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FEES vs MBSS Comparisons

FEES vs MBSS comparisons seem to be important to some SLPs when making decisions on which instrumental procedure to use with patients with suspected dysphagia. Unfortunately, some clinicians have been erroneously taught that one procedure is better than the other.  Some ask, Which one is the ‘gold standard’ in diagnosing swallowing disorders?”  It really comes down to the clinician and what information is needed, and to the patient and whether they can be moved and where they are located.  In some patient situations, BOTH procedures may be necessary to completely understand the complexity of their disorder.  Current clinical literature supports that both FEES and MBSS are their own “gold-standards.”   Both exams have significant value in the SLP’s toolbox, and clinical research continues to demonstrate this value, particularly when compared to non-instrumental bedside screening assessments.  FEES and MBSS each has unique advantages, disadvantages, and clinical indications, which are outlined below.  This chart was created from a combination of resources including Dr. Susan Langmore’s textbook on FEES (Langmore, 2001), SA Swallowing Service’s FEES training course manual (Ashford, 2017), our SASS clinical experience, and from clinical literature published primarily in the journal, Dysphagia.




Which stages of the swallow does it assess? Pharyngeal stage before, during, & after the swallow. Inferences are made about the oral (containment) & esophageal stages (reflux). Primarily from the superior view. Oral, pharyngeal & cervical esophageal stages. Primarily from the lateral view.
Where can it be performed? Any location: hospital, SNF, OP clinic, pt’s home; bedside, wheelchair, chair Hospital radiology suite, mobile radiology van, & sometimes with portable C-Arm fluoroscope at bedside
Which pts cannot have the exam? Very few patients. Problems may occur with craniofacial trauma, dementia, brain trauma, confused or comatose pts Pts unable to leave bed, room, or ward, or unable to position in upright position. Ventilator, intensive care, uncooperative pts.
What are the best indicators for the exam? Pt complaints of choking on food; suspicion of aspiration/larynx penetration. Pt. Need for diet consistency up or downgrade. Pt complaints of oral stage preparation problems; suspicion of aspiration or larynx penetration; complaints of food sticking in throat.
What are the limitations of the exam? Some pts will not/cannot tolerate nose insertion with nasoendoscope. “White out” period at moment of swallow. May miss seeing aspiration/penetration. Does not address oral & esophageal stages. To reduce radiation exposure, fluoro is turned on & off with each swallow trial & prone to miss behaviors after the swallow.   Unable to view laryngeal surface anatomy, Barium is mixed with foods changing viscosity.
Bonus Secondary assessment of velopharyngeal closure and/or laryngeal/pharyngeal surfaces & functions, Bilateral cavity residue; therapy biofeedback Screening of esophagus to lower esophageal sphincter during swallow.

Works Cited:

Ashford, J.A. (2017). FEES: Instrumental Dysphagia Assessment Training Manual.   Nashville,  TN: Author

Langmore, S. (2001). Endoscopic Evaluation and Treatment of Swallowing Disorders. New York: Thieme.

Aviv, J.E., Kaplan, S.T., Thomson, J.E., Spitzer, J., Diamond. B., & Close, L.G. (2000). The safety of flexible endoscopic evaluation of swallowing with sensory testing   (feesst): An analysis of 500 consecutive evaluations. Dysphagia, 15, 39–44.

Kelly, A.M., Drinnan, M.J., & Leslie, P. (2007). Assessing penetration and aspiration: How do videofluoroscopy and fiberoptic endoscopy evaluation of swallowing compare? Laryngoscope, 117, 1723-1727.

Brady, S. & Donzelli, J. (2013).  The modified barium swallow and the functional endoscopic evaluation of swallowing. Otolaryngology Clinics of North America, 46, 1009-1022.

Pisegna, J.M. & Langmore, S.E. (2016). Parameters of instrumental swallowing evaluations: Describing a diagnostic dilemma.  Dysphagia, DOI 10.1007//s004455-016-9700-3, March, 17, 2016.