周围神经缺损在临床上常见，也是临床治疗的难点［1］。创伤性神经缺失、神经肿瘤医源性切除、神经延期修复时的神经短缩等均可导致不同程度的神经缺损［2-5］，我国每年周围神经缺损患者高达30~50万例。对于小的周围神经缺损，可通过神经游离、转位、改变患肢体位和姿势等方法，将神经两断端接近后进行直接缝合［6］。对于较大的周围神经缺损，应用上述方法无法达到神经的无张力修复时，则需采用其他方法进行神经修复。目前临床上最常采用的是神经移植术［7-8］，即采用自体神经段桥接缺损的神经，进而达到神经缺损修复的效果，但由于神经移植术的移植神经来源有一定的限制, 且通常还要以牺牲供区神经功能为代价［9-10］，因此寻找其他修复方法和技术一直是周围神经缺损研究领域的热点。
我们从肢体延长手术中获得启示：周围神经的特殊组织结构及力学性质使得神经干具有一定限度的抗张性，一定范围内延长神经不会对神经造成损伤。经过延长神经可以使神经断端长度得到增加，从而达到缩短神经缺损距离的目的，使得缺损的神经能够直接缝合修复，因此我们开展了用周围神经延长技术修复周围神经缺损的系统研究：完成了周围神经延长器研发、周围神经延长极限、延长神经修复神经缺损效果等多个研究，现将此系统性研究成果报道如下。

Peripheral nerve defects are still a major challenge in clinical practice, and the most commonly used method of treatment for peripheral nerve defects is nerve transplantation, which has certain limitations and shortcomings, so new repair methods and techniques are needed. The peripheral nerve is elongated in limb lengthening surgery without injury, from which we got inspirations and proposed a new method to repair peripheral nerve defects: peripheral nerve elongation. The peripheral nerve could beelongated by a certain percent, but the physiological change and the maximum elongation range were still unknown. This study discussed the endurance, the physiological and pathological change of peripheral nerve elongation in detail, and got a lot of useful data. First, we developed peripheral nerve extender which could match the slow and even extension of peripheral nerve. Then, our animal experiment result confirmed that the peripheral nerve had better endurance for chronic elongation than that of acute elongation and cleared the extensibility of peripheral nerve and the range of repair for peripheral nerve defects. Our result also revealed the histological basis and changed the rule for pathological physiology of peri-pheral nerve elongation: the most important structure foundation of peripheral nerve elongation was Fontana band, which was the coiling of nerve fibers under the epineurium, so peripheral nerve could be stretched for 8.5%-10.0% without injury because of the Fontana band. We confirmed that peripheral nerve extending technology could have the same repair effect as traditional nerve transplantation through animal experiments. Finally, we compared the clinical outcomes between nerve elongation and perfor-mance of the conventional method in the repair of short-distance transection injuries in human elbows, and the post-operative follow-up results demonstrated that early neurological function recovery was better in the nerve elongation group than in the conventional group. On the whole, all of these experimental results revealed the physiological phenomenon of peripheral nerve elongation, and described the physiological change and stretch range in detail. The systematic research results have filled the blank in this field, which is very helpful for clinical limb lengthening surgery, the design of elongation surgery and the evaluation of the peripheral nerve stretch injury. Peripheral nerve elongation will become an innovative treatment technology in repairing peripheral nerve defects.