Stroke and traumatic brain injury lead to upper motor neuron syndrome,which is characterized by muscle spasticity or paresis of varying severity depending on the lesion’s location and extent.Current treatments are mo...Stroke and traumatic brain injury lead to upper motor neuron syndrome,which is characterized by muscle spasticity or paresis of varying severity depending on the lesion’s location and extent.Current treatments are mostly symptomatic with limited efficacy and significant side effects.Nerve transfer techniques,such as the contralateral L4 ventral root transfer in animal models and C7 root transfer in both animal and clinical studies,have been shown to reduce spasticity and improve function in upper motor neuron syndrome;however,they lack selectivity.Our hypothesis is that using a selective peripheral donor nerve from the contralateral side,rather than the entire nerve root,may represent an effective nerve transfer and provide a robust basis for future research on selective muscle reinnervation in upper motor neuron syndrome.Ten rats underwent a contralateral ulnar-to-ulnar nerve transfer procedure.Electrophysiological measurements were conducted twelve weeks post-surgery to assess successful reinnervation of the contralateral flexor carpi ulnaris muscle.Additionally,muscle biopsies of the reinnervated flexor carpi ulnaris were harvested to examine the muscle fiber type composition,cross-sectional area,and collagen content as well as compare them to naive counterparts.Axon quantification of the reinnervated nerves was also performed.All rats recovered uneventfully,maintaining the use of both paws post-surgery.Electrophysiological tests confirmed the successful reinnervation of the flexor carpi ulnaris muscle.Muscle fiber type composition,cross-sectional area,and collagen content did not show statistically significant changes.Axon counts indicated successful nerve regeneration without architectural disruption.In conclusion,we were able to demonstrate this novel contralateral nerve transfer model’s feasibility,reproducibility,and safety as well as achieve effective muscle reinnervation.This model provides a valuable tool for further research on selective muscle reinnervation and treatment of upper motor neuron syndrome,with potential implications for improving clinical outcomes in stroke and traumatic brain injury patients.展开更多
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 ad...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.展开更多
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 informa...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.展开更多
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...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.展开更多
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 the...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.展开更多
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 di...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.展开更多
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 re...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.展开更多
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 re...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.展开更多
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 gas...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.展开更多
Introduction:Unilateral vocal fold paralysis(ULVP)is characterized by the complete immobility of a single vocal fold which can cause significant health challenges,including voice impairment,difficulty swallowing,and a...Introduction:Unilateral vocal fold paralysis(ULVP)is characterized by the complete immobility of a single vocal fold which can cause significant health challenges,including voice impairment,difficulty swallowing,and a high risk of aspiration due to glottic incompetency.The aim of this study is to systematically review the effectiveness of laryngeal reinnervation(LR)and medialization thyroplasty(MT)in the treatment of ULVP.Materials and Methods:Medline,PubMed,Cochrane Library,OVID,Scopus,Springer Nature Journals,ScienceDirect,and Directory of Open Access Journals databases were searched.Restriction to non-English studies were applied.Studies were excluded if subjects had previous treatment for ULVP,if they had co-existing neuromuscular disease affecting the larynx,and if they had significant non-laryngeal speech abnormalitiesResults:Fifteen articles were reviewed,all conducted between 2003 and 2023.Among the 864 participants included,48 underwent LR,348 underwent MT,and the remaining 432 were in the comparison group,which involved injection laryngoplasty(IL),voice therapy(VT),placebo,and medialization with arytenoid adduction.Meta-analyses compared LR to MT and MT to alternative treatments,revealing a preference for MT.The comparison between LR and MT in the network meta-analysis yielded a mean difference of 0.33(95%CI:-11.79,12.6)favoring the MT group,ranking using SUCRA values highlighted that MT is the best treatment modality followed by LR.Discussion:The results of the network meta-analysis and the subgroup meta-analysis showed that MT is better than alternative treatments that were included in this study.Moreover,management modalities should be individualized to each patient as many factors are important and may affect the final outcomes.Conclusions:While the network meta-analysis indicates that MT may be more effective than alternative treatments for managing ULVP,the results should be interpreted with caution due to potential confounding factors.One notable limitation is the small sample size in the LR group.Despite these limitations,the findings contribute to the existing literature and can help guide future research on optimal interventions for the treatment of ULVP.展开更多
