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Adult peripheral nerve pathology is quite extensive, it comprises traumatic injuries (closed and open), compressive neuropathies and lesions secondary to other medical procedures. It is important to have a well established protocol for diagnosis, as in some lesions time is a key factor for recovery. This is important for the primary care physician that makes the diagnosis, regardless of who will treat the patient. When proposing a management plan it is important to set goals, as some lesions may be completely resolved, but in other cases all we can offer is palliative treatment due to the evolution and severity of the case.

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As primeiras cirurgias de nervos periféricos começaram a ser realizadas há mais de 150 anos e precocemente se observou que as suturas término-terminais, quando feitas sob tensão, resultavam em limitados resultados funcionais. A utilização de algum tipo de tecido interposto entre os cotos do nervo traumatizado foi logo idealizada como alternativa e, atualmente, o uso de enxertos neurais autólogos permanece como o "padrão-ouro" para o tratamento de lesões extensas do sistema nervoso periférico. Porém, a técnica apresenta algumas limitações,que resultam em morbidade para o paciente. Esses fatos motivaram o desenvolvimento de materiais alternativos para servir como condutor de enxertos, dando início às pesquisas das técnicas de tubulização. Os tubos biológicos, como veias ou de veias enriquecidas com músculo esquelético, demonstaram resultados favoráveis tanto em estudos clínicos quanto em experimentais. O uso de materiais sintéticos também foi alvo de avaliação, apresentando resultados animadores com os tubos de silicone e de ácido poliglicólico. Esta revisão objetiva descrever a evolução histórica e os resultados dos ensaios clínicos e experimentais obtidos com as técnicas de tubulização para o tratamento das lesões traumáticas do sistema nervoso periférico.

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Diffusible factors from the distal stumps of transected peripheral nerves exert a neurotropic effect on regenerating nerves in vivo (specificity). This morphologial study was designed to investigate the existence of tissue specificity in peripheral nerve fiber regeneration through a graft of vein filled with fresh skeletal muscle. This tubulization technique demonstrated experiemtal and clinical results similar to those obtained with traditional autologous nerve grafts. Specifically, we used Y-shaped grafts to assess the orientation pattern of regenerating axons in the distal tissue. Animal models were divided into four experimental groups. The proximal part of the Y-shaped conduit was sutured to a severed tibial nerve in all experiments. The two distal stumps were sutured ot different targets: group A to two intact nerves (tibial and peroneal), group B to tan intact nerve and an unvascularized tendon, group C to an intact nerve and a vascularized tendon, and group D to a nerve graft and an unvascularized tendon. Morphological evaluation by light and electron microscopy was conducted in the distal forks of the Y-shaped tube. Data showed that almost all regenerating nerve fibers spontaneously oriented towards the nerve tissue (attached or not the peripheral innervation field), showing a good morphological pattern of regeneration in both the early and late phases of regeneration. When the distal choice was represented by a tendon (vascularized or not), very few nerve fibers were detected in the corresponding distal fork of the Y-shaped graft. These results show that, using the musclevein-combined grafting technique, regenerating axons are able to correctly grow and orientate within the basement membranes of the graft guided by the neurotropic lure of the distal nerve stump

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Trauma and neurodegenerative diseases commit the nervous system. After an axotomy or nerve injury in the peripheral nervous system the regeneration of the nerve fibers and reinervation of the target are seen. In central nervous system these events are restrictive, however their occurrence are related to the state of glial reaction and the synthesis of neurotrophic factors. Basic fibroblast growth factor (bFGF) has been considered an important trophic factor for neurons and astrocytes of many central nervous system regions. In this study rats were submitted to one of following neurosurgery procedures: callosotomy, pyramidectomy or complete transection of hypoglossal nerve (XII). Sham operations were made in control animals. Seven days later animals were sacrificed and their braims processed for immunohistochemistry. Coronal sections were taken from the central nervous system and incubated with antisera against the glial fibrillary acidic protein (GFAP) or neurofilament (NF), markers for astrocyte and neuronal cell body and fibers, respectively, as well as with the antiserum against the bFGF. The degree of the labelling was quatified with computer assisted stereological methods. The analysis of the NF immunoreactivity revealed a disappearance of fibers in the white matter distal to the pyramidectomy and callosotomy, however no disapperance of NF immunoreactive neurons was found in the XII nucleus following axotomy. These changes was accompanied by a massive astrocytic reaction. The reactive astrocytes synthesized increased amounts of bFGF. These findings suggest that glial reaction synthesizing neurotrophic factors may influence the wound and repair after mechanical lesions of central nervous and subsequent neuronal trophism and plasticity which may be relevant to the regenerative process of the nervous tissue.

