Current Techniques for the Treatment of Velopharyngeal Insufficiency





Introduction


Velopharyngeal insufficiency (VPI) is a significant speech disorder hypernasal resonance. This can result in difficulty with speech intelligibility and swallowing, which can have a major impact on a patient’s quality of life. Although most VPI occurs in the cleft palate population, it has also been identified after sleep surgery. In adults, VPI is more commonly seen after sleep surgery targeting the soft palate as the site of obstruction. Although the rate of VPI after aggressive uvulopalatopharyngoplasty may have been as high as 25%, more recent techniques appear to significantly decrease this risk. VPI after adenotonsillectomy in children is uncommon and can be caused by a variety of etiologies, the presence of velocardiofacial syndrome, or a 22q11 deletion may be elevated. VPI can also occur as a consequence of central nervous system (CNS) disease or injury, peripheral nerve injury, or palate resection with cancer ablation in the adult.


Early postoperative VPI can be observed and treated with speech therapy. Close follow-up is needed in these patients, as VPI that persists beyond 2 to 3 months may require surgical intervention. In this chapter, surgical treatment will be addressed. Prosthetic management can be quite useful as well and will be addressed in the “Patient Selection” section, but will not be fully described here.





Patient Selection


Early involvement of a speech pathologist trained in the evaluation of VPI as well as speech therapy is important. In the case of VPI after CNS injury, the speech pathologist may be needed to address both swallowing and speech. Because recovery of function may take months, surgical intervention in these cases should proceed only after there seems to be a cessation of improvement in function.


The trained listener may hear hypernasality, nasal emission, and nasal turbulence in structured samples or spontaneous speech. The use of a nonheated mirror beneath the nose may give a reasonable assessment of the leakage of air through the nose during speech tasks, but the gold standard for diagnosis remains perceptual speech analysis by a speech language pathologist. As /m, n, ng/ are normally nasalized sounds, the speech sample should focus on the other consonant nonnasal phonemes, including /p, b, t, d, s, sh, z/. If the phoneme is not appropriately articulated it may be hypernasal. If possible the sample should obtain isolated phonemes, single words, phrases, sentences, and spontaneous speech. Focus should be on the phonemes that are accurately articulated. The assessment of appropriate articulation is best done by the speech pathologist. This emphasizes the need for multidisciplinary evaluation and care of patients with VPI. Long-standing VPI may have more articulation errors to be corrected, either before or after surgery for VPI.


Another objective measure of hypernasality is nasometry, also called nasalence testing. The procedure compares the energy coming from the nose versus the mouth in a structured speech environment. With a speech sample loaded with nonnasal phonemes, hypernasality will be documented as a higher number and is compared with an established normal. It is rated as the number of standard deviations from the mean. If the sample is well articulated and there is good cooperation, this can be helpful in deciding the need for surgical intervention.


Occasionally it is felt that the patient needs aggressive intervention, but is not a surgical candidate. These situations include severe airway obstruction, progressive disease, and prior radiation therapy to the airway or medical problems that would reduce the advisability of surgery. In these cases, prosthetic management should be considered. An adequately long palate can be lifted to allow velopharyngeal competence or an obturator placed behind the palate. The prosthesis is especially useful if there is a soft tissue defect from a cancer ablation or if the palate is congenitally short and the palatal lift cannot allow complete closure. The obturator can be helpful after excess soft tissue resection during uvulopalatopharyngoplasty or if scar formation limits palate mobility.


The prosthetic device is clasped to the teeth and may be used during the day, but is removed for cleaning and sleep. This is of special help for both adults and children with a risk of obstructive sleep apnea. Children with other craniofacial syndromes may be at special risk for airway obstruction, and prosthetic management may be a good option for them. Endoscopy can help with determining the need for prosthesis, as well as its fitting.


If the decision is made that surgery is necessary, endoscopic evaluation of the velopharynx during speech is needed to decide the type and extent of surgery needed.


Though some use only a single surgical procedure for all VPI patients, it is wise to select the surgical technique based on the shape and the size of the velopharyngeal “gap.” A coronal or circular closure pattern may be more successful with sphincter pharyngoplasty than the sagittal closure pattern, as the area needing obturation may be more lateral. A pharyngeal flap that obturates the central velopharynx may be more helpful in these situations. If there is a small central gap, one could consider an augmentation.


If the levator veli palatini muscles are sagittally rather than transversely oriented, consideration must be given to a Furlow double opposing Z-plasty. In this operation, the palate is lengthened and the levator is reoriented to improve palatal function, thereby hoping to correct the VPI. The Furlow procedure will be described in detail here.


Regardless of which surgical intervention is chosen, there is a potential effect on the airway. The Furlow lengthens and thickens the palate. All of the others to a greater degree reduce the cross-sectional airway area at the velopharynx. This unfortunately may precipitate immediate postsurgical airway obstruction and may also result in postoperative OSA or lesser sleep-disordered breathing. In general, it seems the procedures from least to most obstructive are Furlow, augmentation, sphincter, and pharyngeal flap. Of course, each of the latter three may be altered to some extent to increase or decrease nasopharyngeal obturation and hence airway obstruction. This is based on the degree of motion of the velopharynx during speech. Care must be taken in the decision for surgical intervention to counsel carefully with regard to the airway issues.