Neural machine interface technology is a pioneering approach that aims to address the complex challenges of neurological dysfunctions and disabilities resulting from conditions such as congenital disorders,traumatic i...Neural machine interface technology is a pioneering approach that aims to address the complex challenges of neurological dysfunctions and disabilities resulting from conditions such as congenital disorders,traumatic injuries,and neurological diseases.Neural machine interface technology establishes direct connections with the brain or peripheral nervous system to restore impaired motor,sensory,and cognitive functions,significantly improving patients'quality of life.This review analyzes the chronological development and integration of various neural machine interface technologies,including regenerative peripheral nerve interfaces,targeted muscle and sensory reinnervation,agonist–antagonist myoneural interfaces,and brain–machine interfaces.Recent advancements in flexible electronics and bioengineering have led to the development of more biocompatible and highresolution electrodes,which enhance the performance and longevity of neural machine interface technology.However,significant challenges remain,such as signal interference,fibrous tissue encapsulation,and the need for precise anatomical localization and reconstruction.The integration of advanced signal processing algorithms,particularly those utilizing artificial intelligence and machine learning,has the potential to improve the accuracy and reliability of neural signal interpretation,which will make neural machine interface technologies more intuitive and effective.These technologies have broad,impactful clinical applications,ranging from motor restoration and sensory feedback in prosthetics to neurological disorder treatment and neurorehabilitation.This review suggests that multidisciplinary collaboration will play a critical role in advancing neural machine interface technologies by combining insights from biomedical engineering,clinical surgery,and neuroengineering to develop more sophisticated and reliable interfaces.By addressing existing limitations and exploring new technological frontiers,neural machine interface technologies have the potential to revolutionize neuroprosthetics and neurorehabilitation,promising enhanced mobility,independence,and quality of life for individuals with neurological impairments.By leveraging detailed anatomical knowledge and integrating cutting-edge neuroengineering principles,researchers and clinicians can push the boundaries of what is possible and create increasingly sophisticated and long-lasting prosthetic devices that provide sustained benefits for users.展开更多
Avulsion injury of one or more spinal ventral roots induces a critical loss of motoneurons,followed by irreversible locomotor function impairment ranging from inadequate limb movement to complete paralysis of the limb...Avulsion injury of one or more spinal ventral roots induces a critical loss of motoneurons,followed by irreversible locomotor function impairment ranging from inadequate limb movement to complete paralysis of the limb.Recent surgical techniques facilitate improvement of limb function,but it remains to be determined exactly how many motoneurons are needed to survive and grow new axons to achieve sufficient muscle reinnervation.The aim of this study was to determine the minimum motoneuron quantity required to reinnervate the denervated skeletal muscles of the limb and produce a functionally satisfactory locomotor pattern.Since none of the commercially available methods and equipment were able to provide a quantifiable and in-depth analysis of the motor pattern of the entire hind limb,we have developed and applied a sensitive movement recording and analyzing system in order to determine the threshold of satisfactory functional reinnervation;we combined video-based footprint analysis and hind limb motion analysis to achieve a new and reliable assessment.Sprague-Dawley rats underwent a lumbar 4-5 ventral root avulsion,and their L4 ventral roots were subsequently reimplanted.The animals received different doses of riluzole treatment in order to rescue incremental numbers of the damaged motoneuron pool.We were able to assess one rear-view and six lateral parameters of the hind limb movement pattern by measuring specific joint angles,footprint,and gait parameters in single video frames.Four months after the operation,we performed Fast Blue retrograde tracing to label and count the reinnervating motoneurons.We then compared the numbers of reinnervating motoneurons and the functional improvement.Our results confirmed a strong relationship between functional restoration of the original movement pattern and morphological reinnervation;approximately 30%of the original motor pool was able to produce a useful locomotor pattern.We believe that our knowledge of the minimal motoneuron numbers required to reinnervate target muscles may help plan the segmental redistribution of the motoneuron pools for reinnervation surgeries.