the patients＇ glands 4–6 months post-transplantation, whereas the cholinergic axon density and acinar area were increased with time. The acinar area or the secretory flow rate of the transplanted glands was statistically correlated with the cholinergic axon density in the rabbit model, respectively. Meanwhile, large cholinergic nerve trunks were found to locate in the temporal fascia lower to the gland, and sympathetic plexus concomitant with the arteries was observed both in the adjacent fascia and in the stroma of the glands. In summary, the transplanted SMGs are reinnervated by autonomic nerves and the cholinergic nerves play a role in the morphological and functional restoration of the glands. Moreover, these autonomic nerves might originate from the auriculotemporal nerve and the sympathetic plexus around the supplying arteries.

Experience of Cervical Plexus Reinnervation for Patients with Unilateral Recurrent Laryngeal Nerve Invasion or Injury

OBJECTIVE To explore the clinical and therapeutic effects of cervical plexus reinnervation for infiltrated or injured unilateral recurrent laryngeal nerve （URLN）. METHODS Functional neck dissection for removal of differentiated thyroid carcinoma （DTC） in patients was performed, in which cervical plexus reinnervation was adopted for patients with stage I disease and URLN with injury or with tumor invasion. Outcomes of surgery were evaluated by examination under fibrolaryngoscope, and the patients＇ voices were evaluated before and after surgery. RESULTS All cases were followed up for 3 mon-2 years （average 8 mon）. Abductory motion of the vocal cords of 15 patients was completely or partly restored, but 3 patients＇ vocal cords were immovable. The recovery rate of abductory motion of the paralyzed vocal cords was 83.33% （15/18）. The function of phonation in the 16 patients was restored to normal or near normal limits, and their hoarseness was improved significantly. CONCLUSION Cervical plexus-URLN reinnervation should be considered when treating patients with unilateral vocal cord paralysis. Removing the tumor simultaneously with cervical plexus reinnervation during surgery for repair of unilateral recurrent laryngeal nerve injury was convenient and easy to perform with less functional damage compared with other methods of reinnervation. The abductory motion of vocal cord could be satisfactorily restored by this reinnervation. Surgical performance skills and application of neurotrophic drugs were important for the success of the surgery.

Nerve function restoration following targeted muscle reinnervation after varying delayed periods

Targeted muscle reinnervation has been proposed for reconstruction of neuromuscular function in amputees.However,it is unknown whether performing delayed targeted muscle reinnervation after nerve injury will affect restoration of function.In this rat nerve injury study,the median and musculocutaneous nerves of the forelimb were transected.The proximal median nerve stump was sutured to the distal musculocutaneous nerve stump immediately and 2 and 4 weeks after surgery to reinnervate the biceps brachii.After targeted muscle reinnervation,intramuscular myoelectric signals from the biceps brachii were recorded.Signal amplitude gradually increased with time.Biceps brachii myoelectric signals and muscle fiber morphology and grooming behavior did not significantly differ among rats subjected to delayed target muscle innervation for different periods.Targeted muscle reinnervation delayed for 4 weeks can acquire the same nerve function restoration effect as that of immediate reinnervation.

Preemptive targeted muscle reinnervation:the single incision approach should be avoided in trans‑tibial traumatic amputation

Dear Editor,Chronic pain is a significant concern after major lower limb amputations that often preclude prosthetic fitting,decrease ambulation,and impact the quality of life[1,2].In the last decade,targeted muscle reinnervation(TMR)has been proposed as a surgical strategy for treating or preventing symptomatic neuromas and phantomlimb phenomena in major amputees[1].This technique involves the transfer of an amputated mixed-motor and sensory nerve to a nearby recipient motor nerve[1,2].Unlike most surgical strategies that aim to hide or protect the neuroma,TMR gives the amputated nerves“somewhere to go and something to do”[2].In a randomized clinical trial on neuroma and phantom pain,Dumanian et al.[1]demonstrated that TMR reduces amputationrelated chronic pain at 1-year post-intervention when compared with the excision and muscle-burying technique,which remains the current gold standard.Valerio et al.[2]also proposed applying TMR at the time of major limb amputation for preventing chronic pain and found that TMR patients experienced less residual limb pain(RLP)and phantom limb pain(PLP)when compared with untreated amputee controls.

