scholarly journals Chemically Extracted Acellular Nerve Allograft Seeded with SDNF and Autogenic ADSCs for Peripheral Nerve Repairment in a Beagle Model

Author(s):  
Li Wei ◽  
Chen Lei ◽  
Gu Dongqiang ◽  
Li Chunbao ◽  
Zhang Shunxin
Hand ◽  
2021 ◽  
pp. 155894472110031
Author(s):  
Blair R. Peters ◽  
Matthew D. Wood ◽  
Daniel A. Hunter ◽  
Susan E. Mackinnon

Background: Acellular nerve allografts have been used successfully and with increasing frequency to reconstruct nerve injuries. As their use has been expanded to treat longer gap, larger diameter nerve injuries, some failed cases have been reported. We present the histomorphometry of 5 such cases illustrating these limitations and review the current literature of acellular nerve allografts. Methods: Between 2014 and 2019, 5 patients with iatrogenic nerve injuries to the median or ulnar nerve reconstructed with an AxoGen AVANCE nerve allograft at an outside hospital were treated in our center with allograft excision and alternative reconstruction. These patients had no clinical or electrophysiological evidence of recovery, and allograft specimens at the time of surgery were sent for histomorphological examination. Results: Three patients with a median and 2 with ulnar nerve injury were included. Histology demonstrated myelinated axons present in all proximal native nerve specimens. In 2 cases, axons failed to regenerate into the allograft and in 3 cases, axonal regeneration diminished or terminated within the allograft. Conclusions: The reported cases demonstrate the importance of evaluating the length and the function of nerves undergoing acellular nerve allograft repair. In long length, large-diameter nerves, the use of acellular nerve allografts should be carefully considered.


2021 ◽  
Vol 35 (03) ◽  
pp. 204-210
Author(s):  
Aslan Baradaran ◽  
Hassan El-Hawary ◽  
Johnny Ionut Efanov ◽  
Liqin Xu

AbstractPeripheral nerve injuries represent a considerable portion of chronic disability that especially affects the younger population. Prerequisites of proper peripheral nerve injury treatment include in-depth knowledge of the anatomy, pathophysiology, and options in surgical reconstruction. Our greater appreciation of nerve healing mechanisms and the development of different microsurgical techniques have significantly refined the outcomes in treatment for the past four decades. This work reviews the peripheral nerve regeneration process after an injury, provides an overview of various coaptation methods, and compares other available treatments such as autologous nerve graft, acellular nerve allograft, and synthetic nerve conduits. Furthermore, the formation of neuromas as well as their latest treatment options are discussed.


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.


2017 ◽  
Vol 22 (2) ◽  
pp. 3-5
Author(s):  
James B. Talmage ◽  
Jay Blaisdell

Abstract Physicians use a variety of methodologies within the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition, to rate nerve injuries depending on the type of injury and location of the nerve. Traumatic injuries that cause impairment to the peripheral or brachial plexus nerves are rated using Section 15.4e, Peripheral Nerve and Brachial Plexus Impairment, for upper extremities and Section 16.4c, Peripheral Nerve Rating Process, for lower extremities. Verifiable nerve lesions that incite the symptoms of complex regional pain syndrome, type II (similar to the former concept of causalgia), also are rated in these sections. Nerve entrapments, which are not isolated traumatic events, are rated using the methodology in Section 15.4f, Entrapment Neuropathy. Type I complex regional pain syndrome is rated using Section 15.5, Complex Regional Pain Syndrome for upper extremities or Section 16.5, Complex Regional Pain Syndrome for lower extremities. The method for grading the sensory and motor deficits is analogous to the method described in previous editions of AMA Guides. Rating the permanent impairment of the peripheral nerves or brachial plexus is similar to the methodology used in the diagnosis-based impairment scheme with the exceptions that the physical examination grade modifier is never used to adjust the default rating and the names of individual nerves or plexus trunks, as opposed to the names of diagnoses, appear in the far left column of the rating grids.


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