Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1999: ¥2,400,000 (Direct Cost: ¥2,400,000)
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Research Abstract |
In an experimental study in rats we tested treatment of a peripheral nerve gap by incremental stretch to lengthen the nerve. An external fixator was used to progressively lengthen the femur, and consequently the sciatic nerve, by 3 mm/day (group 3 mm) or 5mm/day (group 5 mm). In both groups, total lengthening was 15mm. Seven days after initiating nerve lengthening, the external fixator was removed and the nerve was transected and sutured. At 2, 4, 6, or 8 weeks after this suturing, semithin sections were prepared from sciatic and tibial nerves. Although regeneration of nerve fibers was observed beginning at 2 weeks, nerve regeneration showed a delay in group 5 mm at 6 weeks, when group 3 mm showed nerve regeneration as good as in the unstretched control group. Fibroblasts and myelin debris were abundant in group 5 mm. Differences in nerve regeneration after nerve lengthening at different rates were considered results of mechanical nerve injury, nerve degeneration, ischaemia, and fibrosis, all worse with more rapid lengthening. Nerve lengthening at a more moderate rate (3 mm/day) does not compromise regeneration.
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