The Proof is the Pudding (Part 1)

We here at SDX know that an SLP can always better their craft through education which is why we asked Karen Sheffler, MS, CCC-SLP, BCS-S to share her expertise with us. 


Please enjoy the article “The Proof is in the Pudding: A Tribute to Steven Leder & His Contributions to FEES” which has been broken up into 3 sections.


Can you imaging not being able to safely and easily swallow a delicious chocolate pudding? How would that affect your quality of life?

June is National Dysphagia Awareness Month. Dysphagia Awareness means quickly identifying a person’s swallowing problem (dysphagia) before adverse events happen, as well as preserving that person’s quality of life.

What better way to commemorate Dysphagia Awareness Month than to honor the legacy of Steven Leder, PhD, CCC-SLP (Formerly of Yale University School of Medicine since 1991). He tirelessly promoted patient safety, by creating valid and reliable screening methods to identify a person’s risk of aspiration (Read More: Aspirations & Lessons from Steven Leder). Additionally, armed with the reliable and valid instrumental examination called the Fiberoptic Endoscopic Evaluation of Swallowing (FEES), he fought to prevent unnecessarily restrictive care, dispel “erroneous logic” (23), and remind clinicians what they can and cannot detect without instrumental evaluations. Read more from Steven Leder (2015, SIG13) on this topic with: Comparing Simultaneous Clinical Swallow Evaluations and Fiberoptic Endoscopic Evaluation of Swallowing: Findings and Consequences

Steven Leder and Joseph Murray, PhD, CCC-SLP, BCS-S (22) summarized this well:

“If the clinical (bedside) evaluation does not provide sufficient information to allow for confident patient management, an instrumental assessment should be performed (p788).”

They noted that the goal of the FEES is to evaluate the safety and efficiency of the swallow for improved nutrition and hydration and “for the maintenance and enhancement of quality of life.” Imagine being discharge from the hospital on a pureed diet with honey thickened liquids. Your first question would be: how long do I have to eat and drink this stuff? A FEES can be performed easily at your rehabilitation center or skilled nursing facility to guide your diet upgrades.

With FEES, clinicians and people with difficulty swallowing are “rewarded with an unequaled view of airway protective patterns,” and it is “a sensitive tool for detecting laryngeal penetration and aspiration,” per Leder and Murray (22, p791). When Leder wrote about a FEES exam in which he witnessed aspiration of pudding that triggered a cough reflex, which ejected a previously aspirated pill, he stated: (23, p 73)

“The proof, was literally, in the pudding.”

In 2008, Leder & Murray assured clinicians that after 20 years of research, FEES and Videofluoroscopic Swallow Studies (VFSS) have equivalent sensitivity and specificity. The VFSS is no longer considered the only gold-standard.

Goals of this article

This article will briefly explore the now 30-year history of FEES, with a special focus on Dr Leder’s work from 1997 to 2016 (references are listed chronologically to reflect history).

I will review Leder’s early contributions, research regarding the benefits of FEES, some of his work with specific populations, and finally other exam considerations (i.e., the use of dyes and the need for a residue rating scale).

This is not meant to be an exhaustive summary of FEES history, but it must start with Dr Langmore.

The Early Days of FEES: A New Procedure

In 1986, Susan Langmore, PhD, CCC-SLP, BCS-S, along with her colleagues in speech-language pathology and otolaryngology developed the Fiberoptic Endoscopic Examination of Swallowing Safety (FEESS) at the Department of Veterans Affairs Medical Center in Ann Arbor, Michigan. In 1988, they published the first article, describing this new procedure (1) and how they modified the standard otolaryngology assessment of the larynx to include the direct view of the pharyngeal stage of swallowing and aspiration. They marveled at how the clinician may see aspiration better before and after the swallow than with the VFSS, as one is not limited by the radiologist turning the camera on and off.

The team changed the procedure’s name to Fiberoptic Endoscopic Examination of Swallowing (FEES) with the 1991 publication. In this second publication (2), they studied 21 subjects, comparing FEES to videofluoroscopic (VFSS) results. However, these studies were not simultaneous, so some normal variation was to be expected when detecting penetration, aspiration, residue and premature spillage. FEES detected all patients with penetration and all but one case of aspiration and residue. Also in 1991, Langmore debated with Jeri A. Logemann in “After the Clinical Bedside Swallowing Examination: What Next?” (3). I love how Langmore practically described the game of Twister in positioning a patient for the videofluoroscopic swallow study. “We were all tired, in pain, and hot.” Additionally, she said the observed aspiration was “no more representative of his true swallowing status than if we had asked him to swallow upside down” (3, p16). Even with special swallow study chairs, Langmore noted that positioning still “requires considerable effort on the part of hospital staff” (3, p20). In response to the white-out period during the actual swallow, she stated that with training and experience, the clinician “can learn how to interpret the swallow… quite satisfactorily” (3, p17). Aspiration is predicted accurately as patients leave behind evidence in the larynx and trachea (1).

