Regeneration of rat sciatic nerve across a LactoSorb bioresorbable conduit with interposed short-segment nerve grafts

2003 ◽  
Vol 99 (3) ◽  
pp. 549-554 ◽  
Author(s):  
Paul C. Francel ◽  
Kevin S. Smith ◽  
F. Alan Stevens ◽  
Soon C. Kim ◽  
James Gossett ◽  
...  

Object. This study was conducted to evaluate peripheral nerve regeneration through a conduit composed of a bioresorbable material (LactoSorb). Methods. Sprague—Dawley rats weighing approximately 250 g were randomized into five groups. A 20-mm-long sciatic nerve gap was created, then it was bridged by a reverse nerve autograft (Group I), an empty silicone tube (Group II), a silicone tube containing a short (2-mm) interposed nerve segment (Group III), an empty LactoSorb conduit (Group IV), or a LactoSorb conduit containing a 2-mm interposed nerve segment (Group V). The intact sciatic nerve served as the control in each animal. At 16 weeks postoperatively, no nerve regeneration was observed through either the empty silicone tube or the empty LactoSorb conduit. There was regeneration in all animals receiving the reverse autograft as well as in all animals receiving the silicone or LactoSorb conduit containing the 2-mm interposed nerve segment. Effective regeneration was assessed based on histological, electrophysiological, and morphometric criteria. Conclusions. The results indicate that a conduit made of resorbable material will support sciatic nerve regeneration over a critical gap defect.

2004 ◽  
Vol 101 (5) ◽  
pp. 806-812 ◽  
Author(s):  
Toshiro Mimura ◽  
Mari Dezawa ◽  
Hiroshi Kanno ◽  
Hajime Sawada ◽  
Isao Yamamoto

Object. Bone marrow stromal cells (BMSCs) can be induced to form Schwann cells by sequentially treating the cells with β-mercaptoethanol and retinoic acid, followed by forskolin and neurotrophic factors including heregulin. In this study the authors made artificial grafts filled with BMSC-derived Schwann cells (BMSC-DSCs) and transplanted them into the transected sciatic nerve in adult rats to evaluate the potential of BMSCs as a novel alternative method of peripheral nerve regeneration. Methods. The BMSC-DSCs were suspended in Matrigel and transferred into hollow fibers (12 mm in length), which were transplanted into the transected sciatic nerve in adult Wistar rats. Six months after cell transplantation, electrophysiological evaluation and walking track analysis were performed. Results of these studies showed significant improvement in motor nerve conduction velocity and sciatic nerve functional index in the BMSC-DSC—transplanted group compared with the control group (Matrigel graft only). Immunohistochemical study data demonstrated that transplanted BMSCs labeled with retrovirus green fluorescent protein were positive for P0 and myelin-associated glycoprotein and had reconstructed nodes of Ranvier and remyelinated regenerated nerve axons. The number of regenerated axons in the axial section of the central portion of the graft was significantly greater in the transplanted group. Although BMSCs can differentiate into several types of cells, tumor formation did not occur 6 months after engraftment. Conclusions. Results in this study indicate that BMSC-DSCs have great potential to promote regeneration of peripheral nerves. The artificial graft made with BMSC-DSCs represents an alternative method for the difficult reconstruction of a long distance gap in a peripheral nerve.


1997 ◽  
Vol 87 (6) ◽  
pp. 887-892 ◽  
Author(s):  
Paul C. Francel ◽  
Thomas J. Francel ◽  
Susan E. Mackinnon ◽  
Cathy Hertl

✓ Isolated nerve segments may inherently contain all of the necessary factors required to support regeneration within a silicone tube conduit placed across a nerve gap. Thirty-six adult Lewis rats each weighing approximately 250 g were randomized into three groups. A sciatic nerve gap (13–15 mm in length) was bridged by an empty silicone tube (Group I), a silicone tube containing a short 2-mm interposed nerve segment (Group II), or a nerve autograft (Group III). At 16 weeks postoperatively, no regeneration was observed through the empty silicone tube. In contrast, regeneration across the silicone tube containing the isolated nerve segment was equivalent to that noted through nerve autografts as assessed by histological, electrophysiological, and functional criteria. Thus, an interposed nerve segment will extend the length of successful nerve regeneration through a silicone tube conduit.


