End-to-side versus end-to-end neurorrhaphy at the peroneal nerve in rats

Abstract Purpose: To evaluate three different kinds of neurorrhaphy of the peroneal nerve. Methods: Eigthy rats were divided into 5 groups. Control: nerve had no intervention. End-to-end (EE): nerve was cut and elongated with a nerve graft with two end-to-end neurorrhaphies. End-to-side (ES): nerve was cut and sutured to the graft with at the lateral side of the nerve. Side-to-end (SE): the nerve was cut and sutured to the graft with end-to-end neurorrhaphy. Denervated: nerve was cut and both endings were buried into the muscle. The evaluation was done by walking track analysis, electrophysiology, body mass, cranial tibial muscle mass, nerve and muscle fibers morphometry. Results: The EE, ES and SE have the same potential of reinnervation. Conclusion: There is no functional or histological difference between these different types of neurorrhaphy.

Tibial and fibular nerves evaluation using intraoperative electromyography in rats

ABSTRACT PURPOSE: To evaluate a new model of intraoperative electromyographic (EMG) assessment of the tibial and fibular nerves, and its respectives motor units in rats. METHODS: Eight Wistar rats underwent intraoperative EMG on both hind limbs at two different moments: week 0 and week 12. Supramaximal electrical stimulation applied on sciatic nerve, and compound muscle action potential recorded on the gastrocnemius muscle (GM) and the extensor digitorum longus muscle (EDLM) through electrodes at specifics points. Motor function assessment was performaced through Walking Track Test. RESULTS: Exposing the muscles and nerves for examination did not alter tibial (p=0.918) or fibular (p=0.877) function between the evaluation moments. Electromyography of the GM, innervated by the tibial nerve, revealed similar amplitude (p=0.069) and latency (p=0.256) at week 0 and at 12 weeks, creating a standard of normality. Meanwhile, electromyography of the EDLM, innervated by the fibular nerve, showed significant differences between the amplitudes (p=0.003) and latencies (p=0.021) at the two different moments of observation. CONCLUSION: Intraoperative electromyography determined and quantified gastrocnemius muscle motor unit integrity, innervated by tibial nerve. Although this study was not useful to, objectively, assess extensor digitorum longus muscle motor unit, innervated by fibular nerve.

Neurorrhaphy techniques: comparative stereological and experimental axonal study / Técnicas de neurorrafia: estudio experimental estereológico axonal comparativo

There is a great variety of injuries that affect peripheral nerves derived from acquired or congenital degenerative diseases affecting the central nervous system that cause loss of sensorimotor functions. The objective of this work was to perform an end-to-side or side-to-side experimental axonal stereological study in order to compare volume density of axons, endouneuro and myelin sheath (and muscle mass) in peroneal and tibial nerves, with anastomosis contact from 0.25 cm to 0.50 cm. After approval of the Ethics Committe, 20 male Wistar rats were divided into four groups of five rats each (G1= end-to-side neurorrhaphy; G2= side-to-side neurorrhaphy of 0.25 cm; G3= side-to-side neurorrhaphy of 0 cm and G4= Control of normality). After 180 days, fragments of peroneal and tibial nerves were collected for histological and stereological study. In comparative stereological experimental study between neurorraphies, the volume density of axons, myelin sheath of tibial and fibular nerves, as well as the post-surgical muscle mass, remains the same in end-to-side and side-to-side neurorraphies, regardless of contact area of anastomosis. It can be inferred, as surgical repair options, both end-to-side neurorrhaphy to recover and prevents atrophy of the endplate as side-to-side neurorraphy that is independent of the distance between the nerve stumps.

