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Nerve Repair (nerve + repair)
Selected AbstractsNerve Repair: A Conducting-Polymer Platform with Biodegradable Fibers for Stimulation and Guidance of Axonal Growth (Adv. Mater.ADVANCED MATERIALS, Issue 43 200943/2009) Effective functional innervation of medical bionic devices, as well as re-innervation of target tissue in nerve and spinal cord injuries, requires a platform that can stimulate and orientate neural growth. Gordon Wallace and co-workers report on p. 4393 that conducting and nonconducting biodegradable polymers show excellent potential as suitable hybrid substrata for neural regeneration and may form the basis of electrically active conduits designed to accelerate nerve repair. [source] Rapid cortical reorganisation and improved sensitivity of the hand following cutaneous anaesthesia of the forearmEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2009Anders Björkman Abstract The cortical representation of various body parts constantly changes based on the pattern of afferent nerve impulses. As peripheral nerve injury results in a cortical and subcortical reorganisation this has been suggested as one explanation for the poor clinical outcome seen after peripheral nerve repair in humans. Cutaneous anaesthesia of the forearm in healthy subjects and in patients with nerve injuries results in rapid improvement of hand sensitivity. The mechanism behind the improvement is probably based on a rapid cortical and subcortical reorganisation. The aim of this work was to study cortical changes following temporary cutaneous forearm anaesthesia. Ten healthy volunteers participated in the study. Twenty grams of a local anaesthetic cream (EMLA®) was applied to the volar aspect of the right forearm. Functional magnetic resonance imaging was performed during sensory stimulation of all fingers of the right hand before and during cutaneous forearm anaesthesia. Sensitivity was also clinically assessed before and during forearm anaesthesia. A group analysis of functional magnetic resonance image data showed that, during anaesthesia, the hand area in the contralateral primary somatosensory cortex expanded cranially over the anaesthetised forearm area. Clinically right hand sensitivity in the volunteers improved during forearm anaesthesia. No significant changes were seen in the left hand. The clinically improved hand sensitivity following forearm anaesthesia is probably based on a rapid expansion of the hand area in the primary somatosensory cortex which presumably results in more nerve cells being made available for the hand in the primary somatosensory cortex. [source] Effect of neurotrophin-3 on reinnervation of the larynx using the phrenic nerve transfer techniqueEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2007Paul J. Kingham Abstract Current techniques for reinnervation of the larynx following recurrent laryngeal nerve (RLN) injury are limited by synkinesis, which prevents functional recovery. Treatment with neurotrophins (NT) may enhance nerve regeneration and encourage more accurate reinnervation. This study presents the results of using the phrenic nerve transfer method, combined with NT-3 treatment, to selectively reinnervate the posterior cricoarytenoid (PCA) abductor muscle in a pig nerve injury model. RLN transection altered the phenotype and morphology of laryngeal muscles. In both the PCA and thyroarytenoid (TA) adductor muscle, fast type myosin heavy chain (MyHC) protein was decreased while slow type MyHC was increased. These changes were accompanied with a significant reduction in muscle fibre diameter. Following nerve repair there was a progressive normalization of MyHC phenotype and increased muscle fibre diameter in the PCA but not the TA muscle. This correlated with enhanced abductor function indicating the phrenic nerve accurately reinnervated the PCA muscle. Treatment with NT-3 significantly enhanced phrenic nerve regeneration but led to only a small increase in the number of reinnervated PCA muscle fibres and minimal effect on abductor muscle phenotype and morphology. Therefore, work exploring other growth factors, either alone or in combination with NT-3, is required. [source] Nerve Repair: A Conducting-Polymer Platform with Biodegradable Fibers for Stimulation and Guidance of Axonal Growth (Adv. Mater.ADVANCED MATERIALS, Issue 43 200943/2009) Effective functional innervation of medical bionic devices, as well as re-innervation of target tissue in nerve and spinal cord injuries, requires a platform that can stimulate and orientate neural growth. Gordon Wallace and co-workers report on p. 4393 that conducting and nonconducting biodegradable polymers show excellent potential as suitable hybrid substrata for neural regeneration and may form the basis