展开更多
Neuronal connections with their targets manifest selectivity during the development and regeneration. In 1963, Sperry proposed the chemoaffinity hypothesis. Through changing the relative positions of the neuron and it...Neuronal connections with their targets manifest selectivity during the development and regeneration. In 1963, Sperry proposed the chemoaffinity hypothesis. Through changing the relative positions of the neuron and its target, we can test this hypothesis by investigating the regeneration. Results from the experiments of changing the neuronal posi-展开更多
Background Replacement of spiral ganglion neurons would be one prioritized step in an attempt to restore sensory neuronal hearing loss.However,the possibility that transplanted neurons could regenerate new synaptic co...Background Replacement of spiral ganglion neurons would be one prioritized step in an attempt to restore sensory neuronal hearing loss.However,the possibility that transplanted neurons could regenerate new synaptic connections to hair cells has not been explored.The objective of this study was to test whether neural stem cell （NSC）-derived neurons can form synaptic connections with hair cells in vitro.Methods NSCs were mechanically separated from the hippocampus in SD rat embryos （E12-E14） and cultured in a serum-free medium containing basic fibroblast growth factor and epidermal growth factor.Rat NSCs were co-cultured with explants of cochlea sensory epithelia obtained from postnatal Day 3 rats under transway filter membrane.Results At Day 3,the NSCs began to show chemotactic differentiation and grew toward cochlea sensory epithelia.After 9-day co-culture,neurites of NSC-derived neurons predominantly elongated toward hair cells.Immunohistochemical analyses revealed the fibers overlapped with synapsin and hair cells,indicating the formation of new synaptic connections.After 14-day culture,triple staining revealed the fibers overlapped with PSD95 （postsynaptic density） which is juxtaposed with CtBP2 （presynaptic vesicle）,indicating the formation of new ribbon synapse.Conclusions NSC-derived neurons can make synaptic connections with hair cells and provide a model for studying synaptic plasticity and regeneration.Whether the newly forming synapse is functional merits further electrophysiological study.展开更多
To the Editor:Targeted muscle reinnervation(TMR)is a surgical technique of multiple nerve transfers,providing a potential of improved intuitive prosthetic control via surface electromyography(sEMG)in the high-level up...To the Editor:Targeted muscle reinnervation(TMR)is a surgical technique of multiple nerve transfers,providing a potential of improved intuitive prosthetic control via surface electromyography(sEMG)in the high-level upper extremity amputees.[1]However,there is a risk that some of the reinnervations might be unsuccessful,especially for the ulnar nerve.[2]Both the quality control of nerve stumps and the receptor are important factors for the surgery.Assessing the nerve stumps during the surgery and finding more muscles as receptor might address the problem.Biceps,triceps,and brachialis muscles were mostly chosen as receptors for reinnervation in the trans-humeral amputees.Pectoralis major and pectoralis minor were mostly chosen as receptors for reinnervation in the shoulder disarticulation patients.展开更多
In modern neuroscience,the most relevant is the study of the problem of reinnervation of tissues after severe injuries.Complete restoration of lost physiological functions is still impossible with lesions of periphera...In modern neuroscience,the most relevant is the study of the problem of reinnervation of tissues after severe injuries.Complete restoration of lost physiological functions is still impossible with lesions of peripheral nerves with the formation of extensive diastasis between their proximal and distal sites.In this case,the standard neurorrhaphy cannot be carried out because of the eruption of the filaments during tension and convergence of the ends.To solve this problem,a technique was developed for autotransplantation of the nerve sections,which is still the gold standard for the reconstruction of extensive nerve defects.However,the presence of significant shortcomings led to the development of the doctrine of the direction of regeneration with the help of conduits.Currently,the use of nerve channels is the most promising technology for peripheral nerve repair after trauma.The most actively developing now is the direction of reinnervation,such as neurotization.Neurotization,in some way,combined all the methods of restoring nerves.The overall goal of all these methods—the restoration of extensive nerve defects—allows them to be combined into a new industry:reinnervating neurosurgery.展开更多