The American Speech-Language Hearing Association (ASHA) endorsed the procedure and created guidelines in May of 1991. (Here is a link to the Latest ASHA Positioning Statement)

Leder’s Early Contributions to FEES:

In the mid 1990’s, Steven Leder collaborated with Clarence Sasaki, MD, Otolaryngologist to stress the importance of early identification of silent aspiration. They first presented on endoscopic evaluation at the 1996 Dysphagia Research Society Meeting (5). Did you know that they initially called the examination “FEED” for Fiberoptic Endoscopic Evaluation of Dysphagia (5)? However, by the time of their 1997-1998 publications, Leder and colleagues returned to the term FEES (6,7,8).

In 1998, Leder, Sasaki & Burrell were the first to use a large sample size, reporting on a heterogeneous population of 400 subjects (age 10 to 101). They showed that FEES was a reliable and patient-friendly method to identify silent aspiration (8). They cautioned that up to 30% of patients referred for clinical bedside evaluations of swallowing at the acute phase may be silent aspirators. Agreement between FEES and VFSS (aka, MBS or Modified Barium Swallow studies) reached 96%. Again, the studies were not simultaneous (i.e., a subject did not aspirate during a VFSS but did so silently on the FEES).

Leder, et al (1997) noted in a prospective, double-blind, randomized study that there was no significant difference in comfort levels when the nares was treated with topical anesthetics or vasoconstrictors versus a placebo or nothing at all (6). By demonstrating this, Leder proved that trained and experienced speech-language pathologists could perform FEES independently. That was a huge contribution to clinicians in the field of dysphagia.

Side Note: Recently, research has indicated that small amounts of topical nasal anesthetics do not affect swallowing. Specifically, 2% gel lidocaine applied to one nares with a cotton-tip applicator did not alter sensation in the pharynx or larynx and did not change swallowing physiology, delay the swallow response, or increase penetration or aspiration (25). O’Dea and colleagues determined that a dose of 0.2 ml of 4% lidocaine to the nares was appropriate and did not increase penetration, aspiration or residue, even in patients with dysphagia (26).

In the early 1990’s Jonathan Aviv, MD, F.A.C.S and colleagues from Columbia University added an air pulse method of testing of sensation, creating the Flexible Endoscopic Evaluation of Swallowing with Sensory Testing (FEESST). In 2000, Aviv and team studied patient safety and tolerance without topical anesthesia in 500 consecutive examinations (11). More than 99% of the FEESST evaluations were successfully completed, and 81% of the patients rated their discomfort as none to mild. Only two patients with amyotrophic lateral sclerosis (ALS) were unable to tolerate the passage of the scope (11). However, Leder, et al (2004) studied 17 consecutive patients with ALS and only one additional patient had refused testing (16). Five out of the 17 patients even had multiple FEES as their disease progressed. He showed that FEES was “ideally suited for this particular patient population (p180)” due to the following:
      • ability to visualize pooled secretions that are predictive of aspiration on food and liquid,
      • avoidance of irradiation in order to perform a longer assessment to determine if fatigue is an issue, and
      • ability to repeat the study as often as is needed.

Langmore and Leder, among others, have written extensively about the many benefits of FEES. Langmore mentioned in 1988 that FEES is indicated for people who are in nursing facilities, but little did she know then how mobile and portable the equipment would become.

Let’s take a more detailed look at why you would evaluate with FEES.


As stated by Langmore in 1988, FEES is not meant to replace videofluoroscopic studies, but speech-language pathologists and healthcare providers need to know when to select FEES as the method of choice (1). Both tests help explain the nature of the dysphagia (3). As instructed by Leder and Murray in 2008, the skilled endoscopist makes appropriate referrals for further testing. For example, the VFSS better visualizes the oral and esophageal phases of the swallow, as well as the submucosal elements (22). The decision of which test to choose is based on your specific patient’s needs and your clinical questions (Read more: Good Dysphagia Evaluation Guides Treatment).

It is often pointed out that FEES avoids the need for schedule coordination with the radiology department and eliminates radiation exposure (1), but there are many more reasons to perform a FEES.