Gran variedad de lesiones atingen a los nervios periféricos, derivadas de enfermedades adquiridas o degenerativas congénitas que afectan la parte central del sistema nervioso y que ocasionan pérdida de funciones sensoriomotoras. El objetivo de ese trabajo fue realizar un estudio experimental estereológico axonal post neurorrafias termino-lateral o latero-lateral para comparar densidad de volumen de axones, endoneuro y vaina de mielina (así como masa muscular) en nervios fibular y tibial, con unión de contacto entre 0,25 cm y 0,50 cm. Tras la aprobación del comité de ética, fueran utilizados 20 ratones machos de la raza Wistar divididos en cuatro grupos de 5 ratones cada uno (G1= Neurorrafia término lateral; G2= Neurorrafia latero lateral de 0,25 cm; G3= Neurorrafia latero lateral de 0,50 cm y G4= Control). Posteriormente, fragmentos de los nervios tibiales y fibulares fueron procesados para estudios histológicos y estereológicos. En el estudio experimental estereológico comparativo entre neurorrafias termino-lateral y latero-lateral, la densidad de volumen de axones, endoneuro y vaina de mielina de nervios tibial y fibular y también la masa muscular post quirúrgica se mantuvo equitativa, independientemente del área de unión de contacto. Podemos inferir como opciones de reparación quirúrgica, que el tratamiento de la neurorrafia termino-lateral y latero-lateral previnen la atrofia de placa motora, independiente de la distancia entre los muñones nerviosos.

End-to-side loop neurorrhaphy: axonal comparative stereological study / Neurorrafia de blucle termino-lateral: estudio axonal estereológico comparativo

Accidents or diseases can affect the peripheral part of the nervous system, which raises clinical and surgical therapies, among others. In this context, the technique of end-to-side neurorrhaphy is a treatment option, yet its modification loop needs some additional efficacy studies. The purpose of this study was to compare, among rats, stereological results (axons volume density) after end-to-side neurorrhaphy and after end-to-side loop neurorrhaphy. Thirty Wistar rats were used, divided into six groups (five animals per group), consisting of two control groups (for the fibular and tibial nerves), two study groups for the fibular nerve (one with an end-to-side neurorrhaphy, and the other with an end-to-side loop neurorrhaphy) and two study groups for the tibial nerve (with an end-to-side neurorrhaphy and the other one with an end-to-side loop neurorrhaphy). After 180 days, all groups were sacrificed for axonal stereological analysis (volume density) in distal nerve stumps. There was significant maintenance of neuronal-axonal density in the distal stumps to neurorrhaphy (p<0.005) compared with the normal stumps. The end-to-side loop neurorrhaphy is a therapeutic option as suture technique after complete nerve section, in order to restore most of the axonal functional integrity.

Accidentes o enfermedades pueden afectar a la parte periférica del sistema nervioso, lo que plantea terapias clínicas y quirúrgicas, entre otras. En este contexto, la técnica de neurorrafia término-lateral es una opción terapéutica, sin embargo, su modificación en bucle necesita algunos estudios adicionales de eficacia. El objetivo de este estudio fue comparar, en ratas, resultados estereológicos (densidad de volumen axonal) después de la neurorrafia término-lateral y de la neurorrafia en bucle término-lateral. Fueron utilizadas 30 ratas Wistar, divididas en seis grupos (cinco animales por grupo), siendo dos grupos control (para los nervios fibular y tibial), dos grupos estudio del nervio fibular (uno con neurorrafia término-lateral y otro con neurorrafia en bucle termino-lateral) y dos grupos estudio del nervio tibial (uno con neurorrafia término-lateral y otro con neurorrafia en bucle término-lateral). Después de 180 días, todos los grupos fueron eutanasiados y se realizó el análisis estereológico axonal (densidad de volumen) en muñones nerviosos distales. Hubo un mantenimiento significativo de la densidad neuronal-axonal en los muñones distales a la neurorrafia (p<0,005) en comparación con los muñones normales. La neurorrafia en bucle término-lateral es una opción terapéutica como técnica de sutura después de la sección completa del nervio, con el fin de restaurar la mayoría de la integridad funcional axonal.

