Autologous Muscle Grafts Research Articles

A critical size volumetric muscle loss model in mouse masseter with impaired mastication on nutrition.

Orofacial muscle defect due to congenital anomalies, tumour ablation or traumatic accident that exceeds endogenous regeneration capacity may lead to sustained deficits in masticatory function and nutrition intake. Functional recovery has always been the goal of muscle tissue repair, but currently, there is no suitable model for quantitative analyses of either functional consequences or treatment efficacy of orofacial muscle defect. This study proposed a critical size volumetric muscle loss (VML) model in mouse masseter with impaired mastication on nutrition. Full-thickness VML defects in diameter of 1.0, 1.5, 2.0 and 3.0 mm were generated in the centre of the mouse masseter using a biopsy punch to determine the critical size for functional impairment. In the VML region, myogenesis was dampened but fibrogenesis was activated, as long with a reduction in the density of the neuromuscular junction and an increase in vascular density. Accordingly, persistent fibrosis was observed in the centre region of VML in all diameters. The 2.0 mm diameter was the critical threshold to masticatory function impairment after VML in the masseter. VML of 3.0 mm diameter led to a significant impact on nutrition intake and body weight gain. Autologous muscle graft effectively relieved the fibrosis and functional deficit after VML injury in the masseter. This model serves as a reliable tool in studying functional recovery strategies for orofacial muscle defects.

Microvascular decompression using autologous muscle graft for trigeminal neuralgia: a case series and meta-analysis.

We aimed to describe a case series of patients diagnosed with trigeminal neuralgia (TN) who were submitted to microvascular decompression (MVD) using autologous muscle graft (AMG) and perform a systematic review and meta-analysis. Forty-four adult patients who underwent MVD using AMG between 2012 and 2022 were studied retrospectively. Demographic, clinical, and surgical factors were assessed. We systematically reviewed PubMed, Embase, and Cochrane Library from inception to May 2023. We used random-effects model for all outcomes. Heterogeneity was assessed with I2. We used R software 4.3.1 for all statistical analyses. Among patients in the case series, the mean age was 52 ± 12.9 years, and the proportion of females was 65.9%. Forty-one patients (93.2%) presented complete pain relief after a mean follow-up of 7.7 years. The pooled analysis of immediate pain relief was 91.3% (95% CI 82-96%; I2=78%). The good pain relief during follow-up was 88.2% (95% CI 78-94%; I2=80%) at follow-up. The recurrence rates at 6, 12, 36 months, and during follow-up were 6.2%, 10.5%, 10.3%, and 11%, respectively. In this case series and meta-analysis of over 440 patients, our findings suggest that the practice of MVD using AMG may be an efficient option in the short term as surgical treatment for TN. Further trials should compare AMG with other materials and its effectiveness in a long-term follow-up.

Endoscopic Endonasal Transsphenoidal Approach to Repair Cerebrospinal Fluid Rhinorrhea After an Anterior Clinoidectomy for Aneurysm Clipping: Series of 4 Cases.

Cerebrospinal fluid (CSF) rhinorrhea through a pneumatized optic strut is a known potential complication after an anterior clinoidectomy that is used to microsurgically clip a proximal internal carotid artery aneurysm. The original craniotomy site can be reopened to repair the skull base defect, but this technique has disadvantages. To avoid a repeat craniotomy and address the limitations of a transcranial approach, a straightforward alternative was used for skull base repair-the binostril endoscopic endonasal transsphenoidal approach. This retrospective case series describes the use of endoscopic transsphenoidal repair and outcomes for patients with CSF leaks after anterior clinoidectomy for aneurysm repair between January 1, 2015, and December 31, 2019. Four adult patients (3 women and 1 man) with a mean age of 59.5 years were reviewed. Skull base repair occurred on average 24 days (range, 4-75 days) after the index operation. After demucosalization of the parasellar sphenoid sinus, the fistula in the pneumatized optic strut was reconstructed with a free nasal mucosal graft with or without an autologous muscle graft. None of the patients developed a recurrent CSF leak at a mean follow-up of 12.5 months (range, 8-22 months), and none experienced complications. The endoscopic endonasal transsphenoidal approach was safe and effective for skull base repair in 4 patients with CSF rhinorrhea after an anterior clinoidectomy for aneurysm clipping.