of electrically active conduits designed to accelerate nerve repair. [source] Thyroid hormone enhances transected axonal regeneration and muscle reinnervation following rat sciatic nerve injuryJOURNAL OF NEUROSCIENCE RESEARCH, Issue 8 2010Petrica-Adrian Panaite Abstract Improvement of nerve regeneration and functional recovery following nerve injury is a challenging problem in clinical research. We have already shown that following rat sciatic nerve transection, the local administration of triiodothyronine (T3) significantly increased the number and the myelination of regenerated axons. Functional recovery is a sum of the number of regenerated axons and reinnervation of denervated peripheral targets. In the present study, we investigated whether the increased number of regenerated axons by T3-treatment is linked to improved reinnervation of hind limb muscles. After transection of rat sciatic nerves, silicone or biodegradable nerve guides were implanted and filled with either T3 or phosphate buffer solution (PBS). Neuromuscular junctions (NMJs) were analyzed on gastrocnemius and plantar muscle sections stained with rhodamine ,-bungarotoxin and neurofilament antibody. Four weeks after surgery, most end-plates (EPs) of operated limbs were still denervated and no effect of T3 on muscle reinnervation was detected at this stage of nerve repair. In contrast, after 14 weeks of nerve regeneration, T3 clearly enhanced the reinnervation of gastrocnemius and plantar EPs, demonstrated by significantly higher recovery of size and shape complexity of reinnervated EPs and also by increased acetylcholine receptor (AChRs) density on post synaptic membranes compared to PBS-treated EPs. The stimulating effect of T3 on EP reinnervation is confirmed by a higher index of compound muscle action potentials recorded in gastrocnemius muscles. In conclusion, our results provide for the first time strong evidence that T3 enhances the restoration of NMJ structure and improves synaptic transmission. © 2010 Wiley-Liss, Inc. [source] Immediate anti-tumor necrosis factor-, (etanercept) therapy enhances axonal regeneration after sciatic nerve crushJOURNAL OF NEUROSCIENCE RESEARCH, Issue 2 2010Kinshi Kato Abstract Peripheral nerve regeneration begins immediately after injury. Understanding the mechanisms by which early modulators of axonal degeneration regulate neurite outgrowth may affect the development of new strategies to promote nerve repair. Tumor necrosis factor-, (TNF-,) plays a crucial role in the initiation of degenerative cascades after peripheral nerve injury. Here we demonstrate using real-time Taqman quantitative RT-PCR that, during the time course (days 1,60) of sciatic nerve crush, TNF-, mRNA expression is induced at 1 day and returned to baseline at 5 days after injury in nerve and the corresponding dorsal root ganglia (DRG). Immediate therapy with the TNF-, antagonist etanercept (fusion protein of TNFRII and human IgG), administered systemically (i.p.) and locally (epineurially) after nerve crush injury, enhanced the rate of axonal regeneration, as determined by nerve pinch test and increased number of characteristic clusters of regenerating nerve fibers distal to nerve crush segments. These fibers were immunoreactive for growth associated protein-43 (GAP-43) and etanercept, detected by anti-human IgG immunofluorescence. Increased GAP-43 expression was found in the injured nerve and in the corresponding DRG and ventral spinal cord after systemic etanercept compared with vehicle treatments. This study established that immediate therapy with TNF-, antagonist supports axonal regeneration after peripheral nerve injury. © 2009 Wiley-Liss, Inc. [source] Nerve conduits and growth factor delivery in peripheral nerve repairJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 2 2007Lukas A. Pfister Abstract Peripheral nerves possess the capacity of self-regeneration after traumatic injury. Transected peripheral nerves can be bridged by direct surgical coaptation of the two nerve stumps or by interposing autografts or biological (veins) or synthetic nerve conduits (NC). NC are tubular structures that guide the regenerating axons to the distal nerve stump. Early synthetic NC have primarily been made of silicone because of the relative flexibility and biocompatibility of this material and because medical-grade silicone tubes were readily available in various dimensions. Nowadays, NC are preferably made of biodegradable materials such as collagen, aliphatic polyesters, or polyurethanes. Although NC assist in guiding regenerating nerves, satisfactory functional restoration of severed nerves may further require exogenous growth factors. Therefore, authors have proposed NC with integrated delivery systems for growth factors or growth factor,producing cells. This