Periteral nerve elongation for nerve repair

在一项大鼠实验研究中，我们测试了通过增量拉伸延长神经来治疗周围神经间隙。使用外固定架以3mm /天（3mm组）或5mm/天（5mm组）的速度逐渐延长股骨，从而延长坐骨神经。两组总长度均为15mm。开始神经延长7天后，取出外固定架，横切并缝合神经。缝合后2、4、6或8周，从坐骨神经和胫骨神经制备半薄切片。虽然神经纤维的再生在2周开始，但在6周时，5mm组的神经再生出现延迟，而3mm组的神经再生与未拉伸的对照组一样好。5 mm组纤维母细胞和髓鞘碎片丰富。不同速度的神经延长后神经再生的差异被认为是机械性神经损伤、神经变性、缺血和纤维化的结果，随着神经延长的速度越快，情况越糟。神经以更适度的速度延长（3毫米/天）不影响再生。

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.