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.

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.

Nervo alógeno conservado em glicerol: estudo experimental em ratos / Glycerol-preserved allogenous nerve: an experimental study with rats

A utilização de aloenxerto de nervo conservado em glicerol é uma alternativa a auto-enxertia em casos de lesões de nervos periféricos com perda de substância que diminui a morbidade cirúrgica e provem material suficiente para a reparação neural. O objetivo deste trabalho foi comparar o grau de reparação nervosa, utilizando análises histológica e funcional, através da interposição de enxerto autógeno (grupo A), de tubo de veia conservada em glicerol (grupo B) e de interposição de nervo alógeno conservado em glicerol (grupo C) em defeitos de 5 mm no nervo fibular de ratos Wistar. A análise histológica foi feita após o sacrifício dos animais( 6 semanas) , usando o corante azul de toluidina a 1 por cento. No grupo A (auto-enxerto) verificou-se reação tecidual perineural e escape de fibras axonais mielinizadas para fora dos limites do epineuro que foi maior se comparada ao verificado no Grupo B (Veia autógena + glicerol) e Grupo C (aloenxerto de nervo).A avaliação funcional foi feita através da análise dos padrões das pegadas das patas posteriores dos ratos ("Walking Track Analysis"), nos períodos: pré-operatório, pós-operatório imediato, na terceira e sexta semanas. Na recuperação funcional, não houve diferença estatisticamente significativa entre os três grupos em nenhum dos períodos avaliados.

The use of glycerol-preserved nerve allograft is an alternative to autografting in cases of peripheral nerve injury with loss of substance, which decreases surgical morbidity and provides sufficient material for neural repair. The objective of this study was to compare the degree of nervous repair, through interposition of autogenous graft (Group A), of glycerol-preserved vein tube (Group B), and interposition of glycerol-preserved allogenic nerve (Group C) in 5-mm defects of Wistar rats' fibular nerve, using histological and functional analyses. In group A (autograft) a perineural tissue reaction and myelinated axonal fibers escape out of the epineurium boundaries were greater when compared to those observed in Group B (autogenous vein + glycerol) and Group C (nerve allograft). The functional evaluation was made by analysis of the patterns of rats' posterior footprints (Walking Track Analysis) in preoperative, early postoperative period, week 3 and week 6. Regarding functional recovery, in none of the evaluated periods was there a statistically significant difference between the three groups.

End-to-side neurorrhaphy with and without perineurium

Objective: We compared end-to-side neurorraphy with and without the perineural sheath. Method: Twenty rats were used. The peroneal nerve was sectioned and the distal end was sutured to the lateral face of the tibial nerve. We removed the perineural sheath only on the right side, but not on the left side. The proximal end of the peroneal nerve was curved back approximately at a 100 angle and implanted into the adductor muscle. Six months later, the 14 surviving animals were submitted to electrophysiological tests, sacrificed, and the nerves and muscles were taken for histological exams. Results: On the right side, the muscles that had positive response needed and average of 258.89 mV (+ 92.31) of electric stimulus and on the left side 298.34 mV (+139.32). The average weight of the tibial cranial muscles of the right side was 0.47 g (0.18) and for the left side 0.45 g (0.15). The distal end of the peroneal nerve showed averages of 310.29 (+191.34) nerve fibers on the right side and 287.71 (+183.60) on the left side. The tibial nerve above the neurorraphy showed averages of 939.46 (+223.51) nerve fibers on the right side and 959.46 (+327.48) on the left side. The tibial nerve below the neurorraphy showed averages of 935.17 (+298.65) nerve fibers on the right side and 755.31 (+323.26) on the left side. The average areas of the right tibial cranial muscles were 0.0162 m2 (+0.008), after 230 magnification, and 0.0152 m2 (0.0064) for the left tibial cranial muscles. The histological features of the tibial cranial muscles, taking normal as 100 per cent, were 78.21 (+20.75) on the right side and 82.14 (+15.89) on the left side. The statistical analysis (Student's t test) did not reveal any difference (p<0.05) among right and left sides for all variables. Conclusion. The authors concluded that the two neurorraphies (with and without perinerium) did not show any difference regarding morphological and electrophysiological features studies.