Aim:Targeted muscle reinnervation(TMR)surgery has fundamentally changed the management of patients who have suffered or are about to undergo amputation.Providing nerve stumps with a muscle target has been shown to hav...Aim:Targeted muscle reinnervation(TMR)surgery has fundamentally changed the management of patients who have suffered or are about to undergo amputation.Providing nerve stumps with a muscle target has been shown to have profound effects on levels of post-amputation pain in relation to phantom limb pain(PLP)and neuroma pain(NP).The primary objective of this report was to quantify pain parameters for this population and to measure the impact on health-related quality of life(HRQol)before and after TMR surgery.In this case series,we evaluate the role of TMR in addressing both pain and the impact of the surgery on the patient’s quality of life.Methods:A retrospective analysis of 15 upper limb amputee patients who underwent TMR by the Relimb Unit in London,UK.Participants’perceptions of pain were determined using the 11-point numerical(Pain)rating scale(NRS)and HRQoL was calculated using the Euroqol EQ-5D-5L questionnaire at two time points,comparing both pain and perceived quality of life pre and post surgery.The Wilcoxon Signed Rank Test was used for the NRS data and a paired sample t-test was used for the EQ-VAS data.Results:A total of 15 patients completed the evaluation.We observed statistically significant reductions in both PLP(pre-operative mean:7.6,post-operative mean:2.7,P<0.05)and NP(pre-operative mean:6.4,post-operative mean:2.5,P<0.05)in these patients.Similarly,HRQoL observed on the EQ-VAS scale demonstrated a significant improvement in quality of life,from 68 pre-operatively to 78 post-procedure(P<0.05).Conclusion:This is the first quantified evaluation of changes in HRQoL after TMR surgery for upper limb amputation.There appears to be a significant improvement in both HRQoL and overall perception of pain.This finding may have important implications for funding and national resource allocation for TMR surgery.展开更多
Targeted muscle reinnervation(TMR)is a peripheral nerve procedure that can prevent and treat postamputation pain.The nerve transfer allows for organized nerve regeneration and repair after amputation surgery.The proce...Targeted muscle reinnervation(TMR)is a peripheral nerve procedure that can prevent and treat postamputation pain.The nerve transfer allows for organized nerve regeneration and repair after amputation surgery.The procedure can successfully prevent neuromas despite large size mismatches between the donor and recipient nerves.Here,we discuss the fundamentals of peripheral nerve injury and regeneration as it pertains to TMR.We propose axonal pruning to explain axon behavior when there are large size mismatches between transferred nerves.Given the increasing use of TMR for amputees,future studies should investigate the basic science of peripheral nerves in TMR.Advances in this field have the potential to significantly improve clinical outcomes for these patients.展开更多
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 ...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.展开更多
Osseointegration(OI),targeted muscle reinnervation(TMR),and vascularized composite allotransplantation(VCA)are just a few ways by which our reconstructive ladder is evolving.It is important to recognize that amputatio...Osseointegration(OI),targeted muscle reinnervation(TMR),and vascularized composite allotransplantation(VCA)are just a few ways by which our reconstructive ladder is evolving.It is important to recognize that amputation does not necessarily denote failure,but surgeons should strive to find ways to provide these patients with means for obtaining better satisfaction and quality of life postoperatively.TMR and OI have added options for mutilating lower extremity injuries that necessitate amputation.More recently,the senior author(Levin LS)described the"penthouse"floor of the reconstructive ladder being VCA.Despite the advances in VCA over the last 20 years,there are many challenges that face this discipline including indications for patient selection,minimizing immunosuppressive regimens,standardizing outcome measures,establishing reliable protocols for monitoring,and diagnosing and managing rejection.Herein,the authors review TMR,OI,and VCA as additional higher rungs of the reconstructive ladder.展开更多
基金supported by the European Research Council(ERC)under the European Union’s Horizon 2020 Research and Innovation Programme,No.810346.