Peroneal nerve reconstruction by using glycerol-preserved veins: histological and functional assessment in rats

PURPOSE: To compare the degree of neural regeneration in rats upon interposition of autologous nerve graft, autogenous vein, glycerol-preserved autogenous vein, and glycerol-preserved allogeneic vein using qualitative and quantitative histological analyses as well as functional assessments. METHODS: Peroneal nerves were reconstructed differently in four groups of animals. Functional assessments were performed pre- and postoperatively for a period of six weeks. After six weeks, the animals were sacrificed and histological evaluations were performed. RESULTS: Histological patterns of autogenous veins without preservation showed pronounced neoangiogenesis and extensive axonal rarefaction, as confirmed by axonal counting and functional assessments. Glycerol-preserved veins had results similar to the control. CONCLUSIONS: Glycerol-preserved autogenous or allogeneic veins showed similar results to autograft results. The autogenous vein (without preservation in glycerol) presented histological and functional outcomes statistically lower than other groups.

Effect of electrical stimulation of the cranial tibial muscle after end-to-side neurorrhaphy of the peroneal nerve in rats

PURPOSE: To investigate the efficiency of electrical stimulation in the muscle maintenance and nerve regeneration after end-to-side neurorrhaphy (ESN). METHODS: Sixty male Wistar rats (Rattus norvegicus) were divided into four experimental groups. Control group (Control), Denervated Group (Denervated); Group with End-to-side neurorrhaphy (ESN); Group with End-to-side neurorrhaphy and electrical stimulation (ESN + ES). We perform electrical stimulation in rats after they had undergone muscle reinnervation by ESN. We collected morphometric and functional data. RESULTS: When comparing the mass of the treated side of cranial tibial muscle (CTM) and that of normal side of CTM, the group ESN + ES (26.12%) exhibited lower mass loss than that of group ESN (37.23%). The peroneal functional index showed that group ESN + ES equaled that of the Control group and showed an evolution of 60.5% while group ESN showed an evolution of 9.5%. In measuring maximum strength of CTM, the group ES + ESN outperformed group ESN. The muscle and nerve morphometry showed superiority of group ES+ESN over ESN group in all parameters. CONCLUSION: Electrical stimulation is an effective means of maintaining functional muscle and nerve regeneration after end-to-side neurorrhaphy.

Efeitos da laserterapia na regeneração nervosa periférica / Effects of laser therapy in peripheral nerve regeneration

OBJETIVO: Analisar o efeito do laser nas doses de 5, 10 e 20J/cm2 na reparação do nervo fibular de ratos após esmagamento. Os resultados foram avaliados por meio da análise funcional da marcha e de parâmetros morfométricos.MÉTODOS: Lesão por esmagamento controlado do nervo fibular comum direito e submetidos a intensidades crescentes (G1: sem irradiação; G2: sham; G3: 5J/cm2; G4: 10J/cm2; G5: 20J/cm2) de irradiação do laser diretamente sobre o local da lesão por 21 dias consecutivos. A análise funcional da marcha foi realizada a intervalos semanais, tendo sido medido o índice funcional do fibular (IFF). Os animais foram sacrificados nos 21º dia pós-operatório para remoção do nervo fibular, que foi preparado para a análise morfométrica.RESULTADOS: Não houve diferença significativa (p>0,05) dos valores da análise de marcha (IFF) entre os grupos em qualquer momento de avaliação para o parâmetro. A área total da secção transversal do nervo foi significantemente maior no grupo 2 do que nos grupos 3 e 4, enquanto a densidade de fibras foi significantemente maior no grupo 4 do que no demais grupos.CONCLUSÃO: A irradiação com o laser AsGaAl de baixa potência não acelerou a regeneração do nervo fibular com nenhuma das doses utilizadas. Nível de Evidência I, Estudos terapêuticos - Investigação dos Resultados do Tratamento.

