Keywords
velopharyngeal closure - velopharyngeal port - nasendoscopy - cleft palate - velopharyngeal
incompetence - velopharyngeal sphincter - palatoplasty
Introduction
Velopharynx is defined as space connecting nasal and oral cavities. Respiration, swallowing,
and speech production are important functions which require separation of these two
anatomical cavities by closure of the velopharyngeal space. Anatomically the velopharyngeal
space is surrounded by velum anteriorly, pharyngeal walls on both sides, and posteriorly.[1] The velopharyngeal port with surrounding muscular structures form a dynamic three–dimensional
(3D) muscular valve referred to as “velopharyngeal sphincter.”[2] The contraction of various muscular components closes the port during speech production.
The closure pattern of the velopharyngeal port varies among individuals, though closure
of the port varies with different speech sounds. The plosives require complete velopharyngeal
closure, while vowels and nasal consonants require variable opening of velopharyngeal
port.[2] There are four established closure pattern of velopharyngeal valve, namely, coronal,
circular, sagittal, and circular with Passavant's ridge.[3] The last pattern is also called as “bowtie pattern” ([Video 1]).[4]
Perceptual speech assessment, nasendoscopy, and video fluoroscopy are now commonly
performed to evaluate pre and postoperative results of palatoplasty. Sagar and Nimkin
have now reported pre and postoperative 3D magnetic resonance imaging (MRI) assessment
of airway during speech for velopharyngeal surgery.[5]
There is always a doubt that does the cleft palate or repair of cleft palate affect
the natural mobility of the velopharyngeal sphincter. With this question in mind,
the nasendoscopic findings in operated patients of cleft palate were compared with
those of normal volunteers.
Methods
This is a cross-sectional study done from December 2013 to June 2015 in a tertiary
cleft care hospital to assess the nasendoscopic findings in patients with operated
cleft and compare the velopharyngeal sphinteric closure with the cohort having normal
speech. This study was cleared by the protocol committee and institute ethical committee.
Two study groups of 30 patients each between 10 and 30 years were formed. The older
age group was selected as nasendoscopy is feasible in awake patients under local anesthesia
and they can easily follow commands.
In control group, patients with normal speech were included. In other group, operated
cleft patients after 6 months of surgery were included. The patients were classified
as per Nagpur classification advocated by Prof. Chakkiri Balakrishnan.[6] Most were cleft group-II patients. Few patients were in group III, already operated
for lip. Veau-Wardill-Kilner palatoplasty or Bardach's palatoplasty was done according
to the length of palate. Patients who developed postoperative palatal fistula were
excluded from the study.
After counseling and appraisal, written informed consent was obtained from each patient
included in the study. Prior to nasendoscopy, the nasal cavity of the patients were
anaesthetized locally by spraying 10% lignocaine and applying 4% lignocaine viscous
using the swab sticks inserted into the nostrils. Both the groups of the patients
were evaluated with the 70-degree rigid endoscope and/or pediatric fiber optic nasendoscope
available in the department by three observers. The larger and patent nostril was
chosen. The endoscope was passed along the inferior or middle meatus of the nasal
cavity to view the velopharyngeal portal. To study the dynamic sphincter, the subjects
of both the groups were instructed to count 1 to 10 and from 60 to 70 and were asked
to speak certain sets of words. The speech and endoscopic video (using Fentex Hi cam
Nasendoscopy System) were recorded simultaneously using computer software (Cyberlink
power director). The recorded video was repeatedly played for three observers. Two
observers were internal and one observer was external practicing plastic surgery.
The observations of the three observers are recorded separately and most common of
the three observations was taken. Speech evaluation was not done because it was beyond
the scope of the study. Observations were made in both groups as per the points shown
in the [Table 1].
