Aman Martin, Sporer Matthias, Bergmeister Konstantin, Aszmann Oskar
Medizinische Universität Wien Christian Doppler Labor für Extremitätenrekonstruktion, Univ. Klinik für Chirurgie.
BG Unfallklinik Ludwigshafen Klinik für Hand-, Plastische und Rekonstruktive Chirurgie, Schwerbrandverletztenzentrum, Klinik für Plastische und Handchirurgie der Universität Heidelberg.
Handchir Mikrochir Plast Chir. 2019 Aug;51(4):319-326. doi: 10.1055/a-0802-8851. Epub 2019 Apr 8.
Nerve transfers are an important tool to restore muscle function. Despite their popularity in reconstructive surgery, their effects on the motor unit remain largely unknown. Therefore, a realistic animal model is needed for the upper extremity, which is where the majority of nerve transfers are conducted. This work shows different upper extremity nerve transfer models in the rat, where elbow flexion was restored with different types of nerve transfer in adult and neonatal rats.
Anatomy and microsurgical feasibility was first evaluated in 10 adult and 5 neonate Sprague Dawley rats. In 40 rats (30 adult and 10 neonate), a nerve transfer of the whole ulnar nerve or just the deep branch was performed to reinnervate the long head of the biceps muscle. After 12 weeks of regeneration, the transfer was evaluated for functional aspects such as muscle force and weight.
Neural anatomy was constant in all rats. All nerve transfers were successful and functional analyses showed a maximum tetanic muscle force of 2.47 + 0.25 N after an ulnar nerve transfer. Deep branch transfers achieved 1.96 + 0.65 N, and neonates achieved 1.1 + 0.23 N. Control side was 2.78 + 0.24 N. The muscle weight was 325.6 + 0.24 mg for the control, 313.8 + 0.25 mg after UN transfer, 226.7 + 0.65 mg after deep branch transfer and 85.5 + 0.23 mg for neonates.
For proper clinical translation, an upper extremity model is needed. Successful reinnervation in all groups was demonstrated, which indicates an excellent model for future research. Variations in functional parameters are likely the effect of different donor axon ratios. Neuronal plasticity also appears to play a major role in the regeneration potential.
This work illustrates several animal models to further investigate nerve transfers on all levels of the motor unit.
神经移植是恢复肌肉功能的重要手段。尽管其在重建手术中很常用，但其对运动单位的影响仍 largely 未知。因此，需要一个针对上肢的逼真动物模型，因为大多数神经移植都在上肢进行。这项研究展示了大鼠不同的上肢神经移植模型，其中成年和新生大鼠通过不同类型的神经移植恢复了肘部屈曲功能。
首先在 10 只成年和 5 只新生的斯普拉格 - 道利大鼠中评估解剖结构和显微手术可行性。在 40 只大鼠（30 只成年和 10 只新生）中，进行了尺神经整体或仅其深支的神经移植，以重新支配肱二头肌长头。再生 12 周后，对移植进行功能方面的评估，如肌肉力量和重量。
所有大鼠的神经解剖结构恒定。所有神经移植均成功，功能分析显示尺神经移植后最大强直肌肉力量为 2.47 + 0.25 N。深支移植达到 1.96 + 0.65 N，新生大鼠达到 1.1 + 0.23 N。对照侧为 2.78 + 0.24 N。对照侧肌肉重量为 325.6 + 0.24 mg，尺神经移植后为 313.8 + 0.25 mg，深支移植后为 226.7 + 0.65 mg，新生大鼠为 85.5 + 0.23 mg。
为了进行恰当的临床转化，需要一个上肢模型。所有组均成功实现了重新支配，这表明该模型非常适合未来的研究。功能参数的差异可能是不同供体轴突比例的影响。神经可塑性似乎在再生潜力中也起主要作用。
这项研究展示了几种动物模型，可用于进一步研究运动单位各级别的神经移植。
