Effect of Laryngofissure on the Developing Canine Larynx

Abstract

Tracheostomy during infancy often results in serious complications and even death. The current policy in many medical centers is to recommend extended hospitalization of an infant whenever tracheostomy is necessary. Almost all obstructing diseases of the infant larynx are treated by tracheostomy because of the concern that surgical intervention of the larynx may result in impaired laryngeal growth inadequate for airway or phonation. Since no applicable clinical or experimental reports could be found in the literature, a study was designed to determine the effect of laryngofissure on laryngeal development and function. Six five-week-old dogs underwent an anterior laryngofissure, three of which had placement of a Teflon® keel. The keels were removed six weeks later. Four five-week-old dogs served as controls. At maturity eight months later the ten animals were sacrificed just after direct laryngoscopy. Full vocal cord mobility was found, and the glottic aperture, including the anterior commissure, appeared to be normal. The larynges were excised and found to have the same dimensions and weight as did the controls. Microscopic studies revealed little scarring at the anterior commissure, and the thyroid lamina were bridged by fibrous and cartilaginous tissue with minimal displacement of the lamina. The results of this study suggest that the infant larynx may be divided by a midline vertical thyrotomy without impairment of laryngeal development or function.