Fig. 1

Illustration of the comprehensive steps in vivo study. (I) Step1 The preparation of autogenous PRP. (II) Step 2 The detailed procedure of repair of 12 mm tibial nerve defect with vein graft. A Schematic illustration of autogenous vein graft filling of PRP, nerve microtissues, and a combination of the two. An autogenous vein graft was transplanted to the tibial nerve to repair the 12 mm nerve defect. A 18-mm-long autogenous vein graft was harvested from the superficial subcutaneous vein at the surgical approach below the right femur (B). The Figure C showed the blood clot inside the vein was removed by rinsing in saline solution. (III) Step 3 Multimodality ultrasound evaluation of nerve graft and innervated calf muscle. (IV) Step 4 Evaluation of electrophysiological recovery and histopathological examination of regenerated nerve and target muscle