How should chronic rhinosinusitis with ostiomeatal unit (OMU) and spheno‑ethmoidal recess (SER) inflammation be evaluated and managed?

Evaluation and Management of Chronic Rhinosinusitis with OMU and SER Inflammation

Initial Diagnostic Evaluation

Nasal endoscopy is essential to directly visualize inflammation in the ostiomeatal unit (OMU) and sphenoethmoidal recess (SER), as these areas may appear inflamed when other regions appear normal. 1

Key Endoscopic Findings to Document

• Middle meatus examination: Look for purulent drainage, mucosal edema, and polyps in the uncinate process and hiatus semilunaris region, which are highly predictive of bacterial sinusitis when present 1
• Sphenoethmoidal recess assessment: Visualize the superior turbinate and sphenoid ostium, observing for pus streaming from posterior ethmoid or sphenoid ostia 1
• Mucosal appearance: Document color, consistency of secretions (yellow-green, green, or gray indicates chronic inflammation), and degree of obstruction 1

Imaging Strategy

High-resolution CT with coronal views is the imaging modality of choice for evaluating OMU and SER disease, as it demonstrates the extent of ostiomeatal complex obstruction and anatomic variants not visible on endoscopy. 1

• CT is mandatory before considering surgical intervention, particularly for ethmoid and ostiomeatal complex involvement 1
• Standard radiographs are inadequate for ethmoid disease evaluation (only 20% sensitivity) and should not be used 1
• Coronal scans best demonstrate ostiomeatal drainage areas and relationships between critical structures 1

Medical Management Algorithm

First-Line Therapy (Minimum 8-12 Weeks)

Initiate aggressive medical therapy combining intranasal corticosteroids, nasal saline irrigations, and systemic corticosteroids for bilateral OMU occlusion before considering surgery. 2, 3

1. Intranasal corticosteroids: Mometasone furoate, fluticasone propionate, or beclometasone dipropionate as primary anti-inflammatory agents 3
2. Nasal saline irrigations: Isotonic saline solutions to optimize mucociliary clearance 2, 3
3. Oral corticosteroids: Prednisolone for severe bilateral soft tissue occlusion 2
4. Antibiotics: Only if significant purulent discharge is present on examination (amoxicillin/clavulanic acid, ciprofloxacin, clarithromycin, or trimethoprim/sulfamethoxazole) 4, 3

Additional Evaluation During Medical Management

• Allergy testing: Assess IgE sensitization to inhalant allergens, as allergic inflammation contributes to ostiomeatal obstruction 2
• Immunodeficiency screening: Measure quantitative immunoglobulins (IgG, IgA, IgM) in patients with recurrent disease 2
• Environmental factors: Address smoking, which significantly worsens outcomes 2

Surgical Indications

Proceed to functional endoscopic sinus surgery (FESS) when symptoms persist ≥8-12 weeks despite maximal medical therapy, with CT confirmation of persistent OMU obstruction and mucosal disease. 2

Specific Criteria for Surgery

• Persistent symptoms after 8-12 weeks of aggressive medical management including oral corticosteroids 2
• CT demonstration of persistent ostiomeatal complex obstruction with mucosal disease in dependent sinuses 2
• Nasal endoscopy confirming significant disease burden (e.g., polyps occluding 50-70% of airway) 2

Important Surgical Considerations

• Bilateral OMU occlusion requires ENT evaluation before any surgical intervention 2
• Surgery should be functional, widening natural drainage openings while preserving ciliated epithelium 3
• The 2025 AAO-HNS guidelines specifically state surgeons should not require a predefined duration of medical therapy as an absolute prerequisite when anatomical obstruction is clearly contributing to disease 4

Critical Pitfalls to Avoid

• Do not proceed directly to surgery without adequate medical trial: The majority of patients benefit from aggressive medical management first, and surgery without addressing underlying inflammatory conditions leads to poor outcomes 2
• Do not rely on standard radiographs: They miss approximately 80% of ethmoid disease and are inadequate for surgical planning 1
• Do not assume all anatomical variants require surgery: While concha bullosa (30-47.5%), deviated septum (72.5%), and agger nasi cells (80%) are common in chronic rhinosinusitis patients, their presence alone does not mandate surgery without failed medical management 5, 6
• Do not perform limited procedures for extensive disease: Patients with nasal polyps, osteitis, or fungal disease require comprehensive FESS with wide openings 2

Postoperative Management

Continue intensive medical therapy after FESS, as surgery alone is insufficient for long-term disease control. 2, 3

• Nasal saline irrigations for local management 2
• Intranasal corticosteroids to maintain sinus patency 2
• Ongoing allergy management when allergic rhinitis is present 2
• Medical treatment should be continued indefinitely post-surgery 3