低强度超声促进周围神经修复的研究进展

The research progress of low-intensity pulsed ultrasound to promote peripheral nerve repair and regeneration

周围神经损伤后的修复一直是医学界研究的热点和难点。虽然显微外科学的发展以及组织工程的出现,为周围神经损伤后的修复带来了佳音,但是目前其临床疗效仍不十分理想。低强度超声波作为物理治疗的一种方式,被研究认为能促进周围神经损伤的修复。低强度超声主要利用超声波的机械效应,提高细胞膜和细胞壁的通透性,增强细胞的新陈代谢,促进细胞生长。低强度超声治疗最早在临床上主要应用于促进骨折愈合、肌腱愈合及软骨、椎间盘等组织的愈合中。早期人们也研究过低强度超声在神经系统中的作用,争论的焦点主要在连续超声或脉冲超声方式的选择以及热效应是否发挥作用上。初步研究表明:低强度超声可以促进雪旺细胞增生以及在大鼠坐骨神经挤压伤、坐骨神经截断伤、神经导管修复缺损坐骨神经等神经损伤过程中的修复和再生。对于其作用的机制的研究也从细胞学、分子生物学、酶学、离子通道等多个角度进行了探索。作为无创便捷的治疗方法,低强度超声虽然还有很多方面的问题尚待商榷研究,其未来广阔的临床应用空间是值得肯定和期待的。

Nowadays,peripheral nerve injury is becoming the focus of social attention.Although microsurgery and tissue engineering provide new methods for repair and regeneration of peripheral nerve,their clinic effects are far from ideal.In recent years,different methods have been used to improve peripheral nerve recovery,such as physical stimulus like laser,electricity magnetic field,shock waves and ultrasound.And promising results have been achieved.Mechanical effect was recognized as main effect in the biologic action of low -intensity pulsed ultrasound （LIPUS）while thermal mechanisms were not.Micromechanical stimulation and cavitation mecha-nisms played an important role.Mechanical strains may result in increasing enzyme activity and modifying cell metabolism.Studies showed that LIPUS could promote the permeability and selectivity of cell membrane and cell wall,enhance mass transfer and increase absorbing of nutritional elements.LIPUS has been proved to have therapeutic effect on a lot of tissue damage.The US Food and Drug Administration approved LIPUS for accelerating fresh fracture healing in 1994 and for the treatment of existing nonunions in 2000 sepa-rately.LIPUS could also promote healing in various soft tissues such as cartilage,intervertebral disc,etc.It could improve bone -ten-don junction through effect on osseous tissue.The ultrasonic effect on the nervous system was first concerned in the early stage of the ultrasonic biological effect.Many studies have been performed to identify the potential mechanisms.Those studies mainly concentrated on continuous -ultrasound and the mechanisms were argued at thermal or non -thermal effects.Previous studies demonstrated that the therapeutic effect of LIPUS on Schwann cells or damaged rat sciatic nerve and explained the mechanism of LIPUS on peripheral nerve regeneration.As a noninvasive and convenient treatment,although low -intensity ultrasound still has many problems to be researched, its future and broad space for clinical application is confirmed.