OBJECTIVE: The influence of dose of low power lasertherapy (AsGaAl, 830 nm) on the regeneration of the fibular nerve of rats after a crush injury was evaluated by means of the functional gait analysis and histomorphometric parameters.METHODS: Controlled crush injury of the right common fibular nerve, immediately followed by increasing doses (G1: no irradiation; G2: simulated; G3: 5 J/cm2; G4: 10 J/cm2; G5: 20 J/cm2) laser irradiation directly on the lesion site for 21 consecutive days. Functional gait analysis was carried out at weekly intervals by measuring the peroneal/fibular functional index (PFI). The animals were killed on the 21st postoperative day for removal of the fibular nerve, which was prepared for the histomorphometric analysis.RESULTS: The PFI progressively increased during the observation period in all groups, without significant differences between them (p>0.05). The transverse nerve area was significantly wider in group 2 than in groups 3 and 4, while fiber density was significantly greater in group 4 than in all remaining groups.CONCLUSION: The low power AsGaAl laser irradiation did not accelerate nerve recovery with any of the doses used. Level of Evidence I, Therapeutic Studies Investigating the Results of Treatment.

The embracing end-to-side neurorrhaphy in rats / A neurorrafia término-lateral abraçante em ratos

PURPOSE: Compare two new methods with the traditional end-to-side neurorrhaphy. METHODS: Rats were divided into four groups. In A-L group the peroneal nerve was sectioned and the distal stump was connected to the lateral of the tibial nerve (donor) with two 10-0 nylon points. In A-R group two perineurium flaps embraced the donor nerve. In the B-R group a suture embraced the donor nerve. Group B-L was the control. After six months tibial cranial muscle mass and morphometry of the distal stump of the peroneal nerve were evaluated. RESULTS: Muscle mass in groups A-R, A-L and B-R were lower than B-L group (p<0.0001) an equal between themselves (p>0.05). Groups A-R, B-R and A-L had a lower number of nerve fibers when compared with B-L (p=0.0155, p=0.016, p=0.0021). CONCLUSION: The three types of neurorrhaphy showed no differences related to muscle mass and number of nerve fibers suggesting that the embracing with a single suture has great potential due its simplicity and usefulness in deep areas.

OBJETIVO: Comparar dois novos métodos com o método tradicional da neurorrafia término-lateral. MÉTODOS: Os ratos foram separados em quatro grupos. No grupo A-E o nervo peroneal foi seccionado e o coto distal foi suturado à lateral do nervo tibial com dois pontos de nylon 10-0. No grupo A-D duas abas de epi-perineuro abraçaram o nervo doador. No grupo B-D foi realizada sutura com um único ponto abraçando o nervo doador. O grupo B-E foi o controle. Após seis meses foram observados massa do músculo tibial cranial e morfometria do coto distal do nervo peroneal. RESULTADOS: Foi encontrada menor massa muscular nos grupos A-D, A-E e B-D quando comparados com o grupo B-E (p<0.0001) e mesma massa quando comparados entre si (p>0,05). Os grupos A-D, A-E e B-D apresentaram menor número de fibras nervosas quando comparados ao grupo B-E (p=0,0155; p=0,016; p=0,0021) e mesmo número quando comparados entre si. CONCLUSÃO: Os três tipos de neurorrafia não apresentaram diferenças relacionadas à massa muscular e número de fibras nervosas sugerindo que a sutura abraçante com apenas um ponto apresente grande potencial em áreas cirúrgicas mais profundas.

Double muscle innervation using end-to-side neurorrhaphy in rats / Dupla inervação muscular com neurorrafia término-lateral em ratos

