Velopharyngeal Dysfunction Evaluation and Treatment




Velopharyngeal dysfunction (VPD) can significantly impair a child’s quality of life and may have lasting consequences if inadequately treated. This article reviews the work-up and management options for patients with VPD. An accurate perceptual speech analysis, nasometry, and nasal endoscopy are helpful to appropriately evaluate patients with VPD. Treatment options include nonsurgical management with speech therapy or a speech bulb and surgical approaches including double-opposing Z-plasty, sphincter pharyngoplasty, pharyngeal flap, or posterior wall augmentation.


Key points








  • Perceptual speech analysis and nasal endoscopy are essential for the evaluation of children with velopharyngeal dysfunction.



  • The double-opposing Z-plasty technique reorients the levator veli palatini muscle fibers and lengthens the palate, and may be the ideal approach to children with a cleft of the soft palate, a submucous cleft palate, or a shortened palate with a small velopharyngeal gap.



  • The sphincter pharyngoplasty creates a dynamic flap that is preferred for patients with a coronal or circular closure pattern. With a large velopharyngeal gap, this can be used in combination with the double-opposing Z-plasty.



  • The pharyngeal flap operation can be used to obturate a large velopharyngeal port in patients with sagittal closure.






Introduction


All sounds in the English language, other than /n/, /m/, and /ng/, are produced via oral airflow. Normal speech, therefore, relies on appropriate closure of the velopharyngeal port. Inadequate closure of the velopharynx during speech production results in velopharyngeal dysfunction (VPD). VPD can arise from structural, neurogenic, or iatrogenic causes. This article reviews the normal functional anatomy of the velopharynx, discusses the evaluation of children with VPD, and outlines treatment options for children with VPD.




Introduction


All sounds in the English language, other than /n/, /m/, and /ng/, are produced via oral airflow. Normal speech, therefore, relies on appropriate closure of the velopharyngeal port. Inadequate closure of the velopharynx during speech production results in velopharyngeal dysfunction (VPD). VPD can arise from structural, neurogenic, or iatrogenic causes. This article reviews the normal functional anatomy of the velopharynx, discusses the evaluation of children with VPD, and outlines treatment options for children with VPD.




Velopharyngeal anatomy


Velopharyngeal closure during speech occurs through the action of several muscles. The levator veli palatini, innervated by the pharyngeal plexus, provides the main muscle mass to the velum. This muscle arises from the inferior surface of the petrous temporal bone and the cartilaginous eustachian tube. The muscle fibers fan out within the soft palate to interdigitate with the contralateral levator veli palatini muscle. The levator veli palatini functions as a sling to pull the velum in a posterosuperior direction. The tensor veli palatini, innervated by cranial nerve V, originates from the medial pterygoid plate, spine of the sphenoid, and eustachian tube. This muscle’s tendon wraps around the hamular process and functions to tense and stabilize the soft palate while also opening and closing the eustachian tube. The musculus uvulae serve to add bulk to the dorsal surface of the soft palate and assist in elevating the uvula. The palatoglossus and palatopharyngeus muscles constrict the anterior and posterior tonsillar pillars, respectively. The action of the palatopharyngeus muscle stretches the velum laterally to increase the velar area. The uppermost fibers of the superior pharyngeal constrictor muscle contribute to lateral and posterior pharyngeal wall movement, helping to narrow the velopharyngeal port.




Causes of velopharyngeal dysfunction


VPD includes an array of disorders and often confusing nomenclature has been used to distinguish the origin. Historically, velopharyngeal insufficiency includes any structural defect, such as a cleft palate, that results in insufficient tissue to achieve velopharyngeal closure. Velopharyngeal incompetence represents causes related to neurologic dysfunction or impaired motor control. To simplify, VPD can result from anatomic or neuromuscular causes.




  • Anatomic



  • Cleft palate



  • Submucous cleft palate



  • Palatal fistula



  • Short palate



  • Tonsillar hypertrophy or other condition tethering the palate



  • Previous adenoidectomy




  • Neuromuscular



  • Acute neurovascular injury (stroke)



  • Intracranial process (brain tumor)



  • Neurologic deterioration of pharyngeal plexus (amyotrophic lateral sclerosis, Parkinson disease, cerebral palsy, Moebius syndrome)



  • Tumor of cranial nerve





Evaluation of velopharyngeal dysfunction


The initial evaluation of any child with possible VPD includes a complete history and physical examination. The onset when symptoms were noted, any exacerbating factors, and severity of speech difficulty along with family members’ perceptions can help with the initial assessment. In a patient with a history of cleft lip or palate, understanding the technique used to repair the cleft is essential. Asking about any additional pharyngeal procedures, particularly adenoidectomy and/or tonsillectomy, is imperative.


Early in the examination, an informal perceptual speech evaluation can be obtained if the examiner can successfully get the patient talking. If the child is shy or will not communicate in the presence of the physician, the parents may have a recording of their child speaking that can be used to assess speech. Evaluating the length and the mobility of the palate, palpating for a notch at the hard and soft palate junction, and using a mirror to detect fogging with non-nasal sounds are all important aspects of the physical examination.


VPD significantly affects both the child’s and the family’s quality of life. The Velopharyngeal Incompetence Effects on Life Outcomes (VELO) survey measures speech problems, swallowing problems, situational difficulty, perception by others, emotional impact, and caregiver impact and has been validated as an effective measure of quality of life for children with VPD.


