[An experimental study on the regeneration of the peripheral nerve--adaptation of the funiculus at the sutured site (author's transl)].

UNLABELLED

We consider it necessary to investigate the passage of axon through the sutured site, besides problems of misdirection, in order to understand the factors which affect the regeneration of the peripheral nerve. We performed the following experiments assuming that different situations occurring at sutured site is to be considered as mono-funiculus situation, and studied them mainly from the histological point of view.

METHOD

Twenty-five adult hybrid dogs were used. We performed several different experiments, mentioned below, on the sciatic nerve, at about 3 cm below the greater trochanter with 9-0 monofilament nylon by microsurgical technique. The sciatic nerve was separated 4 cm away from the surrounding tissue, and only the peroneal nerve funiculus was isolated 2 cm away from the other funiculus and was cut at the center. Models of experiment. 1. Proper suture of both cut end...Optimum. 2. Suture by tension after excision of 1 cm in length...Tension, 3. Suture by compression...Compression, 4. Suture by shifting both cut ends about 1/2 of their surface...Offset, 5. Suture by buckling...Buckling, 6. Suture with gap of 5 mm after excision of 5 mm in length...Gap. Five weeks and ten weeks after the operation, the nerves were examined electrophysiologically and histologically. The nerve was stimulated at about 1 cm proximal to the sutured site directly using needle electrode, and the most distal part was searched for, where the nerve action potential was recorded. For the histological study, the nerve was sectioned longitudinally and transversely. These specimens were stained by H. E., Holmes' (for the axon), and L. F. B. method (for the myelin sheath). The regeneration of the nerve was classified into four grades, according to the number and the size of the axon passing through the sutured site, namely poor, fair, good, excellent.

RESULTS

1. The offset of the funiculus at the sutured site is the most important factor which disturbs the regeneration of the axon. 2) The influence of about 5 mm gap is not so big for the regeneration of the axon, compared to the severe offset. 3) The moderate tension which can be produced by the ordinary microsurgical suture does not much influence the regeneration of the axon, and the compression at the sutured site has not much influence to the nerve regeneration as long as the adaptation is good.