Velopharyngeal Insufficiency



Velopharyngeal Insufficiency


Jennifer L. McGrath

Arun K. Gosain





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.


    • The incidence of lasting VPI after primary palatoplasty is about 10% to 20%.1,2


  • 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


  • Imaging is indicated when VPI is documented on PSA.2,4


  • 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.




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.



      • Autologous fat grafting has gained popularity recently but is in need of standardized protocols and prospective studies to evaluate retention of the augmentation and its utility over time. Still, it is most likely only useful in small velopharyngeal gaps.6,7,8


Preoperative Planning

Feb 27, 2020 | Posted by in Pediatric plastic surgery | Comments Off on Velopharyngeal Insufficiency
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