The Modified Barium Swallow Study (MBSS), also referred to as Videofluoroscopy Swallow Study (VFSS) and Fiberoptic/Flexible Endoscopic Evaluation of Swallowing (FEES), are the most thorough examinations for assessing dysphagia. Now, let's analyze the advantages and disadvantages of each test.
MBSS is a radiographic technique that offers a direct visualization of the mouth, throat, and upper esophageal function. During this procedure, patients ingest barium-infused food and liquids, enabling real-time monitoring of the swallowing process as the x-ray captures the images.
Advantages and recommended uses
· Anatomy is viewed from the side
· Front/back view (Anterior-Posterior) may be available, subject to facility approval
· Allows visualization of the oral, pharyngeal, and esophageal aspects of swallowing
Limitations and contraindications for using this method include:
· Exposure to radiation, limited time under x-ray
· Focuses on the motor aspect of swallowing (sensory responses are not well observed)
· Requires access to a radiology suite, and some facilities mandate the presence of a radiologist
· Requires positioning in an upright position, often sitting
· Limited shoulder clearance (typically less than 26” wide)
· Risk of allergic reactions to barium contrast
· Possible aversion to consuming barium contrast due to its taste
· Barium contrast may alter the consistency of liquids/foods to some extent
FEES starts by inserting a flexible endoscope from the bottom of the nose to the soft palate.
Once the scope is positioned, the patient consumes liquids and food of different colors and textures, such as green, white, and blue, in varying amounts. The swallowing process is observed live and recorded for later analysis and biofeedback purposes.
Advantages and Recommended Usage
· Completed by a speech-language pathologist, typically with assistance from staff
· Offers a clear view of pharyngeal and laryngeal anatomy
· Provides continuous monitoring of anatomy throughout the study without interruptions in video recording
· Serves as a real-time biofeedback tool for patients to modify their swallowing behaviors instantly
· Sensitivity to detecting fatigue
· Capable of evaluating secretions and salivary problems
· Suitable for patients who are pregnant, immobile, have postural challenges, or cannot undergo X-ray examinations due to radiation concerns, contrast issues, or size considerations
· Feasible for patients on mechanical ventilation
Restrictions and limitations on usage
· Restricted visibility during the peak of swallowing (white-out phase)
· Patients might experience mild discomfort and may find the exam's invasiveness intolerable
· Challenging for patients with movement disorders or a high risk of bleeding
· Not feasible for individuals with a history of nasal cavity or surrounding tissue trauma to undergo the procedure
X-Rays vs Endoscopes
Criteria | Modified Barium Swallow Study (MBS) | Fiberoptic Endoscopic Evaluation of Swallowing (FEES) |
Primary Use | Visualize swallowing mechanics and assess aspiration risk | Assess swallow function and evaluate anatomy without radiation |
Indications | - Unknown medical etiology - Anatomical visualization (e.g., cervical osteophytes) - Assess oral stage/base-of-tongue movement - UES stricture/hypertonicity? - Movement examination during swallow | - Fluoroscopy unavailable - Risky transportation (medically fragile) - Family input desired - Positioning issues (contractures, quad, etc.) |
Anatomical Visualization | Yes, including submucosal structures | Yes, visualizes surface anatomy and mucosal abnormalities |
Functional Assessment | Yes, assesses swallow mechanics | Yes, assesses laryngeal movement and velopharyngeal competence |
Radiation Exposure | Yes, involves radiation | No radiation exposure |
Therapeutic Evaluation | Limited, mainly diagnostic | Extended therapeutic evaluation possible, including biofeedback |
Patient Population | Suitable for a wide range of patients | Particularly useful for high-risk patients or those unable to travel |
Secretions Management | Not specifically evaluated | Can assess and manage secretions |
Pros | - Comprehensive view of swallowing - Excellent for detecting aspiration | - No radiation - Immediate feedback - Can be performed at bedside |
Cons | - Involves radiation - May not assess all swallowing phases | - Limited visualization of the oral phase - Possible discomfort for patients |
Adapted from: Langmore, S.E. (2006). Endoscopic evaluation and pharyngeal phases of swallowing. GI Motility Online. https://www.nature.com/gimo/contents/pt1/fig_tab/gimo28_T1.html
When to choose MBSS vs FEES?
Adapted from: Langmore, S.E. (2006). Endoscopic evaluation and pharyngeal phases of swallowing. GI Motility Online. https://www.nature.com/gimo/contents/pt1/fig_tab/gimo28_T1.html
Scenario | Choose MBSS | Choose FEES |
Vague Symptoms (Comprehensive View) | Yes | Depends* |
Globus Sensation | Yes & esophagram | Yes & esophagram |
Esophageal Concerns | Yes & A-P View | Depends* & esophagram |
Oral Phase Only | Yes | No |
Visualize Submucosal Anatomy (i.e., Cervical Osteophytes) | Yes | No |
UES Stricture / Hypertonicity | Yes | No |
Difficult to Transport | No - consider C-Arm | Yes |
Secretion Management | No | Yes |
Examine Surface Anatomy | No | Yes |
Dysphagia & Dysphonia | Yes | Yes |
History or Suspected Vocal Fold Paresis/Paralysis | No | Yes |
Extended Exam Time Needed | No | Yes |
Biofeedback Beneficial | No | Yes |
Post-Intubation | With C-Arm | Yes |
Tracheotomy | Possibly | Yes |
Wet Vocal Quality | Yes - FEES is preferred | Yes |
Laryngectomy Complications | Yes | No - cannot visualize aspiration events |
Tracheoesophageal Fistula (TE) | Yes | No - cannot visualize aspiration events |
*If access to MBSS is limited, FEES can be a great option to rule out aspiration or other diagnosis as etiology of symptoms
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