Diagnosis and management of velopharyngeal insufficiency following cleft palate repair

Michael S Gart; Arun K Gosain

doi:10.4103/2348-2125.126536

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REVIEW ARTICLE

Year : 2014 | Volume : 1 | Issue : 1 | Page : 4-10

Diagnosis and management of velopharyngeal insufficiency following cleft palate repair

Michael S Gart¹, Arun K Gosain²
¹ Department of Surgery, Division of Plastic Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
² Department of Surgery, Division of Plastic Surgery, Northwestern University Feinberg School of Medicine; Department of Surgery, Division of Plastic Surgery, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA

Date of Web Publication

5-Feb-2014

Correspondence Address:
Arun K Gosain
Department of Surgery, Division of Plastic & Reconstructive Surgery, Ann and Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Avenue, Chicago, IL 60611
USA

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/2348-2125.126536

Abstract

Background: Cleft lip and palate repair seeks to restore normal form, improve feeding and achieve normal speech, which requires velopharyngeal competence. The absence of this ability, termed velopharyngeal insufficiency (VPI), is seen in a wide range of patients following primary cleft palate repair. This review article focuses on patient assessment and the surgical management of VPI. Recent trends and future directions in management are also presented. After reading, one should be able to describe the various treatment approaches for a patient with suspected VPI. Materials and Methods: A PubMed search was conducted using the following search terms: VPI, velopharygneal incompetence, VPI, velopharynx, velopharyngeal port, velopharyngeal mechanism, veloplasty, intravelar veloplasty and hypernasal speech. Relevant manuscripts were identified by abstract review and additional articles selected based on bibliography review. Articles were restricted to those in the English language. A total of 88 articles were selected for further review. Conclusions: VPI is a common complication following primary palatoplasty. The decision to operate, as well as the selection of operative procedure, depends on a multimodal patient assessment, including speech evaluation and imaging studies of the pharyngeal mechanism. A thorough understanding of velopharyngeal anatomy and physiology is crucial to understanding the deficits in patients with VPI as well as the myriad methods of surgical correction. While many techniques are available, there are no conclusive data to guide procedure choice and newer techniques of imaging and treating patients with VPI continue to evolve.

Keywords: Velopharyngeal incompetence, velopharyngeal insufficiency, velopharynx, veloplasty

How to cite this article:
Gart MS, Gosain AK. Diagnosis and management of velopharyngeal insufficiency following cleft palate repair. J Cleft Lip Palate Craniofac Anomal 2014;1:4-10

How to cite this URL:
Gart MS, Gosain AK. Diagnosis and management of velopharyngeal insufficiency following cleft palate repair. J Cleft Lip Palate Craniofac Anomal [serial online] 2014 [cited 2022 Oct 4];1:4-10. Available from: https://www.jclpca.org/text.asp?2014/1/1/4/126536

Introduction

The primary goal of cleft palate (CP) repair is to create an anatomically and functionally intact palate to improve feeding and achieve normal speech. To produce normal speech, a person must be able to completely close the velopharyngeal sphincter that separates the oro-and nasopharynx. ^[1] The absence of this ability, termed velopharyngeal insufficiency (VPI), is a known complication following primary palatoplasty for CP and requires surgical correction in approximately 25% of affected patients. ^{[2],[3],[4],[5]} Here, we present a review of the available literature on veopharyngeal insufficiency and its surgical management, intended to help guide practitioners through patient and procedure selection. Recent trends and future directions in management are also presented. After reading, one should be able to describe an approach to the patient with suspected VPI.