Complications of Microvascular Decompression in patients with Trigeminal Neuralgia

Objective: To determine the frequency of complications of microvascular decompression for patients with trigeminal neuralgia undergoing surgical decompression. Materials and Methods: A descriptive case study was carried out in the Neurosurgery Unit 1, Lahore General Hospital. The study included 80 patients who fulfilled the inclusion criteria. Informed consent was obtained and possible outcomes and complications of surgery were explained beforehand to the patients. Demographic details were noted. Surgical site infection, CSF leak, Facial numbness, Facial palsy, Hearing impairment, and Postoperative hematoma as complications were assessed. The presence of complications was recorded. Data was stratified for age and gender from. Chi-square was used as a statistical test, taking a p-value ?0.05 as the level of significance. Results: The study included 80 patients. The mean age of the patients was 40.8 ± 11.7 years. Overall complications were reported in 21 (26.3%) patients. Distribution of complications was as follows; surgical site infection 2 (9.5%), CSF leak (19.0%), facial palsy 5 (23.8%), facial numbness 9 (42.9%), hearing impairment 2 (9.5%) and post-operative hematoma 5 (23.8%). Conclusion: Microvascular decompression (MVD) is recommended neurosurgical procedure for medically refractory patients with trigeminal pain if there is no contraindication for surgery. Surgical complications can be minimized by meticulous surgery resulting in adequate tissue respect. Another means to get better and long-lasting results with fewer complications is by using an autologous muscle graft.

Microvascular Decompression using muscle graft for interposition: A retrospective study

Objective: This studies aims to evaluate the outcome of Microvascular Decompression (MVD) using a muscle graft for interposition in Trigeminal Neuralgia (TN), Hemifacial Spasm (HFS) and Glossopharyngeal Neuralgia (GPN). All surgeries were performed by a single surgeon (G.R.S).
 Methods: In total, 26 patients with TN, HFS and GPN underwent MVD from September 2007 to April 2019. All the patients were either medically refractory or poor symptom tolerance. The mean follow-up period was 72 months. 
 Results: Each MVD was performed using an autologous muscle graft with interposition of vessels. One patient (3.84%) had reoccurrence after MVD with muscle graft and two patients (7.69%) had partial relief.
 Conclusion: Various types of prosthesis are used for transposition and interposition of vessels in MVD surgeries. Although in our case series we didn't use any prosthesis for the comparative outcome, the use of muscle graft showed minimal reoccurrence rate with benefit of being cost effective. Therefore, we need randomized controlled trials to prove the superiority of muscle graft from other prosthesis material.

Humanized skeletal muscle in MYF5/MYOD/MYF6-null pig embryos.

Because post-mortem human skeletal muscle is not viable, autologous muscle grafts are typically required in tissue reconstruction after muscle loss due to disease or injury. However, the use of autologous tissue often leads to donor-site morbidity. Here, we show that intraspecies and interspecies chimaeric pig embryos lacking native skeletal muscle can be produced by deleting the MYF5, MYOD and MYF6 genes in the embryos via CRISPR, followed by somatic-cell nuclear transfer and the delivery of exogenous cells (porcine blastomeres or human induced pluripotent stem cells) via blastocyst complementation. The generated intraspecies chimaeras were viable and displayed normal histology, morphology and function. Human:pig chimaeras generated with TP53-null human induced pluripotent stem cells led to higher chimaerism efficiency, with embryos collected at embryonic days 20 and 27 containing humanized muscle, as confirmed by immunohistochemical and molecular analyses. Human:pig chimaeras may facilitate the production of exogenic organs for research and xenotransplantation.