article reviews the most important designs of NC with integrated delivery systems for localized release of growth factors. The various systems discussed comprise NC with growth factors being released from various types of matrices, from transplanted cells (Schwann cells or mesenchymal stem cells), or through genetic modification of cells naturally present at the site of injured tissue. Acellular delivery systems for growth factors include the NC wall itself, biodegradable microspheres seeded onto the internal surface of the NC wall, or matrices that are filled into the lumen of the NC and immobilize the growth factors through physical-chemical interactions or specific ligand-receptor interactions. A very promising and elegant system appears to be longitudinally aligned fibers inserted in the lumen of a NC that deliver the growth factors and provide additional guidance for Schwann cells and axons. This review also attempts to appreciate the most promising approaches and emphasize the importance of growth factor delivery kinetics. [source] Improvement of peripheral nerve regeneration in acellular nerve grafts with local release of nerve growth factorMICROSURGERY, Issue 4 2009Hailong Yu M.D. Previous studies have demonstrated the potential of growth factors in peripheral nerve regeneration. A method was developed for sustained delivery of nerve growth factor (NGF) for nerve repair with acellular nerve grafts to augment peripheral nerve regeneration. NGF-containing polymeric microspheres were fixed with fibrin glue around chemically extracted acellular nerve grafts for prolonged, site-specific delivery of NGF. A total of 52 Wister rats were randomly divided into four groups for treatment: autografting, NGF-treated acellular grafting, acellular grafting alone, and acellular grafting with fibrin glue. The model of a 10-mm sciatic nerve with a 10-mm gap was used to assess nerve regeneration. At the 2nd week after nerve repair, the length of axonal regeneration was longer with NGF-treated acellular grafting than acellular grafting alone and acellular grafting with fibrin glue, but shorter than autografting (P < 0.05). Sixteen weeks after nerve repair, nerve regeneration was assessed functionally and histomorphometrically. The percentage tension of the triceps surae muscles in the autograft group was 85.33 ± 5.59%, significantly higher than that of NGF-treated group, acellular graft group and fibrin-glue group, at 69.79 ± 5.31%, 64.46 ± 8.48%, and 63.35 ± 6.40%, respectively (P < 0.05). The ratio of conserved muscle-mass was greater in the NGF-treated group (53.73 ± 4.56%) than in the acellular graft (46.37 ± 5.68%) and fibrin glue groups (45.78 ± 7.14%) but lower than in the autograft group (62.54 ± 8.25%) (P < 0.05). Image analysis on histological observation revealed axonal diameter, axon number, and myelin thickness better with NGF-treated acellular grafting than with acellular grafting alone and acellular grafting with fibrin glue (P < 0.05). There were no significant differences between NGF-treated acellular grafting and autografting. This method of sustained site-specific delivery of NGF can enhance peripheral nerve regeneration across short nerve gaps repaired with acellular nerve grafts. © 2009 Wiley-Liss, Inc. Microsurgery, 2009. [source] Nerve regeneration along bioengineered scaffoldsMICROSURGERY, Issue 5 2007S. Geuna M.D. Tissue engineering has recently seen great advancements in many medical fields, including peripheral nerve reconstruction. In the rat median nerve model, we investigated nerve repair by means of bioengineered tissue scaffolds (muscle-vein-combined tubes) focusing on changes in the neuregulin-1/ErbB-receptor system which represents one of the main regulatory systems of axo-glial interaction in peripheral nerves. Repaired nerves were withdrawn at 5, 15, and 30 days postoperative and processed for morphological and retro-transcriptase polymerase chain reaction (RT-PCR) analysis. Results revealed an early and progressive increase in the expression of NRG1, isoform only, while the appearance of the , isoform of NRG1, which is normally present in peripheral nerves, was delayed. In regards to ErbB2 and ErbB3 receptors, their expression increased progressively inside the muscle-vein-combined scaffolds, though with different kinetics. Taken together, these results suggest that variations in neuregulin-1/ErbB system activation play a key role in peripheral nerve regeneration along bioengineered muscle-vein-combined scaffolds. Since similar variations are also detectable in denervated skeletal muscles, it can be hypothesized that the existence of a NRG1's autocrine/paracrine trophic loop shared by both glial and muscle fibers could be responsible for the effectiveness of muscle-vein-combined conduits for repairing