How is a diagnostic nasal endoscopy performed and in which patients is it indicated?

Diagnostic Nasal Endoscopy

Diagnostic nasal endoscopy should be performed as part of the routine examination for any patient with chronic rhinosinusitis, suspected nasal polyps, or unexplained nasal/sinus symptoms, using either rigid (4.0-mm 0° and 30° telescopes) or flexible endoscopes after topical decongestion and anesthesia. 1, 2

Indications for Nasal Endoscopy

Primary Indications

• Chronic rhinosinusitis (CRS): Endoscopy is essential for assessing and localizing sinus pathology with far greater precision than routine anterior rhinoscopy 1
• Suspected nasal polyps: Small polyps in the middle meatus or posterior nasal cavity may only be detected by endoscopy, not by anterior rhinoscopy alone 2
• Unexplained nasal/sinus symptoms: Studies show that 38.7% of patients with normal anterior and posterior rhinoscopy had pathology detected on endoscopy 3
• Post-surgical rhinosinusitis patients: For evaluating surgical outcomes and managing relapses 1

Additional Indications

• Suspected sinonasal neoplasms (with biopsy capability) 4
• Unilateral nasal masses requiring differentiation from carcinoma, inverting papilloma, or antrochoanal polyps 2
• Evaluation of obstructed sinus ostia, middle meatus pathology, and ostiomeatal complex 5

How to Perform the Procedure

Equipment Selection

Rigid endoscopes (most common):

• 4.0-mm telescopes with 0° and 30° angles
• 2.7-mm telescopes with 30° and 70° angles 6

Flexible endoscopes offer advantages for:

• Sphenoethmoidal recess examination
• Anterior maxillary sinus wall (post-surgical patients)
• Sphenoid sinus visualization 1

Technique

1. Preparation: Apply topical vasoconstrictor (e.g., oxymetazoline) and anesthetic to improve visualization and patient comfort 2

2. Systematic examination:

   • Pass endoscope along the floor of the nasal cavity
   • Examine middle meatus and ostiomeatal complex by elevating the middle turbinate
   • Pass medial to middle turbinate to inspect sphenoid recess and nasopharynx 5
   • Evaluate for polyps, mucosal inflammation, anatomic abnormalities, and ostial patency

3. Documentation: Endoscopy provides excellent photodocumentation and teaching opportunities 6

Safety Profile

Nasal endoscopy is remarkably safe with minimal complications 1:

• Most common adverse event: vasovagal reactions
• Minimal bleeding risk when biopsies are not performed
• No risk of complications if you avoid forcibly entering small ostia or areas with sharp bony fragments

Important caveat: Office-based biopsy for suspected neoplasms has limitations with 71% sensitivity and 24% false-negative rate, though it remains safe and diagnostically valuable 4

Clinical Impact

Endoscopy improves diagnostic accuracy and reduces unnecessary medication use (particularly antibiotics) 1. It identifies pathology missed by traditional examination in nearly 40% of symptomatic patients with normal anterior rhinoscopy 3. If you suspect nasal polyps or CRS but cannot perform endoscopy, refer the patient to a clinician who can thoroughly examine the entire nasal cavity 2.

Who Should Perform This

All specialists treating nasal and sinus disease should be able to perform complete endoscopic evaluation 1. Allergists are particularly well-positioned to incorporate this into routine care, as it is considered part of normal procedures and is typically covered by malpractice insurance 1.