Poor Speech Following the Pharyngeal Flap Operation: Etiology and Treatment

Abstract

Although the pharyngeal flap operation is generally successful in the correction of palato-pharyngeal incompetence, a significant number of patients continue to have hypernasal speech following the procedure. The purpose of this paper is to; 1) discuss the physiology of the poorly functioning pharyngeal flap; 2) present electromyographic and histologic evidence that the pharyngeal flap is an adynamic fibrotic bridge; 3) describe our approach to the secondary surgical management of poor speech asso— ciated with an inadequately functioning pharyngeal flap. Normal velopharyngeal closure is dependent upon the action of the palatine levator muscles. Contraction of these muscles produces upward and posterior excursion of the soft palate and medial constriction of the lateral pharyngeal walls. This action results in a sphincteric closure of the nasopharynx and contact of the mid soft palate with the pharyngeal wall at or above the level of the tubercle of the atlas. It has been observed by measurement of cinefluorographic films (1) that minimal posterior wall movement occurs during normal speech. This suggests that the pharyngeal constrictor muscles play little if any role in normal speech production (2). Owsley and Blackfield (3), Skoog (4), and Webber, Chase and Jobe (5), have all emphasized the importance of maintaining the upward-pos— terior vector of motion of the soft palate when attaching a pharyngeal flap. The lOW pharyngeal flap attached at the posterior margin of the soft palate produces traction in an inferior or straight posterior direction, and may actually restrict normal palatal elevation. A significant number of patients with residual velopharyngeal incompetence after a pharyngeal flap operation have been found in our experience to have just this type of restrictive flap (6). Clinical and cinefiuorographic examination of these patients suggest that the central pharyngeal flap acts as a static obtura-tor. It appears that closure of the lateral pharyngeal apertures at the low level of such a flap occurs as an acquired action of the pharyngeal constrictor muscles. The authors are with the Division