ABSTRACT
Teflon injection has been used for vocal fold medialization following paralysis. Recently, numerous articles have discussed the complications of Teflon injection, including overinjection, airway obstruction. Teflon granuloma, and an abnormal mass effect creating a decreased vibratory character of the true vocal fold. Multiple techniques for Teflon removal have been described. This report details our experience with complete Teflon granuloma removal via a lateral laryngotomy under local anesthesia. Microscopic dissection of the entire granuloma and the paraglottic space was accomplished in all patients. Due to extensive destruction caused by the granuloma, the vocal ligament was resected in 3 patients; it was partially resected and reanastomosed in 1 case, and spared in 6 patients. Laryngeal reconstruction was accomplished with an inferiorly based sternohyoid muscle rotation flap and arytenoid adduction. Effortful speech secondary to pressed vocal quality resolved in all patients. Near-normal to normal vocal quality was obtained in 4 patients, with the average "voice desirability" improving 60% and the effective glottic width increasing 29%. Factors that contributed to a successful outcome included noninvolvement of the vocal ligament and sparing of the mucosal cover.
Subject(s)
Granuloma, Foreign-Body/surgery , Larynx/surgery , Microsurgery , Polytetrafluoroethylene , Adult , Anesthesia, Local , Endoscopes , Female , Granuloma, Foreign-Body/pathology , Humans , Injections , Laryngoscopes , Larynx/pathology , Male , Microsurgery/instrumentation , Middle Aged , Polytetrafluoroethylene/administration & dosage , Polytetrafluoroethylene/adverse effects , Postoperative Complications/pathology , Postoperative Complications/surgery , Sound Spectrography , Treatment Outcome , Vocal Cord Paralysis/etiology , Vocal Cord Paralysis/therapy , Voice Quality/physiologyABSTRACT
This study represents the first attempt to electrically pace the paralyzed human larynx. The goal was to determine if electrical stimulation of the posterior cricoarytenoid muscle could produce functional abduction of the vocal fold in pace with inspiration. An external apparatus was used to sense inspiration and reanimate the unilaterally paralyzed larynx of a thyroplasty patient. Stimuli were delivered through a needle electrode to locate and pace the abductor muscle. The magnitude of electrically induced abduction was comparable to spontaneous movement on the normal side. The abduction was appropriately timed with inspiration: this finding demonstrated that this simple pacing system could effectively modulate stimulation with patient respiration.
Subject(s)
Electric Stimulation Therapy , Vocal Cord Paralysis/therapy , Adolescent , Electric Stimulation Therapy/instrumentation , Electric Stimulation Therapy/methods , Humans , Laryngeal Muscles/physiopathology , Male , Vocal Cord Paralysis/physiopathologyABSTRACT
The effects of chronic posterior cricoarytenoid muscle denervation were assessed at 3 and 7 months in 26 animals following resection of 10 cm of recurrent laryngeal nerve with stump ligation. The physiology of denervation was characterized by a decrease in contraction strength and an increase in contraction time. The reduction in contraction strength reflected the loss in muscle weight and atrophic changes in fiber density and diameter. A change in muscle composition occurred because of the increased susceptibility of fast-twitch (type 2) fibers to degeneration. However, the compositional change alone could not account for the slowing of muscle contraction. Muscle fibrosis was negligible at 3 months, but encompassed one third of the fiber population by 7 months. In view of the irreversible nature of fibrosis, this study suggested that clinical intervention to rescue denervated posterior cricoarytenoid muscle fibers should be delayed no longer than 7 months to improve the chances for full recovery.
Subject(s)
Laryngeal Muscles/physiopathology , Muscle Denervation , Muscular Atrophy/physiopathology , Animals , Dogs , Laryngeal Muscles/chemistry , Laryngeal Muscles/innervation , Muscle Contraction/physiology , Muscle Fibers, SkeletalABSTRACT
Functional electrical stimulation (FES) of the posterior cricoarytenoid (PCA) muscle to produce vocal fold abduction offers an alternative approach to current surgical therapies for bilateral vocal fold paralysis. The purpose of this study was to characterize the application of FES to chronically denervated PCA muscles. Specific goals were to develop a stimulus delivery system for the PCA muscle, determine a practical means of implantation, and identify stimulus parameters effective in activating chronically denervated muscle. Seventeen dogs were implanted with planar electrode arrays 3 months after unilateral recurrent laryngeal nerve resection. A nail-bed electrode array allowed discrete activation of the PCA muscle and gave the greatest abductions, with minimal charge dissipation. Muscle mapping revealed hot-spot regions on the PCA muscle surface, in which stimulation produced maximum abduction. A conservative stimulus paradigm effective in activating chronically denervated muscle was a 1-second pulse train of 2-millisecond-duration pulses, delivered at a tetanizing frequency of 30 Hz and an amplitude of 4 to 14 mA.