A PubMed search was conducted using the following search terms: VPI, velopharygneal incompetence, VPI, velopharynx, velopharyngeal port, velopharyngeal mechanism, veloplasty, intravelar veloplasty and hypernasal speech. Relevant manuscripts were identified by abstract review and additional articles selected based on bibliography review. Articles were restricted to those in the English language. A total of 88 articles were selected for further review. Articles were chosen to address the specific aims of this review, namely diagnosis and surgical treatment. For more in-depth coverage, readers are directed to several comprehensive reviews articles available in the literature. ^{[6],[7],[8],[9],[10],[11],[12],[13],[14],[15]}

Background

The velopharyngeal mechanism is a muscular valve extending from the posterior bony palate to the posterior pharynx. With the exception of three sounds in the English language (/m/, /n/, /ng/), all speech is produced with a closed velopharyngeal port. ^[13] Surgical manipulation of the velopharyngeal port dates back to the 19 ^th century and has undergone significant evolution, from local flaps to injectable synthetic or biologic materials. ^{[8],[16],[17],[18],[19],[20],[21],[22],[23],[24],[25],[26],[27],[28],[29],[30],[31],[32],[33],[34]}

Patient Assessment

History

As with all surgical patients, the assessment should begin with a thorough medical history and physical examination. The most common cause of VPI is a history of repaired or unrepaired CP. ^[8] In children who have undergone primary palatoplasty, the most common causes are: Inadequate lengthening of the velum at the time of primary palatoplasty, abnormal function of the levator musculature and cicatricial contracture of the velum. ^[35] In patients without a history of CP repair, submucous CP is a notable cause of VPI. ^{[36],[37],[38],[39]} The causes of VPI are many and may be structural, functional, or dynamic in nature. Examples include neurogenic VPI, due to insult to the cranial nerves innervating the velopharyngeal mechanism; and iatrogenic VPI following maxillary resection, uvulopalatopharyngoplasty, or adenoidectomy. ^{[8],[40],[41],[42],[43],[44],[45],[46]} Here, we focus on VPI following primary palatoplasty. For a more comprehensive discussion of VPI, including diagnosis and management, readers are directed to several excellent review articles. ^{[8],[11],[14],[15],[37],[38],[39],[47],[48]}

Speech assessment

Assessment by a speech-language pathologist is essential to the workup of velopharyngeal dysfunction. This begins with a perceptual speech evaluation to assess articulation, resonance, nasal airway emission and voice. ^[49] The Pittsburgh weighted speech score (PWSS), originally described in 1979 by McWilliams and Phillips ^[12] is one tool that serves to grade VPI on a quantitative scale. This scale uses a standardized scoring system to evaluate a patient based on nasal air emission, facial grimace, resonance, voice quality and articulation. A sample patient assessment worksheet is shown in [Figure 1]. The individual scores are summed and the total scores are used to classify patients into one of four categories of velopharyngeal function (in increasing order of dysfunction): Competence, borderline competence, borderline incompetence and incompetence.

Figure 1: Velopharyngeal insufficiency assessment worksheet. Adapted from: McWilliams, BJ, and Phillips BJ. Velopharyngeal Incompetence: Audio Seminars in Speech Pathology. Philadelphia: W.B. Saunders, Inc.; 1979

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A PWSS score of 3 or greater indicates borderline or frank velopharyngeal incompetence adjunctive studies are needed to determine the best treatment course.

Adjunctive studies

There are three basic closure patterns of the velopharyngeal port, described as:

Coronal: Posterior and superior movement of the velum is primarily responsible for velopharyngeal closure, with little contribution from the lateral pharyngeal walls.
Sagittal: Medial displacement of the lateral pharyngeal walls is primarily responsible for closure, with little posterior movement of the velum.
Circular: Combined movements of the velum and pharyngeal walls contribute equally to close the port in a "purse-string" fashion.

