Tiam Mana Saffari

218 CHAPTER 10 The left sciatic nerve of each rat was fully exposed proximally from the inferior margin of the piriformis muscle to approximately 5 mm distal to the bifurcation, under an operating microscope (Zeiss OpMi 6, Carl Zeiss Surgica, Oberkochen, Germany). A 10-mm segment of the sciatic nerve was excised by sharp transection with microsurgical scissors. In group I, the nerve segment was reversed and placed as an interposition autograft with six 10-0 nylon (10-0 Ethilon, Ethicon Inc., Sommerville, NJ, USA), epineural interrupted sutures on either side of the repair. In group II, the nerve gap was bridged with a 10-mm decellularized allograft with use of a similar surgical technique. In group III-V, surgical angiogenesis was provided to the allograft (group III), combined with undifferentiated MSCs (group IV) and differentiated MSCs (group V), respectively. In detail, the nerve gap was repaired with an allograft which was consecutively wrapped in the pedicled SIEF flap 6 . Briefly, the femoral artery was identified in the groin on the ipsilateral side of the nerve reconstruction, whereafter the superficial inferior epigastric (SIE) vessels were exposed. The 4 x 3 cm SIEF flap containing subcutaneous fat, inguinal fat, the femoral vasculature and SIE vessels, was tunneled subcutaneously toward the nerve reconstruction and wrapped around the nerve, covering both the proximal and distal nerve repair, providing surgical angiogenesis to the entire nerve allograft (Figure 1B). In all groups, wounds were closed in layers, approximating muscle with two 5-0 absorbable interrupted sutures (5-0 Vicryl Rapide, Ethicon Inc.). The skin was closed subcutaneously, using the same suture. Postoperatively, the rats were individually housed and provided with food and water ad libitum with a 12-hour light-dark cycle. Nonsurvival procedure Two weeks after surgery, rats were anesthetized and euthanized with 1mL intraperitoneal injection of Pentobarbital Sodium. After preserving nerve vasculature by injection of yellow Microfil® compound (MV 8mL, diluent 15mL, and curing agent 1.2mL, Flow Tech, Inc., Carver, MA, USA) in the descending aorta according to protocol, nerve samples were harvested bilaterally and cleared using graded series of ethanol 12 .