nerve regeneration study

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Abstract from J Reconstr Microsurg. 2004 Mar;20(2):159-66.

Functional, electrophysiologic, and morphometric evaluation of nerve

regeneration from coaptation on regenerated nerve fibers: experimental

study in rabbits.

Beer GM, Burg D, Zehnder A, Seifert B, Steurer M, Grimaldi H, Meyer VE.

Division for Plastic, Hand, and Reconstructive Surgery, Department of

Surgery, University Hospital Zurich (Academic Medical Center),

Switzerland.

The importance of a sufficient number of nerve fibers at a proximal

coaptation site is indisputable for the successful repair of nerves;

however, the quality of nerve fibers required at this site has yet to be

defined. The present study deals with the question of whether it is

necessary to trim nerves back to unaffected neuronal tissue or whether

the coaptation on recently regenerated nerve fibers, commonly believed

to produce a poor quality of repair can, in fact, produce adequate nerve

regeneration. Twenty New Zealand White rabbits received a standardized

crush lesion on the peroneal nerves of both hind legs. Four weeks later,

the nerves of the left hind legs (n = 20) were transected 10 mm distal

to the previous crush lesion and coapted to the freshly regenerated

nerve fibers. For comparison, on 10 right hind legs, the nerves were

transected at the site of previous crushing (Group A, superimposition)

or 10 mm proximal to the site of crushing on unscathed nerve fibers

(Group . Eleven weeks later, the quality of nerve regeneration was

assessed by the toe-spreading reflex, electrophysiologic data, muscle

weight, and histomorphologic evaluation. In the animals of Group A, the

quality of nerve regeneration following coaptation on the regrown axons

did not differ in any of the examined parameters from the quality of

nerve fibers outgrown from the site of the superimposed lesion. Both

lesions led to a completely functional reinnervation. Also in Group B,

nerve action potential recording and histologic data on both sides did

not reveal a significant difference between the number and maturation of

nerve fibers equidistant from the suture site, shortly before muscle

entrance. With this coaptation model, it could be demonstrated in the

peroneal nerve of rabbits, that coaptation to recently regenerated nerve

fibers leads to a significant functional regeneration.