Abstract:
Swallowing, as one of the critical life-skills for newborn infants and brain-developing children,
is one of the most complex physiological mechanisms involving the upper aerodigestive
system. Due to increased survival rates of infants with complex medical etiologies, prematurity,
and severe disabilities, the prevalence of infants and children diagnosed with swallowing
disorders is rising. Videofluoroscopic study of swallowing (VFSS) provides visualization of
oral, pharyngeal, and esophageal phases of swallowing, as well as airway during swallowing.
It is one of the most common instrumental swallowing assessment tools. However, the current
practice of pediatric VFSS is non-standardized and subjective, both in choice of the
administration protocol and in the assessment of recorded images, resulting in limited
reliability and credibility. Given that VFSS entails radiation exposure and is an expensive
instrumental assessment, we believe it should be optimized to obtain maximal clinically
significant information on swallowing biomechanics in children. In this thesis, we obtained
objective quantitative VFSS measures in a large cohort of children from 0-21 years (n=553).
Our aims were to (1) study the potential of these measures to determine the risk of swallow
impairments in children such as penetration-aspiration and post-swallow residue, (2) provide
clinicians with threshold scores/ reference values of objective quantitative swallow measures
to identify children at risk of swallowing impairments and (3) develop a standard protocol of
objective quantitative swallow measures for children, which will aid objective VFSS
interpretation in children. We identified vital measures including bolus clearance ratio (BCR),
pharyngeal constriction ratio (PCR), total pharyngeal transit time (TPT), coordination of
airway closure with bolus transit (BP1AEcl), maximum opening of PES during a swallow
(PESmax) and duration to maximum hyoid elevation (Hdur) to describe swallow biomechanics
with satisfactory rater-reliability. The protocol for objective interpretation of pediatric VFSS
will aid clinicians in describing swallow biomechanics in children. Further, the threshold scores
can be used to identify children at risk that will require closer observation and potential
intervention before sequelae of swallow impairments are seen. Through utilizing VFSS to its
full potential, meaningful comparison of swallowing skills over time and treatment effects can
be made and will lead to clinicians offering more individualized treatment for children with
swallowing disorders.