Basilar Artery Injury During Endonasal Surgery: Stepwise to Control Bleeding.

Intraoperative injury during endoscopic endonasal surgery of the carotid artery has been previously described in the literature. However, the accidental damage of the basilar artery in such scenario is not defined. To define the protocol of action for massive bleeding from an artery in the posterior fossa. The reported patient was diagnosed with a partially calcified clival chordoma featured by a huge intradural component. An endoscopic endonasal transpterygoid transclival approach was selected for the treatment of this tumor. During the surgical procedure, the basilar artery injury was injured, causing intense bleeding. We present and discuss the surgical maneuvers that could save a patient's life after this dramatic complication. Different techniques were performed in order to control the massive bleeding, including injection of hemotastic matrix with thrombin (Floseal©), bipolar coagulation, and vessel reconstruction by means of a vascular clip. Finally, an autologous muscle graft reinforced with an overlying fibrin sealant patch (Tachosil©) was chosen and was an effective technique. Afterwards, the patient was treated with a flow diverter device to occlude an iatrogenic pseudoaneurysm. A monoplegia of the right upper limb was the only remarkable sequel 6 mo after surgery. The muscle graft together with the coordinated action with interventional neuroradiology for the reconstruction of the vessel are possibly the best options to try to preserve the neurological function. In such a scenario, the assumption of potential ischemic events prevails over the intraoperative death of the patient.

Microvascular Decompression using Muscle Graft for Vertebral Artery Medullary Compression Syndrome


 It is well known that brainstem dysfunction may be caused by vascular compression of the medulla oblongata. However, only a limited number of reports have found microvascular decompression surgery to be an effective treatment for symptomatic patients with medulla oblongata dysfunction.
 This report describes a patient with vertebral artery compression of lateral medulla oblongata who presented with lateral medullary syndrome. Microvascular decompression surgery using the transcondylar fossa approach was effective in relieving patient symptoms.
 The transcondylar fossa approach and the transposition of vertebral artery along with autologous muscle graft interposition technique is appropriate in microvascular decompression surgery to relieve vertebral artery compression of medulla oblongata.
 

Revision Surgery Technique in the Treatment of Refractory Subcutaneous Cerebrospinal Fluid Collection Combined with Intracranial Infection Following Posterior Fossa Surgery.

ObjectiveCerebrospinal fluid (CSF) leakage remains the most common and serious complication following posterior fossa surgery. Persistent subcutaneous CSF collections can cause wound dehiscence and predispose patients to intracranial infection. Management with conservative treatment fails in up to 40% of patients, and revision surgery remains the last resort. We hereby introduce a novel surgical technique using muscle graft or pedicled trapezius muscle flaps to repair dura and skull base defect for the treatment of subcutaneous CSF collections refractory to conservative management.MethodsA retrospective chart review was conducted for six patients who presented to our institution from 2012 to 2020, with subcutaneous CSF collections following posterior fossa surgeries and had undergone revision surgeries after unsuccessful management with conservative treatments. Patient demographics, etiologies, culture results, revision procedures, follow-ups, and recurrences of fluid collections were collected.ResultsOf these six patients, two underwent repair of dura and skull base defect with pedicled trapezius muscle flaps, and four had arachnoid fistula repaired with autologous muscle graft. All six patients fully recovered. CSF leakage and subcutaneous fluid collections were resolved. No recurrences occurred upon the last follow-ups.ConclusionA revision surgery using muscle graft or pedicled trapezius muscle flaps to repair the dura and skull base defect is effective at treating persistent cerebrospinal fluid leakage and subcutaneous fluid collection refractory to conservative treatment.

Integrin-α7 signaling regulates connexin 43, M-cadherin, and myoblast fusion.

