Velopharyngeal Insufficiency

Velopharyngeal insufficiency

Velopharyngeal insufficiencyrefers to the inability of the velopharyngeal sphincter to close completely during production of the oral (nonnasal) sounds of speech.
The primary effects of velopharyngeal insufficiency are nasal air escape and hypernasality.

Incidence

Satisfactory speech results occur in about 80% of pts after primary palatoplasty
Further 15 % achieve normal speech with speech therapy
5% require further management with due to insufficient secondary palate closure
In this 5% air escapes through the nasopharynx when attempting to produce certain sounds precludes normal speech
Important to realize that the presence of abnormal speech is not an indication for surgery and thorough assessment of the defect is need

Normal speech production

Sphinter remains open
Nasal sounds – M N
Useful to test for overcorrection post surgery – Mamma made some mittens
Complete closure required
Plosive consonants – K T P – Pick up the book
Fricative consonants – F S- Suzy sees the scissors

Voice requires quality, richness and carrying power
Also clear, precise consonants

Classification based on aetiology

1)velopharyngeal insufficiency(VPI) - structural origin and includes structural problems associated with the velum or the side walls at the level of the nasopharynx with insufficient tissue to accomplish adequate closure

2)velopharyngeal incompetence(VP incompetence) – neurogenic origin

3)velopharyngeal mislearning -mislearning or functional origin

Velopharyngeal dysfunction – all encompassing term for the above and does not imply a specific etiology

Pathophysiology

Previously thought that VP closure resulted from a short velum. And thus the push back procedures were used with little success. Now known that the closure of the VP is a complex mechanism and thus need accurate Ix

Four closure patterns (Skolnick)
Coronal - mostly palate (most common)
Sagittal - mostly lateral wall (least common)
Circular - both palatal and lateral wall
Circular with Pasavants ridge – posterior, palatal and lateral walls

Aetiology

Cleft

unrepaired
repaired
submucous cleft
fistula

NonCleft

anatomic
neuromuscular
behavioral/functional

Cleft palate

poor muscle sling
poor elevation
short palate
immobile scarred palate
subclinical disease may manifest later due to:
adenoidal involution at the time of puberty
adenoidectomy
Orthognatic (LeFort) advancement – controversial.
Mr Baker says this does not occur

Noncleft

Anatomic

> congenitally short palate

> reduced palatal bulk

> deep/enlarged pharynx

>adenoidectomy

> maxillary advancement

> tumour resection

Neuromuscular

> cerebral palsy

> head injury

> cva

> neuromuscular disorder – amyotrophic lateral sclerosis

combined

velocardiofacial syndrome (shprintzen syndrome)

•square nose, narrow ala base

•long face, retruded chin

•hypotonia

•cardiac defects

•intellectual impairment or learning disabilities(50%)

CLINICAL

•hypernasality

•nasal emission

•nasal turbulence

•nasal substitution

•compensatory articular patterns (distortions, substitutions, and omissions).

•weak omitted consonants

•nasal/facial grimace

•hoarseness

•low volume voice

•monotonous voice

•breathiness

•unusual pitch variations

•nasal fluid regurgitation

•utterances or sentences are short and their speech tends to take on a choppy pattern because of the leak

DIAGNOSIS

Oral examination

•size

•movement

•symmetry

•elevation on phonation

•dentition

•occlusion

•fistula

•nasal air escape using mirror

Perceptual evaluation – the most important

•attempts to define characteristic speechof vpi and quantify severity

•consult speech therapist

Investigations

information on :

type of closure
size of vp gap
evidence of fatigue
consistency of performance

Videofluroscopy

•video recorded radiograph

•barium paste nasally

•lateral and frontal views

•Townes view(30 head down, mouth wide open)

•info on size of gap, pattern of closure and degree of palate elevation

Method

•barium paste instilled intranasally which coats the surface of the oropharynx and then the pt is asked to duplicate certain sounds while the fluoroscopic images are taken with the lateral , frontal and submental views being the most important

•when the adenoids are enlarged the Townes view demonstrates the VP orifice better than the basal views

Nasendoscopy

•direct visualization of the velopharyngeal mechanism

•recommended in conjunction with video fluoroscopy giving mainly quantitative information and the nasendoscopy giving mainly qualitative information

•fine flexible scope

•rigid scope

•type and degree of closure

•not successful in young children

•useful adjunct to vf in difficult cases

•some use routinely

Nasometer

•Nasalanceis a ratio of the nasal acoustic output relative to oral plus nasal acoustic output and isexpressed as a percentage.