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Wook Jeong ◽  
Hsichiang Kung ◽  
Chia Chi Cheng ◽  
Changwoo Lim ◽  
Min Jung Jung ◽  
...  

Background. Several studies have shown that dexmedetomidine (DXM), a selective α2-adrenoceptor agonist, also has neuroprotective effects. However, its effect on impaired peripheral nerve regeneration has not been studied. Materials and Methods. Forty-five Sprague-Dawley rats were randomly assigned to three groups: group 1 (control SHAM), group 2 (sciatic nerve injury + normal saline), and group 3 (sciatic nerve injury + DXM). The rats of group 3 were subdivided into the following three groups: DXM 0.5, 6, and 20 μg·kg−1 (groups 3A, 3B, and 3C, resp.). The sciatic nerve injury was assessed for nerve regeneration at 2 and 6 weeks. Results. There were no differences between groups 2 and 3 in their sciatic functional index (SFI) values or histological findings at 2 weeks postinjury. However, SFI differences were statistically significant at 6 weeks postinjury in group 3. The gross findings with H&E staining showed that the number of axons was higher in group 3 than in group 2. There was no histological difference according to the DXM concentration. Conclusion. The coincidental functional and histological assessment results of this study suggest that DXM for 6 weeks positively affects damaged peripheral nerves.


2003 ◽  
Vol 98 (2) ◽  
pp. 371-377 ◽  
Author(s):  
Güzin Yeşim Özgenel ◽  
Gülaydan Filiz

Object. Peripheral nerve repair surgery is still replete with challenges. Despite technical improvements in microsurgery, classic methods of nerve repair have failed to provide satisfactory results. The purpose of this study was to investigate the effects of amniotic fluid from humans on peripheral nerve scarring and regeneration in rats. Methods. Forty adult Sprague—Dawley rats were used in this study. After the right sciatic nerve in each rat was transected and repaired using an epineural suture procedure, the nerves were divided into two groups according to the solution applied around the repair site: experimental group, 0.3 ml human amniotic fluid (HAF); and control group, 0.3 ml saline. Macroscopic and histological evaluations of peripheral nerve scarring were performed 4 weeks postsurgery. Nerves treated with HAF demonstrated a significant reduction in the amount of scar tissue surrounding the repair site (p < 0.05). No evidence of a reaction against HAF was noted. Functional nerve regeneration was measured once every 2 weeks by using a sciatic function index until 12 weeks postsurgery. Functional recovery in nerves treated with amniotic fluid occurred significantly faster than that in nerves treated with saline (p < 0.05). Peripheral nerve regeneration was evaluated histomorphologically at 12 weeks postsurgery. Nerves treated with amniotic fluid showed significant improvement with respect to the indices of fiber maturation (p < 0.05). Conclusions. Preliminary data show that HAF enhances peripheral nerve regeneration. The preventive effect of HAF on epineural scarring and the rich content of neurotrophic and neurite-promoting factors possibly contribute to this result.


1987 ◽  
Vol 67 (3) ◽  
pp. 428-437 ◽  
Author(s):  
Eduardo Fernandez ◽  
Carlo Gangitano ◽  
Aurora Del Fà ◽  
Corrado Olivieri Sangiacomo ◽  
Giuseppe Talamonti ◽  
...  

