| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1991: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1990: ¥1,600,000 (Direct Cost: ¥1,600,000)
|
|---|
| Research Abstract |
Major nerve injuries are often difficult to appropriately match and coapt proximal and distal fibers. More proximal lesions are even more difficult due to intermingling of the fibers. Recent investigations strongly suggests that neurotropic factor induces proximal motor or sensory nerve fibers to regenerate to the matched specific end organ.
We compared the results following nerve repair using tubulization with or without a small gap in rabbit median nerve.
Forty New Zealand white rabbits were divided into four groups. The radial sensory nerve and motor branch (posterior interosseous nerve) were used at their branching site from the trunk nerve. The contralateral radial nerve served as the control. In group A, both sensory and motor branches were severed and coapted using a 5-mm-long collagen. In group B, the same procedure was performed as Group A except nerves were rotated 180ﾟ. In Group C, the same procedure as Group A, but a 10-mm-long collagen tube was used and 5-mm gap left at the
… More
coaptation site. Group D, had 10-mm long tube, 5mm gap and nerve stumps rotated 180ﾟ, At 24 weeks postoperatively, nerve conduction velocities, compound action potential area were obtained from the both the sensory and motor branches. Contraction force and muscle weight of the extensor digitorum communis were determined on the repaired side ; this was followed immediately by identical evaluation on the contralateral forelimb. The results were expressed as the Percentage of normal control.
Nerve conduction velocity and compound action potential area did not demonstrate statistically significant differences between groups. Muscle power of group B (45.7%) was significantly less than that of any other groups. Group D (97.7%) recorded comparable muscle power to that of group A (93.6%) or C(111.4%). Dry muscle weight demonstrated good correlation with the muscle contraction force, however, there was no significant difference between groups.
Nerve coaptation with misdirected nerve fiber alignment does not allow sufficient functional recovery. If a closed, small gap between the proximal and distal nerve stumps is provided, however, misaligned proximal nerve fiber may detect a distal fiber connecting to the matched target organ probably by the aid of neurotropic factors. Nerve repair using biodegradable, inert tubing with a short gap may be a useful, clinically applicable method in proximal nerve injury. Less
|
