FEES (Flexible Endoscopic Evaluation of Swallowing) is a procedure to assess the swallow. Currently, a laryngoscope is passed transnasally (through the nose) and into the upper pharynx to observe the swallow and the swallow structures through a camera.
Picture from: www.mc.vanderbilt.edu
FEES was first described in the literature in 1988. The procedure initially involved a mirror or more invasive equipment. This equipment was viewed by one person through an eyehole and much of the swallow was missed at that time.
Initially the exam was not recorded so the SLP completing the exam not only was the lone viewer of the exam, they also had to remember what they were seeing to develop the report.
Fortunately, over the years the equipment has changed drastically with equipment using distal chip technology and/or giving the SLP a picture in High Definition (HD). The view of the swallow/swallowing structures is now viewed on the screen of a tablet/computer. The study can be viewed by multiple viewers in real time and is recorded for review of the swallow.
Comparison of visualization of equipment from the article in reference 2.
Development of FEES
FEES was developed by Dr. Susan Langmore, Dr. Nels Olson (ENT) and Ken Schatz (SLP). They had the idea of visualizing the swallow, using the same equipment as the ENT to view the structures.
Upon viewing a healthy individual using FEES, the authors were disappointed by the lack of information they saw, however when they started to assess patients with dysphagia, the authors were excited with the results. They were able to visualize spillage into the pharynx, aspiration, residue, structural movements and secretions.
Another Gold Standard in Swallowing Assessment
FEES was once thought to be a suboptimal assessment for swallowing, however it is now considered a gold standard assessment tool along with the MBSS (Modified Barium Swallow Study).
Langmore, S. E., Kenneth, S. M., & Olsen, N. (1988). Fiberoptic endoscopic examination of swallowing safety: a new procedure. Dysphagia, 2(4), 216-219.
Langmore, S. E. (2017). History of fiberoptic endoscopic evaluation of swallowing for evaluation and management of pharyngeal dysphagia: changes over the years. Dysphagia, 32(1), 27-38.