Regenerative medicine treatments for severe skeletal muscle injuries are limited, resulting in persistent functional deficits. Clinical options include neglecting the wound with the expectation that fibrosis will develop or using an autologous muscle graft with minimal functional improvement. A regenerative matrix can be used, but muscle fiber development on these matrices remains a challenge in vivo. Here, we explored the fundamental mechanisms that mediate cell-substrate signaling and its effect on cell-cell communication during myoblast fusion and tube formation to improve outcomes following implantation of matrices used to stimulate muscle regeneration. We previously reported that integrin-α7 was increased on anisotropic biomaterials, suggesting a role for α7β1 signaling in myoblast communication via connexin 43 and M-cadherin. Our results demonstrated that α7 silencing blocked expression of myogenic differentiation factor 1 (Myod), myogenin (Myog), myogenic factor 6 (Myf6), myosin heavy chain type 1 (Myh1), and transmembrane protein 8c (Tmem8c), indicating that myoblast fusion was inhibited. Expression of α5 and M-cadherin decreased but β1 and connexin 43 increased. We examined protein production and observed reduced extracellular-signal regulated kinase 1/2 (ERK) in α7-silenced cells that correlated with upregulation of connexin 43 and M-cadherin, suggesting a compensatory pathway. These results indicate that α7 signaling plays a critical role in ex vivo fusion and implicates a relationship with connexin 43 and M-cadherin.

The Effect of Laminin-111 Hydrogels on Muscle Regeneration in a Murine Model of Injury.

Extremity injuries make up the most common survivable injuries in vehicular accidents and modern military conflicts. A majority of these injuries involve volumetric muscle loss (VML). The potential for donor site morbidity may limit the clinical use of autologous muscle grafts for VML injuries. Treatments that can improve the regeneration of functional muscle tissue are critically needed to improve limb salvage and reduce the rate of delayed amputations. The development of a laminin-111-enriched fibrin hydrogel will offer a potentially transformative and "off-the-shelf" clinically relevant therapy for functional skeletal muscle regeneration.

Management of Dural Tears in Endoscopic Lumbar Spinal Surgery: A Review of the Literature

The incidental dural tear is a common complication in lumbar spine surgery. It has been reported that the incidence of dural tears is much greater in endoscopic procedures. Primary closure via suturing remains challenging in endoscopic procedures. The objective of this study was to conduct a literature review on the surgical technique for dural closure and repair in endoscopic spine surgery. A systematic literature search was performed using the database PubMed. In total, 12 studies reported specifically about the surgical treatment for dural tear in percutaneous and tubular assisted endoscopic technique. The dural tear rate, the technique of dural closure, postoperative time of bed rest, postoperative symptoms related to cerebrospinal fluid fistula, and revision surgery were assessed. The overall rate of dural tears in endoscopic spinal surgery was 2.7%, with a range from 0% to 8.6%. The incidence of a dural tear was much greater in cases with lumbar stenosis (3.7%) than in lumbar disc herniation (2.1%). The greatest rate was accompanied by resecting synovial cysts. In addition, the risk of dural tear is greater in bilateral decompression procedures via a unilateral approach. There is no consensus about the ideal technique for dural closure in endoscopic procedures. Furthermore, there is a debate whether dural tear requires surgical treatment or not. An autologous muscle or fat graft in combination with fibrin glue or a fibrin-sealed collagen sponge seems to be a good and safe method for the management of dural tear in lumbar endoscopic spine surgery.

Decellularized Muscle Supports New Muscle Fibers and Improves Function Following Volumetric Injury.