nerve defects. © 2007 Wiley-Liss, Inc. Microsurgery, 2007. [source] Origin and history of end-to-side neurorrhaphyMICROSURGERY, Issue 1 2007I. Papalia M.D. This historical note offers a perspective concerning the origin of the employment of end-to-side (termino-lateral) anastomosis for nerve repair and summarizes the works that have been published on this surgical technique through the first part of the 20th Century. While the origin of end-to-side neurorrhaphy is usually dated to the beginning of the 20th Century, some works referring to this technique were published earlier, the first of which dates as far back as 1873. A number of interesting clinical and experimental studies have been carried out on end-to-side nerve anastomosis during the first years of the twentieth century. However, this literature is not easily detectable through current online scientific databases. In this paper we will give an overview of these early works. This history contributes interesting information to the debate surrounding this surgical concept and adds perspective to the use of a technique that has attracted a great deal of attention over the last 15 years. © 2007 Wiley-Liss, Inc. Microsurgery, 2007. [source] Factors affecting the outcome of peripheral nerve surgeryMICROSURGERY, Issue 4 2006Hanno Millesi M.D. Over the last 40 years, various factors that influence the outcome of peripheral nerve surgery have been recognized. Some of these factors, such as age of the patient and time interval between injury and surgery, cannot be controlled by the surgeon. On the other hand, other factors related to technical details are the topic of constant debate and improvement. Recently, surgeons have become increasingly aware of issues such as the environment at the site of the nerve repair, compression from an integument that is too tight, or muscle balance. © 2006 Wiley-Liss, Inc. Microsurgery, 2006. [source] Recovery of touch after median nerve lesion and subsequent repairMICROSURGERY, Issue 1 2003M.F. Meek M.D., Ph.D. Many techniques have been developed for the evaluation of peripheral nerve function. Consequently, physicians use different techniques in the clinic. This study describes the evaluation of touch after median nerve lesions in the forearm and repair. In order to evaluate touch, 25 patients, aged 11,51 years (mean, 29 years), were evaluated 3,10.5 years (mean, 5 years) after median nerve repair. The evaluation included the moving two-point discrimination test and Semmes-Weinstein monofilaments. We showed that 32% good,excellent results can be obtained with difficult nerve lesions. The results could have been improved if a sensory reeducation regime had been applied. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:2,5 2003 [source] Inside-out vein graft and inside-out artery graft in rat sciatic nerve repairMICROSURGERY, Issue 1 2003Alécio Santos Barcelos Ph.D. Although veins and arteries present similar wall structures, there are differences which may be relevant in peripheral nerve reconstruction. Inside-out vein grafts (IOVG) have been satisfactorily used to repair both motor and sensitive nerves. However, the inside-out artery graft (IOAG) is a new technique and not fully investigated. Our study presents comparative morphological data on nerve regeneration achieved with IOVG and IOAG in the repair of Wistar rat sciatic nerves. Jugular veins and aorta arteries were harvested from donor animals and used "inside-out" to bridge a 10-mm gap. Animals were sacrificed at 10 weeks to evaluate nerve regeneration. Both techniques presented great variability in nervous tissue, though some animals showed satisfactory results. Different intensities of scarring processes might have interfered with nerve regeneration. Although IOVG and IOAG techniques showed similar morphometric results, in general, IOVG presented a closer-to-normal nerve organization than IOAG. © 2003 Wiley-Liss, Inc. MICROSURGERY 23:66,71 2003 [source] Sonographic measurements of longitudinal median nerve sliding in patients following nerve repairMUSCLE AND NERVE, Issue 3 2010Ertan Erel FRCS Abstract Nerve sliding may be restricted following nerve repair. This could result in increased tension across the repair site and lead to poor functional recovery of the nerve. Ultrasound was used to examine longitudinal median nerve sliding in 10 patients who had previously undergone nerve repair surgery following complete division of the median nerve. The median longitudinal movement in the forearm in response to metacarpophalangeal (MCP) joint movements was 2.15 mm on the injured side, compared with 2.54 mm on the uninjured side, a difference that was significant. There was a significant reduction in nerve sliding following repair (median = 8%, range ,8% to 54%; P = 0.02), which correlated