CONTEXT AND OBJECTIVE: One of the techniques used for treating facial paralysis is double muscle innervation using end-to-end neurorrhaphy with sectioning of healthy nerves. The aim of this study was to evaluate whether double muscle innervation by means of end-to-side neurorrhaphy could occur, with maintenance of muscle innervation. DESIGN AND SETTING: Experimental study developed at the Experimental Research Center, Faculdade de Medicina de Botucatu, Unesp. METHODS: One hundred rats were allocated to five groups as follows: G1, control group; G2, the peroneal nerve was sectioned; G3, the tibial nerve was transected and the proximal stump was end-to-side sutured to the intact peroneal nerve; G4, 120 days after the G3 surgery, the peroneal nerve was sectioned proximally to the neurorrhaphy; G5, 120 days after the G3 surgery, the peroneal and tibial nerves were sectioned proximally to the neurorrhaphy. RESULTS: One hundred and fifty days after the surgery, G3 did not show any change in tibial muscle weight or muscle fiber diameter, but the axonal fiber diameter in the peroneal nerve distal to the neurorrhaphy had decreased. Although G4 showed atrophy of the cranial tibial muscle 30 days after sectioning the peroneal nerve, the electrophysiological test results and axonal diameter measurement confirmed that muscle reinnervation had occurred. CONCLUSION: These findings suggest that double muscle innervation did not occur through end-to-side neurorrhaphy; the tibial nerve was not able to maintain muscle innervation after the peroneal nerve had been sectioned, although muscle reinnervation was found to have occurred, 30 days after the peroneal nerve had been sectioned.

CONTEXTO E OBJETIVO: Uma das técnicas utilizadas para tratamento da paralisia facial é a dupla inervação muscular com neurorrafia término-terminal, seccionando-se nervos sadios. O objetivo deste trabalho foi avaliar a ocorrência de dupla inervação muscular através de neurorrafia término-lateral e a manutenção da inervação. TIPO DE ESTUDO E LOCAL: Estudo experimental desenvolvido no Centro de Pesquisa Experimental da Faculdade de Medicina de Botucatu, Unesp. MÉTODOS: Cem ratos foram distribuídos em cinco grupos: G1, controle; G2, secção do nervo fibular; G3, o nervo tibial foi seccionado e o coto proximal suturado na lateral do nervo fibular íntegro; G4, 120 dias após a cirurgia do G3, o nervo fibular foi seccionado proximal à neurorrafia; G5, 120 dias após a cirurgia do G3, os nervos fibular e tibial foram seccionados proximal à neurorrafia. RESULTADOS: Após 150 dias da cirurgia, não foi observada variação na massa do músculo tibial ou no diâmetro das fibras musculares no G3, porém, houve redução do diâmetro da fibra axonal do nervo fibular distal à neurorrafia. Embora, no G4, tenha ocorrido atrofia do músculo tibial cranial 30 dias após a secção do nervo fibular, os resultados do teste eletrofisiológico e da medida do diâmetro axonal confirmaram a ocorrência de reinervação muscular. CONCLUSÃO: Estes resultados sugerem que a dupla inervação muscular não ocorreu através da neurorrafia término-lateral; o nervo tibial não foi capaz de manter a inervação muscular após a secção do nervo fibular; contudo, ocorreu reinervação muscular 30 dias após a secção do nervo fibular.

Efeito da exposição cirúrgica de nervos e músculos no teste neurofisiológico em ratos / The effect of surgical exposure of nerves and muscles in neurophysiologic tests on rats

O estudo neurofisiológico, na modalidade da eletroneuromiografia (ENMG), determina e quantifica a integridade de componentes da unidade motora. Os principais dados fornecidos pelo exame eletroneuromiográfico são os estudos de condução nervosa motora, sensitiva e eletromiografia. No entanto, vários fatores podem interferir sobre a resposta nervosa à eletroestimulação, tais como: idade, sexo, temperatura, umidade e outros. O objetivo deste trabalho foi verificar o efeito da exposição cirúrgica dos nervos ciático, fibular comum, tibial e do músculo tibial cranial no teste neurofisiológico em ratos. Foram utilizados 20 ratos, Wistar, machos com aproximadamente 80 dias, divididos em dois grupos. No grupo normal o exame foi realizado sem a exposição cirúrgica do nervo fibular. No grupo cirúrgico houve a exposição do nervo fibular comum. Com o modelo experimental utilizado, concluiu-se que o teste neurofisiológico realizado em animais com nervos e músculos expostos cirurgicamente é viável, uma vez que a alteração da temperatura do animal não interferiu significativamente nos valores dos parâmetros eletrofisiológicos observados. Além disso, a exposição de nervos e músculos permite estimular um ponto exato no nervo alvo.

