Muscle basal lamina: a new graft material for peripheral nerve repair.

The suitability of muscle basal lamina as a graft material for the repair of peripheral nerves was investigated. Grafts were prepared by evacuating the myoplasm from muscles excised from rats and rabbits. This produced a material consisting mainly of basal lamina and connective tissue, with the basal lamina arranged as parallel tubes. Rat- and rabbit-derived graft material in 0.5-cm lengths was sutured into rat sciatic nerves, and 4-cm lengths of rabbit-derived graft material were interposed into rabbit sciatic nerves. For controls, 0.5-cm nerve autografts were grafted into rats and 4-cm autografts into rabbits. After 2 to 3 months, the success of the grafts was assessed functionally, electrophysiologically, and anatomically. By all these criteria the basal lamina grafts were as successful as nerve autografts; essentially the same number of axons of the same size grew through both graft types, animals recovered their limb function equally well, and the nerve conduction velocities and relative refractory periods were the same in both groups of animals. In rats, following both basal lamina and nerve autografts, the number of axons distal to the grafts was approximately the same as that proximal to them, but axon diameter and speed of conduction were significantly less than normal. The authors conclude that muscle basal lamina grafts are as effective as nerve autografts for repairing severed rat or rabbit peripheral nerves, and suggest that grafts prepared in this way may prove to be useful for nerve repair in humans.