Current strategies to treat volumetric muscle loss use primarily pedicle or free muscle transfers, but these grafts fail to adequately regenerate functional tissue. Decellularized soft tissue grafts possess physical and chemical cues to promote muscle regeneration, suggesting their potential for use in large muscle defects. In this study, we developed a decellularized muscle matrix (DMM) graft using rat gastrocnemius. Anisotropy and chemical components of the extracellular matrix were retained, including laminin, fibronectin, and collagen. We compared the ability of DMM, autologous muscle grafts (clinical standard), and type I collagen plugs (negative control) to support muscle regeneration. DMM supported regeneration over a 56-day period in 1 × 1 cm and 1.5 × 1 cm gastrocnemius defects in rats. Muscle function tests demonstrated improved muscle recovery in rats with DMM grafts when compared to collagen. Histological sections were assessed using morphometrics and immunostaining. DMM supported muscle regeneration with less fibrosis and more de novo neuromuscular receptors than either autograft or collagen. Overall, our results indicate that DMM may be used as a muscle replacement graft based on its ability to improve muscle function recovery, promote muscle regeneration, and support new neuromuscular junctions.

Tacrolimus as an adjunct to autologous minced muscle grafts for the repair of a volumetric muscle loss injury

BackgroundVolumetric muscle loss (VML) following extremity orthopaedic trauma or surgery results in chronic functional deficits and disability. A current translational approach to address the devastating functional limitations due to VML injury is the use of an autologous minced muscle graft (~1 mm3 pieces of muscle tissue) replacement into the injured defect area, although limitations related to donor site morbidity are still unaddressed. This study was designed to explore adjunct pharmacological immunomodulation to enhance graft efficacy and promote muscle function following VML injury, and thereby reduce the amount of donor tissue required.FindingsUsing a validated VML porcine injury model in which 20% of the muscle volume was surgically removed, this study examined muscle function over 3 months post-VML injury. In vivo isometric torque of the peroneus teritus (PT) muscle was not different before surgery among sham, non-repaired, non-repaired with tacrolimus, graft-repaired, and graft-repaired with tacrolimus VML groups. Bi-weekly torque analysis of the VML injured musculature presented a significant strength deficit of ~26% compared to pre-injury in the non-repaired, non-repaired with tacrolimus, and graft-repaired groups. Comparatively, the strength deficit in the graft-repair with systemic tacrolimus was marginally improved (~19%; p = 0.056). Both of the minced graft repaired groups presented a greater proportion of muscle tissue in full-thickness histology specimen.ConclusionsWe demonstrate that adjunctive use of tacrolimus with an ~50% minced muscle graft replacement resulted in modest improvements in muscle function 3 months after injury and repair, but the magnitude of improvement is not expected to elicit clinically meaningful functional improvements.

Cerebrospinal Fluid Leakage During Temporal Bone Surgery: Selecting Intra-operative Dural Closure with a Dumbbell-Shaped Muscle Graft as a Surgical Approach.

Cerebrospinal fluid (CSF) leakages of the temporal bone may arise during mastoid surgery. The leakages can have multiple potential etiologies, for instance, using a cutting burr near the bony tegmen or monopolar electrocautery on the surface of the dura mater. In this paper, we introduced an effective and simple technique for the management of CSF leakages of the temporal bone. In a prospective case series, 36 patients (16 males and 20 females) who have had an experience of incidental or inevitable CSF otorrhea or otorhinorrhea during temporal bone surgery were selected. All patients were treated using a muscle graft in a dumbbell-shaped design through the dura defect at the Amir-Alam University Hospital between April 2005 and November 2008. The mean size of the defects was 5mm (a range of 2-10mm). A dumbbell-shaped autologous muscle graft was immediately successful in sealing the leakage in all patients. Only five patients (13.8%) had some evidence of leakage remaining on the day after the operation, which was subsequently resolved by conservative management in four of them (11.1%). Only one patient (2.7%) was subjected to a second operation for a new defect. Recurrence of CSF leakage or other related complications were not observed during about 7years of follow up. A free autologous muscle graft, using the dumbbell technique through a small to moderate dura defect is an effective, easily performed, and safe method to seal iatrogenic leakages of the temporal bone.

Full endoscopic treatment of dural tears in lumbar spine surgery.

