脉冲射频术和射频热凝术对大鼠臂丛的损伤作用

Damage to the brachial plexus produced by pulsed radiofrequency and radiofrequency thermocoagulation in rats

目的研究脉冲射频术(PRF)和射频热凝术(RFTC)对大鼠臂丛的损伤作用。方法Wistar大鼠55只,随机分为PRF组(n=25)、RFTC组(n=25)和正常组(N组,n=5),PRF、RFTC组大鼠左臂丛神经分别行PRF和RFTC,记录手术前、后的阻抗,记录PRF、RFTC组术前及术后神经功能评分(Tarlov评分),PRF组和RFTC组术后即刻、1、7、14、30d分别处死5只大鼠,光镜、电镜下观察神经的病理学改变,并对有髓神经进行体视学分析。结果与术前及PRF组比较,RFTC组术后阻抗和Tarlov评分降低；与N组比较,RFTC组术后有髓神经纤维的形态学以沃勒变性和再生为特点,轴索内线粒体严重损伤或消失；PRF组术后即刻、1d有髓神经纤维的形态学有损伤,但程度较轻,并在术后7 d恢复,而轴索内线粒体轻度损伤,但在术后7、14d损伤加重,术后30d恢复。结论与RFTC比较,PRF对大鼠的臂丛损伤较轻。

Objective To evaluate the damage to the brochial plexus produced by pulsed radiofrequency （PRF） and radiofrequency thermocoagulation （RFTC）. Methods Fifty-five male Wistar rats weighing 250-300 g were randomly divided into 3 groups ： group T PRF （ n = 25 ） ： group Ⅱ RFTC （ n = 25 ） and group m normal control （ n = 5）. The animals were anesthetized with intraperitoneal chloral hydrate. The left brochial plexus was exposed and PRF or RFrc was applied to the left brochial plexus. The voltage and current of the minimal stimulation which elecited muscle twitching and the impedance before and after operation were recorded in group PRF and RFTC. The nerve function was scored according to Tarloo （0 = flaccid paresis, 5 = normal gait） before and at 3d after operation. The animals were killed and the left brachial plexus was removed immediately and at 1, 7, 14, 30 d after operation （n = 5 at each time point） for determination of histopathological changes using microscope. Results The impedance and Tarlov score were significantly decreased after operation as compared to the baseline values before operation in group RFTC and were also significantly lower than in group PRF. Microscopic examination showed that the myelinated nerve fibers exhibited Wallefian degeneration and axon regeneration and the cytochondfia in cylindraxile were severely injured or disappeared in group RFTC. The myelinated nerve fibers and the cytochondria in cylindraxile were significantly less injured after operation in group PRF than in group RFTC and returned to normal at 7 d and 30 d respectively. Conclusion The injury to brachial plexus produced by PRF is slighter than that produced by RFTC.