✓ To study oculomotor nerve regeneration in rats, the oculomotor nerve was approached microsurgically and was sectioned at the base of the skull. The nerve stumps were reapproximated and affixed with a plasma clot in Group I animals and were separated by a gap in Group II animals. Visceral eye motility was evaluated weekly between 1 day and 40 weeks after surgery by recording the pupillary diameter under standardized photic stimulation. Somatic eye motility was assessed after 26 weeks by measuring the ocular displacement evoked by vestibular stimulation in the horizontal and vertical planes. Nerve regeneration was documented histologically and morphometrically at 8, 16, and 40 weeks after section. The selectivity of axonal regeneration to the extraocular muscles was investigated after 26 weeks by mapping (with injection of retrograde horseradish peroxidase) the motoneurons that supplied each reinnervated muscle. Between 6 and 20 weeks after section, the pupil diameter showed a progressive reduction in Group I rats, and no changes were observed in Group II rats. Compared with normal rats, the amplitude of horizontal and vertical ocular displacements was decreased, respectively, by 30% and 45% in Group I and by 65% and 80% in Group II. In Group I rats, the vestibular stimulation in the horizontal plane evoked anomalous eye movements with vertical components. On histological examination, regenerated nerves showed a progressive increase of axonal diameter and myelin-sheath thickness. Reinnervated muscles were associated with a less specific, bilateral representation in the midbrain compared with normal muscles, which have unilateral representation. The changes of the somatotopic organization were interpreted as being the result of the misdirected regrowth of axons in the postlesional nerve stump and of the collateral sprouting in the midbrain.


2001 ◽  
Vol 95 (2) ◽  
pp. 316-323 ◽  
Author(s):  
Peter Scherman ◽  
Göran Lundborg ◽  
Martin Kanje ◽  
Lars B. Dahlin

Object. The authors have previously shown that longitudinal sutures without artificial tube support regeneration across a 7-mm gap in the rat sciatic nerve. In the present study, the authors compared this new approach with the use of autologous nerve grafts across short defects and examined whether the approach could be used to support regeneration across extended gaps and whether the interposition of a short nerve segment (the stepping-stone procedure) was applicable in this model. Methods. Longitudinal sutures were used to bridge 7- and 15-mm gaps in the rat sciatic nerve. Contralateral comparisons were made to nerve autografts in the 7-mm group and to sutures plus a short interposed nerve segment in the 15-mm group. Regeneration was evaluated at 2, 4, and 12 weeks by using immunocytochemical analysis for Schwann cells, neurofilament protein, and macrophages and at 12 weeks also by using histological examination, including morphometry in the distal tibial trunk and tetanic force measurements in the gastrocnemius muscle. Conclusions. The authors found that the results of regeneration after repair with longitudinal polyglactin sutures across short defects were not significantly different from those produced by the use of autologous nerve grafts. Regeneration, although poor, occurred along sutures across extended gaps and was significantly enhanced by an interposed nerve segment acting as a Schwann cell resource in this model.


Author(s):  
Arthur J. Wasserman ◽  
Azam Rizvi ◽  
George Zazanis ◽  
Frederick H. Silver

In cases of peripheral nerve damage the gap between proximal and distal stumps can be closed by suturing the ends together, using a nerve graft, or by nerve tubulization. Suturing allows regeneration but does not prevent formation of painful neuromas which adhere to adjacent tissues. Autografts are not reported to be as good as tubulization and require a second surgical site with additional risks and complications. Tubulization involves implanting a nerve guide tube that will provide a stable environment for axon proliferation while simultaneously preventing formation of fibrous scar tissue. Supplementing tubes with a collagen gel or collagen plus extracellular matrix factors is reported to increase axon proliferation when compared to controls. But there is no information regarding the use of collagen fibers to guide nerve cell migration through a tube. This communication reports ultrastructural observations on rat sciatic nerve regeneration through a silicone nerve stent containing crosslinked collagen fibers.Collagen fibers were prepared as described previously. The fibers were threaded through a silicone tube to form a central plug. One cm segments of sciatic nerve were excised from Sprague Dawley rats. A control group of rats received a silicone tube implant without collagen while an experimental group received the silicone tube containing a collagen fiber plug. At 4 and 6 weeks postoperatively, the implants were removed and fixed in 2.5% glutaraldehyde buffered by 0.1 M cacodylate containing 1.5 mM CaCl2 and balanced by 0.1 M sucrose. The explants were post-fixed in 1% OSO4, block stained in 1% uranyl acetate, dehydrated and embedded in Epon. Axons were counted on montages prepared at a total magnification of 1700x. Montages were viewed through a dissecting microscope. Thin sections were sampled from the proximal, middle and distal regions of regenerating sciatic plugs.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Feixiang Chen ◽  
Weihuang Liu ◽  
Qiang Zhang ◽  
Ping Wu ◽  
Ao Xiao ◽  
...  

