Classification of sequential swallowing types using videoendoscopy with high reproducibility and reliability

This study aimed to classify sequential swallowing types using videoendoscopy (VE) avoiding radiation exposure and compare the results using videofluoroscopy (VF).

Twenty-one healthy adults simultaneously underwent VF and VE during sequential straw drinking. Each discrete swallow was classified into an L-segmental type (laryngeal vestibule opens after swallow) or L-continuous type (laryngeal vestibule closure continues after swallow) using VF and a V-segmental type (velopharynx opens after swallow) or V-continuous type (velopharynx closure continues after swallow) using VE. Test-retest reproducibility and interrater and intrarater reliability were evaluated in ten healthy adults.

Of 128 swallows, 94 were L-segmental and 34 were L-continuous types as per VF, whereas 95 were V-segmental and 33 were V-continuous types as per VE. The leading edge of the bolus at swallow onset was significantly deeper in L-continuous types (P = 0.001). Laryngeal vestibule closure on VF images corresponded to velopharyngeal closure on VE images for 127 of 128 swallows (κ = 0.98, P < 0.001). All subjects showed the same types of swallows in the first and the second studies. Both interrater and intrarater reliability were high.

VE showed high reproducibility and reliability in the classification of sequential swallowing types.