How to identify a tracheoesophageal fistula (TEF) in a patient with recurrent pyriform sinus cancer experiencing worsening chest fullness with swallowing?

Identifying Tracheoesophageal Fistula (TEF)

Combined flexible bronchoscopy with simultaneous upper endoscopy is the gold standard for diagnosing TEF, achieving identification rates exceeding 90%, and should be performed urgently in this patient with recurrent pyriform sinus cancer and swallowing-related chest symptoms. 1

Initial Diagnostic Approach

Begin with contrast-enhanced CT with CT esophagography if the patient is hemodynamically stable, as this provides high sensitivity (95%) and specificity (91%) for detecting upper digestive tract perforations and shows indirect signs of TEF including paraesophageal collections, free air, and pleural effusions. 1

• CT esophagogram offers superior diagnostic accuracy compared to traditional contrast studies, which miss up to 30% of small esophageal perforations. 1
• In this cancer patient, CT also evaluates for associated complications such as mediastinal involvement, abscess formation, and tumor extent. 1

Definitive Diagnostic Procedure

Proceed directly to combined flexible bronchoscopy and esophageal endoscopy for direct visualization and confirmation of the fistula. 1

Key Technical Considerations During Endoscopy:

• Use positive pressure insufflation, dye or contrast injection, and gentle probing during bronchoscopy to identify the fistula opening, particularly for small fistulae that may be obscured by airway secretions. 1
• Employ CO2 insufflation with capnography monitoring during esophagoscopy—a spike in end-tidal CO2 ≥68 mmHg (typically ≥90 mmHg for recurrent TEF) indicates gas passage from esophagus to trachea through the fistula. 2
• Perform simultaneous bronchoscopy and endoscopy rather than sequential procedures, as this allows real-time correlation and achieves the highest diagnostic accuracy. 1
• Use low-flow insufflation and CO2 rather than air to minimize mediastinal contamination risk through the perforation. 1

Alternative Technique for Small Fistulae:

Upper gastrointestinal 'pull-back' study is particularly effective for diagnosing small TEFs—this involves injecting contrast under pressure using catheters in the esophagus, forcing contrast through small fistulae that standard swallow studies miss. 1

Critical Pitfalls to Avoid

• Never rely on nasogastric tube-administered contrast alone, as this technique frequently misses esophageal perforations and fistulae. 1
• Do not exclude TEF based on a single negative imaging study—if clinical suspicion remains high (as in this case with worsening chest fullness with swallowing), persistent respiratory symptoms warrant escalation to bronchoscopy regardless of initial imaging results. 1, 3
• Avoid excessive insufflation during endoscopy, as this may promote mediastinal contamination by enlarging the perforation. 1
• Recognize that the site of fistula in the posterior tracheal wall may be obscured by secretions—meticulous suctioning and multiple viewing angles are essential. 1

Diagnostic Algorithm for This Patient

1. Obtain contrast-enhanced CT with CT esophagography to assess fistula presence, location, and associated complications. 1
2. Schedule combined flexible bronchoscopy and upper endoscopy with CO2 insufflation and capnography monitoring. 1, 2
3. During bronchoscopy: Use positive pressure insufflation, dye injection, and gentle probing to identify the fistula opening. 1
4. During esophagoscopy: Monitor for etCO2 spike ≥68-90 mmHg indicating fistula communication. 2
5. If initial combined endoscopy is negative but suspicion remains high: Perform pull-back contrast study under fluoroscopy or repeat combined endoscopy with enhanced techniques. 1

Additional Investigations for Comprehensive Assessment

In patients with confirmed or suspected TEF, also investigate for:

• Aspiration risk factors: Perform objective swallow assessment and pH-impedance testing to evaluate for GERD and esophageal dysfunction. 4
• Tracheomalacia: Assess during bronchoscopy, as this commonly coexists and affects management. 4
• Pulmonary complications: Obtain chest X-ray and consider CT scan if chronic cough, worsening pulmonary function, or persistent radiographic changes suggest ongoing aspiration or bronchiectasis. 4

The combination of intra-esophagoscopy fluoroscopy with bronchoscopy and capnography ≥68 mmHg achieves the highest diagnostic sensitivity (88.1%) for TEF identification. 2