文摘Stroke and traumatic brain injury lead to upper motor neuron syndrome,which is characterized by muscle spasticity or paresis of varying severity depending on the lesion’s location and extent.Current treatments are mostly symptomatic with limited efficacy and significant side effects.Nerve transfer techniques,such as the contralateral L4 ventral root transfer in animal models and C7 root transfer in both animal and clinical studies,have been shown to reduce spasticity and improve function in upper motor neuron syndrome;however,they lack selectivity.Our hypothesis is that using a selective peripheral donor nerve from the contralateral side,rather than the entire nerve root,may represent an effective nerve transfer and provide a robust basis for future research on selective muscle reinnervation in upper motor neuron syndrome.Ten rats underwent a contralateral ulnar-to-ulnar nerve transfer procedure.Electrophysiological measurements were conducted twelve weeks post-surgery to assess successful reinnervation of the contralateral flexor carpi ulnaris muscle.Additionally,muscle biopsies of the reinnervated flexor carpi ulnaris were harvested to examine the muscle fiber type composition,cross-sectional area,and collagen content as well as compare them to naive counterparts.Axon quantification of the reinnervated nerves was also performed.All rats recovered uneventfully,maintaining the use of both paws post-surgery.Electrophysiological tests confirmed the successful reinnervation of the flexor carpi ulnaris muscle.Muscle fiber type composition,cross-sectional area,and collagen content did not show statistically significant changes.Axon counts indicated successful nerve regeneration without architectural disruption.In conclusion,we were able to demonstrate this novel contralateral nerve transfer model’s feasibility,reproducibility,and safety as well as achieve effective muscle reinnervation.This model provides a valuable tool for further research on selective muscle reinnervation and treatment of upper motor neuron syndrome,with potential implications for improving clinical outcomes in stroke and traumatic brain injury patients.
文摘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.
基金funded by the National Natural Science Foundation of China,Nos.81760416,81960419,81927804(all to LY)Science and Technology foundation of Guizhou Province,No.[2017]1226(to LY)Support Plan for High Level Talents in Guizhou High Education Institutions,No.KY[2018]056(to LY).
文摘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.
基金sponsored by the Armed Forces Institute of Regenerative Medicine award number W81XWH-08-2-0034supported by the Sundt Fellowship fund,Department of Neurologic Surgery,Mayo Clinic,USA
文摘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.
基金supported by grants from the National Natural Science Foundation of China(No.81671005 and 81470756)
文摘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.
文摘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.
基金supported in part by the National Natural Science Foundation of China,Nos.U1913601,81927804the Key-Area Research and Development Program of Guangdong Province,No.2020B0909020004(GL)the National Natural Science Foundation of China,Nos.81960419,82260456(both to LY)。
文摘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.
文摘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.
文摘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.
文摘Introduction:Unilateral vocal fold paralysis(ULVP)is characterized by the complete immobility of a single vocal fold which can cause significant health challenges,including voice impairment,difficulty swallowing,and a high risk of aspiration due to glottic incompetency.The aim of this study is to systematically review the effectiveness of laryngeal reinnervation(LR)and medialization thyroplasty(MT)in the treatment of ULVP.Materials and Methods:Medline,PubMed,Cochrane Library,OVID,Scopus,Springer Nature Journals,ScienceDirect,and Directory of Open Access Journals databases were searched.Restriction to non-English studies were applied.Studies were excluded if subjects had previous treatment for ULVP,if they had co-existing neuromuscular disease affecting the larynx,and if they had significant non-laryngeal speech abnormalitiesResults:Fifteen articles were reviewed,all conducted between 2003 and 2023.Among the 864 participants included,48 underwent LR,348 underwent MT,and the remaining 432 were in the comparison group,which involved injection laryngoplasty(IL),voice therapy(VT),placebo,and medialization with arytenoid adduction.Meta-analyses compared LR to MT and MT to alternative treatments,revealing a preference for MT.The comparison between LR and MT in the network meta-analysis yielded a mean difference of 0.33(95%CI:-11.79,12.6)favoring the MT group,ranking using SUCRA values highlighted that MT is the best treatment modality followed by LR.Discussion:The results of the network meta-analysis and the subgroup meta-analysis showed that MT is better than alternative treatments that were included in this study.Moreover,management modalities should be individualized to each patient as many factors are important and may affect the final outcomes.Conclusions:While the network meta-analysis indicates that MT may be more effective than alternative treatments for managing ULVP,the results should be interpreted with caution due to potential confounding factors.One notable limitation is the small sample size in the LR group.Despite these limitations,the findings contribute to the existing literature and can help guide future research on optimal interventions for the treatment of ULVP.