EXPERIMENTAL STUDY ON INFLUENCE OF MUSCLE TENSION TOWARDS THE FUNCTION OF THE SKELETAL MUSCLE FOLLOWING ITS REINNERVATION

Objective To investigate the influence of tension on the function of the denervated skeletalmuscle after its reinnervation. Methods Fifty-four Sprague-Dawley (SD) rats were randomly divided into 3 groups. The left gastrocnemius muscles of the rats were dissected with only the neurovascular pedicles intact; the tib-ial nerves were cut and immediately repaired by epineurial suture. Then the Achilles tendons were isolated and treated accordingly; the Achilles tendon was lengthened by 0. 5cm in lengthened group, shortened by 0. 5cm in shortened group and left alone in normal (control) group. In the 2nd, 4th and 8th week after operation, the isometric twitch contractile force of both the right and the left gastrocnemius muscles were measured; specimens were taken from gastrocnemius muscle for histological study by light microscope. Results In comparison between the groups, the gastrocnemius muscles in the shortened group showed less severe muscle atrophy and connective tissue proliferation, bigger diameter and cross section dimension of the muscle fiber and greater isometric twitch contractile strength of the bilateral gastrocnemius muscles than those in the normal and lengthened groups in all the postoperative periods. Conclusion A proper high tension of the muscle may improve the function of the denervated skeletal muscle after its reinnervation.

Chitosan-based thermosensitive hydrogel with long-term release of murine nerve growth factor for neurotrophic keratopathy

Neurotrophic keratopathy is a persistent defect of the corneal epithelium,with or without stromal ulceration,due to corneal nerve deficiency caused by a variety of etiologies.The treatment options for neurotrophic keratopathy are limited.In this study,an ophthalmic solution was constructed from a chitosan-based thermosensitive hydrogel with long-term release of murine nerve growth factor(CTH-mNGF).Its effectiveness was evaluated in corneal denervation(CD)mice and patients with neurotrophic keratopathy.In the preclinical setting,CTH-mNGF was assessed in a murine corneal denervation model.CTH-mNGF was transparent,thermosensitive,and ensured sustained release of mNGF for over 20 hours on the ocular surface,maintaining the local mNGF concentration around 1300 pg/mL in vivo.Corneal denervation mice treated with CTH-mNGF for 10 days showed a significant increase in corneal nerve area and total corneal nerve length compared with non-treated and CTH treated mice.A subsequent clinical trial of CTH-mNGF was conducted in patients with stage 2 or 3 neurotrophic keratopathy.Patients received topical CTH-mNGF twice daily for 8 weeks.Fluorescein sodium images,Schirmer’s test,intraocular pressure,Cochet-Bonnet corneal perception test,and best corrected visual acuity were evaluated.In total,six patients(total of seven eyes)diagnosed with neurotrophic keratopathy were enrolled.After 8 weeks of CTH-mNGF treatment,all participants showed a decreased area of corneal epithelial defect,as stained by fluorescence.Overall,six out of seven eyes had fluorescence staining scores<5.Moreover,best corrected visual acuity,intraocular pressure,Schirmer’s test and Cochet-Bonnet corneal perception test results showed no significant improvement.An increase in corneal nerve density was observed by in vivo confocal microscopy after 8 weeks of CTH-mNGF treatment in three out of seven eyes.This study demonstrates that CTH-mNGF is transparent,thermosensitive,and has sustained-release properties.Its effectiveness in healing corneal epithelial defects in all eyes with neurotrophic keratopathy suggests CTH-mNGF has promising application prospects in the treatment of neurotrophic keratopathy,being convenient and cost effective.

建立人工膀胱反射弧恢复脊髓损伤患者排尿功能的初步报告

目的：探索建立人工膀胱反射弧恢复脊髓损伤患者排尿功能的治疗途径。方法：对３ 例圆锥上脊髓损伤（ＳＣＩ）患者行两侧Ｌ５ ～Ｓ２ 或Ｓ１～Ｓ３ 前根吻合，经１０～１２ 个月轴索再生后，检测膀胱排尿功能。结果：建立人工膀胱反射弧手术后，通过刺激躯体传入神经，可经内脏传出神经引发膀胱内压升高，在膀胱充盈较满时能引起排尿反应。结论：建立人工膀胱反射弧对ＳＣＩ患者排尿有一定作用，但尚需进一步研究完善。

