Authors (including presenting author) :
Yiu OY (1), Chan CSS (1), Tang MY (2), Chan KW (2), Liu SW (2), Tsui SY (2), Wong WHS (3), Lee KH (2), Chao SY (2)
Affiliation :
(1) Department of Speech Therapy, Hong Kong Children’s Hospital, (2) Department of Paediatric Surgery, Hong Kong Children’s Hospital, (3) Department of Paediatrics, The University of Hong Kong
Introduction :
Some children with cleft palate may develop velopharyngeal insufficiency (VPI) even after primary palate repair. The condition would cause hypernasality, audible nasal emission, non-oral articulation errors, soft and hoarse voice, grimace – affecting speech function that requires further surgical management. VPI is first picked up in perceptual speech assessment, while combination of multiview-videofluoroscopy (MVF) and nasopharyngoscopy (NPS) has been reported as the golden standard in assessing velopharyngeal function. The two latter examinations are complementary to each other in diagnosing VPI, and facilitate treatment formulation including tailored surgical planning. Yet the use of MVF has become controversial because of side effects of radiation exposure, especially in young children. Mutual accommodation should be achieved between obtaining necessary information in the assessment and the risks of radiation exposure in extensive examination. A MVF assessment protocol which provides sufficient information to surgeons with least radiation is warranted.
Objectives :
This study aimed to review current practice of MVF including fluoroscopic time and radiation dosage, as well as the correlation of velopharyngeal function evaluation in MVF and perceptual speech assessment. It also investigated the correlation of recommendation based on MVF alone and all related assessments (MVF, NPS and perceptual speech assessment). Furthermore, it compared the visual information obtained in different views in MVF in aiding surgeons’ recommendation on VPI.
Methodology :
A consecutive case series study of patients underwent MVF at Hong Kong Children’s Hospital from August to November in 2019 was conducted. Seven exams were reviewed with fluoroscopic time and radiation dosage value (dose area product, DAP) charted. Management plan on velopharyngeal function based on all related examinations was also collected. Video recordings of speech sample in perceptual speech assessment was reviewed by speech therapists to rate velopharyngeal function with a 3-point scale (incompetent, marginal, competent). Pediatric surgeons reviewed the MVF videos in different views (lateral, anterior-posterior, Towne), and further rated the velopharyngeal function with the same 3-point scale. They then recommended further actions (surgery, speech therapy, observe) and picked the best projection plane to aid the decision. Descriptive statistics using the means and standard deviation were applied to demonstrate the outcome of continuous measurements. Kappa analysis with percentage of agreement was used to detect any variation between ratings of each outcome measure.
Result & Outcome :
The mean fluoroscopic time was 4.76 +/- 2.34 min, while the mean DAP was 106.26 +/- 136.849 Gycm2. Velopharyngeal function evaluation in perceptual speech assessment and MVF reached an agreement of 80.95% (Kappa 0.708). Percentage agreement between surgeons’ recommendation based on MVF video alone and all examinations was 61.9% (Kappa 0.325). Lateral projection was rated the best plane in aiding surgeons’ decision in recommendation (71.43%), as compared to anterior-posterior view (17.86%) and Towne view (10.71%). Examination time of MVF was found to be similar to another fluoroscopy examination on swallowing in pediatric population as in a local published reference, however with a higher DAP value. Nature of examination and thus the projection planes accounted for this difference. The fair to substantial agreement in velopharyngeal function evaluation and recommendation confirmed the application of MVF in VPI diagnosis and management. Lateral projection is recommended as the first plane to be used for visualizing velopharyngeal function. Other views should be considered for understanding movement of particular muscles, yet Towne view is of lower priority given it provided the least information and that the same view could be supplemented by NPS. Application of these findings in MVF assessment protocol design would help with reducing fluoroscopic time and radiation dosage to patients.
