Reappraisal of timing for exploration of civilian peripheral nerve injuries

Operative as well as electrophysiologic experience with 213 major nerve injuries over the last 8 years and primate experiments form the basis of this reappraisal. Those lesions in continuity resected (58 of 172) usually had no response to stimulation or nerve action potential (NAP) at 8 weeks or longer after injury but were not necessarily complete lesions on clinical examination or electromyography. Axonal organization and maturity were of such poor quality that functional regeneration would not have resulted. Despite preoperative evidence of an incomplete lesion, operative studies confirmed a complete lesion in 21 instances. In 103 lesions NAP's could be recorded and, where neurolysis was done, recovery was acceptable in 91 percent. Many of these lesions had appeared complete on preoperative evaluation. Nerves transected by glass and repaired primarily had superior electrical and functional recovery to those repaired secondarily, although variations in clinical settings prevented statistical analysis. Experimental work in 20 primates with glass-wounded nerves favored primary repair, for NAP, evoked muscle action potential, and strain gauge studies of muscle power were superior in 14. Lesions in continuity should have exploration delayed until 8 weeks so that physiologic decisions regarding need for resection and repair can be made. Transecting injuries should be explored primarily, those without contusinve element repaired immediately, and those with contusion repaired 3 weeks after injury.