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Bendale GS, Sonntag M, Clements IP, Isaacs JE. Biomechanical Testing of a Novel Device for Sutureless Nerve Repair. Tissue Eng Part C Methods 2022; 28:469-475. [PMID: 35850519 PMCID: PMC9526470 DOI: 10.1089/ten.tec.2022.0080] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 07/14/2022] [Indexed: 11/12/2022] Open
Abstract
Suboptimal nerve end alignment achieved with conventional nerve repair techniques may contribute to poor clinical outcomes. In this study, we introduce Nerve Tape®, a novel nerve repair device that integrates flexible columns of Nitinol microhooks within a biologic backing to entubulate, align, and secure approximated nerve ends. This study compares the repair strength of Nerve Tape with that of conventional microsuture repairs. Thirty small (2 mm) and 30 large (7 mm) diameter human cadaveric nerves were transected and repaired utilizing Nerve Tape or appropriate microsuture technique. Biomechanical testing was performed using a horizontal tensile tester. The repaired nerves were loaded until failure at a distraction rate of 40 mm/min, and the maximum failure load was determined. In the small nerve groups, the load-to-failure for Nerve Tape repairs (2.33 ± 0.66 N) was significantly higher than for suture repairs (1.22 ± 0.52 N; p < 0.05). In the large nerve groups, no significant difference in load-to-failure was found between Nerve Tape (7.45 ± 2.66 N) and suture repairs (5.82 ± 1.59 N: p = 0.12). Suture repairs tended to fail by rupture, whereas Nerve Tape failures resulted from microhook pullout. Nerve Tape is a novel nerve coaptation device that provides mechanical repair strength equal or greater to clinically relevant microsuture repairs.
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Affiliation(s)
- Geetanjali S. Bendale
- Department of Orthopedic Surgery, Virginia Commonwealth University, Richmond, Virginia, USA
| | | | | | - Jonathan E. Isaacs
- Department of Orthopedic Surgery, Virginia Commonwealth University, Richmond, Virginia, USA
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Shiah E, Laikhter E, Comer CD, Manstein SM, Bustos VP, Bain PA, Lee BT, Lin SJ. Neurotization in Innervated Breast Reconstruction: A Systematic Review of Techniques and Outcomes. J Plast Reconstr Aesthet Surg 2022; 75:2890-2913. [DOI: 10.1016/j.bjps.2022.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 03/22/2022] [Accepted: 06/05/2022] [Indexed: 11/25/2022]
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A comparative assessment of lengthening followed by end-to-end repair and isograft repair of chronically injured peripheral nerves. Exp Neurol 2020; 331:113328. [DOI: 10.1016/j.expneurol.2020.113328] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 04/02/2020] [Accepted: 04/20/2020] [Indexed: 01/09/2023]
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Howarth HM, Kadoor A, Salem R, Nicolds B, Adachi S, Kanaris A, Lovering RM, Brown JM, Shah SB. Nerve lengthening and subsequent end-to-end repair yield more favourable outcomes compared with autograft repair of rat sciatic nerve defects. J Tissue Eng Regen Med 2019; 13:2266-2278. [PMID: 31670904 DOI: 10.1002/term.2980] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 09/17/2019] [Accepted: 10/04/2019] [Indexed: 12/31/2022]
Abstract
Outcomes of end-to-end nerve repairs are more successful compared with outcomes of repairs bridged by nerve grafts. However, end-to-end repairs are not always possible for large nerve gaps, as excessive tension may cause catastrophic failure. In this study, we built on previous nerve-lengthening studies to test the hypotheses that gradual lengthening of the proximal stump across a large nerve gap enables an end-to-end repair and such a repair results in more favourable regenerative outcomes than autografts, which represent the gold standard in bridging nerve gaps. To test these, we compared structural and functional outcomes in Lewis rats after repair of sciatic nerve gaps using either autografts or a novel compact internal fixator device, which was used to lengthen proximal nerve stumps towards the distal stump over 2 weeks, prior to end-to-end repair. Twelve weeks after the initial injury, outcomes following nerve lengthening/end-to-end repair were either comparable or superior in every measure compared with repair by autografting. The sciatic functional index was not significantly different between groups at 12 weeks. However, we observed a reduced rate of contracture and corresponding significant increase in paw length in the lengthening group. This functional improvement was consistent with structural regeneration; axonal growth distal to the injury was denser and more evenly distributed compared with the autograft group, suggesting substantial regeneration into both tibial and peroneal branches of the sciatic nerve. Our findings show that end-to-end repairs following nerve lengthening are possible for large gaps and that this strategy may be superior to graft-based repairs.