基金supported in part by the National Natural Science Foundation of China,Nos.81927804(to GL),82260456(to LY),U21A20479(to LY)Science and Technology Planning Project of Shenzhen,No.JCYJ20230807140559047(to LY)+3 种基金Key-Area Research and Development Program of Guangdong Province,No.2020B0909020004(to GL)Guangdong Basic and Applied Research Foundation,No.2023A1515011478(to LY)the Science and Technology Program of Guangdong Province,No.2022A0505090007(to GL)Ministry of Science and Technology,Shenzhen,No.QN2022032013L(to LY)。
文摘Neural machine interface technology is a pioneering approach that aims to address the complex challenges of neurological dysfunctions and disabilities resulting from conditions such as congenital disorders,traumatic injuries,and neurological diseases.Neural machine interface technology establishes direct connections with the brain or peripheral nervous system to restore impaired motor,sensory,and cognitive functions,significantly improving patients'quality of life.This review analyzes the chronological development and integration of various neural machine interface technologies,including regenerative peripheral nerve interfaces,targeted muscle and sensory reinnervation,agonist–antagonist myoneural interfaces,and brain–machine interfaces.Recent advancements in flexible electronics and bioengineering have led to the development of more biocompatible and highresolution electrodes,which enhance the performance and longevity of neural machine interface technology.However,significant challenges remain,such as signal interference,fibrous tissue encapsulation,and the need for precise anatomical localization and reconstruction.The integration of advanced signal processing algorithms,particularly those utilizing artificial intelligence and machine learning,has the potential to improve the accuracy and reliability of neural signal interpretation,which will make neural machine interface technologies more intuitive and effective.These technologies have broad,impactful clinical applications,ranging from motor restoration and sensory feedback in prosthetics to neurological disorder treatment and neurorehabilitation.This review suggests that multidisciplinary collaboration will play a critical role in advancing neural machine interface technologies by combining insights from biomedical engineering,clinical surgery,and neuroengineering to develop more sophisticated and reliable interfaces.By addressing existing limitations and exploring new technological frontiers,neural machine interface technologies have the potential to revolutionize neuroprosthetics and neurorehabilitation,promising enhanced mobility,independence,and quality of life for individuals with neurological impairments.By leveraging detailed anatomical knowledge and integrating cutting-edge neuroengineering principles,researchers and clinicians can push the boundaries of what is possible and create increasingly sophisticated and long-lasting prosthetic devices that provide sustained benefits for users.