Nasoendoscopy (NE) and multiview video fluoroscopy (MVF) are the most commonly used methods for studying the closure pattern of the velopharyngeal mechanism. ^[50] NE utilizes a flexible endoscope to provide a "bird's eye" view of the velopharyngeal mechanism during speech. In addition to providing direct measurements of the size and location of the velopharyngeal opening and relative contributions of the velum, lateral pharyngeal walls and posterior pharynx during attempted velopharyngeal closure, NE is also useful to assess for palatal scarring, oronasal fistulae, submucous clefting and the status of the tonsils and adenoids. ^{[10],[48],[51]}

MVF uses multiple images obtained during a speech sample to determine the relative contributions of the velum and lateral pharyngeal walls to velopharyngeal closure. ^[52] Whereas MVF can be useful in identifying the point of attempted velar contact, it is limited in its ability to measure multiple variables in a single view. ^[53] Therefore, most clinicians prefer to use MVF as an adjunct to NE, or in cases where the patient will not tolerate invasive imaging. ^[8],[54]

Advances in magnetic resonance imaging (MRI) have led to the use of this technology in uncooperative patients and in cases where more precise anatomical information is needed. Benefits of MRI include its non-invasive nature and avoidance of ionizing radiation in a mostly pediatric population. ^[55] Further refinement of this technique may offer a more precise and better-tolerated assessment of the velopharyngeal mechanism during speech.

Nasometry is a method of objectively measuring the acoustic energy emitted from the nasal cavity as a percentage of acoustic energy. ^[56] A nasometer consists of a headset with two microphones positioned in front of the nose and mouth with an intervening metallic plate to isolate acoustic energy from each cavity. The headset is connected to a computer which interprets and graphically represents the percentage of nasal energy as a nasalance score, which is compared to available normative data. ^[57] Although this modality provides a purely objective assessment of acoustic energy distribution, it is currently best used as an adjunct to formal speech assessment. ^[52]

Surgical Treatment

Available treatments

Available treatment options for VPI include speech therapy, prosthetic devices and surgical management. Speech therapy is used for mild cases that are correctable with speech modification. Prostheses are usually reserved for poor surgical candidates; however, they have demonstrated considerable success in treating VPI. ^{[14],[58],[59]} Interested readers are directed to several available comprehensive reports. ^{[40],[41],[42],[43],[44],[58],[60],[61],[62],[63]}

The most commonly utilized techniques for the surgical management of VPI are:

Furlow palatoplasty, or double opposing Z-palatoplasty (DOZ): Restores the velar levator musculature to a more physiologic condition and simultaneously lengthens the velum.
Pharyngeal flap: Static structure that reduces the size of the velopharyneal port and relies on the lateral wall motion for closure.
Dynamic sphincter pharyngoplasty (DSP): Augments the pharyngeal musculature to improve lateral wall motion.
Posterior pharyngeal augmentation: Injectable or implantable alloplastic and autologous materials are used to augment the posterior pharyngeal wall in select cases. ^{[17],[18],[27]} This modality is not discussed in detail here and readers are directed to the references for additional information.

Pre-operative planning

An understanding of the velopharyngeal motion patterns will usually guide the selection of the best surgical procedure, with a few important exceptions. Closure of the velopharyngeal mechanism depends primarily on the elevation and posterior motion of the velum; however, important contributions are made by movement of the lateral pharyngeal walls toward the midline as well as anterior "bulging" of the posterior pharyngeal wall. ^[13] To be successful, any surgical procedure performed to address VPI must take into consideration the existing pattern of velopharyngeal closure.

Author's preference

Our approach is based upon the pattern of velopharyngeal closure and the size of the "pharyngeal gap" present with attempted closure.

Saggital closure pattern

Posterior velar motion or velar length is deficient in this closure pattern.

For patients with this pattern and a pharyngeal gap of <9 mm, palatal lengthening alone is often sufficient. For this, we prefer a DOZ.
In patients with a sagittal closure pattern and a gap of >9 mm, a superiorly based pharyngeal flap is effective, as the post-operative airway concerns are less likely to occur in these patients because of the retained lateral pharyngeal wall motion.

Coronal closure pattern

Lateral wall motion is deficient and velum is the primary contributor to velopharyngeal closure.