with time from injury to surgery (rho = 0.87; P = 0.001). These results indicate that ultrasound can be used as an adjunct assessment tool to monitor both morphology and sliding of the nerve through the repair site. It may have future application in the investigation of patients with persisting functional impairment following primary nerve repair. Muscle Nerve, 2009 [source] Outcomes of static and dynamic facial nerve repair in head and neck cancerTHE LARYNGOSCOPE, Issue 3 2010Tim A. Iseli MBBS Abstract Objectives/Hypothesis: Determine outcomes associated with nerve grafting versus static repair following facial nerve resection. Study Design: Retrospective chart review. Methods: Charts from 105 patients who underwent facial nerve reconstruction between January 1999 and January 2009 were reviewed. The majority had parotid malignancy (78.1%), most commonly squamous cell carcinoma (50.5%). Patients underwent static (n = 72) or dynamic (n = 33) reconstruction with nerve grafting. Facial nerve function was measured using the House-Brackmann (H-B) scale. Results: Patients receiving static reconstruction were on average 10.3 years older (P = .002). Mean overall survival for tumor cases was 61.9 months; parotid squamous cell carcinoma was associated with worse prognosis (P = .10). Median follow-up was 16.1 months (range, 4,96.1 months). Most (97%) patients receiving a nerve graft had some return of function at a median of 6.2 months postoperatively (range, 4,9 months) and the majority (63.6%) had good function (H-B score ,4). Patients having static reconstruction (29.2%) were more likely to have symptomatic facial palsy than those having a nerve graft (15.2%, P = .12). Conclusions: Where possible, nerve grafting is the preferred method of facial nerve reconstruction. Although elderly patients with parotid malignancy have traditionally been considered poor candidates for nerve grafting, we demonstrate good results within 9 months of facial nerve repair even with radiotherapy, the use of long grafts (>6 cm), and prolonged preoperative dysfunction. Laryngoscope, 2010 [source] Timing of Human Insulin-Like Growth Factor-1 Gene Transfer in Reinnervating Laryngeal Muscle,THE LARYNGOSCOPE, Issue 4 2004Hideki Nakagawa MD Abstract Objectives/Hypothesis The authors have designed a rat laryngeal paralysis model to study gene transfer strategies using a muscle-specific expression system to enhance local delivery of human insulin-like growth factor-1 (hIGF-1). In preliminary studies, a nonviral vector containing the ,-actin promoter and human hIGF-1 sequence produced both neurotrophic and myotrophic effects 1 month after single injection of plasmid formulation into paralyzed rat thyroarytenoid muscle in vivo. Based on these findings, it is hypothesized that the effects of hIGF-1 will enhance the results of laryngeal muscle innervation procedures. The timing of gene delivery relative to nerve repair is likely to be important, to optimize the results. Study Design Prospective analysis. Methods The effects of nonviral gene transfer for the delivery of hIGF-1 were evaluated in rats treated immediately following recurrent laryngeal nerve transection and repair and in rats receiving a delayed treatment schedule, 30 days after nerve transection and repair. Gene transfer efficiency was determined using polymerase chain reaction and reverse transcriptase,polymerase chain reaction techniques. Muscle fiber diameter, motor endplate length, and percentage of motor endplates with nerve contact were examined to assess hIGF-1 trophic effects. Results Compared with reinnervated untreated control samples, both early and delayed hIGF-1 transfer resulted in significant increase in muscle fiber diameter. Motor endplate length was significantly decreased and nerve/motor endplate contact was significantly increased following delayed gene transfer, but not after early treatment. Conclusion We infer from results of the study that delayed hIGF-1 gene transfer delivered by a single intramuscular injection will enhance the process of muscle reinnervation. The clinical relevance of these findings supports the future application of gene therapy using nonviral vectors for management of laryngeal paralysis and other peripheral nerve injuries. [source] HS07 TOE TRANSFER , TECHNIQUES & RESULTSANZ JOURNAL OF SURGERY, Issue 2007L. C. Teoh Toe to thumb-finger transfer requires the understanding of microsurgery and reconstructive technique. The success is measured by the viability of the toe and eventually recreating the function of the original loss. In harvesting of the toe, the big and second toe follows almost the same technique. Identifying the toe artery over the first web space and then dissecting proximally into the intermetatarsal artery is the best approach. To dissect