What is Fiberoptic Endoscopic Evaluation of Swallowing (FEES)?

What is FEES (Fiberoptic Endoscopic Evaluation of Swallowing)?

FEES is a bedside or clinic-based instrumental swallowing assessment that involves transnasal passage of a flexible nasopharyngoscope to directly visualize the pharynx and larynx before and after swallowing, providing real-time anatomical and functional information to detect aspiration and guide dysphagia treatment. 1

Core Procedure Description

• FEES involves passing a fiberoptic laryngoscope transnasally to visualize the hypopharynx, larynx, and proximal trachea during swallowing assessment. 2
• The procedure is highly portable and can be performed at the bedside or in clinic areas, making it practical for assessing swallowing disorders across various patient populations and settings. 1
• Unlike videofluoroscopic swallow evaluation (VSE), FEES does not involve radiation exposure, making it a safer option for repeated assessments. 1

What FEES Visualizes and Detects

• FEES provides comprehensive assessment of laryngeal morphology and motility, velo-pharyngeal closure competence, and functional deficits such as impaired chewing and tongue muscle weakness that directly impact aspiration risk. 1
• The procedure enables detection of critical safety indicators including pharyngeal residues and secretion pooling, allowing for timely intervention to prevent aspiration. 1
• FEES is particularly valuable for detecting silent aspiration, which occurs in up to 55% of patients who aspirate and would otherwise go undetected on clinical bedside evaluation alone. 1, 3

Clinical Utility and Guideline Recommendations

• The American College of Chest Physicians recommends that patients with dysphagia should undergo either VSE or FEES to identify appropriate treatment (Grade B recommendation), as bedside clinical evaluations alone are insufficient to determine treatment interventions. 1, 4
• FEES allows the examiner to determine the safest and least restrictive level of oral intake, implement appropriate compensatory techniques, and identify a dysphagia rehabilitation plan. 2
• The American Geriatrics Society recommends instrumental assessment including FEES when signs of dysphagia are present at clinical evaluation, silent aspiration is suspected, or the clinical scenario is unclear. 1, 4

Key Advantages Over Clinical Bedside Evaluation

• FEES provides direct visualization of anatomy and physiology during deglutition, unlike clinical swallow evaluations which rely on subjective judgments, allowing for more accurate assessment of swallowing function and aspiration risk. 1
• Visual biofeedback provided by FEES is successful for both patient and family education and allows investigation of individualized therapeutic strategies that can be implemented immediately if successful. 5
• Serial FEES examinations allow for objective monitoring of dysphagia progression and timely implementation of diet changes or therapeutic strategies to maintain safer oral intake. 5

Important Limitations and Contraindications

• FEES cannot visualize the actual moment of swallowing due to "white-out" when the pharynx contracts, unlike videofluoroscopy which captures the entire swallow sequence. 1
• The procedure requires adequate patient cooperation and cannot be performed on patients with lethargy, absent swallow response on command, inability to manage oral pharyngeal secretions requiring frequent suctioning, or respiratory rate greater than 35 breaths per minute. 6, 1
• Patients with reduced level of consciousness are at high risk for aspiration and should not undergo FEES until consciousness improves. 6

Safety Profile

• FEES is a safe and well-tolerated procedure, with complications reported in only 2% of examinations in a large multicenter registry of 2,401 patients. 7
• All reported complications were self-limited and resolved without sequelae, with no correlation to the endoscopist's previous experience. 7
• In the multicenter FEES-registry study, the procedure was well tolerated even when performed by less experienced clinicians. 7

Clinical Impact on Patient Management

• In more than 50% of FEES investigations, the procedure led to changes in feeding strategies, with the majority of cases allowing an upgrade of oral diet. 7
• FEES significantly impacts patients' clinical course and implementation of FEES services in different clinical settings may improve dysphagia care. 7
• The procedure is performed optimally through teamwork involving a speech-language pathologist and otolaryngologist collaborating together to manage individuals with dysphagia safely and efficiently. 2