失肌皮神经后胸大肌部分移位重建屈肘功能模型的建立

Establishment of animal model after musculocutaneous nerve transection and partial pectoralis major muscle transfer for reconstruction of elbow flexion in rats

目的建立胸大肌部分移位重建屈肘功能动物模型,为进一步研究术后供体肌和受体肌的内部变化奠定基础。方法 42只成年SD大鼠随机分为7组:正常组;肌皮神经切断后1、2、4周组;胸大肌部分移位重建屈肘术后1、2、4周组。肌皮神经切断后行胸大肌部分移位重建屈肘术;称量肌湿重,计算肌湿重保持率。结果支配SD大鼠肱二头肌的肌皮神经与肱动脉肌支从该肌肌腹的内侧缘上部入肌;支配胸大肌的胸外侧神经和胸外侧血管从该肌止端深面出入。胸大肌可分为横部和斜部,后者足够长移位缝合至肱二头肌腱止端。胸大肌斜部移位重建屈肘功能术时不会伤及血管神经。切断肌皮神经后1~4周,肱二头肌色泽、肌块体积、湿重和湿重保持率持续下降,步态拖曳,觅食受限。胸大肌斜部移位重建屈肘术后1~4周,上述指标逐渐改善;胸大肌斜部色泽和肌块体积变化不大,肌湿重和湿重保持率下降仅在屈肘重建术后1周时有统计学意义。结论大鼠失肌皮神经后行胸大肌斜部移位重建屈肘功能术是可行的,它能改善肱二头肌萎缩,对供体肌本身仅造成一过性损伤。

Objective To establish the animal model of partial pectoralis major muscle transfer for reconstruction of elbow flexion and lay the foundation for further study on the internal changes of postoperative donor and recipient muscles. Methods Forty-two adult Sprague-Dawley(SD) rats were divided into 7 groups: normal, 1 week post-, 2 weeks post-, and 4 weeks postmusculocutaneous transection; and 1 week post-, 2 weeks post-, and 4 weeks post-reconstruction of elbow flexion. A reconstruction operation of elbow flexion was done by partial pectoralis major muscle transfer after musculocutaneous nerve transection. Muscle wet weights were assessed, and wet weight retention rate was calculated. Results In SD rats, the musculocutaneous nerve and artery of the biceps brachii enter the superior part of the muscle belly from its medial edge, and the lateral pectoral nerve and lateral thoracic artery of the pectoralis major enter the muscle insertion from the profundal face of the muscle. The pectoralis major can be divided into 2 parts: transverse and oblique. The oblique part of pectoralis major is long enough for suture to the biceps brachii tendon.There is no risk of injury to the blood vessels and nerves during transfer of the oblique part of the pectoralis major muscle for reconstruction of elbow flexion in an animal model. After the musculocutaneous nerve transection 1-4 weeks, the color of the biceps brachii muscle faded progressively and the muscle mass shrunk, the limp worsened and the foraging movements were restricted, the muscle wet weight and the wet weight retention rate of the biceps brachii continued to decline. After reconstruction of elbow flexion1-4 weeks, the indexes have been gradually improved; The color and muscle mass of oblique part of the pectoralis major showed minor changes postoperatively, the decreased muscle wet weight and the wet weight retention rate was statistically significant only at1 w postoperatively. Conclusion The transfer of the oblique part of the pectoralis major for elbow flexion reconstruction is feasible and can improve the muscle atrophy of biceps brachii and causes only transient damage to the donor muscle in rats.