Bionic larynx: electronic control of the reimplanted organ in the dog.

Complete rehabilitation of paralyzed head and neck structures has been difficult, and attempts at reinnervation of striated muscles have not consistently succeeded. Recent studies have shown that disabled muscles can be electronically "paced." This, together with recent developments in microelectronics, has led to the concept of the Bionic Larynx. The current experiments involve transposed nerve-muscle pedicles used to selectively reinnervate larynges which were denervated, entirely detached from the animal except for their vascular supply, and then reimplanted. These pedicles were later stimulated using a potentially implantable "pacing unit." It was possible to selectively control the critical functions of the larynx, using as stimuli physiological events that are preserved even when the vocal folds are paralyzed or uncoordinated. Although laryngeal transplantation in humans remains theoretical, these studies show that it could be feasible in the future.