Table 1
Velopharyngeal function evaluation done for the following parameters
|
1.
|
The pattern of velopharyngeal closure
|
|
2.
|
Degree of palatal movement while velopharyngeal closure
-
A. Good
-
B. Moderate
-
C. Poor
|
|
3.
|
Dominant mobile element in the velopharyngeal sphincter closure
|
|
4.
|
Degree of closure of velopharyngeal sphincter
-
A. Complete
-
B. Incomplete/inadequate
-
C. Wide open
|
Results
In our study, we categorized the patients in age groups to see if the patients are
statistically comparable as shown in [Fig. 1].
Fig. 1 Distribution of patients according to age.
On applying Chi-square test, there was no significant difference (p–value = 0.76) between two groups. In our study, there were 19 males and 11 females
out of 30 in the normal population group and 24 males and 6 females out of 30 in the
postoperative group (p value is not significant i.e. 0.15).
Using nasendoscopy examination, we are able to visualize the dominant mobile element
closing the velopharyngeal port in both the study groups as shown in [Fig. 2]. On applying the Chi-square test, there was no significant difference (p–value = 0.14) between the two groups.
Fig. 2 Figure showing dominant element in closure of velopharyngeal port.
The pattern of closure of the velopharyngeal closure in both the groups has been summarized
in [Table 2]. Chi-square test showed no significant difference (p = 0.14) between the two groups.
Table 2
Distribution of patients according to pattern of velopharyngeal closure
|
Pattern
|
Normal population (n = 30)
|
Postoperative group (n = 30)
|
|
Circular
|
8 (%)
|
7
|
|
Coronal
|
10
|
17
|
|
Circular with Passavant's ridge
|
8
|
2
|
|
Sagittal
|
2
|
2
|
|
Irregular
|
2
|
2
|
All the normal patients showed good palatal movement and have complete closure of
the velopharyngeal port. But in postoperative group, only 12 patients showed complete
closure of the port, whereas nine had wide open port and rest of the nine had incomplete
closure. While assessing the palatal movement, there were 15 individuals with good
palatal movements, but seven were classified as moderate and rest of the eight individuals
had poor palatal movement.
Discussion
Patients with cleft palate have difficulty in speech and articulation. This results
from abnormal anatomy of the soft palate musculature causing inadequate functioning
of the velopharyngeal port. Pre- and postoperative assessment of the velopharyngeal
port and sphincter mechanism is a prerequisite in cleft palate patients to match the
outcome of an intervention for optimum speech outcome. Simple perceptual speech evaluation
provides easy identification of impaired velopharyngeal sphinter but tells nothing
about the anatomy and closure characteristics that underlie the impairment. Assessment
of velopharyngeal sphincter can be performed by direct visualization using nasendoscopy
and or fluoroscopy and the effect of the sphincter on physical parameters like sound,
airflow, and air pressure.[2] All the above techniques have some merits and limitations. The direct visualization
of the sphinteric mechanism using nasendoscopy is cheap, easy, and reproducible method
of evaluation in pre- and postoperative period. The present study was undertaken to
evaluate the characteristics of velopharyngeal sphincter closure in operated patients
of cleft palate and compare with that of normal population, using nasendoscopy.
Croft et al in 1981 found multiple patterns of velopharyngeal valving in 80 normal
and 500 operated patients of cleft palate using nasopharyngoscopy and video fluoroscopy.
Authors described coronal, sagittal, circular, and circular with Passavant's ridge
patterns of closure in both the groups and concluded that the coronal is the most
common pattern of closure in both the groups.[2] Also, different patterns of closure were found in similar frequency in both normal
and postoperated population. In our study, coronal type of velopharyngeal valve closure
was most common finding ([Video 2]). Frequency of occurrence of other various patterns of closure (circular, sagittal,
circular with Passavant's ridge, and irregular) in both the groups showed no significant
difference (p = 0.14; [Fig. 3]). This indicates that cleft palate and its repair do not change the velopharyngeal
closure pattern in a given population. But in a study by Manochiopining et al on normal
Thai individuals, circular was the most common pattern of closure ([Video 3]).[7] The assessment of pattern of closure is a subjective observation. It is likely that
different observers have difference in the assessment.
