Respiratory rhythmically regulated electrical stimulation of paralyzed laryngeal muscles

Abstract

Electrical stimulation of the posterior cricoarytenoid muscle, synchronized with inspiration, was achieved in dogs, utilizing a radio frequency stimulus triggered by a chest wall expansion transducer. This system brings about the abduction of the paralyzed vocal cord for the entire duration of inspiration, which allows a normal flow of air through the larynx. The stimulation system could be tested successfully in actual experiments in dogs with artificial paralysis of the recurrent laryngeal nerve. Its effectiveness could be proved through observation of the vocal cord movements (photographic documentation) and recording subglottic pressure variations. Transmission of stimulation energy is effected by electrical induction.

Bilateral motion restored to the paralyzed canine larynx with implantable stimulator

“…A more physiologic approach, termed laryngeal pacing, involves functional neuromuscular stimulation (FNS) of the posterior cricoarytenoid (PCA) muscle to abduct the vocal folds during inspiration. Both animal and human trials have demonstrated the feasibility of laryngeal pacing 4–15…”

Selective recurrent laryngeal nerve stimulation using a penetrating electrode array in the feline model

“…Due to this gap in the definitive interventions for bilateral VFP, previous studies have evaluated the utility of neuromuscular stimulation of the PCA muscle to evoke vocal fold abduction. The utility of laryngeal pacing stimulated by inspiration has been examined in both animals and humans . Most notably, a multicenter clinical trial with an implantable PCA muscle stimulation device (Itrel II) was conducted .…”

“…The utility of laryngeal pacing stimulated by inspiration has been examined in both animals and humans. [14][15][16][17]20,21,[34][35][36][37][38][39][40][41][42][43] Most notably, a multicenter clinical trial with an implantable PCA muscle stimulation device (Itrel II) was conducted. [14][15][16] In five of six patients, unilateral laryngeal stimulation via 1-to 2-second trains of pulses paced with inspiration improved airflow without affecting voice or swallowing, and three of six patients were successfully decannulated.…”

Rehabilitation of bilaterally paralyzed canine larynx with implantable stimulator

“…During noninspiratory phases, the vocal folds passively relax to the midline allowing for normal voice and airway protection. Both animal and human trials have demonstrated the feasibility of laryngeal pacing 4–15…”