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Affiliation(s)
- Holly M Howarth
- Department of Bioengineering, University of California, San Diego, La Jolla, CA
| | - Adarsh Kadoor
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA
| | - Rayeheh Salem
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA
| | - Brogan Nicolds
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA
| | - Stephanie Adachi
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA
| | - Achilles Kanaris
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA
| | - Richard M Lovering
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD
| | - Justin M Brown
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA
| | - Sameer B Shah
- Department of Bioengineering, University of California, San Diego, La Jolla, CA.,Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA.,Research Service, VA San Diego Healthcare System, San Diego, CA
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Sung J, Sikora-Klak J, Adachi SY, Orozco E, Shah SB. Decoupled epineurial and axonal deformation in mouse median and ulnar nerves. Muscle Nerve 2019; 59:619-628. [PMID: 30697763 DOI: 10.1002/mus.26437] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 01/18/2019] [Accepted: 01/27/2019] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Peripheral nerves accommodate mechanical loads during joint movement. Hypothesized protective features include increased nerve compliance near joints and axonal undulation. How axons perceive nerve deformation is poorly understood. We tested whether nerves increase local axonal undulation in regions of high epineurial strain to protect nerve fibers from strain-induced damage. METHODS Regional epineurial strain was measured near the elbow in median and ulnar nerves of mice expressing axonal fluorescence before and after decompression. Regional axonal tortuosity was quantified under confocal microscopy. RESULTS Nerves showed higher epineurial strain just distal to the medial epicondyle; these differences were eliminated after decompression. Axonal tortuosity also varied regionally; however, unlike in the epineurium, it was greater in proximal regions. DISCUSSION In this study we have proposed a neuromechanical model whereby axons can unravel along their entire length due to looser mechanical coupling to the peri/epineurium. Our findings have major implications for understanding nerve biomechanics and dysfunction. Muscle Nerve 59:619-619, 2019.
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Affiliation(s)
- Jaemyoung Sung
- Division of Biological Sciences, University of California, San Diego, La Jolla, California, USA
- Department of Orthopaedic Surgery, University of California, San Diego, 9500 Gilman Drive, MC 0863, La Jolla, California 92093, USA
| | - Jakub Sikora-Klak
- Department of Orthopaedic Surgery, University of California, San Diego, 9500 Gilman Drive, MC 0863, La Jolla, California 92093, USA
| | - Stephanie Y Adachi
- Division of Biological Sciences, University of California, San Diego, La Jolla, California, USA
- Department of Orthopaedic Surgery, University of California, San Diego, 9500 Gilman Drive, MC 0863, La Jolla, California 92093, USA
| | - Elisabeth Orozco
- Department of Orthopaedic Surgery, University of California, San Diego, 9500 Gilman Drive, MC 0863, La Jolla, California 92093, USA
- Research Division, Veterans Affairs San Diego Healthcare System, San Diego, California, USA
| | - Sameer B Shah
- Department of Orthopaedic Surgery, University of California, San Diego, 9500 Gilman Drive, MC 0863, La Jolla, California 92093, USA
- Research Division, Veterans Affairs San Diego Healthcare System, San Diego, California, USA
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
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Howarth HM, Alaziz T, Nicolds B, O'Connor S, Shah SB. Redistribution of nerve strain enables end-to-end repair under tension without inhibiting nerve regeneration. Neural Regen Res 2019; 14:1280-1288. [PMID: 30804260 PMCID: PMC6425842 DOI: 10.4103/1673-5374.251338] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
End-to-end repair under no or low tension leads to improved outcomes for transected nerves with short gaps, compared to repairs with a graft. However, grafts are typically used to enable a tension-free repair for moderate to large gaps, as excessive tension can cause repairs to fail and catastrophically impede recovery. In this study, we tested the hypothesis that unloading the repair interface by redistributing tension away from the site of repair is a safe and feasible strategy for end-to-end repair of larger nerve gaps. Further, we tested the hypothesis that such an approach does not adversely affect structural and functional regeneration. In this study, we used a rat sciatic nerve injury model to compare the integrity of repair and several regenerative outcomes following end-to-end repairs of nerve gaps of increasing size. In addition, we proposed the use of a novel implantable device to safely repair end-to-end repair of larger nerve gaps by redistributing tension away from the repair interface. Our data suggest that redistriubution of tension away from the site of repair enables safe end-to-end repair of larger gap sizes. In addition, structural and functional measures of regeneration were equal or enhanced in nerves repaired under tension – with or without a tension redistribution device – compared to tension-free repairs. Provided that repair integrity is maintained, end-to-end repairs under tension should be considered as a reasonable surgical strategy. All animal experiments were performed under the approval of the Institutional Animal Care and Use Committee of University of California, San Diego (Protocol S11274).