the artery from proximal to distal is often fraught with many dangers. In my cases about 50% the plantar artery is dominant. Anticipation and planning of the artery length is crucial. In toe to thumb transfer the choice can be 2nd toe, total big toe, trimmed big toe or wrap around transfer. In our local populations, 2nd toe is always a good choice. First reconstruction with flap resurfacing may be necessary if the thumb amputation is very proximal. Toe to fingers transfer is usually indicated in 4 finger loss of the hand. In toe to finger transfer I prefer the two 2nd toes transfer into the middle and ring finger position. As the transferred toes can regain less that 50% of motion, the positioning of the toes should be opposable to the thumb. The concept of total reconstruction should be closely followed. Stable skeletal fixation, tendon weave technique, good nerve repair, adequate skin coverage and primary healing are important to ensure good outcome result. [source] HS09 REPLANTATION SURGERY , THE RECONSTRUCTIVE APPROACHANZ JOURNAL OF SURGERY, Issue 2007L. C. Teoh The function of the replanted parts can be improved if attention to reconstruction techniques is carried out. These reconstructive techniques are: 1) adequate debridement and shortening, 2) stable skeletal fixation, 3) strengthened tendon repairs, 4) quality nerve repair, 5) extensive vascular anastomosis, 6) complete skin coverable, and 7) Early intensive active rehabilitation. 1) The debridement should be generous and the shortening judicious. More than 50% of the skin should be in direct contact, and direct anastomosis of some of vessels should be possible. 2) The skeletal stabilization should be of good very quality that will allow free mobilization of the joints. 3) The repair of the tendons should take advantage of the excess length for a strengthen repair. Some degree of active mobilization should be make possible. 4) Primary nerve grafting or nerve transfer should be considered if there is loss of nerve length. 5) Vascular repair should be on the basis of as many as possible the number of arteries and veins that can be found for anastomosis. 6) Any residual skin defect should be planned for a proper resurfacing within the next 5 to 10 days. 7) Early intensive active rehabilitation should be prescribed. Gradual active ROM for tendon gliding should be instituted with in the first week. The function of the replanted digit and hand has continued to improve with the reconstructive approach. With further experience the reconstructive approach can be done in all cases with confidence. [source] A Novel Approach to Align Adult Neural Stem Cells on Micropatterned Conduits for Peripheral Nerve Regeneration: A Feasibility StudyARTIFICIAL ORGANS, Issue 1 2009Shan-hui Hsu Abstract There is a strong need for nerve-tissue engineering using the guide conduit and Schwann cells or neural stem cells (NSCs) with regeneration potential for injured peripheral nerves. In this study, micropatterned poly(d,l -lactide) (PLA) conduits were fabricated by microlithography and solvent-casting. The PLA conduits were seeded with the novel green fluorescent protein (GFP)-positive adult mouse NSCs obtained using the patented method of one of the authors. About 85% of the seeded NSCs were successfully aligned on the micropatterned conduits within 72 h and expressed the genes related to the production of neurotrophic factors. Gene expressions for the neurotrophic factors, such as nerve growth factor and brain-derived neurotrophic factor were upregulated by the micropatterned conduits at 72 h. The micropatterned PLA conduits seeded with the aligned NSCs were used to bridge the 10-mm sciatic nerve gaps in rats and were found to facilitate nerve repair and functional recovery during a period of 6 weeks compared with the nonseeded group. This model can be used to study the role of adult NSCs in peripheral-nerve regeneration in the future. [source] Repair of the trigeminal nerve: a reviewAUSTRALIAN DENTAL JOURNAL, Issue 2 2010RHB Jones Abstract Nerve surgery in the maxillofacial region is confined to the trigeminal and facial nerves and their branches. The trigeminal nerve can be damaged as a result of trauma, local anaesthesia, tumour removal and implant placement but the most common cause relates to the removal of teeth, particularly the inferior alveolar and lingual nerves following third molar surgery. The timing of nerve repair is controversial but it is generally accepted that primary repair at the time of injury is the best time to repair the nerve but it is often a closed injury and the operator does not know the nerve is injured until after the operation. Early secondary repair at about three months after injury is the most accepted time frame for repair. However, it is also thought that a