文摘Avulsion injury of one or more spinal ventral roots induces a critical loss of motoneurons,followed by irreversible locomotor function impairment ranging from inadequate limb movement to complete paralysis of the limb.Recent surgical techniques facilitate improvement of limb function,but it remains to be determined exactly how many motoneurons are needed to survive and grow new axons to achieve sufficient muscle reinnervation.The aim of this study was to determine the minimum motoneuron quantity required to reinnervate the denervated skeletal muscles of the limb and produce a functionally satisfactory locomotor pattern.Since none of the commercially available methods and equipment were able to provide a quantifiable and in-depth analysis of the motor pattern of the entire hind limb,we have developed and applied a sensitive movement recording and analyzing system in order to determine the threshold of satisfactory functional reinnervation;we combined video-based footprint analysis and hind limb motion analysis to achieve a new and reliable assessment.Sprague-Dawley rats underwent a lumbar 4-5 ventral root avulsion,and their L4 ventral roots were subsequently reimplanted.The animals received different doses of riluzole treatment in order to rescue incremental numbers of the damaged motoneuron pool.We were able to assess one rear-view and six lateral parameters of the hind limb movement pattern by measuring specific joint angles,footprint,and gait parameters in single video frames.Four months after the operation,we performed Fast Blue retrograde tracing to label and count the reinnervating motoneurons.We then compared the numbers of reinnervating motoneurons and the functional improvement.Our results confirmed a strong relationship between functional restoration of the original movement pattern and morphological reinnervation;approximately 30%of the original motor pool was able to produce a useful locomotor pattern.We believe that our knowledge of the minimal motoneuron numbers required to reinnervate target muscles may help plan the segmental redistribution of the motoneuron pools for reinnervation surgeries.
文摘Neuronal connections with their targets manifest selectivity during the development and regeneration. In 1963, Sperry proposed the chemoaffinity hypothesis. Through changing the relative positions of the neuron and its target, we can test this hypothesis by investigating the regeneration. Results from the experiments of changing the neuronal posi-
文摘Background Replacement of spiral ganglion neurons would be one prioritized step in an attempt to restore sensory neuronal hearing loss.However,the possibility that transplanted neurons could regenerate new synaptic connections to hair cells has not been explored.The objective of this study was to test whether neural stem cell （NSC）-derived neurons can form synaptic connections with hair cells in vitro.Methods NSCs were mechanically separated from the hippocampus in SD rat embryos （E12-E14） and cultured in a serum-free medium containing basic fibroblast growth factor and epidermal growth factor.Rat NSCs were co-cultured with explants of cochlea sensory epithelia obtained from postnatal Day 3 rats under transway filter membrane.Results At Day 3,the NSCs began to show chemotactic differentiation and grew toward cochlea sensory epithelia.After 9-day co-culture,neurites of NSC-derived neurons predominantly elongated toward hair cells.Immunohistochemical analyses revealed the fibers overlapped with synapsin and hair cells,indicating the formation of new synaptic connections.After 14-day culture,triple staining revealed the fibers overlapped with PSD95 （postsynaptic density） which is juxtaposed with CtBP2 （presynaptic vesicle）,indicating the formation of new ribbon synapse.Conclusions NSC-derived neurons can make synaptic connections with hair cells and provide a model for studying synaptic plasticity and regeneration.Whether the newly forming synapse is functional merits further electrophysiological study.
基金supported by grants from the National Natural Science Foundation of China(Nos.81801941,81525009,81830063,81702228)Shanghai Municipal Clinical Medical Center Project(No.2017ZZ01006)+1 种基金Program of Shanghai Municipal Commission of Health and Family Planning(Nos.20164Y0018,20174Y0212)Fudan University-SIBET Medical Engineering Joint Fund(No.YG2017-012)。
文摘To the Editor:Targeted muscle reinnervation(TMR)is a surgical technique of multiple nerve transfers,providing a potential of improved intuitive prosthetic control via surface electromyography(sEMG)in the high-level upper extremity amputees.[1]However,there is a risk that some of the reinnervations might be unsuccessful,especially for the ulnar nerve.[2]Both the quality control of nerve stumps and the receptor are important factors for the surgery.Assessing the nerve stumps during the surgery and finding more muscles as receptor might address the problem.Biceps,triceps,and brachialis muscles were mostly chosen as receptors for reinnervation in the trans-humeral amputees.Pectoralis major and pectoralis minor were mostly chosen as receptors for reinnervation in the shoulder disarticulation patients.
