Specificity in peripheral nerve regeneration: a discussion of the issues and the research.

Epineurial and epiperineurial nerve suturing with orientation of the intraneurial funicular pattern are the only useful nerve repair techniques. The research on axonal regeneration was reviewed to determine whether basic research findings may support a new clinical approach to nerve repair. The research indicates that Schwann cell migration from the distal nerve stump is important in tissue specificity; sensory regeneration, but not motor regeneration, shows selectivity; sensory Schwann cells in the distal nerve segment induce not only sensory axons but also motor axons, which are the strongest 1 week after denervation and are influenced by the stump area and the volume of the distal nerve segment; and evidence of topographic specificity is weak. The strong inductive ability of sensory Schwann cells to misdirect motor nerve regeneration to the distal sensory Schwann tubes may not support the use of tube techniques for nerve repair.