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Objetive: Revision and questioning of orthodox principles regarding the conduction of nerve impulse. Design: Retrospective study with clinical analysis of results. Site: Hospital das Clinicas (HCFMSP), public university institution with research programs and tertiary attention to health. Group members: Author and a team of residents and trainees. Operation:Direct suture of nervous stumps utilizing auxiliary technical procedures:- joint-flexion, nerve transpositon, tendon transplants, bone shortening. Measurement: Clinical evaluation and objective tests for tactile and stereognostic function recovery (Weber Test). Results: Variable, depending on preoperative conditions: - type of lesion, time elapsed since injury. Conclusions: Neurorrhaphy should be the procedure of choice even for long term lesions, although the expected results may be less favourable. Periodical evaluation from 24 hs. Postoperative, checking for early undefined signals of nervous function recovery. Association of specific drugs for chemical biophysics of the nerve.

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OBJECTIVE: Revision and questioning of orthodox principles regarding the conduction of nerve impulse. DESIGN: Retrospective study with clinical analysis of results. SITE: Hospital das Clinicas (HCFMSP), public university institution with research programs and tertiary attention to health. GROUP MEMBERS: Author and a team of residents and trainees. OPERATION: Direct suture of nervous stumps utilizing auxiliary technical procedures:- joint-flexion, nerve transposition, tendon transplants, bone shortening. MEASUREMENT: Clinical evaluation and objective tests for tactile and stereognostic function recovery (Weber Test). RESULTS: Variable, depending on preoperative conditions:- type of lesion, time elapsed since injury. CONCLUSIONS: Neurorrhaphy should be the procedure of choice even for long term lesions, although the expected results may be less favourable. Periodical evaluation from 24 hs. postoperative, checking for early undefined signals of nervous function recovery. Association of specific drugs for chemical biophysics of the nerve.

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Os processos isquêmicos de membros inferiores costumam cursar com dor de grande intensidade e a revascularizaçao pode nao ser factível em todos os casos. A neurotripsia é uma forma de tratamento da dor que proporciona alívio por impedir a transmissao do impulso nervoso pela secçao, maceraçao ou pela destruiçao química do nervo. O objetivo do presente estudo foi avaliar esse procedimento em pacientes com dor isquêmica de membros inferiores onde a revascularizaçao nao foi possível. Realizou-se o procedimento em 10 pacientes com idade entre 32 e 87 anos e média de 59 anos, sendo 7 do sexo masculino, que apresentavam necrose digital, dor incapacitante e impossibilidade de revascularizaçao. Observou-se a limitaçao da necrose em sete pacientes e estes foram submetidos a amputaçao digital. Em três deles a isquemia evoluiu para gangrena e grande amputaçao. A neurotripsia constitui-se em procedimento alternativo nos casos onde a revascularizaçao nao é possível, com objetivo do alívio da dor.

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Nerve regeneration experiments were carried out using tubular nerve guides of poly[(ethylalanato)1.4(imidazolyl)0.6phosphazene] (PEIP). By means of in vivo tests, this polymer was found to be biodegradable and transformed into harmless products. The tubular nerve guides were prepared by deposition of the dissolved polymer on a glass capillary tube, followed by evaporation of the solvent (methylene dichloride). After transectioning, rat sciatic nerve stumps were immediately sutured into the ends of 10-mm-long polymer tubes. On removal of the prosthesis, after implantation for 45 d, a tissue cable was found bridging the nerve stumps in all cases. Histological analysis revealed that the tissue cable was essentially composed of a regenerated nerve fibre bundle. A parallel series of experiments was undertaken to compare the use of silicone tubes that are not biodegradable and are most frequently used for studies of nerve regeneration with tubulization techniques. The advantages of biodegradable PEIP tubular nerve guides used for peripheral nerve repair are discussed.

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