•sensitivity and specificity of nasometry in correctlyidentifying subjects with more than mild hypernasality in their speech - 89% and 95%, respectively.

other

accelermeter
aeromechanics

CT and MRI angiography

useful in picking up abnormal medial displacement of the carotid artery
abnormality of the internal carotid is common in VCF syndrome
10% found to be located just under the pharyngeal mucous membrane and thus can be endangered in raising pharyngeal flap
Sommerlad (Cleft Palate Craniofac J. 2004 Jul) - Examination and palpation of the pharyngeal walls after the patient is positioned for surgery appear to be reliable in detecting abnormal pulsations and allow accurate surgical planning. Routine vascular imaging, even in patients with pulsations on preoperative nasendoscopy is not essential and may not always be reliable, as shown by the variation in endoscopic, MRA, and intraoperative findings.

Management

Nonoperative treatment

Speech therapy
generally not enough in itself for structural problems related to VPI.
It is, however, valuable for small gaps or inconsistent closure
very valuable either before or after surgery, or both, in order to eliminate compensatory strategies that patients develop over time.
Prosthesis
Poorly tolerated in children. Mainly indicated where surgical risks are prohibitive.
obturators (speech bulb) - provides a bulky apparatus for the pharynx against which the lateral walls and the palate can close during speech
Palatal lifts - attaches to the patient’s teeth and roof of the mouth. Reserved for patients with adequate tissue to effect closure but there is poor control or coordination. May also be used as a preoperative trial to see if VP closure alone will improve the speech disturbance. Elevatesthe palate towards the pharyngeal walls during speech and the residual palate motion does the rest. Used mainly in amyotrophic lateral sclerosis

Operative treatment

Main treatment methods

1)pharyngeal flap surgery

benefit patients with sagittal closure patterns.

2)sphincter pharygoplasty

those with circular and coronal closure patterns as it does not interfere with the posterior motion of the palate.

3)Furlow palatoplasty

4)Others

Intravelar veloplasty – if not already performed
post pharyngeal wall augmentation
prosthetic speech appliances

most surgeons regard lateral pharyngeal wall motion as the single most important determinant with regard to surgical planning.

Armour A, Fisher D; Does Velopharyngeal Closure Pattern Affect the Success of Pharyngeal Flap Pharyngoplasty? PRS Jan 2005
pharyngeal flap pharyngoplasty was successful in correcting nasalance in a significantly greater percentage of patients with noncoronal closure pattern velopharyngeal insufficiency (57%) than with coronal pattern velopharyngeal insufficiency (35%)
Sphincter pharyngoplasty is thus recommended for coronal closure patterns

Pre-VP management tonsillectomy and/or adenoidectomy are advised if the initial airway evaluation findings indicate that the lymphoid mass will compromise the operation or patency of the ports.

Pharyngeal flap pharyngoplasty

first true pharyngeal flap operation was described by Schoenborn (1875) and was an inferiorly based flap, he then changed to a superiorly based flap.
Use of a pharyngeal flap is best when a sagittal closure pattern exists (ie, when the greatest contribution to velar closure is lateral wall movement).
May also be used for circular closure patterns
No additional benefit with intravelar veloplasty

Principle:

tissue/flap from the post pharyngeal wall is attached to the soft palate creating a midline obstruction of the oral and nasal cavities with two patent lateral ports that ideally remain patent during respiration and nasal consonant production
depth of the flap is down to the prevertebral fascia so it includes the superior constrictor muscle

Modifications

1)construction of the appropriate width of flap

2)the use of a superiorly or inferiorly based flap

3)whether the flap should be lined to reduce post op contraction of the flap

4)correct width and level of attachment to the flap

Superior based pharyngeal flap

Correct width and level of attachment to the flap

Width and level of insertion are crucial
The flap must not be too wide that the lateral ports are occluded which will result in mouth breathing and sleep disturbances as sleep apnoea and snoring and hypo nasal speech
Lateral port control (introduced by Hogan) –aim for total port size of 10-20mm2 cross sectional area (oropharyngeal air pressure decreases significantly when the orifice size exceeds 10 mm2, with nasal escape of air obvious above 20 mm2)
Thus 10 mm2 catheters are placed on each side to control the size of the port ( this does not however account for the effects of flap contraction)
Shprintzen et al. (1979 - Flaps are tailored according to the amount of lateral pharyngeal wall motion and gap size as based on the preoperative on videofluoroscopy and nasopharyngoscopy. Narrow, moderately wide, or very wide flap, depending on whether the preoperative lateral pharyngeal wall motion was rated as excellent, moderate, or poor, respectively