FEES Benefits: Why and When FEES is Needed

Transport to the radiology suite, mobile swallow study van, or hospital for the VFSS may be impossible due to:
      ◦Fatigue, anxiety and agitation with transport may hinder swallowing performance (3)
      ◦Positioning issues: essentially bedridden, kyphotic, severe arthritis, bariatric, too weak/paralyzed, quadriplegic, contracted, pressure sores/ulcers causing pain, or when the shoulder blocks the hypopharynx and upper esophagus (1,2,3,22)
      ◦ Many tubes and lines tethered to the patient (e.g., on a ventilator) (1,2,3,22)
      ◦ Critically ill and cannot leave the intensive care unit (1,2,9,22)
      ◦ Poor respiratory status: patient cannot tolerate aspirating even a trace of barium      in foods and liquids. A FEES can evaluate secretion management, ability to phonate and cough, and protect the airway. You can carefully assess only ice chips (1,2,4,22). Patients with pooled secretions, especially in the laryngeal vestibule, have an increased likelihood for aspiration of food and/or liquid (4).
      ◦ Minimally alert: again, the clinician can assess if the patient is pooling and aspirating secretions (1).
• Answer the question: “Can my patient swallow with safety,” in an immediate or at least timely fashion, especially when discharge is eminent (1,3).
• Identify aspiration and dysphagia early to reduce pulmonary complications. If the FEES does find that a patient can swallow safely, then oral feeding will not be delayed, which reduces length of stay and lowers medical costs (9).
• Examine at bedside, especially important for critically ill trauma patients (9).
• Test without the need for specific directions for patients with significantly reduced mental status (1). Pt is allowed to swallow spontaneously without any commands to swallow, which can alter function and timing (32).
• View actual structures and pharyngeal and laryngeal anatomy (1,2,3,31).
• Assess for velopharyngeal incompetence, nasal regurgitation and identify the source of perceived hypernasality (22).
• Assess pharyngeal and laryngeal sensation for airway protection. Note the patient’s reaction to the scope and the movement of the structures in reaction to the bolus (1,2).
Localize secretions, bolus position and residue with great precision (1,2,3,4).
• Assess vocal fold movement (1,2,3,18,24). Vocal fold immobility can be noted by the SLP. “Natural airway protection becomes a real entity.” (3, page 17)
• Assess vocal cord adduction and anterior arytenoid tilt prior to the swallow. This can be an anticipatory protective mechanism in response to large bolus sizes (3).
• Monitor time period before and after the swallow closely. Whereas, during the VFSS, you only see a few swallows, and the camera may be turned off too quickly or not back on fast enough (1).
Serial retesting may be necessary to document progress or decline in function (7,8,22).
• Provide real-time visual feedback during swallowing therapy (22).
• Digitally record the videoendoscopy for careful frame-by-frame review (8). You can also educate your patient, family and medical team, showing them the video after the study.
• Test many therapeutic interventions without a time limit. Whereas, during a VFSS, the study must be fairly short to limit radiation exposure. Testing many strategies in a longer study is especially helpful when the patient’s intake and quality of life depend on a diet upgrade (22).
• Use regular food and not barium-laced foods and liquids. Barium paste may add too much moisture to foods when you may want to assess crumbly textures. Barium can be constipating. Additionally, barium may affect the viscosity, familiarity, flavor, and palatability (8).
• Assess at a meal in a functional, real-life situation (poor positioning and all). You can see not only if fatigue increases as the meal progresses, but also if positioning, rate of intake, and method of feeding will impact safety (22).

Contraindications to FEES:

• Immediate post-op and recovering from general anesthesia (11)
• Acute facial fractures (22)
• Recent refractory epistaxis (nose bleeds) (22)
• Bilateral obstruction of nasal passages (22)
• Severe agitation or inability to cooperate (1, 22)

Stay Tuned for Parts 2 and 3.

More About Karen:

Karen Sheffler, MS, CCC-SLP, BCS-S graduated from the University of Wisconsin-Madison in 1995 with her Master’s degree. There, she was under the influence of the great mentors in the field of dysphagia like Dr John (Jay) Rosenbek, Dr JoAnne Robbins, and Dr James L. Coyle. Once the “dysphagia bug” bit, she has never looked back. 

