Velopharyngeal Insufficiency
Jennifer L. McGrath
Arun K. Gosain
DEFINITION
Velopharyngeal insufficiency (VPI) refers to a structural inadequacy of the velopharyngeal apparatus, resulting in inadequate closure of the velopharyngeal port during speech.
VPI may be congenital or acquired.
It is characterized by nasal air emission and hypernasality of speech, articulation errors, decreased speech intelligibility, and nasal reflux of food and liquids.
ANATOMY
The velopharyngeal sphincter is a complex, 3D arrangement of muscles that serves to separate the nasal cavity from the oral cavity during speech and swallowing.
Muscles of the soft palate: levator veli palatini, tensor veli palatini, palatoglossus, palatopharyngeus, and musculus uvulae.
Paired levators are primarily responsible for velum closure by moving the velum posteriorly and superiorly.
Superior pharyngeal constrictor moves the posterior and lateral pharyngeal walls centrally.
Innervation:
Predominantly CN IX and X: levator veli palatini and pharyngeal constrictors
CN V3: Tensor veli palatini
Three patterns of closure have been described:
Coronal: majority of closure from posterior movement of the velum
Sagittal: majority of closure from medial movement of the lateral pharyngeal walls to meet the velum
Circular: contributions of both movement of the velum posteriorly and movement of the lateral pharyngeal walls medially. Passavant ridge may contribute to closure.
PATHOGENESIS
The cause of VPI may be structural, functional, or dynamic.
Four main categories of VPI are frequently encountered. They include
Postpalatoplasty: after primary cleft palate repair
Inappropriate levator veli palatini positioning
Palatal scarring preventing functional contraction of repaired levator sling
Length discrepancy preventing contact with the posterior pharynx
Submucous cleft palate (SMCP)
May be classic (bifid uvula, palatal muscle diastasis) or occult
Often present later than cleft lip and palate
Not always associated with VPI (see section Natural History below)
Palatopharyngeal disproportion
No anatomic abnormality to reconstruct
Disproportion may result from a short palate and/or a deep nasopharynx.
May be seen after tonsillectomy and adenoidectomy
Neurogenic
More common in adults than children
Etiology may be upper motor neuron, nuclear, or lower motor neuron or generalized hypotonia.
Examples: muscular dystrophy, neurofibromatosis, cerebral palsy, apraxia, dysarthria
This subset tends to do more poorly with surgery.
NATURAL HISTORY
Transient VPI is common after primary palatoplasty.
Patients are referred to speech-language pathologist (SLP) as early as 2 weeks postoperatively.
Perceptual speech assessment (PSA) by a SLP is obtained when the patient is of a cooperative age, often age 3 or above.
Submucous cleft palate (SMCP)
Not all patients with SMCP will develop VPI. Studies suggest roughly 5% to 10% of patients with SMCP will develop VPI warranting intervention.3,4
The incidence of VPI in the pediatric plastic surgery population is higher due to referral bias.
Children with SMCP should undergo PSA by a SLP. Intervention should be delayed until reliable PSA can be performed by a trained SLP, which is usually after age 3 years.
Some children with SMCP may improve with speech therapy. Surgery is indicated for SMCP only when VPI is present and cannot be corrected with speech therapy.
VPI caused by palatopharyngeal disproportion tends to worsen as the tonsils and adenoids regress or are surgically removed.
In general, if VPI is diagnosed on PSA by an SLP and is secondary to previous palatoplasty, submucous cleft palate, or palatopharyngeal disproportion, VPI will persist indefinitely.
Speech outcomes are better when surgery is performed at a younger age, but there is not a specific age cutoff for surgical treatment. However, misarticulations are harder to correct as a child ages.
PATIENT HISTORY AND FINDINGS
Patients are frequently identified by parents, teachers, and/or SLPs.
Patients with a history of cleft palate are frequently followed by SLP as part of a multidisciplinary approach to cleft care.
Patients and parents may report nasal regurgitation, liquids worse than solids.
Hypernasal speech and nasal air emission are the classic findings. Nasal air emission is normally only observed in /m/ and /n/ sounds.
Compensatory articulations occur when patients are unable to seal off the nasopharynx.
IMAGING AND OTHER DIAGNOSTIC STUDIES
PSA by an SLP. Note that PSA is a subjective assessment of speech, one component of which is nasal air emission.
Nasometry: objective test of nasal air emission, which can correlate subjective assessment of nasal air emission on PSA
Multiview videofluoroscopy
Quantify lateral wall motion on AP view
Quantify velopharyngeal gap on lateral view
Requires reference landmarks for quantification
Nasendoscopy
Qualitatively assesses closure pattern
Helpful in identifying stigmata of SMCP in patients without overt clefting
Roughly quantifies closure ratio: fraction of the diameter of the velopharyngeal port that is closed off during attempted sphincter closure
Nasendoscopy does not provide reference landmarks, so it cannot quantify motion and gap as in videofluoroscopy. It does allow visualization of nasopharyngeal and oropharyngeal structures, such as the adenoids.
