Peripheral nerve reconstruction using freeze-thawed muscle grafts: a comparison with group fascicular nerve grafts in a large animal model.

There is evidence to suggest that the 'freeze-thawed muscle graft' may function as an alternative to established methods of nerve reconstruction. Using a large animal model we compared this method with group fascicular nerve grafting in peripheral nerve reconstruction. We excised a 3 cm segment of right median nerve in 10 anaesthetized sheep. The resulting gaps were repaired with either group fascicular cable grafts (GFCGs) or freeze-thawed muscle grafts (FTMGs). After six months the right (grafted) and left (control) median nerves of each sheep were exposed and assessed for nerve blood flow, nerve conduction velocity and morphological indices of recovery. Nerve blood flow was reduced by 40% in those repaired with FTMGs. All the repaired nerves contained a population of significantly smaller nerve fibres and displayed a reduced peak nerve conduction velocity. Those repaired with FTMGs (mean velocity 30.96 m/s) had a peak velocity significantly faster than the GFCG group (mean 13.16 m/s). This study shows that peripheral nerve reconstruction with freeze-thawed muscle grafts compares well with repair using nerve grafts.