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Fiberoptic Endoscopic Evaluation of Swallowing: Without Sensory Testing (FEES) or With Sensory Testing (FEESST)

Fiberoptic Endoscopic Evaluation of Swallowing (FEES) is a procedure in which a fiberoptic endoscope is inserted through the nose and into the throat to obtain a direct visualization of structures, a dynamic view of the oral–pharyngeal transfer, and indirect evidence of the pharyngeal–esophageal transfer during swallows.

Saliva swallowing can be evaluated, and the anatomy and physiology of saliva swallow can be viewed in the absence of acceptance of food and/or liquids. The swallow is then assessed with presentation of food and liquid.

Fiberoptic Endoscopic Evaluation of Swallowing With Sensory Testing (FEESST), a modification of FEES, is a test of the Laryngeal Adductor Response (LAR), a reflexive vocal fold adduction in response to a pressure- and duration-calibrated air puff delivered anterior to the arytenoids along the aryepiglottic folds. The test measures the intensity level at which the LAR is elicited.

FEES procedures are indicated when there is a need for

  • visualizing structures and observing a dynamic view of the oral–pharyngeal transfer with or without presentation of food and/or liquid;
  • additional instrumental assessment, based on previous VFSS findings;
  • assessment of the LAR sensitivity and vocal fold dynamics; or
  • alternate testing—for example, when the child is not a good candidates for VFSS because he or she
        • cannot be positioned adequately for VFSS or
        • cannot be transferred to the radiology suite.

      Test Protocol

      • The appropriate endoscope size is chosen, and a decision is made about whether the endoscope should be equipped with air puff capability.
      • The endoscope is then passed by the SLP or physician, and the child is given an opportunity to calm.
      • The nasal, oral, pharyngeal, and laryngeal anatomy is examined.
      • FEESST is administered, if indicated, to determine LAR sensitivity and vocal fold dynamics.
      • The child eats and/or drinks a variety of preferred and problem foods under fiberoptic observation.


      • Monitoring (e.g., cardiovascular) during FEES procedures may be warranted for children with significant pulmonary disease, cardiac arrhythmia, seizure disorders, or other medical conditions.
      • It is advisable to have suction equipment available and trained personnel on hand during testing.
      • The possible risks for localized nasal trauma and bleeding are considered.

      Special care is taken with use of topical anesthesia in medically fragile infants and children. Clinicians are encouraged to consult with the child’s medical team prior to using anesthesia with these children.

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