Karen is a medical speech-language pathologist. She worked in skilled nursing facilities and rehabilitation centers in the 1990’s, and has been in acute care in the Boston area since 1999. She trained graduate student clinicians during their acute care internships for over 10 years. Special interests are too numerous to list, but they include neurological conditions, geriatrics, end-of-life considerations, oral hygiene and aspiration pneumonia and patient safety/risk management. She has lectured on dysphagia in webinars, at hospitals, at the MGH Institute of Health Professions, at Tufts University Dental School, and on Lateral Medullary Syndrome at the 2011 ASHA convention. She is a member of the Dysphagia Research Society (DRS), the National Foundation of Swallowing Disorders (NFOSD), and the Special Interest Group 13: Swallowing and Swallowing Disorders. 

Karen obtained her BCS-S (Board Certified Specialist in Swallowing and Swallowing Disorders) in August of 2012. Karen embraced the world of social media in 2014 when she founded a Dysphagia Resource for Professionals and Patients. She was the official dysphagia blogger for the ASHA convention in 2014 and was the official blogger for the Dysphagia Research Society’s annual meetings in 2015 and 2016. You can follow her on Twitter at and on Facebook at, as well as on Pinterest at https://


FEES References (listed chronologically):

  1. Langmore, S.E., Schatz, K. & Olsen, N. (1988). Fiberoptic endoscopic examination of swallowing safety: A new procedure. Dysphagia, 2, 216-219.
  2. Langmore, S.E., Schatz, K. & Olson, N. (1991). Endoscopic anad videofluoroscopic evaluations of swallowing and aspiration. Annals of Otology, Rhinology & Laryngology, 100 (8), 678-681. 
  3. Langmore, S.E. & Logemann, J.A. (1991). After the clinical bedside swallowing examination: What next? AJSLP, September, 13-20.
  4. Murray, J, Langmore, S.E., Ginsberg, S. & Dostie, A.(1996). The significance of oropharyngeal secretions and swallowing frequency in predicting aspiration. Dysphagia, 11, 99-103. 
  5. Leder, S.B. & Sasaki, C.T. (1997). Identifying silent aspiration with a fiberoptic endoscopic evaluation of dysphagia (FEED). Dysphagia, 12, 117.
  6. Leder, S.B., Ross, D.A., Briskin, K.B. & Sasaki, C.T. (1997). A prospective, double-blind, randomized study on the use of a topical anesthetic, vasoconstrictor, and placebo during transnasal flexible fiberoptic endoscopy. JSLHR, 40, 1352-1357. 
  7. Leder, S.B. (1998). Serial fiberoptic endoscopic swallowing evaluations in the management of patients with dysphagia. Arch Phys Med Rehabil, 79, 1264-1269.
  8. Leder, S.B., Sasaki, C.T. & Burrell, M.I. (1998). Fiberoptic endoscopic evaluation of dysphagia to identify silent aspiration. Dysphagia, 13, 19-21. 
  9. Leder, S.B., Cohn, S.M. & Moller, B.A. (1998). Fiberoptic endoscopic documentation of the high incidence of aspiration following extubation in critically ill trauma patients. Dysphagia, 13, 208-212. 
  10. Leder, S. (1999). Fiberoptic endoscopic evaluation of swallowing in patients with acute traumatic brain injury. Journal of Head Trauma Rehabilitation, 14 (5), 448-453. 
  11. 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. 
  12. Leder, S.B., & Karas, D. (2000). Fiberoptic endoscopic evaluation of swallowing in the pediatric population. The Laryngoscope, 110, 1132-1136. 
  13. Leder, S.B. & Sasaki, C.T. (2001). Use of FEES to assess and manage patients with head and neck cancer. In Langmore, S.E., editor. Endoscopic evaluation and treatment of swallowing disorders. New York: Thieme; 201-212. 
  14. Leder, S.B. & Espinosa, J.F. (2002). Aspiration risk after acute stroke: Comparison of clinical examination and fiberoptic endoscopic evaluation of swallowing. Dysphagia, 17, 214-218.
  15. Leder, S.B. (2002). Incidence and type of aspiration in acute care patients requiring mechanical ventilation via a new tracheostomy. Chest, 122, 1721. 