The neurophysiologic study in the modality of electroneuromyography (ENMG) determined and quantified the components in the motor ambit. The main data supplied by the examination was from the motor and sensory nerve conduction studies and by electromyography. However, many factors can interfere with the nervous response to electro-stimulation, such as: age, gender, temperature, humidity, and other things. The aim of this work was to verify the effect of surgical exposure of the sciatic, common fibular, tibial, and cranial tibial muscle nerves in a neurophysiologic test on rats. Twenty (20) Wistar male rats were utilized, with approximately 80 days of age, divided into two groups. In the normal group the exam was made without the surgical exposure of the fibular nerve. In the surgical group the common fibular nerve was exposed. With the experimental model utilized, it was concluded that the neurophysiologic test done on animals with nerves and muscles surgically exposed is viable, since the alteration in animal temperature did not interfere significantly with the values of the electrophysiological parameters observed. In addition, the exposure of nerves and muscles allows stimulation of an exact point on the target nerve.

End-to-side nerve repair using fibrin glue in rats / Anastomose nervosa término-lateral usando cola de fibrina em ratos

Purpose: To evaluate axonal regeneration after end-to-side nerve repair with fibrin glue in rats. Methods: Forty-five Wistar rats were divided into three groups: group A (n=15), were not submitted to surgery (control group); group B (n=15) were submitted to fibular transection without repair; and group C (n=15), were submitted to fibular transection with end-to-side nerve anastomosis using fibrin glue, in the lateral surface of an intact tibial nerve. The three groups were submitted to walking track (30 and 90 days) and posterior morphometrical analysis (90 days). Results: The functional tests demonstrated that there was no difference in the walking track during the study in group A (p>0.05). The group B had walking pattern impairment in the two tests (p>0.05). The group C had walking pattern impairment in the first test, with important recovery in the second test (p<0.05). The morphometrical assessment revealed significantly higher number of regenerated mielinates axons in group C, compared to group B (p<0.05). Conclusion: The end-to-side nerve repair with fibrin glue shows axonal recovery, demonstrated through functional and morphometrical ways in rats.

Objetivo: Avaliar a regeneração axonal após anastomose nervosa término-lateral (ATL) usando cola de fibrina em ratos. Métodos: Quarenta e cinco ratos Wistar distribuídos em três grupos: os animais do grupo A (n=15) não foram submetidos à secção nervosa (grupo controle); os animais do grupo B (n=15) foram submetidos apenas à secção do nervo fibular, sem posterior anastomose; e os animais do grupo C (n=15) foram submetidos à secção do nervo fibular e à ATL com cola de fibrina no nervo tibial. Posteriormente, os animais foram submetidos a dois testes de marcha (30 e 90 dias) e à análise morfométrica (90 dias). Resultados: A análise estatística dos testes de marcha demonstrou que o grupo A não apresentou alteração no padrão de caminhada durante o estudo (p>0,05). O grupo B apresentou prejuízo motor no primeiro e no segundo teste (p>0,05). O grupo C apresentou um padrão de atrofia no primeiro teste, com recuperação da marcha no segundo teste (p<0,05). Na análise morfométrica, o grupo C apresentou regeneração axonal significativamente superior ao grupo B (p<0,05). Conclusão: A ATL realizada com cola de fibrina resultou em regeneração axonal no rato, demonstrada tanto histologicamente quanto funcionalmente.