DIFFERENTIAL DIAGNOSIS
Although the vast majority of patients will present with a history of previous palatoplasty or submucous cleft palate, it is important to recognize other mechanisms of velopharyngeal dysfunction that are less adequately treated with surgery.
Velopharyngeal mislearning
Articulation errors with no anatomic disturbance; treat with speech therapy
Velopharyngeal incompetence: neurologic or neuromuscular origin
Globalized hypotonia with no structural abnormalities
Poor muscular competence of the lip and tongue may predict poor surgical outcomes. However, many patients will benefit from traditional surgical approaches.
NONOPERATIVE MANAGEMENT
Speech therapy: all patients should be evaluated and treated by an SLP prior to intervention to minimize articulation errors.
Prosthetics
Speech bulb
Palatal lift
Disadvantages: compliance, fit, growth
Prosthetics may be a helpful training tool in conjunction with surgery to improve oromuscular coordination and articulation placement.
If a true mechanical insufficiency exists, nonoperative management is not recommended if a patient can tolerate surgery.
SURGICAL MANAGEMENT
The overall goal of surgical management is to recapitulate a velopharyngeal port that can be closed during speech.
Surgical approach typically depends on deficiencies seen on videofluoroscopy and/or nasendoscopy. Common approaches include
Intravelar veloplasty
In cases of SMCP only, primary palatoplasty with intravelar veloplasty repositions the aberrant insertion of the levator veli palatine muscles to create a functional sling.
This approach does not increase palatal length and is often passed over for Furlow palatoplasty.
Furlow palatoplasty or double-opposing Z-plasty (DOZ)
Initially described by Leonard Furlow as a technique for primary repair of cleft palate, this technique has gained favor as an approach to the management of VPI due to its ability to lengthen the palate via Z-plasty while also opposing the levator veli palatini muscles to recreate an anatomic muscular sling.
The major benefits of this technique are as follows:
It does not mechanically alter the closure mechanism of the velopharyngeal port, leaving open the option of other surgical techniques for refractory cases.
It is not associated with airway obstruction as are other techniques.
Dynamic sphincter pharyngoplasty
Dynamic sphincter pharyngoplasty (DSP) uses myomucosal flaps transposed to the posterior pharynx to create a smaller, circular velopharyngeal port.
This procedure is typically selected for patients with a coronal or circular closure pattern. When lateral wall movement is poor, DSP narrows the velopharyngeal port and adds bulk to the posterior pharyngeal point of velum contact.
The senior author has advocated use of the DSP in conjunction with the DOZ in cases of large velopharyngeal gaps.5
Pharyngeal flap pharyngoplasty
Based on the palatopharyngeal adhesion described by Passavant in the 1800s, pharyngeal flaps have been described as a surgical treatment for VPI for over a century.
Superiorly based pharyngeal flaps are widely utilized as a preferred treatment for VPI.
We describe a high inset pharyngeal flap, which is used as a last resort procedure due to its association with airway obstruction.
Posterior pharyngeal wall augmentation
In cases of small gaps, implants and injectables have been used to augment the posterior wall of the pharynx to reduce the velopharyngeal gap.
Like many other applications of implants, implants in the posterior pharynx have been associated with failure due to migration, extrusion, and infection.
Silicone, Teflon, Gore-Tex, and polyethylene implants and calcium hydroxyapatite injections have been used. Despite successful reports, these techniques have not enjoyed widespread acceptance.
Preoperative Planning
Surgical procedures are usually selected based on the preoperative closure pattern and velopharyngeal closure gap.9,10,11
For sagittal closure, velum may be too short and/or not move well, but lateral wall movement is preserved; therefore:
For small gaps less than 9 mm, we recommend doubleopposing Z-plasty (DOZ) to lengthen the palate.
For gaps larger than 9 mm, we recommend a superiorly based pharyngeal flap.
For coronal closure patterns in which lateral movement is poor, we recommend dynamic sphincter pharyngoplasty (DSP).
For gaps less than 9 mm, we recommend DSP alone.
For gaps greater than 9 mm, we recommend DSP in conjunction with DOZ.
For circular closure patterns, many approaches have been used. DOZ may be used in smaller gaps. Narrow pharyngeal flaps or sphincter pharyngoplasty is recommended for larger gaps.2
Pharyngeal flaps may have better outcomes in noncoronal closure patterns.9
DSP may be most appropriate in coronal and circular closure patterns.10Related posts:
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