What is the role of a barium swallow in evaluating dysphagia?

Role of Barium Swallow in Evaluating Dysphagia

Fluoroscopy remains the imaging modality of choice to evaluate dysphagia, with the specific type of barium study selected based on whether the patient has oropharyngeal versus esophageal symptoms. 1

Oropharyngeal Dysphagia

For oropharyngeal dysphagia, order a combined study with both modified barium swallow AND complete esophageal imaging—this combination has higher diagnostic value than either study alone and is essential because distal esophageal or gastric cardia lesions can cause referred dysphagia to the pharynx. 2

Modified Barium Swallow (Videofluoroscopic Swallow Study)

• This is a video fluoroscopic procedure performed with a speech therapist that focuses on the oral cavity, pharynx, and cervical esophagus to assess the oral and pharyngeal phases of swallowing 1
• It evaluates bolus manipulation, tongue motion, hyoid and laryngeal elevation, pharyngeal constrictor motion, epiglottic tilt, laryngeal penetration, aspiration, and cricopharyngeus muscle function 1
• Patients are given varying consistencies of barium and barium-impregnated food to assess swallowing ability 1
• Modified barium swallow alone identifies a cause for dysphagia in 76% of patients, with 75% accuracy for structural findings but only 18% for physiologic findings 2

Critical Pitfall to Avoid

Do not rely on modified barium swallow alone for initial dysphagia evaluation—it does not evaluate the esophagus or gastric cardia, missing one-third of cases where esophageal pathology is the sole finding. 2 The combination of video fluoroscopy and static images of the pharynx with examination of the esophagus has higher diagnostic value, with 68% of patients with dysphagia complaints having abnormal esophageal transit 2

Superior Detection of Structural Pharyngeal Abnormalities

• Barium studies have superior sensitivity for detecting structural pharyngeal abnormalities like Zenker's diverticulum and pharyngeal tumors compared to endoscopy 2, 3
• This is particularly important because pharyngeal carcinomas carry a significantly increased risk of synchronous esophageal carcinomas, making complete esophageal examination mandatory once a pharyngeal tumor is identified 2

Retrosternal (Esophageal) Dysphagia

For retrosternal dysphagia, a biphasic esophagram is the preferable imaging procedure, detecting both structural and functional abnormalities with 96% sensitivity for diagnosing esophageal or gastroesophageal junction cancer. 1, 2

Biphasic Esophagram Components

• Double-contrast views best detect mucosal lesions such as tumors and esophagitis 1
• Prone single-contrast views with continuous drinking of low-density barium best detect lower esophageal rings or strictures 1
• Lower esophageal rings are two to three times more likely to be diagnosed on prone single-contrast views than on upright double-contrast views due to inadequate distention of the distal esophagus when upright 1

Diagnostic Performance

• Biphasic esophagram depicts about 95% of all lower esophageal rings, whereas endoscopy detected only 76% of these rings 1
• Sensitivity of about 95% for detection of peptic strictures, sometimes revealing strictures missed with endoscopy 1
• Videofluoroscopy has overall sensitivity of 80% to 89% and specificity of 79% to 91% for diagnosing esophageal motility disorders (achalasia, diffuse esophageal spasm) compared with esophageal manometry 1
• Occasionally reveals dysmotility not seen at manometry, such as patients with the beak-like distal esophageal narrowing of achalasia who have complete relaxation of the lower esophageal sphincter on manometry 1

When Endoscopy is Preferred Over Barium Studies

• Endoscopy is more sensitive than double-contrast esophagography for detecting mild reflux esophagitis or other subtle forms of esophagitis 1
• In immunocompromised patients with dysphagia or odynophagia, endoscopy is preferred because of the ability to obtain specimens for histology, cytology, immunostaining, or culture 1
• However, two large patient series showed endoscopy failed to reveal any cases of esophageal carcinoma that had been missed on barium studies, suggesting endoscopy is not routinely warranted to rule out missed tumors in patients who have normal findings on radiologic examinations 1

Special Clinical Scenarios

Aspiration Risk Assessment

Clinical examination alone is insufficient to rule out aspiration risk—55% of patients with aspiration have silent aspiration without protective cough reflex, necessitating objective swallowing assessment with videofluoroscopy. 2, 3

Post-Surgical Patients

• In the immediate postoperative scenario, a full-column, mucosal relief study using water-soluble contrast (diatrizoate meglumine and diatrizoate sodium solution or iohexol) rather than barium sulfate is preferred 1
• Bariatric surgery patients require modified protocols, with standard barium swallow tests being inappropriate due to altered anatomy, and single-contrast esophagram with water-soluble contrast being preferred 2

Progressive Dysphagia Pattern Recognition

• Progressive dysphagia that begins with solids only and later includes liquids indicates mechanical obstruction 4
• Dysphagia to both solids and liquids simultaneously from onset strongly suggests a motor/motility problem (achalasia, diffuse esophageal spasm) rather than mechanical obstruction 4
• Biphasic esophagram has 96% sensitivity for esophageal cancer and 80-89% sensitivity for motility disorders like achalasia 4