Estudo morfológico da regeneração axonial na síntese terminolateral de nervo periférico de ratos com adesivo de fibrina e micro-sutura / Morphological study of axonal regeneration in mice peripherical nerve terminolateral synthesis with fibrin adhesive and microsuture

Quando um nervo periférico é seccionado, com freqüência, há um intervalo variável entre os cotos. Se esta distância é muito grande ou o leito aonde serão colocados os enxertos nervosos não é adequado, podese usar os reparos terminolaterais. Existe, na literatura médica, uma expressiva quan- tidade de trabalhos experimentais sobre este tipo de reparo que constatam resultados satisfatórios com a utilização de fio de poliamida 9-0 e sem a retirada do epineuro. O objetivo deste trabalho é mostrar as alterações morfológicas do reparo terminolateral comparando o adesivo de fibrina ao fio de poliamida. Criou-se dois grupos (A e B) com 11 ratos em cada um deles. No grupo A foi realizado, de um lado, o reparo terminolateral entre o nervo tibial e o fibular com fio de poliamida. No grupo B, no lado contra-lateral, realizouse o mesmo procedimento com adesivo de fibrina. Os animais operados foram observados até o nonagésimo dia de pós-operatório. Sob microscopia óptica contou-se o número de axônios regenerados e seu diâmetro. Do ponto de vista morfológico não se encontrou nenhuma diferença entre os tipos de sínteses empregados. Pode-se, entretanto, inferir que o adesivo de fibrina diminui o tempo operatório e não causa lesões no nervo doador.

When a peripheral nerve is sectioned there is frequently a gap between the stumps. If the distance between them is too wide or there is a lot of fibrosis, we can use the end-to-side repair. In the medical literature, there are quite a few experimental papers about this kind of repair with good results using nylon 9-0 without epineural removal. The objective of the present paper is to show the morphologic alterations of the end to side repair, comparing the fibrin glue with the nylon. For that purpose, we used two groups (A and B) with 11 rats each. In group A, it was conducted, on one side, an end-to-side repair of the tibial and fibular nerves with nylon. In group B, on the other side, we did the same procedure using fibrin glue. The operated animals were observed until the 90th day after the surgery. With optic microscopy, we counted the axons and their diameter. Morphologically, there was not any statistical difference between the two groups. However, one can infer that the fibrin glue reduces the operative time, and does not cause lesion in the donor nerve.

Regeneraçäo de nervo periférico após anastomose término-lateral, com manutençäo do epineuro, em ratos / Regeneration of peripheral nerve after termino-lateral anastomosis with epineurium maintenance in rats

A reinervaçäo dos nervos periféricos pode ser realizada através de anastomoses término-terminais ou término-laterais, e este fenômeno tem sido amplamente estud ado. As anastomoses nervosas término-laterais tem sido utilizadas com pouca freqüência em relaçäo as anastomoses término-terminais e contestada por alguns autores quanto a possibilidade de reinervaçäo, quando a integridade do epineuro é mantida. Devido a estas divergências, estudou-se o efeito do epineuro na reinervaçäo em anastomoses término-laterais, em ratos. Foram utilizados 20 ratos Wistar, adultos, distribuídos em dois grupos (A e B). No grupo A, 10 animais foram submetidos à secçäo do nervo fibular no membro pélvico direito e fixaçäo desde à musculatura; no membro pélvico esquerdo foi realizada a secçäo do nervo fibular e anastomasado término-lateral com o nervo tibial. No grupo B, os procedimentos foram idênticos aos realizados no grupo A, sendo somente invertido os membros pélvicos. No nonagésimo dia do ato operatório, foi realizada uma biópsia em cada nervo fibular para análise histológica à microscópia óptica, onde a reinervaçäo foi objeto de estudo. A reinervaçäo ocorreu mostrando que a integridade do epineuro näo impediu a regeneraçäo axonal.