Fig. 3 Different types of closure pattern; (A) circular type, (B) circular with Passavant's ridge, (C) coronal type, and (D) irregular type.
Normal population have good palatal movement in all the individuals with complete
closure of the velopharyngeal port as in our study, where as in postoperative group
only 15 out of 30 individuals had good palatal movements. On searching the literature,
we could not find study evaluating the movement of palate postoperatively. Although
Igawa et al in 1998 described three types of velopharyngeal closure patterns in cleft
palate patients postoperatively, depending on the dominant element closing the velopharyngeal
sphincter, namely, (1) soft palate type, in which the soft palate mainly operates;
(2) lateral wall type, in which compensational medial movement of the lateral pharyngeal
wall is mainly observed; and (3) mixed type, in which both the soft palate and the
lateral pharyngeal walls operate.[8]
Good palatal movement cannot be the sine qua non of the complete closure of the velopharyngeal
sphincter. Of our 30 patients of postoperative group, despite good soft palate movements
in 15, only 12 patients showed complete closure of the velopharyngeal port on the
nasendoscopy. Matsuya et al also reported that his 40 of 68 patients did not achieve
complete closure during any activity operated for cleft palate.[9] Similarly, Yellinedi et al[10] performed videofluroscopy in 117 operated cleft palate patients and reported 48
patients had a resting gap of >10 mm who did not achieve velopharyngeal (VP) closure
on phonation, thus having full blown velopharyngeal incompetence (VPI). In our study,
nasendoscope has been used that permits subjective analysis regarding closure of sphincter.
There is no objectivity as we cannot measure the exact gap size in incomplete closure.
The determination of the dominant element in the valving mechanism is important for
planning surgery for velopharyngeal incompetence. In our both study groups, the dominant
element of velopharyngeal valving is soft palate. Various sphincter pharyngoplasty
procedures bring the tissue toward the center and thus is most useful for closure
pattern with lateral defects like coronal and bowtie patterns in which lateral wall
motion is poor. Similarly, after pharyngeal flap surgery, the closure of the lateral
pharyngeal port requires lateral wall motion. Hence, it can only be effective in patients
with sagittal or circular closure patterns having adequate lateral wall motion.[4]
From the above results and discussion, it is clear that there is no significant difference
between the mobile dominant element and closure patterns of normal population versus
postoperative individuals of cleft palate indicating that velopharyngeal valving is
not physiologically affected by surgery. Although due to small sample size of the
study groups there are chances of type-II statistical error. Apart from four established
closure pattern of velopharyngeal valve, namely, coronal, circular, sagittal, and
circular with Passavant's ridge,[3] we have described a new “irregular type” closure pattern after examining the normal
and operated patients of cleft palate patients in our study ([Video 4]). The degree of palatal movement and thus completeness of the closure in postoperative
patient depends upon multiple factors like degree of clefting and meticulous surgical
technique. Nasendoscopy plays a pivotal role in the evaluation of operated cleft palate
patients and planning surgical management velopharyngeal insufficiency associated
with cleft palate repair. Surgery may be avoided if nasendoscopy does not reveal a
significant defect and an appropriate speech therapy can be assigned to the patient;
later surgery may be planned in case of indication after adequate speech therapy and
evaluation.
Despite so many advantages, nasendoscopy does have its shortcomings. Information obtained
to assess the velopharyngeal port is in the ratio or percentage rather than an absolute
value. It is difficult to obtain standardized views or infer relative dimensions.
Patient cooperation is a critical factor that further limits the use of nasendoscopy,
especially in pediatric population. The examination relies on the observer for interpretation
of results, making it a subjective investigation.
Disclosures
-
All authors have no financial disclosure to make.
-
None of the authors has a financial interest in any of the products, devices, or drugs
mentioned in this manuscript.
-
The manuscript, figures, tables, and data are not been published previously and are
not under consideration for publication elsewhere.
