Abstract
Background: Flexible endoscopic evaluation of swallowing (FEES) is one of the basic methods for objective diagnostics of swallowing disorders. The principle is to swallow boluses of various consistencies under endoscopic control.
According to available data and our experience, the quality and accuracy of the examination depends on the visibility of the tested bolus. Aim of the study: Verify that the use of fluorescein improves the sensitivity of the FEES compared to a standard food colouring.
Methods: In the study, we performed FEES on 40 patients using green food colouring and fluorescein dyed water. The presence of pre-deglutive leak, bolus stagnation in the pharynx (valleculas, pharyngeal walls, piriform sinuses), bolus penetration into the airways based on the Rosenbek Penetration-Aspiration Scale (PAS), tendency to penetrate through the posterior commissure and subjective comparison of both methods in parameters mentioned above were evaluated.
Results: The results show a statistically significantly higher detection of bolus stagnation on the pharyngeal walls (P <0.001) and in the epiglottic valleculas (P = 0.038) with fluorescein-dyed water. When assessing airway bolus penetration, the reliability value reached statistical significance (k = 0.438; P <0.001) between the tested methods (green food colouring vs. fluorescein), which indicates good sensitivity of both methods.
However, on the Rosenbek score scale (1-8 points), the methods differed statistically significantly in the assessment of penetration/ aspiration severity (P = 0.001). A statistically significantly greater depth of airway penetration was detected with fluorescein (PAS 3.13) compared to green food colouring (PAS 2.10) (P = 0.001).
In a subjective comparison of both methods by the examining physician, the visibility of fluorescein is statistically significantly better in all evaluated parameters. Conclusions: The study showed a better sensitivity of FEES when using fluorescein compared to conventional food colouring.
Fluorescein appears to be a good colouring for diagnostics of swallowing disorders.