reasonable result can be obtained at a later time. It is also generally accepted that the best results will be obtained with a direct anastamosis of the two ends of the nerve to be repaired. However, if there is a gap between the two ends, a nerve graft will be required to bridge the gap as the two ends of the nerve will not be approximated without tension and a passive repair is important for the regenerating axons to grow down the appropriate perineural tubes. Various materials have been used for grafting and include autologous grafts, such as the sural and greater auricular nerves, vein grafts, which act as a conduit for the axons to grow down, and allografts such as Neurotube, which is made of polyglycolic acid (PGA) and will resorb over a period of time. [source] Effect of weak, interrupted sinusoidal low frequency magnetic field on neural regeneration in rats: Functional evaluationBIOELECTROMAGNETICS, Issue 5 2005Marijan Bervar Abstract A study of the effect of weak, interrupted sinusoidal low frequency magnetic field (ISMF) stimulation on regeneration of the rat sciatic nerve was carried out. In the experiment, 60 Wistar rats were used: 24 rats underwent unilateral sciatic nerve transection injury and immediate surgical nerve repair, 24 rats underwent unilateral sciatic nerve crush injury, and the remaining 12 rats underwent a sham surgery. Half of the animals (n,=,12) with either sciatic nerve lesion were randomly chosen and exposed between a pair of Helmholtz coils for 3 weeks post-injury, 4 h/day, to an interrupted (active period to pause ratio,=,1.4 s/0.8 s) sinusoidal 50 Hz magnetic field of 0.5 mT. The other half of the animals (n,=,12) and six rats with sham surgery were used for two separate controls. Functional recovery was followed for 6 weeks for the crush injuries and 7½ months for the transection injuries by video assisted footprint analysis in static conditions and quantified using a recently revised static sciatic index (SSI) formula. We ascertained that the magnetic field influence was weak, but certainly detectable in both injury models. The accuracy of ISMF influence detection, determined by the one-way repeated measures ANOVA test, was better for the crush injury model: F(1, 198),=,9.0144, P,=,.003, than for the transection injury model: F(1, 198),=,6.4826, P,=,.012. The Student,Newman,Keuls range test for each response day yielded significant differences (P,<,.05) between the exposed and control groups early in the beginning of functional recovery and later on from the points adjacent to the beginning of the plateau, or 95% of functional recovery, and the end of observation. These differences probably reflect the ISMF systemic effect on the neuron cell bodies and increased and more efficient reinnervation of the periphery. Bioelectromagnetics 26:351,356, 2005. © 2005 Wiley-Liss, Inc. [source] Clinical significance of suprascapular nerve mobilizationCLINICAL ANATOMY, Issue 8 2005Kale D. Bodily Abstract The anatomy of the suprascapular nerve is important to surgeons when focal nerve lesions necessitate surgical repair. Recent experience with a patient who had a complete suprascapular nerve lesion in the retroclavicular region (combined with axillary and musculocutaneous nerve lesions) is presented to illustrate that successful direct nerve repair is possible despite resection of a neuroma. Specifically, we found that neurolysis and mobilization of the suprascapular nerve and release of the superior transverse scapular ligament provided the necessary nerve length to achieve direct nerve repair after the neuroma was removed. A combined supraclavicular and infraclavicular approach to the suprascapular nerve provided excellent visualization, especially in the retroclavicular region. Postoperatively, the patient recovered complete shoulder abduction and external rotation with the direct repair, an outcome uncommonly achieved with interpositional grafting. Based on our operative experience, we set out to quantify the length that the suprascapular nerve could be mobilized with neurolysis. Mobilization of the nerve and release of the superior transverse scapular ligament generated an average of 1.6 cm and 0.7 cm of extra nerve length respectively, totaling 2.3 cm of additional usable nerve length overall. The ability to expose the suprascapular nerve in the retroclavicular/infraclavicular region and to mobilize the suprascapular nerve for possible direct repair has not been previously emphasized and is clinically important. This surgical approach and technique permits direct nerve repair after resection of a focal neuroma in the retroclavicular or infraclavicular region, thus avoiding interpositional grafting, and improving outcomes. Clin. Anat. 18:573,579, 2005. © 2005 Wiley-Liss, Inc. [source] | |||||||||||||