As one considers surgery for VPI, it is important to plan the procedure based on the endoscopic findings. As was discussed earlier, one should consider the Furlow procedure for any submucous cleft palate, as one could hope the reorientation of the levator sling would allow improved closure. If there is substantial lateral wall motion, the pharyngeal flap is ideal, as it allows obturation without as much airway risk as a wide flap. Sphincter pharyngoplasty works well for most situations, as most will have a circular or coronal closure pattern, and this obturates the lateral and posterior velopharynx.


The association of 22q11 microdeletions (velocardiofacial syndrome) with noncleft VPI makes it imperative to consider cardiac disease in the population of children with VPI. Careful examination and clearance by pediatrics or cardiology are important. Additionally, many children with this syndrome will have medialization of the great vessels. This is often seen endoscopically as a pulsatile area in the hypopharynx or velopharynx. Though usually one may be able to successfully and safely complete the speech surgery even in this setting, it is critical to know this is present and avoid injury to the vertebral or carotid artery. Some institutions require a magnetic resonance angiography of the neck in a patient with 22q11 who is undergoing pharyngeal surgery. Not only should this be considered at endoscopy, but as the pharynx is inspected as the mouth gag is placed, one should always reevaluate for pulsation.





Common Considerations for These Procedures


The surgery is performed under general anesthesia. Usually the use of an oral Ring-Adair-Elwyn (RAE) tube will allow less interference with the field. The Dingman mouth gag is usually used. It has the advantage of self-retaining lateral retractors and springs to allow suture retention. Other mouth gags used in tonsil surgery can be employed as well. Senders and Eisele suggested that releasing the pressure on the tongue during the surgery allowed improved blood flow and likely decreased pain.


Local infiltration of the flap areas is necessary for hemostasis and will decrease local pain to stabilize the anesthesia during the procedure. Lidocaine with epinephrine may be used, but has a relatively shorter duration of pain control.


A throat pack is suggested, especially if the endotracheal tube is noncuffed. This will hopefully prevent both aspiration of blood around the endotracheal tube and swallowing of blood that could increase the chance of postoperative nausea.


At the end of surgery, a tongue suture can be placed. This is tied loosely and the tail remains long. It is taped to the side of the mouth. In the event of postoperative airway obstruction, pulling the tongue anteriorly with the suture will improve the airway. This is usually removed the next morning if the airway is secure.





Furlow Double Opposing Z-Plasty


The Furlow double opposing Z-plasty is quickly becoming a standard way of repairing a cleft of the soft palate. The advantage is the reorientation of the levator. If the levators are sagittally oriented, one must consider either the Furlow or completely dissecting the levators to perform an intravelar veloplasty. In this chapter the focus will be on the Furlow.


A Z-plasty lengthens a scar. In VPI the problem often includes a short palate. The double Z-plasty lengthens the palate. The initial “Z” can be made in either direction, but the right-handed surgeon seems to do better as pictured ( Fig. 64.1A ). The posteriorly based flaps are always the myomucosal flaps. The anteriorly based flaps are mucosa only. Sie and Gruss suggest rounding the tips of the flaps to improve the vascular supply. The incision is carried through the oral cavity mucosa. As the incision is made in the left hemipalate, care must be taken to maintain a small amount of mucosa behind the posterior edge of the hard palate so that suturing is easier. Careful dissection through the levator and tensor veli palatini tendon brings one to the nasal mucosal layer. The plane is usually well defined. Meticulous blunt and sharp dissection separates the undersurface of the muscle bundle from the nasal mucosa. Once the plane is developed near the junction of the hard and soft palate, the use of a freer can help facilitate rapid flap elevation.










FIG. 64.1


Furlow. (A) The dashed line indicates the location of the incisions for the initial Z-plasty. The dotted line describes the posterior border of the hard palate. Flap (A) is the oral cavity myomucosal flap and flap (B) is the mucosal flap. (B) The posteriorly based myomucosal flap (A) has been elevated, as has the anteriorly based mucosal flap (B). The dashed lines show the location for the incisions to create the nasal layer myomucosal flap (D) and the nasal mucosal flap (C). (C) The flaps (C) and (D) have been rotated and sutured into position. The uvula is often divided at this point to grant more mobility to the flap (D). The flaps (A) and (B) are retracted out of the field to improve the access for suturing the nasal layer. (D) The flaps (A) and (B) have been rotated to create the second Z-plasty. They have been sutured into position. The uvula has been closed. The dashed line shows the location of the closure of the nasal Z-plasty.

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Jun 10, 2019 | Posted by in OTOLARYNGOLOGY | Comments Off on Current Techniques for the Treatment of Velopharyngeal Insufficiency
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