Study of Microcirculation of Rat Femoral Nerve and Development of a New Vascularized Nerve Graft Model

ABSTRACT

This study was designed to investigate the microcirculation of the rat femoral nerve and to develop a vascularized nerve graft (VNG) model which is reliable, consistent, and simple. The rat was chosen for considerations of cost and simplicity of the model. One and 2 cm long femoral nerve segments were transected proximally and distally and left attached to the femoral artery and vein in all animals. Experimental groups included the following procedures: 1) the femoral artery and vein were ligated distally and an arteriovenous (AV) fistula just proximal to the ligature was constructed; 2) distal ligation only of the femoral artery and vein was done; 3) ligation of the femoral artery and vein was done both distally and proximally; 4) control: no ligation or construction of an AV fistula were done.

Neurovascular segments in all groups were wrapped with a thin silicone sheath to prevent neuro-vascularization from the surrounding tissues. At seven days postoperatively, viability of the segments was assessed by fluorescein dye and microangiography studies, followed by histologic evaluation.

Results showed that a 1- or 2-cm long femoral nerve segment, when left attached to distally ligated femoral vessels and an intact neurovascular sheath, is a simple design to reproduce and can serve reliably as a VNG model in the rat.