An incidental durotomy is a common complication of spinal surgery. Its treatment remains challenging, especially in endoscopic procedures. The objective of this study is to describe a technique for endoscopic dural closure which is safe and effective. From a prospective database all endoscopic spinal procedures with incidental durotomy were identified. Retrospectively, video recordings were analysed with a special reference to the applied technique of dural closure. Additionally 1, 6 and 12week follow-up examinations were evaluated for clinical outcome and associated complications. Out of 212 consecutive patients, an intraoperative dural tear was observed in nine patients (4.2%). A dural tear occurred in 1.1% of cases of lumbar disc herniation, in 7.9% of cases with lumbar spinal stenosis, in 37.5% of cases with a synovial cyst. An autologous muscle sample was harvested within the operative field and grafted at the dural defect in several layers. Fixation of the transplantation and watertight closure were achieved by the application of fibrin sealant with gelfoam. The mean time for dural closure was 209s (range 47-420s). Postoperatively no CSF fistula, no new deficits nor worsening of a pre-existing neurological deficit occurred. None of the patients had problems with wound healing, or discomfort which could be related to the CSF leak. Dural closure with an autologous muscle graft in combination with fibrin sealant patch is a fast, safe and alternative technique for the management of dural tear in microendoscopic surgery.

Sellar repair with autologous muscle and composite septal cartilage grafts for treatment of cerebrospinal fluid leakage following trans-sphenoidal pituitary surgery.

Context:Many reconstructive techniques have been proposed to prevent postoperative cerebrospinal fluid (CSF) leakage after trans-sphenoidal pituitary surgery. However, no total agreement has been reached to the best technique.Aim:Assessment of the efficacy of sellar repair with autologous muscle and composite septal cartilage grafts for treatment of intraoperative and delayed postoperative CSF leakage following trans-sphenoidal pituitary surgery without the use of postoperative external lumbar CSF drain.Study Design:This is a retrospective case series study, level IV evidence.Materials and Methods: Twenty three patients were involved in this study. Seventeen patients had intraoperative CSF leakage and were treated immediately by our technique. Six patients had postoperative CSF rhinorrhea and had delayed treatment with our technique after failure of conservative measures and external lumbar CSF drainage for more than three days. The technique involved intradural placement of autologous muscle graft supplemented with extradural composite septal cartilage graft, composed of a piece of the posterior cartilaginous septum with its covering mucoperichondrium on one side only to fit into the sellar defect as a double layer button.Results:CSF leak was of grade 1 in 6 patients (26.1%), grade 2 in 10 patients (43.5%) and grade 3 in 7 patients (30.4%). None of the patients in our study had postoperative CSF leak after the use of our technique during the follow up period (mean 24 ± 10.47 standard deviation months). None of the patients developed treatment-related complications. All the patients had well developed mucosal covering of the sellar defect after two months.Conclusion:Our technique of sellar repair by using autologous muscle and composite septal cartilage grafts is effective in treatment of intraoperative and delayed postoperative CSF leakage following trans-sphenoidal pituitary surgery without the use of postoperative external lumbar CSF drain even in the high-output CSF leaks.

A Porcine Urinary Bladder Matrix Does Not Recapitulate the Spatiotemporal Macrophage Response of Muscle Regeneration after Volumetric Muscle Loss Injury

Volumetric muscle loss (VML) results in irrecoverable loss of muscle tissue making its repair challenging. VML repair with acellular extracellular matrix (ECM) scaffolds devoid of exogenous cells has shown improved muscle function, but limited de novo muscle fiber regeneration. On the other hand, studies using minced autologous and free autologous muscle grafts have reported appreciable muscle regeneration. This raises the fundamental question whether an acellular ECM scaffold can orchestrate the spatiotemporal cellular events necessary for appreciable muscle fiber regeneration. This study compares the macrophage and angiogenic responses including the remodeling outcomes of a commercially available porcine urinary bladder matrix, MatriStem™, and autologous muscle grafts. The early heightened and protracted M1 response of the scaffold indicates that the scaffold does not recapitulate the spatiotemporal macrophage response of the autograft tissue. Additionally, the scaffold only supports limited de novo muscle fiber formation and regressing vessel density. Furthermore, scaffold remodeling is accompanied by increased presence of transforming growth factor and α-smooth muscle actin, which is consistent with remodeling of the scaffold into a fibrotic scar-like tissue. The limited muscle formation and scaffold-mediated fibrosis noted in this study corroborates the findings of recent studies that investigated acellular ECM scaffolds (devoid of myogenic cells) for VML repair. Taken together, acellular ECM scaffolds when used for VML repair will likely remodel into a fibrotic scar-like tissue and support limited de novo muscle fiber regeneration primarily in the proximity of the injured musculature. This is a work of the US Government and is not subject to copyright protection in the USA. Foreign copyrights may apply. Published by S. Karger AG, Basel