A DSP is used in patients with a gap of 9 mm or less. This flap is preferred over a pharyngeal flap, as lateral wall motion s deficient and may increase post-operative airway complications with a pharyngeal flap.
Patients with a coronal closure pattern and a pharyngeal gap of >9 mm are difficult to correct. In this case, both the posterior velar motion and the lateral wall motion are deficient. Our previous work has indicated that the combination of DOZ and DSP can effect velopharyngeal competence. ^[64] In our previous study, 15% of patients had persistent hypernasality, which was corrected in all cases with secondary placement of a narrow pharyngeal flap. The combination of DOZ and DSP was shown to significantly improve speech and voice ratings on a standardized scale. ^[64]

Sphincteric closure pattern

Posterior velar and lateral wall motion are intact, but not effective.

DOZ is our procedure of choice with a pharyngeal gap of <9 mm, as the length gained in the velum provides adequate closure.
With a gap >9 mm, narrow pharyngeal flaps are utilized, as the adequate lateral wall motion will allow for closure while minimizing risk of airway obstruction.

Velocardiofacial syndrome (VCFS)

In general, we utilize pharyngeal flaps as a last resort option, except in cases of VCFS, where we employ a modification of the pharyngeal flap procedure. ^[65] Historically, multiple factors have contributed to poor outcomes and persistent VPI following secondary palatoplasty in these patients, including poor lateral wall motion due to pharyngeal hypotonia, abnormal muscular action and an obtuse basicranium, which contributes to the pharyngeal gap. ^[66] While DSP has been advocated, VCFS patients have shown twice the revision rate of patients without VCFS (22% vs. 11%). ^[67] The high wide pharyngeal flap, proposed by Shprintzen et al., ^{[68],[69],[70]} has become an accepted form of treatment for these patients; however, the success of this operation depends on high flap inset, which is technically very demanding due to limited visualization. The senior author has developed a technique for high pharyngeal flap inset that avoids such difficulties, described below.

Operative techniques

Furlow palatoplasty/DOZ

First described by Leonard Furlow, the DOZ transposes the abnormally inserted levator musculature into a more anatomic, posterior and transverse orientation, thus recreating the levator sling and simultaneously lengthening the velum and constricting the velopharyngeal port. ^[71],[72] To distinguish this technique of primary palatoplasty from secondary DOZ for VPI management, we will utilize the term "Furlow palatoplasty" to refer to primary CP repair and "DOZ" for secondary palatoplasty for VPI management.

In secondary palatoplasty, the levator musculature will be encased in scar. It is essential to remove all scar tissue to promote better post-operative function of the levator sling. We utilize a muscle stimulator to differentiate functional muscle in the oro-and nasomuscular flaps from scar tissue. The flaps are then transposed in standard fashion, re-creating the levator sling and lengthening the palate simultaneously.

Advantages and disadvantages

This technique can be performed in any patient, regardless of previous intravelar veloplasty. Moreover, the velum is lengthened by the Z-plasty at the expense of palatal width, tightening the velopharyngeal port. Lastly, this technique leaves all future options available should any revisional surgery become necessary.

The most common pitfall in this technique is inadequate gain in palatal length or levator muscle function. Levator muscle function can be optimized by complete removal of all scar tissue encasing the velar musculature. We find that the use of an intraoperative muscle stimulator works well to identify functional muscle tissue from encasing scar.

High-inset pharyngeal flap

A superiorly-based myomucosal flap containing the superior pharyngeal constrictor muscle is elevated in a plane anterior to the pharyngobasilar fascia. A fish mouth incision is created on the nasal side of the velum, superior to the uvula and a counter incision is made on the oral surface of the velum immediately posterior to the junction of the hard and soft palate. A pocket is developed and the pharyngeal flap is then passed through this pocket and inset into the oral mucosa. The donor site is closed or left to heal secondarily.

Advantages and disadvantages

The pharyngeal flap is the most widely utilized flap for VPI surgery and most surgeons are comfortable with the technique. However, a flap designed too narrow will fail to close the velopharyngeal port and result in persistent nasal airway emission and hypernasal speech, whereas a flap designed too wide will obstruct the nasopharyngeal passage, resulting in hyponasality, or airway compromise with obstructive sleep apnea.