  16. Leder, S.B. Novella, S. & Patwa, H. (2004). Use of Fiberoptic Endoscopic Evaluation of Swallowing (FEES) in patients with Amyotrophic Lateral Sclerosis. Dysphagia, 19, 177-181. 
  17. Leder, S.B., Acton, L.M., Lisitano, H.L., Murray, J.T. (2005). Fiberoptic endoscopic evaluation of swallowing (FEES) with and without blue-dyed food. Dysphagia, 20, 157-162. 
  18. Leder, S.B. & Ross, D.A. (2005). Incidence of vocal fold immobility in patients with dysphagia. Dysphagia, 20, 163-167.
  19. Kelly, A.M., Leslie, P., Beale, T, et al. (2006). Assessing endoscopic evaluation of swallowing and videofluoroscopy: Does examination type influence perception of pharyngeal severity? Clinical Otolaryngol, 31, 425-432.
  20. Kelly, A.M., Drinnan, M.J. & Leslie, P. (2007). Assessing penetration and aspiration: How do videofluoroscopy and fiberoptic endoscopic evaluation of swallowing compare? Laryngoscope, 117, 1723-1727.
  21. Leder, S.B., Sasaki, C.T. & Bayar, S. et al. (2007). Fiberoptic endoscopic evaluation of swallowing in the evaluation of aspiration following transhiatal esophagectomy. J Am Coll Surg, 205, 581-585. 
  22. Leder, S.B. & Murray, J.T. (2008). Fiberoptic endoscopic evaluation of swallowing. Phys Med Rehabil Clin N Am, 19, 787-801. 
  23. Leder, S.B. (2012). Nil per os except medications order in the dysphagic patient. QJM: An International Journal of Medicine, 106 (1), 71-75.
  24. Leder, S.B., Suiter, D.M., Duffey, D. & Judson, B.L. (2012). Vocal fold immobility and aspiration status: A direct replication study. Dysphagia, 27, 265-270. 
  25. Kamarunas, E.E., McCullough, G.H., Guidry, T.J., Mennemeier, M. & Schluteman, K. (2014). Effects of topical nasal anesthetic on Fiberoptic Endoscopic Examination of Swallowing with Sensory Testing (FEESST). Dysphagia, 29(1), 33-43. 
  26. O’Dea, M.B., Langmore, S.E., Krisciunas, G.P., Walsh, M. Zanchetti, L.L., Scheel, R., et al (2015). Effect of lidocaine on swallowing during FEES in patients with dysphagia. Ann Otol Rhinol Lanryngol, 124(7), 537-44. doi: 10.1177/0003489415570935
  27. Neubauer, P.D., Rademaker, A.W. & Leder, S.B. (2015). The Yale Pharyngeal Residue Severity Rating Scale: An anatomically defined and image-based tool. Dysphagia, 30, 521-528. 
  28. Leder, S.B., Siner, J.M., Bizzarro, M.J., McGinley, B.M. & Lefton-Greif, M.A. (2016). Oral alimentation in neonatal and adult populations requiring high-flow oxygen via nasal cannula. Dysphagia, 31, 154-159. 
  29. Marvin, S., Gustafson, S. & Thibeault, S. (2016). Detecting aspiration and penetration using FEES with and wtihout food dye. Dysphagia, Published online: 18 March 2016. DOI 10.1007/s00455-016-9703-0 
  30. Neubauer, P.D., Hersey, D.P. & Leder, S.B. (2016). Pharyngeal residue severity rating scales based on Fiberoptic Endoscopic Evaluation of Swallowing: A systematic review. Dysphagia, 31, 352-359.
  31. Pisegna, J.M. & Langmore, S.E. (2016). Parameters of instrumental swallowing evaluations: Describing a diagnostic dilemma. Dysphagia, 31, 462-272.           

  32. Daniels S.K., Schroeder M.F., DeGeorge P.C., Corey D.M. & Rosenbek J.C. (2007). Effects of verbal cue on bolus flow during swallowing. J Am Speech Lang Pathol, 16, 140–16.Daniels S.K., Schroeder M.F., DeGeorge P.C., Corey D.M. & Rosenbek J.C. (2007). Effects of verbal cue on bolus flow during swallowing. J Am Speech Lang Pathol, 16, 140–16. 
  33. Gross, R. D., Atwood, C. W.Jr., Ross, S. B., Olszewski, J. W., & Eichhorn, K. A. (2009). The coordination of breathing and swallowing in chronic obstructive pulmonary disease. Am J Respir Crit Care Med, 179(7), 559–565. doi: 10.1164/rccm.200807-1139OC
  34. Gross, R.D. (2014). Lung volumes and their significance for pharyngeal and esophageal swallowing function. SIG 13 Perspectives on Swallowing and Swallowing Disorders (Dysphagia), 23, 91-99. doi:10.1044/sasd23.3.91
  35. Martin-Harris, et al. (2014). Respiratory-swallow training in patients with head and neck cancer. Arch Phys Med Rehabil, 96, 885-893.

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