A comparison of immediate and delayed repair of peripheral nerves using freeze-thawed autologous skeletal muscle grafts--in the rat.

A group of rats in which each animal received immediate repair of a transected sciatic nerve using freeze-thawed muscle autografts was compared with groups where repair was carried out after delays of 3, 5, 7, 14, 28 and 56 days following transection. All rats were studied 100 days after graft insertion. A delay of 56 days was found to be incompatible with useful recovery. In the groups studied after shorter delays, myelinated nerve fibre numbers and diameters were not found to differ significantly from those seen after immediate repair. There was, however, a significant reduction in the rate of remyelination of the fibres following a delay. The implications of this are discussed.