利用跟腱反射建立人工膀胱反射弧的临床研究

为了探讨利用跟腱反射重建圆锥上脊髓损伤后膀胱的神经再支配和人工扳机点排尿的疗效 ,在 8例圆锥以上截瘫患者硬膜内切断双侧S1前根及支配膀胱的最强神经根 (一般为S2 或S3 )前根 ,进行显微吻合以形成跟腱 脊髓 膀胱人工反射弧。其中 5例患者经过平均 2 8年的随访 ,夜间无尿失禁 ,每天排尿 5～ 6次 ,每次尿量 2 5 0～ 5 0 0ml。说明跟腱 脊髓

建立人工膀胱反射弧治疗脊髓损伤后弛缓性膀胱的实验研究

目的探讨利用脊髓损伤平面以上健存的体反射重建人工膀胱反射弧,恢复脊髓损伤(spinalcordinjury,SCI)后膀胱排尿功能。方法1岁龄雄性Beegle犬8只,体重9.5±2.0kg。取后正中切口暴露L4～S3的棘突和椎板,全椎板切除后暴露硬膜和脊神经根,在硬膜外初步分离和确认L6和S2前根。确定犬左侧为实验侧,将左侧L6与S2前根分别在穿神经根管处切断,切开硬膜囊,从硬膜外L6和S2前根追溯硬膜内神经根,在显微镜下将L6和S2前根在硬膜内吻合。经一段时间轴突再生后,建立“膝腱-脊髓中枢-膀胱”人工反射弧。神经缝合术后8个月,在破坏S1～S4脊髓节段前后,分别进行神经电生理、膀胱肌电图及尿流动力学等远期功能观察。结果术后8个月,3只犬死亡,3只犬未能分离出吻合的神经,无实验结果。余2只犬均获得满意结果,定为1号和2号犬,进行观察。刺激(连续刺激强度200μV,刺激间隔为5ms)截瘫前和截瘫后2只犬左侧L6后根、神经吻合口,均可在吻合口远端记录到运动诱发电位,其波形和波幅相似;尿流动力学检查可见,当刺激开始时膀胱内压迅速上升,而腹内压增加幅度较小,刺激中止后膀胱内压迅速下降,证实膀胱内压升高主要是由逼尿肌收缩产生,电刺激左侧L6后根和吻合口膀胱内压升高值均可达到正常的60%左右。结论利用脊髓损伤平面以上健存的体反射重建膀胱反射通路是成功和有效的,体神经的运动支通过轴突再生能够长入自主神经的副交感神经纤维,并具有良好的传导运动兴奋的功能。

大鼠心肌梗塞后梗塞区胆碱能神经支配的变化

目的 :探讨大鼠心肌梗塞区胆碱能神经支配的变化。方法 :实验用 2 0只大鼠 ,以组织化学Karnovsky Roots法显示胆碱能神经纤维 ,应用多功能图像分析仪测定梗塞区胆碱能神经纤维密度。结果 :大鼠心肌梗塞后 4天 ,梗塞区胆碱能神经纤维密度显著下降 ;梗塞后 1 4天 ,梗塞区胆碱能神经纤维完全消失 ;梗塞后 1 2 0天 ,心肌梗塞区的部分区域出现胆碱能神经纤维。结论 :大鼠心肌梗塞后 1 4天 ,梗塞区发生完全的去胆碱能神经支配 ,1 2 0天后部分区域出现胆碱能神经再支配。

带神经血管的肌束使瘫痪肌肉恢复神经支配进一步实验研究

报道在50只家兔腓肠肌外侧头失神经肌肉模型上,随机选择一侧行比目鱼肌神经血管肌束植入,另一侧行比目鱼肌神经分束埋入。18周后,进行肌电图、肌力检查,神经免疫组化染色检查,肌纤维组织形态及超微结构检查。实验结果证明,应用带神经血管的肌束植入能使失神经肌肉恢复神经支配,能使瘫痪肌肉恢复良好的收缩功能。带神经血管的肌束延期植入失神经模型与即刻植入的比较研究发现,延期植入的效果优于即刻植入。