文摘In modern neuroscience,the most relevant is the study of the problem of reinnervation of tissues after severe injuries.Complete restoration of lost physiological functions is still impossible with lesions of peripheral nerves with the formation of extensive diastasis between their proximal and distal sites.In this case,the standard neurorrhaphy cannot be carried out because of the eruption of the filaments during tension and convergence of the ends.To solve this problem,a technique was developed for autotransplantation of the nerve sections,which is still the gold standard for the reconstruction of extensive nerve defects.However,the presence of significant shortcomings led to the development of the doctrine of the direction of regeneration with the help of conduits.Currently,the use of nerve channels is the most promising technology for peripheral nerve repair after trauma.The most actively developing now is the direction of reinnervation,such as neurotization.Neurotization,in some way,combined all the methods of restoring nerves.The overall goal of all these methods—the restoration of extensive nerve defects—allows them to be combined into a new industry:reinnervating neurosurgery.
文摘Aim:Targeted muscle reinnervation(TMR)surgery has fundamentally changed the management of patients who have suffered or are about to undergo amputation.Providing nerve stumps with a muscle target has been shown to have profound effects on levels of post-amputation pain in relation to phantom limb pain(PLP)and neuroma pain(NP).The primary objective of this report was to quantify pain parameters for this population and to measure the impact on health-related quality of life(HRQol)before and after TMR surgery.In this case series,we evaluate the role of TMR in addressing both pain and the impact of the surgery on the patient’s quality of life.Methods:A retrospective analysis of 15 upper limb amputee patients who underwent TMR by the Relimb Unit in London,UK.Participants’perceptions of pain were determined using the 11-point numerical(Pain)rating scale(NRS)and HRQoL was calculated using the Euroqol EQ-5D-5L questionnaire at two time points,comparing both pain and perceived quality of life pre and post surgery.The Wilcoxon Signed Rank Test was used for the NRS data and a paired sample t-test was used for the EQ-VAS data.Results:A total of 15 patients completed the evaluation.We observed statistically significant reductions in both PLP(pre-operative mean:7.6,post-operative mean:2.7,P<0.05)and NP(pre-operative mean:6.4,post-operative mean:2.5,P<0.05)in these patients.Similarly,HRQoL observed on the EQ-VAS scale demonstrated a significant improvement in quality of life,from 68 pre-operatively to 78 post-procedure(P<0.05).Conclusion:This is the first quantified evaluation of changes in HRQoL after TMR surgery for upper limb amputation.There appears to be a significant improvement in both HRQoL and overall perception of pain.This finding may have important implications for funding and national resource allocation for TMR surgery.
文摘Targeted muscle reinnervation(TMR)is a peripheral nerve procedure that can prevent and treat postamputation pain.The nerve transfer allows for organized nerve regeneration and repair after amputation surgery.The procedure can successfully prevent neuromas despite large size mismatches between the donor and recipient nerves.Here,we discuss the fundamentals of peripheral nerve injury and regeneration as it pertains to TMR.We propose axonal pruning to explain axon behavior when there are large size mismatches between transferred nerves.Given the increasing use of TMR for amputees,future studies should investigate the basic science of peripheral nerves in TMR.Advances in this field have the potential to significantly improve clinical outcomes for these patients.
文摘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.
文摘Osseointegration(OI),targeted muscle reinnervation(TMR),and vascularized composite allotransplantation(VCA)are just a few ways by which our reconstructive ladder is evolving.It is important to recognize that amputation does not necessarily denote failure,but surgeons should strive to find ways to provide these patients with means for obtaining better satisfaction and quality of life postoperatively.TMR and OI have added options for mutilating lower extremity injuries that necessitate amputation.More recently,the senior author(Levin LS)described the"penthouse"floor of the reconstructive ladder being VCA.Despite the advances in VCA over the last 20 years,there are many challenges that face this discipline including indications for patient selection,minimizing immunosuppressive regimens,standardizing outcome measures,establishing reliable protocols for monitoring,and diagnosing and managing rejection.Herein,the authors review TMR,OI,and VCA as additional higher rungs of the reconstructive ladder.