Perceptual Speech Analysis


A formal speech evaluation by an experienced speech-language pathologist is essential for any child with suspected VPD. Language level, articulation, resonance, and the absence or presence of nasal airway emissions are all important aspects of the examination. Nasalized consonants include /m/, /n/, and /ng/, whereas all other consonants and most vowels in the English language are non-nasal. Fogging of a mirror under the nostril can confirm normal air escape with nasal sounds or abnormal air escape with non-nasal sounds. Speech analysis evaluates for evidence of hypernasal resonance, nasal emissions, and nasal turbulence. Facial grimacing during speech may be a clue to the presence of VPD as patients narrow the external nares to decrease nasal airflow. Fogging of a mirror under the nostril during the production of non-nasal speech also suggests abnormal air escape.


Nasometry


Nasometry assesses nasal resonance during speech by measuring the ratio of sound intensity between the mouth and the nose. Nasometry provides objective measurements that help in the initial evaluation and also provide feedback after therapy and surgical intervention. During this test, focus must be placed on appropriately articulated phonemes. Standardized scores for specific phonemic sets exist, and the degree of nasalance can be estimated by calculating the number of standard deviations away from normative values. However, discrepancies in the severity of hypernasality may exist between nasometry scores and the perceptual speech analysis.


Speech Endoscopy


Speech endoscopy is a critical component of any child being considered for VPD surgery. Ideally, the procedure is performed with both a physician and speech-language pathologist present. The flexible endoscope should be passed through the nose in the middle meatus region rather than along the floor of the nose so that the endoscope is positioned higher in the nasopharynx, thereby avoiding parallax or fish-eye distortion views. The patient then repeats a series of words, phrases, or sentences while the velopharynx is visualized. The closure pattern of the velopharynx (coronal, sagittal, circular, or circular with Passavant ridge contribution) and the size of velopharyngeal gap remaining during non-nasal speech are assessed. These findings can be used by the surgeon to tailor the appropriate surgical procedure for the patient’s needs.


Speech Videofluoroscopy


In speech videofluoroscopy, a small amount of barium is placed in the nose to coat the velopharynx. The child repeats a set of phoneme-specific speech tasks while fluoroscopic images are recorded. Many centers no longer use speech videofluoroscopy because of limitations, including radiation exposure and the need for multiple views because of the two-dimensional images obtained.


MRI


MRI has recently been investigated as a tool for assessing VPD. MRI avoids ionizing radiation and may be useful in uncooperative children. However, cost and the inability to correlate dynamic velopharyngeal function with speech limit its practical application.




Treatment


Nonsurgical Treatment


Speech therapy


A speech-language pathologist experienced in the management of children with VPD is essential. Speech therapy alone may be appropriate for children with mild VPD who show improvement after appropriate stimulation, phoneme-specific or intermittent VPD, or VPD with significant articulation issues. A time-limited trial of speech therapy is reasonable to consider in many children with VPD. However, in some children, therapy has no chance to cure the problem and surgical intervention should not be delayed. Postsurgical therapy is almost always necessary, often to overcome maladaptive articulation errors that developed before surgical intervention.


Prosthesis


In some cases the use of a prosthesis may be indicated to allow normalization of speech. Prostheses are commonly used in adults after palatal resection for tumor. The use of a palatal lift or obturator may be advantageous in children who have failed surgical intervention or who are at significant risk of extreme airway obstruction if surgical means are used for VPD. The prosthesis may be removed for sleep, allowing a better airway. If there is adequate palatal length, a palatal lift prosthesis or obturator may be used. If it is thought that the palate is too short, the lift is often not the ideal prosthesis and an obturator should be considered. Fabrication requires a prosthodontist with experience in maxillary prostheses. The size may be estimated and the final fit may be done with flexible endoscopy to help define any gaps in the obturation. Using the mobility of each of the walls of the velopharyngeal port may allow nasal respiration at the same time as improved speech and eating. The prosthesis is attached to stable teeth, so it is not used in mixed dentition or during active orthodontia. However, this restriction alone limits its utility in most of the pediatric population.


Surgical Treatment


The optimal surgical approach is uniquely tailored to the individual and dependent on what is found in the preoperative assessment. Each approach has distinct advantages and potential disadvantages and the recommended option for one patient may not be ideal for another. It is imperative that surgeons managing VPD become facile with all techniques so that the appropriate procedure can be performed when indicated. A review of the commonly used techniques for each procedure is presented later.


Double-opposing Z-plasty palatoplasty


The double-opposing Z-plasty for primary palatoplasty was first described by Leonard Furlow in 1986. This procedure transposes the sagittally oriented levator palatini muscle fibers into a more anatomic transverse direction while lengthening the palate and narrowing the nasopharyngeal port. Typically, with right-handed surgeons, a posteriorly based oral myomucosal flap is elevated on the patient’s left palate ( Fig. 1 ). The flap begins laterally at the hook of the hamulus and extends anteromedially to the midline just posterior to the hard-soft palate junction. An anteriorly based oral mucosa flap is elevated on the right side beginning from the base of the uvula medially and extending posterolaterally to the hook of the hamulus. Nasal mucosal flaps are elevated as mirror images of the oral flaps with the lateral incisions extending near the eustachian tube bilaterally. Closure is accomplished by rotating the left nasal mucosal flap across the midline and suturing the flap to the right hard palate. The right nasal myomucosal flap is rotated so that the levator muscle is oriented in the transverse plane and sutured to the posterior edge of the left nasal mucosal flap anteriorly and the free margin of the left soft palate posteriorly. The right oral mucosal flap is rotated and sutured to the posterior edge of the left hard palate and the left myomucosal flap is rotated to again orient the muscle fibers in the horizontal plane. The uvula is reapproximated.


Aug 26, 2017 | Posted by in General Surgery | Comments Off on Velopharyngeal Dysfunction Evaluation and Treatment
Premium Wordpress Themes by UFO Themes