Quantitative and Qualitative Muscular Changes after Selective Neurotomy

Disfigurement of body contour, caused by excessive muscular hypertrophy, can seldom be effectively and safely corrected by lipectomy, liposuction or combined partial myomectomy. This study was conducted to obtain basic knowledge for the development of a safe and effective method of treating patients with excessive and unwelcome muscle hypertrophy. Accordingly, we developed a new experimental rat model, consisting of the peroneal nerve and its target muscles - the anterolateral crural muscle group. After severance of 1/4, 1/2, and 1/1 of the peroneal nerve, functional parameters based on gross movement and electrophysiologic data were monitored. Changes in the external circumference and weight of the anterolateral crural muscle were documented and compared with control sides. Histologic and histomorphometric parameters of the muscle were also documented. Average takeoff latency in 1/4 and 1/2 neurotomy groups was increased to 130% and 154% of the control at 3 months, and 156% and 149% of control at 6months, respectively. Similarly, average peak-to-peak compound action potentials were 72% and 59% of the control at 3months and 57% and 50% of control at 6months. No definite gait disturbances were evident in the partial neurotomy groups. Maximal circumferences of the anterolateral crural muscle group were significantly reduced to 86%, 71% and 66% of the control in the 1/4, 1/2 and 1/1 neurotomy groups at 3 months (p < 0.001), and to 74%, 68% and 64% of the control at 6 months, respectively (p < 0.001). The corresponding weights were 76%, 62%, and 50% of the control sides at 3 months, and 70%, 56%, and 48% at 6 months in 1/4, 1/2 and 1/1 neurotomy groups. Histograms drawn showing the number of muscle fibers per mm2 in cross-sections, showed a total number of 239 +/- 52 in the control group; the size of muscle fibers was mainly medium to large. The more extensive the neurotomy, the greater the was the number of small angulated muscle fibers, up to a total of 1,564 +/- 211. Although more research work and clinical trials are required, we believe that selective neurotomy has the potential of being an effective tool for reducing muscle bulk, and avoiding apparent muscular dysfunction and complications.

Cisto sinoval intraneural do nervo fibular / Intraneural synovial cyst of the peroneal nerve. Case report

Os autores apresentam um caso de um cisto sinovial intraneural ocorrendo no nervo fibular comum. O paciente apresentou-se com quadro de dor e dificuldade para a flexäo dorsal e eversao do pé sendo submetido a exploraçäo cirúrgica com exérese do cisto. Neste estudo säo discutidos a patogênese, manifestaçoes clínicas e tratamento desta rara lesäo.

Compressäo do nervo fibular comum por cisto sinovial: relato de caso / Compression of the peroneus nerve by a synovial cyst: report of a case

Os autores apresentam um caso de paralisia do nervo fibular comum provocado por cisto sinovial e fazem uma breve revisäo da literatura.

Compressäo do nervo fibular profundo do dorso do pé: relato de caso / Deep peroneal nerve entrapment of the foot: report of a case

Os autores relatam um caso de compressäo do ramo sensitivo do nervo fibular profundo no dorso do pé associada à atividade profissional, revisando a literatura concernente à compressäo do nervo fibular profundo no pé e tornozelo.

Latero-terminal neurorrhaphy without removal of the epineural sheath: experimental study in rats

Termino-lateral neurorrhaphies have been used up to the beginning of this century. After this period, they have no longer been reported. We tested the efficacy of a new type of latero-terminal neurorrhaphy and evaluated the role of the epineural sheath. A group of 10 rats had the fibular nerve sectioned and the distal ending was sutured to the lateral face of the tibial nerve without removing the epineurium. All experiments were made on the right side, the left one remaining untouched in half of the animals of each group. The other half were denervated by sectioning and inverting the endings of the fibular nerves. In this way, tibial cranial muscles were either normal or denervated in the left side and reinnervated through latero-terminal neurorrhaphy in the right side. After 7.7 months, the animals were subjected to electrophysiological tests, sacrificed, and the nerves and muscles were taken for histological exams. A response of the tibial cranial muscle was obtained in 75% of the animals. The distal ending of the fibular nerve showed an average of 498 nerve fibers. The average areas of the reinnervated tibial cranial muscles were (mu 2):841.30 for M2n and 1798.33 for M2d. We concluded that the termino-lateral neurorrhaphy was functional, conducting electrical stimuli and allowing the passage of axons from the lateral surface of a healthy nerve, to reconstitute the distal segment of a sectioned nerve. The presence of the epineurium was no impediment to axonal regeneration or to the passage of electrical stimuli.(ABSTRACT TRUNCATED AT 250 WORDS)