C4副神经移位重建斜方肌功能的实验研究

目的探讨以C4神经前支主干作为动力神经移位修复副神经重建大鼠斜方肌功能的可行性,为临床用于副神经缺损的动力性修复提供理论依据。方法取36只成年雄性SD大鼠,体重200～250 g;随机分为实验组与对照组(n=18)。实验组左侧行C4副神经移位重建术,对照组左侧行副神经切除术;两组右侧不做任何处理,作为正常对照。术后1、2、3个月实验组行复合肌肉动作电位(compound muscle action potential,CMAP)及肌肉功能检测,计算潜伏期延迟率、最大波幅恢复率及肌张力恢复率;取两组斜方肌行HE染色,计算肌细胞截面积恢复率;取实验组神经吻合口远端神经行甲苯胺蓝染色,计算吻合口远端有髓神经纤维恢复率。并于术后1、3个月取实验组斜方肌及神经行透射电镜观察。结果随时间延长,实验组斜方肌CMAP最大波幅逐渐增加,潜伏期缩短,肌张力逐步恢复;神经吻合口远端有髓纤维逐渐增加。至术后3个月肩、背斜方肌CMAP最大波幅恢复率为63.61%±9.29%、73.13%±11.85%,潜伏期延迟率为130.45%±37.27%、112.62%±19.57%,肌张力恢复率为77.27%±13.64%、82.47%±22.94%,有髓纤维通过率为82.55%±5.00%。随神经支配恢复,实验组肌细胞截面积亦逐渐增大,且各时间点与对照组比较差异均有统计学意义(P<0.05)。术后1个月时斜方肌肌节排列紊乱,3个月时逐步趋于整齐。结论 C4副神经移位重建术可有效重建大鼠斜方肌的运动功能。

Functional reconstruction of trapezius muscle through transpositional anastomosis of C4 anterior trunk and accessory nerve

Objective To investigate the feasibility of transpositional anastomosis of C4 anterior trunk and accessory nerve for functional reconstruction of the trapezius muscle so as to provide theoretical basis of repairing accessory nerve defects.Methods Thirty-six adult male Sprague-Dawley rats(weighing 200-250 g) were randomly divided into the experimental group(n=18) and control group(n=18).The transpositional anastomosis of C4 anterior trunk and accessory nerve was performed in the left sides of experimental group;the accessory nerve was transected in the left sides of control group;and the right sides of both groups were not treated as within-subject controls.The electrophysiological and histological changes of the trapezius muscle were measured.The values of the latencies and amplitudes of compound muscle action potential(CMAP) were recorded in the experimental group at 1,2,and 3 months;the latency delaying rate,amplitude recovery rate,and restoration rate of muscular tension were caculated.The counts of myelinated nerve fibers from distal to the anastomotic site were analyzed.The transverse area of the trapezius muscle was also measured and analyzed in 2 groups.Meanwhile,the muscles and nerves were harvested for transmission electron microscope observation in the experimental group at 1 and 3 months.Results As time passed by,the experimental group showed increased amplitudes of CMAP,shortened latencies of CMAP,and improved muscular tension.At 3 months,the amplitude recovery rates were 63.61% ± 9.29% in upper trapezius muscle and 73.13% ± 11.85% in lower trapezius muscle;the latency delaying rates were 130.45% ± 37.27% and 112.62% ± 19.57%,respectively;and the restoration rate of muscular tension were 77.27% ± 13.64% and 82.47% ± 22.94%,respectively.The passing rate of myelinated nerve fibers was 82.55% ± 5.00%.With the recovery of innervation,the transverse area of the trapezius muscle increased,showing significant differences between experimental group and control group at different time points(P < 0.05).The transmission electron microscope showed that the myotome arranged in disorder at 1 month and tended to order at 3 months.Conclusion Transpositional anastomosis of C4 anterior trunk and the accessory nerve can effectively reconstruct the function of the trapezius muscle of rats.