Experimental Study Of Nerve Regeneration After Nerve Double End-to-side Neurorraphy By A Grafted Nerve Bridged The Incompletely Injuried Nerve

Objective: This study was done to determine whether the distal nerve regeneration was stimulated after double end-to-side neurorrphy by a grafted nerve bridged the incompletely injuried nerve, and investigated its possibly clinical value.Methods: Twenty male New Zealand rabbits were randomly divided into two groups: group A and group B, with 10 rabbits each. The right sciatic nerve of all the animal was dissected free of connective tissue, and the tibial nerve part was transected at the site of 2.0-cm up sciatic nerve ramification. In group A: a 1.0-cm segment nerve was cut off from the right median nerve. Epineurotomy producing two 1.0×1.0mm windows were carried out on the two site of 0.5 cm up and down the position where tibial nerve was transected. The median nerve segment was anastomosed end-to-side to the two sciatic nerve windows. In group B: no nerve to bridge the transected sciatic nerve. Then all theanimals were maintained on rabbit chow with a 12-hours light-dark cycle.Results: Animal's characteristics: In the early stage of after the operation, the right foot of all animals can't stretch, and not sensitive to pain stimulation. The threptic deficiency in foot skin, such as skin ulcer, toenail falling were found in seven of group A and eight of group B. Three months after the operation: in group A, all the animal's skin ulcers were coalesced, and sensitive to the pain stimulation. In group B: the reaction to pain was not so sensitive to animals in group A. There still 5 rabbit's skin ulcer were not coalesced. Electromyogram: significant difference was found between the group A and the group B in the latency period and the wave amplitude after three months, P＜0.05. Animal in group A: Anatomical microcopy: After three months, the location of the two end-to-side coaption was little thicken than the normal sciatic nerve and the regenerated nerve fibers were well myelinated. The sciatic nerve and media nerve were well integrated in the two end-to-side coaption. There were some cohered fiber tissue around the suture, but the other parts of the sciatic nerve were smooth and the elasticity was good. Light microscope: small myelinated nerve fibers of a great deal of number regenerated in the distal nerve of the sciatic nerve. Electron microspic: the diameter and cross area of myelin were obvious larger than those of normal sciatic nerve. All the above things were not found in theanimals in the group B.Conclusions: Experiment study in rabbits showed that the distal nerves can be regenerated after double end-to-side neurorraphy by a grafted nerve bridged the incompletely injuried nerve, and the residual function of the incompletely injuried nerve was strengthened, and the lost function of the target organs was somehow rectified.