Use of superficial peroneal nerve graft for treating peripheral nerve injuries / Emprego do enxerto do nervo fibular superficial para tratamento de lesões de nervos periféricos

To evaluate the clinical results from treating chronic peripheral nerve injuries using the superficial peroneal nerve as a graft donor source. METHODS: This was a study on eleven patients with peripheral nerve injuries in the upper limbs that were treated with grafts from the sensitive branch of the superficial peroneal nerve. The mean time interval between the dates of the injury and surgery was 93 days. The ulnar nerve was injured in eight cases and the median nerve in six. There were three cases of injury to both nerves. In the surgery, a longitudinal incision was made on the anterolateral face of the ankle, thus viewing the superficial peroneal nerve, which was located anteriorly to the extensor digitorum longus muscle. Proximally, the deep fascia between the extensor digitorum longus and the peroneal longus muscles was dissected. Next, the motor branch of the short peroneal muscle (one of the branches of the superficial peroneal nerve) was identified. The proximal limit of the sensitive branch was found at this point. RESULTS: The average space between the nerve stumps was 3.8 cm. The average length of the grafts was 16.44 cm. The number of segments used was two to four cables. In evaluating the recovery of sensitivity, 27.2% evolved to S2+, 54.5% to S3 and 18.1% to S3+. Regarding motor recovery, 72.7% presented grade 4 and 27.2% grade 3. There was no motor deficit in the donor area. A sensitive deficit in the lateral dorsal region of the ankle and the dorsal region of the foot was observed. None of the patients presented complaints in relation to walking. CONCLUSIONS: Use of the superficial peroneal nerve as a graft source for treating peripheral nerve injuries is safe and provides good clinical results similar to those from other nerve graft sources.

Avaliar resultados clínicos do tratamento das lesões crônicas de nervos periféricos com o nervo fibular superficial como fonte doadora de enxerto. MÉTODOS: Estudo de 11 pacientes com lesões de nervos periféricos nos membros superiores tratados com enxerto do ramo sensitivo do nervo fibular superficial, com intervalo médio de 93 dias entre a data de registro da lesão e a cirurgia. Foram observadas lesões do nervo ulnar em oito pacientes e do nervo mediano em seis. Em três ambos os nervos foram lesados. Na cirurgia faz-se incisão longitudinal na face anterolateral no tornozelo, visualiza-se o nervo fibular superficial, situado anteriormente ao músculo extensor longo dos artelhos. Proximalmente disseca-se a fáscia profunda entre os músculos extensor longo dos artelhos e o fibular longo. A seguir, identifica-se o ramo motor do músculo fibular curto, um dos ramos do nervo fibular superficial. O limite proximal do ramo sensitivo encontra-se nesse ponto. RESULTADOS: A média do espaço entre os cotos nervosos foi de 3,8 cm, comprimento médio dos enxertos de 16,44 cm, número de segmentos usados de dois a quatro cabos. Na avaliação da recuperação da sensibilidade, 27,2% evoluíram para S2+, 54,5% para S3 e 18,1% para S3+. Quanto à recuperação motora, 72,7% apresentavam grau 4 e 27,2%, grau 3. Não houve déficit motor da área doadora, observou-se déficit sensitivo na região dorso lateral do tornozelo e dorsal do pé. Nenhum paciente apresentou queixas à deambulação. CONCLUSÕES: O uso do nervo fibular superficial no tratamento das lesões de nervos periféricos como fonte de enxerto é seguro e proporciona resultados clínicos semelhantes a outras fontes de enxerto de nervos.

Influence of highly purified preparations of hyaluronic acid on peripheral nerve regenrations in vivo

The tubulization repair technique is a useful model for studying perpheral nerve regeneration since it provides quantifiable parameters for assessing the effects of exogenously applied substances on nerve repair. In this study, we observed that the local administration of hyalutonic acid (HA) in a tubular prosthesis at the time of implantaton significantly improved the repair process, and that this effect was dependent on the viscosity of the HA preparation. The sciatic nerve of C57BL/6J mice was transected and the proximal and distal nerve stumps were sutured into a polyethylene tube (PT, 0.76mm i.d.) to bridge a nerve gap of 4 mm. The tubes were implanted either empty, or filled with a low-viscosity (MW = 450 - 1000 kDa) commercial preparatin of HA. After 4 weeks, the PT with the regenerating nerve cables were processed for histological analysis and the total number of myelinated axons was counted using a computer-controlled system. Low-viscosity HA significantly increased peripheral axon regeneration (2191 +- 82 myelinated axons, mean +- SEM) compared to the group with epty tube implants (1597 +- 80). This enhanced regeneratin was not observed in the group implanted with tubes containing high-viscosity HA (1643 +- 69). The stimulatory effect of exogenous HA on nerve regeneration could be due to its activity on non-neural cell proliferation, migration and differentiation which would lead to faster ingrowth of regenerating axons.