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Affiliation(s)
- Holly M Howarth
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
| | - Turki Alaziz
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, USA
| | - Brogan Nicolds
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
| | - Shawn O'Connor
- School of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA, USA
| | - Sameer B Shah
- Department of Bioengineering, University of California; Department of Orthopaedic Surgery, University of California, San Diego, La Jolla; Research Service, VA San Diego Healthcare System, San Diego, CA, USA
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Palispis WA, Gupta R. Surgical repair in humans after traumatic nerve injury provides limited functional neural regeneration in adults. Exp Neurol 2017; 290:106-114. [PMID: 28111229 DOI: 10.1016/j.expneurol.2017.01.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 01/18/2017] [Accepted: 01/18/2017] [Indexed: 12/24/2022]
Abstract
Traumatic nerve injuries result in devastating loss of neurologic function with unpredictable functional recovery despite optimal medical management. After traumatic nerve injury and denervation, regenerating axons must traverse a complex environment in which they encounter numerous barriers on the way to reinnervation of their target muscle. Outcomes of surgical intervention alone have unfortunately reached a plateau, resulting in often unsatisfactory functional recovery. Over the past few decades, many improvements were developed to supplement and boost the results of surgical repair. Biological optimization of Schwann cells, macrophages, and degradation enzymes have been studied due to the key roles of these components in axonal development, maintenance and response to injury. Moreover, surgical techniques such as nerve grafting, conduits, and growth factor supplementation are also employed to enhance the microenvironment and nerve regeneration. Yet, most of the roadblocks to recovery after nerve injury remain unsolved. These roadblocks include, but are not limited to: slow regeneration rates and specificity of target innervation, the presence of a segmental nerve defect, and degeneration of the target end-organ after prolonged periods of denervation. A recognition of these limitations is necessary so as to develop new strategies to improve functional regeneration for these life changing injuries.
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Affiliation(s)
- Winnie A Palispis
- Department of Orthopaedic Surgery, University of California, Irvine, Orange, California, USA; Peripheral Nerve Research Lab, Gillespie Neuroscience Research Facility, Irvine, California, USA.
| | - Ranjan Gupta
- Department of Orthopaedic Surgery, University of California, Irvine, Orange, California, USA; Peripheral Nerve Research Lab, Gillespie Neuroscience Research Facility, Irvine, California, USA; VA Long Beach Healthcare System, Long Beach, CA 90822, USA.