Flap lining and flap contraction

Flaps are raised from wide area and the post surface heals by second intention thus post op contraction is a problem with recurrence of the VPI
The position of the flap may also have effect on the overall post op state
Distal insertion of a wide short flap along the free margin of the soft palate may also lessen the problem of post op contraction

Superior or inferior based flaps

Superior based flaps may be better as the inferiorly based flaps have a

severe length limitation
disadvantage of tethering the flap in a inferior direction away from the palatal plane and in the opposite direction required for palatal closure

Most studies have not found a difference between the 2 methodsin postoperative speech outcome, hearing, complications, or length of hospital stay.
Kapetansky (1973) introduced a third design, bilateral transverse flaps. He believed that basing the flaps laterally would preserve nerve supply, thus maintaining more flap mass, as well as preserving contractile function. Therefore, he made an S-shaped incision in the posterior pharyngeal wall and elevated two laterally based flaps, each 15 to 20 mm in width and 30 to 35 mm in length, using one to provide oral lining and one for nasal lining. However, this design has never become as popular as the superiorly or inferiorly based flaps.

Outcome

speech improvement in 95% butup to 35% are overcorrected

Sphincter pharyngoplast)( Hynes and modified by Jackson)

Hynes(1950) described transposition of bylateral flaps from the lateral pharyngeal walls to join in the palatal midline anterior to Passavant’s ridge
Each flap is 3–4-cm long and consists of salpingopharyngeus muscle and its overlying mucosa.
67% of the flaps were noted to be contractile on postoperative examination, and 95% of patients achieved velopharyngeal competence.

bilateral flaps from the lateral pharyngeal walls to

Orticochea modification

constructed from the posterior tonsillar pillars which are elevated to include the palatopharyngeusmuscle at the top of the tonsillar fossae and are sutured end to end

Jackson modification

sphincter is constructed from the posterior tonsillar pillars, which are elevated to include the palatopharyngeus muscles sutured together in the midline and were attached to the undersurface of a superiorly based posterior pharyngeal flap.

Advocated by many as

1)dynamic sphincter closure as a result of retained neuromusc innervation

2)ease of operation

3)good results

4)low complication rate

5)nonobstruction of the nasal airway and no interference with the velum

Best for those with circular closure patterns with mild nasal resonance

Better results in children under the age of six

Palatallengthening

Theoretical advantage of lengthening the palate without damaging the normal VP mechanism
The V-Y palatal push back was designed to create a retro displacement of the palatal mucoperiosteum and the velar musculature during initial palatoplasty
Double opposing Z plasty (Furlow) now commonly used
Best used in those with small defects only

Posterior pharyngeal wall augmentation

a static augmentation of the posterior wall to allow a compromised palate to achieve contact. It is best with a small gap and with good palate movement, and it has been especially good with patients who get VPI after adenoidectomy.
The goal is to achieve Vp closure without altering the function of the velumor the lateral walls
Many materials have been used to augment the post pharyngeal wall
Materials used include paraffin, cartilage, sialastic, fat, Teflon and collagen
Mostly abandoned due to the unpredictable effect of migration and rejection
folded superior pharyngeal flap technique is an alternative

Palatal fistulae

Large fistulae may be associated with hypernasality and nasal emission and thus may benefit from occlusion

Complication (overall incidence 16%)

1)Obstructive sleep apnoea (90%)

One of the most common complication of pharyngeal flap surgery
Tonsillectomy recommended preop or intraop if enlarged
Affects most pts early post op - it is usually short lived and last for 1-2 days
other factors such as decreased airway size , presence of tonsils, alteration in resp pattern and syndromic contributions are more likely to contribute to OSA than the flap width)

2)snoring

3)bleeding(8%)

4)airway obstruction in the first 24 hrs(9%)

5)OSA(4%)

May require flaps to be taken down or revised

6)Inadequate correction of the VPI

7)Overcorrection

8)flap dehiscence and loss

9)Inhibition of facial growth due to the tethering effect of the velum that may restrict maxillary advancement

No significant change in facial form noted

Predictive factors of complications included the operating surgeon, presence of associated medical conditions, concurrent performance of another major procedure, and leaving the posterior pharyngeal donor site open.

Management of pharyngeal flap with orthognathic advancement

A nasoendoscope- guided clinical examination by a speech pathologist familiar with cleft palate and jaw deformities can reliably predict current and expected velopharyngeal function
When significant postoperative velopharyngeal deterioration is anticipated, the patient and family are educated about the sequencing of treatment, and alternatives are discussed.
Unusual to need to transect an in-placed pharyngeal flap to achieve the desired advancement.

Revision for hypernasality

Sandwich technique

Sandwich technique for persistent hypernasality using superiorly based flap. Donor is left to heal by secondary intention