In vivo characterization of regenerative peripheral nerve interface function

Objective. Regenerative peripheral nerve interfaces (RPNIs) are neurotized free autologous muscle grafts equipped with electrodes to record myoelectric signals for prosthesis control. Viability of rat RPNI constructs have been demonstrated using evoked responses. In vivo RPNI characterization is the next critical step for assessment as a control modality for prosthetic devices. Approach. Two RPNIs were created in each of two rats by grafting portions of free muscle to the ends of divided peripheral nerves (peroneal in the left and tibial in the right hind limb) and placing bipolar electrodes on the graft surface. After four months, we examined in vivo electromyographic signal activity and compared these signals to muscular electromyographic signals recorded from autologous muscles in two rats serving as controls. An additional group of two rats in which the autologous muscles were denervated served to quantify cross-talk in the electrode recordings. Recordings were made while rats walked on a treadmill and a motion capture system tracked the hind limbs. Amplitude and periodicity of signals relative to gait were quantified, correlation between electromyographic and motion recording were assessed, and a decoder was trained to predict joint motion. Main Results. Raw RPNI signals were active during walking, with amplitudes of 1 mVPP, and quiet during standing, with amplitudes less than 0.1 mVPP. RPNI signals were periodic and entrained with gait. A decoder predicted bilateral ankle motion with greater than 80% reliability. Control group signal activity agreed with literature. Denervated group signals remained quiescent throughout all evaluations. Significance. In vivo myoelectric RPNI activity encodes neural activation patterns associated with gait. Signal contamination from muscles adjacent to the RPNI is minimal, as demonstrated by the low amplitude signals obtained from the Denervated group. The periodicity and entrainment to gait of RPNI recordings suggests the transduced signals were generated via central nervous system control.

Regeneración de las lesiones críticas del nervio periférico con factores de crecimiento. Estudio experimental

IntroductionThis project aims to study the regeneration of non-repairable lesions of peripheral nerve by muscle grafts enhanced with growth factors. Material and methodsThe experiment was carried out in two phases. The first one compared direct suture of a critical defect in the sciatic nerve of ten rats, with the interposition of autologous muscle graft, denatured by heat, in another ten. The second phase compared ten rats with nerve repair using an acellular muscle graft, with injection of 2cc of IGF-1 (10mg/ml mecasermin, Injectable solution) into the acellular graft of another ten.A clinical and functional follow-up was carried out including, ambulation, footprint measurement, and «Grasping Test». The animals were sacrificed at 90-100 days, and samples obtained for macro- and microscopic studies with toluidine blue, haematoxylin-eosin and Masson's trichrome staining. ResultsThe first experiment showed the characteristic findings of nerve tissue in muscle graft level sections. The second was an enhancement of the results: post-surgical clinical improvement, early ambulation, decrease in the rate of pressure ulcers in toes, recovery of the footprint, and increasing the percentage of nerve endings in distal sciatic regeneration (47-62%). ConclusionsIn this study the experimental and clinical possibilities of nerve defect repair by denatured muscle are demonstrated, confirming the suitability of the technique. Furthermore, it confirms our hypothesis with clinical and cellular determinations enriched by the addition of growth factors that promote nerve regeneration.