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Félix SP, Pereira Lopes FR, Marques SA, Martinez AM. Comparison between suture and fibrin glue on repair by direct coaptation or tubulization of injured mouse sciatic nerve. Microsurgery 2013; 33:468-77. [DOI: 10.1002/micr.22109] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 02/20/2013] [Accepted: 02/25/2013] [Indexed: 12/12/2022]
Affiliation(s)
- Severina P. Félix
- Laboratório de Neurodegeneração e Reparo; Programa de Pesquisa em Neurociência Básica e Clínica; Instituto de Ciências Biomédicas; Universidade Federal do Rio de Janeiro; Rio de Janeiro RJ Brazil
- Departamento de Patologia; Faculdade de Medicina; Universidade Federal do Rio de Janeiro; Rio de Janeiro RJ Brazil
| | - Fátima R. Pereira Lopes
- Laboratório de Neurodegeneração e Reparo; Programa de Pesquisa em Neurociência Básica e Clínica; Instituto de Ciências Biomédicas; Universidade Federal do Rio de Janeiro; Rio de Janeiro RJ Brazil
| | - Suelen A. Marques
- Laboratórios de Regeneração Neural e Função; Departamento de Neurobiologia; Universidade Federal Fluminense; Niterói RJ Brazil
| | - Ana M.B. Martinez
- Laboratório de Neurodegeneração e Reparo; Programa de Pesquisa em Neurociência Básica e Clínica; Instituto de Ciências Biomédicas; Universidade Federal do Rio de Janeiro; Rio de Janeiro RJ Brazil
- Departamento de Patologia; Faculdade de Medicina; Universidade Federal do Rio de Janeiro; Rio de Janeiro RJ Brazil
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Chuang TH, Wilson RE, Love JM, Fisher JP, Shah SB. A novel internal fixator device for peripheral nerve regeneration. Tissue Eng Part C Methods 2012; 19:427-37. [PMID: 23102114 DOI: 10.1089/ten.tec.2012.0021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Recovery from peripheral nerve damage, especially for a transected nerve, is rarely complete, resulting in impaired motor function, sensory loss, and chronic pain with inappropriate autonomic responses that seriously impair quality of life. In consequence, strategies for enhancing peripheral nerve repair are of high clinical importance. Tension is a key determinant of neuronal growth and function. In vitro and in vivo experiments have shown that moderate levels of imposed tension (strain) can encourage axonal outgrowth; however, few strategies of peripheral nerve repair emphasize the mechanical environment of the injured nerve. Toward the development of more effective nerve regeneration strategies, we demonstrate the design, fabrication, and implementation of a novel, modular nerve-lengthening device, which allows the imposition of moderate tensile loads in parallel with existing scaffold-based tissue engineering strategies for nerve repair. This concept would enable nerve regeneration in two superposed regimes of nerve extension--traditional extension through axonal outgrowth into a scaffold and extension in intact regions of the proximal nerve, such as that occurring during growth or limb-lengthening. Self-sizing silicone nerve cuffs were fabricated to grip nerve stumps without slippage, and nerves were deformed by actuating a telescoping internal fixator. Poly(lactic co-glycolic) acid (PLGA) constructs mounted on the telescoping rods were apposed to the nerve stumps to guide axonal outgrowth. Neuronal cells were exposed to PLGA using direct contact and extract methods, and they exhibited no signs of cytotoxic effects in terms of cell morphology and viability. We confirmed the feasibility of implanting and actuating our device within a sciatic nerve gap and observed axonal outgrowth following device implantation. The successful fabrication and implementation of our device provides a novel method for examining mechanical influences on nerve regeneration.
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Affiliation(s)
- Ting-Hsien Chuang
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland, USA
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Zhao Z, Wang Y, Peng J, Ren Z, Zhang L, Guo Q, Xu W, Lu S. Improvement in nerve regeneration through a decellularized nerve graft by supplementation with bone marrow stromal cells in fibrin. Cell Transplant 2012; 23:97-110. [PMID: 23128095 DOI: 10.3727/096368912x658845] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Acellular nerve grafting is often inferior as well as an inadequate alternative to autografting for the repair of long gaps in peripheral nerves. Moreover, the injection method is not perfect. During the injection of cells, the syringe can destroy the acellular nerve structure and the limited accumulation of seed cells. To resolve this problem, we constructed a nerve graft by acellular nerve grafting. Bone marrow-mesenchymal stromal cells (BM-MSCs) were affixed with fibrin glue and injected inside or around the graft, which was then used to repair a 15-mm nerve defect in rats. The acellular nerve graft maintained its structure and composition, and its tensile strength was decreased, as determined by two-photon microscopy and a tensile testing device. In vitro, MSCs embedded in fibrin glue survived and secreted growth factors such as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). We repaired 15-mm Sprague-Dawley rat sciatic nerve defects using this nerve graft construction, and MSCs injected around the graft helped improve nerve regeneration and functional recovery of peripheral nerve lesions as determined by functional analysis and histology. Therefore, we conclude that supplying MSCs in fibrin glue around acellular nerves is successful in maintaining the nerve structure and can support nerve regeneration similar to the direct injection of MSCs into the acellular nerve for long nerve defects but may avoid destroying the nerve graft. The technique is simple and is another option for stem cell transplantation.
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