瘢痕组织中神经丝蛋白的表达特征及生物学意义

目的 :观察瘢痕组织与成人正常皮肤中神经丝蛋白 (NFP)及其表皮细胞生长因子受体 (EGFR)表达变化 ,阐明神经再支配对增生性瘢痕形成的影响。方法 :标本取自烧伤瘢痕愈合后 1 1～ 2 6个月来我院进行修复手术的患者 ,正常对照选自同一患者的供皮区。利用单克隆抗体免疫组织化学染色技术 ,光镜下观察瘢痕组织及正常皮肤上皮中 NFP的表达和 EGFR在表皮基底层细胞的标记情况。结果 :随着瘢痕的形成 ,瘢痕组织与正常皮肤上皮中神经纤维的数量表现为早期明显增多 ,随着瘢痕的成熟 ,神经纤维的数量逐渐减少。 EGFR的表达与 NFP的动态变化呈现一致性 ,瘢痕早期表皮细胞生长因子受体的表达较强 ,瘢痕后期表达减弱。结论 :增生性瘢痕与正常的皮肤中 NFP的变化和 EGFR活性与创面愈合的结局密切相关。

带神经血管肌束移植术在晚期面瘫修复中的应用

在行吻合血管神经的游离肌肉移植术修复晚期面瘫的４６例中，选择有适应证的２８例行带神经血管的背阔肌肌束移植术。该术式对肌束形态的特殊设计，不仅能作为动力重建，恢复患侧口角活动，使口角呈动态对称，而且由于带神经血管肌束对尖神经肌肉有再神经化的作用，使口周及眼周多块失神经肌肉恢复神经支配及收缩功能，收到了以往手术未能达到的良好效果。详细介绍了手术适应证，手术方法及术后处理。讨论了对再生神经再教育的重要性及进行二期调整手术的必要。

不同部位供皮与神经再支配的关系

目的 研究不同类型的移植皮肤在获得神经再支配后的表现 .方法 猴手指皮肤造成失神经支配并植入神经 ,于术后 12 mo取指腹标本利用免疫组织化学染色技术观察游离末梢和感觉小体再生情况 .结果 术后 12 mo移植皮肤内再生的游离神经末梢数量与正常无差异 ,分布均匀 .植入的神经能再生触觉小体 ,且小体多分布于植皮区的边缘 ,体积为正常组 5 8% ,相对灰度为正常组 80 % ,主要呈单轴突支配 ;各类皮肤中触觉小体的再生率不同 ,上睑、前臂、手掌的再生率分别是 35 % ,40 % ,6 0 % .未发现环层小体的再生 .结论 移植皮肤可再生游离末梢 。

“膝腱-脊髓-膀胱”反射弧重建膀胱功能的解剖与临床

目的 :探索反射弧重建膀胱功能的应用解剖和临床疗效。方法 :在 2 0具尸体标本上观察与膝腱反射有关的解剖 ,并应用于 3例患者 ,随访膀胱尿道功能。结果 :L3 脊神经根中的大部分神经纤维贡献给股神经 ,S2～ 4前根与L2～ 4前根相互间均有重叠。L3 ～S3 前根交叉吻接后 2年 ,刺激膝腱可引发膀胱内压升高并在膀胱充盈时引起排尿。结论 :“膝腱 脊髓 膀胱”反射弧重建膀胱功能时宜选用L3 ～S3 前根交叉吻接 ;

人工反射弧重建膀胱功能动物模型的建立

目的 :建立犬“膝腱 脊髓 膀胱”反射弧重建膀胱功能的动物模型 ,作为实验研究人工膀胱反射弧的基础。方法 :家犬 5条 ,行硬膜外L5 S2前根交叉吻接 ,饲养 1年后刺激反射弧并记录膀胱压和尿道压变化。结果 :5只家犬“膝腱 脊髓 膀胱”反射弧均成功建立 ,刺激反射弧时膀胱压和尿道压都有升高。结论 :通过硬膜外L5 S2前根交叉吻接可以更有效地建立人工反射弧重建膀胱功能的动物实验模型。

带神经血管肌束植入术治疗肌肉瘫痪的临床应用

应用带神经血管的肌束植入，治疗肢体及躯干肌肉瘫痪５例，均收到满意疗效。详细介绍了术前检查，手术设计，操作方法及术后处理。讨论了植入带神经血管的肌束使瘫痪肌肉恢复神经支配的机理及效果良好的原因。指出了带神经血管的肌束解剖学特征：含有大量的神经分支并有良好的血供；肌束切面上裸露的无数神经分支的断端，在植入瘫痪肌肉后就能与失神经肌肉产生多维的广泛紧密接触，能以多种神经再生方式与失神经肌肉连接，从而使其重获神经支配。