Can Severe Spinal Nerve Injury Be Repaired?

To the Editor.—  We wish to respond to the question by Richard G. Cotterman,¹ MD, "Can severe spinal nerve injury be repaired?" Although there is a nihilistic belief, generally shared, that it is impossible to achieve useful reinnervation of denervated structures, new studies have tested this discouraging dogma and identified some factors that may be controlled during peripheral nerve surgery to achieve regeneration and return of useful function.² Recent experiments in our laboratory have demonstrated that surgery using spinal nerve roots can result in regeneration and reinnervation. In a series of animals, we have connected a lumbar mixed nerve root to a sacral mixed nerve root through a nerve graft. The animals were reoperated on after some seven months, and in several, we were able to produce a bladder contraction when the isolated root was electrically stimulated.³Although other past attempts at reinnervating the bladder have produced