AbstractPeripheral nerve injury is a serious health problem and repairing long nerve deficits remains a clinical challenge nowadays. Nerve guidance conduit (NGC) serves as the most promising alternative therapy strategy to autografts but its repairing efficiency needs improvement. In this study, we investigated whether modulating the immune microenvironment by Interleukin-17F (IL-17F) could promote NGC mediated peripheral nerve repair. Chitosan conduits were used to bridge sciatic nerve defect in IL-17F knockout mice and wild-type mice with autografts as controls. Our data revealed that IL-17F knockout mice had improved functional recovery and axonal regeneration of sciatic nerve bridged by chitosan conduits comparing to the wild-type mice. Notably, IL-17F knockout mice had enhanced anti-inflammatory macrophages in the NGC repairing microenvironment. In vitro data revealed that IL-17F knockout peritoneal and bone marrow derived macrophages had increased anti-inflammatory markers after treatment with the extracts from chitosan conduits, while higher pro-inflammatory markers were detected in the Raw264.7 macrophage cell line, wild-type peritoneal and bone marrow derived macrophages after the same treatment. The biased anti-inflammatory phenotype of macrophages by IL-17F knockout probably contributed to the improved chitosan conduit guided sciatic nerve regeneration. Additionally, IL-17F could enhance pro-inflammatory factors production in Raw264.7 cells and wild-type peritoneal macrophages. Altogether, IL-17F may partially mediate chitosan conduit induced pro-inflammatory polarization of macrophages during nerve repair. These results not only revealed a role of IL-17F in macrophage function, but also provided a unique and promising target, IL-17F, to modulate the microenvironment and enhance the peripheral nerve regeneration.


2008 ◽  
Vol 23 (4) ◽  
pp. 364-371 ◽  
Author(s):  
Camila Maria Beder Ribeiro ◽  
Belmiro Cavalcanti do Egito Vasconcelos ◽  
Joaquim Celestino da Silva Neto ◽  
Valdemiro Amaro da Silva Júnior ◽  
Nancy Gurgel Figueiredo

PURPOSE: To analyze the action of gangliosides in peripheral nerve regeneration in the sciatic nerve of the rat. METHODS: The sample was composed of 96 male Wistar rats. The animals were anaesthetized and, after identification of the anaesthesic plane, an incision was made in the posterior region of the thigh, followed by skin and muscle divulsion. The right sciatic nerve was isolated and compressed for 2 minutes. Continuous suture of the skin was performed. The animals were randomly divided into two groups: the experimental group (EG), which received subcutaneous injection of gangliosides, and the control group (CG), which received saline solution (0.9%) to mimic the effects of drug administration. RESULTS: No differences were observed between the experimental and control groups evaluated on the eighth day of observation. At 15 and 30 days the EG showed an decrease in Schwann cell activity and an apparent improvement in fibre organization; at 60 days, there was a slight presence of Schwann cells in the endoneural space and the fibres were organized, indicating nerve regeneration. At 15 and 30 days, the level of cell reaction in the CG had diminished, but there were many cells with cytoplasm in activity and in mitosis; at 60 days, hyperplastic Schwann cells and mitotic activity were again observed, as well as nerve regeneration, but to a lesser extent than in the EG. CONCLUSION: The administration of exogenous gangliosides seems to improve nerve regeneration.


1990 ◽  
Vol 73 (4) ◽  
pp. 638-639 ◽  
Author(s):  
Yusuke Ishiwata ◽  
Shigeo Inomori ◽  
Kazuhiko Fujitsu ◽  
Satoshi Nishimura ◽  
Kazuhiro Hirata ◽  
...  

✓ A new encircling clip made of a silicone tube has been designed for treating accidentally injured cerebral vessels. No special holders are necessary. This clip can be tailored depending on the shape of the injured vessel. The clip is a simple and effective tool for achieving complete hemostasis.


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