The most feared complication with pharyngeal flap surgery is upper airway obstruction, which can occur acutely and result in death. ^{[73],[74],[75],[76],[77],[78],[79]} Intraoperative corticosteroid administration may reduce post-operative edema and is used routinely in some centers. Many of the surgeons prefer the use of a tongue stitch in case of airway obstruction; however, we have found that our technique for management of tongue edema obviates this need.

Sphincter pharyngoplasty

We perform the DSP as described by Orticochea. ^[29] Attempts should be made to inset the flaps high in the pharynx, at or near the point of velar contact, which is determined preoperatively. Note that one limitation to achieving high flap inset is the presence of the adenoid pad at or near the point of velar contact with the posterior pharyngeal wall. ^[80] In this setting, the patient may require adenoidectomy prior to VPI surgery and consultation with an otolaryngologist may be indicated. If tonsillectomy is required, it should be performed a minimum of 6 weeks prior to sphincter pharyngoplasty.

Advantages and disadvantages

The sphincter pharyngoplasty has several advantages as a corrective treatment of VPI. Firstly, it creates a dynamic structure, which alleviates the concerns for persistent hyper-or hyponasality seen with an improperly sized pharyngeal flap. Moreover, this procedure can be easily revised if hypernasality persists by re-elevation and further overlap of the two myomucosal flaps, further narrowing the velopharyngeal port. If hypernasality persists despite revision, the option exists for secondary placement of a narrow pharyngeal flap. Moreover, this technique can be combined with DOZ for patients with coronal closure patterns and large pharyngeal gaps.

Although airway compromise has not been nearly as common historically with sphincter pharyngoplasty compared to pharyngeal flaps, there have been documented cases of acute post-operative sleep apnea. ^[81] Moreover, cicatricial contracture of the vertical donor site scars can result in inferior displacement of the myomucosal flaps and diminished speech outcomes. When able, primary closure of the donor sites is recommended to limit contracture. ^[4]

Outcomes and current practice

Measuring outcomes

We utilize a protocol of repeat perceptual speech assessment at 3 months postoperatively. If there is concern for residual VPI, the subsequent evaluation proceeds in a fashion identical to the pre-operative workup to determine the best available treatment course. Future efforts to standardize.

Practice guidelines

Despite several publications comparing different flap types, there is no current consensus regarding optimal management of patients with VPI. The pharyngeal flap remains the most commonly performed surgical procedure for management of VPI; ^[14] however, the number of surgical options available indicates the lack of consensus. ^{[23],[24],[25],[26],[28],[29],[31],[34],[64],[82],[83],[84]} A recent multicenter, randomized-controlled trial comparing these two operations showed no difference in any measured outcome at 1-year follow-up. ^[85]

Future directions

There has recently been a revival in the use of autologous fat grafting to augment the posterior pharyngeal wall. Fat grafting techniques have improved in recent years, which may account for the reported success in several series. ^{[18],[86],[87],[88]} This technique offers the advantages of considerably less morbidity and ease of repeatability. Augmentation of the posterior pharyngeal wall with autologous fat has the potential to obviate the need to alter the pharyngeal anatomy in patients with mild VPI ^{[86],[87],[88]} and may serve as a powerful adjunct to palatal lengthening in those with more severe cases of VPI. ^[18]

Summary

VPI is a common complication following primary palatoplasty. The decision to operate, as well as the selection of operative procedure, depends on a multimodal patient assessment, including speech evaluation and imaging studies of the pharyngeal mechanism. A thorough understanding of velopharyngeal anatomy and physiology is crucial to understanding the deficits in patients with VPI as well as the myriad methods of surgical correction. Although many techniques are available, there are no conclusive data to guide procedure choice and newer techniques of imaging and treating patients with VPI continue to evolve.

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