What is the nasal swell body of the septum and what is the most effective surgical approach for its removal?

Nasal Septal Swell Body and Surgical Management

The nasal septal swell body (NSB), also called the nasal septal turbinate, is a distinct anatomical structure located in the anterior-superior portion of the nasal septum, positioned at the internal nasal valve region. For symptomatic NSB hypertrophy causing nasal obstruction, coblation reduction is the most effective surgical approach based on current evidence, though long-term outcomes remain incompletely established 1.

What is the Nasal Septal Swell Body?

The NSB is a highly specialized structure with unique histological characteristics that distinguish it from other nasal structures:

• Location: Anterior-superior nasal septum, anterior to the middle turbinate, at the distal valve segment 2, 3
• Dimensions: Average width of 12.85±1.74 mm and length of 28.30±1.92 mm in healthy adults 4
• Composition: Predominantly seromucinous glands (49.9% of tissue area) with moderate venous sinusoidal components (10% of tissue area) 3

Physiological Function

The NSB serves multiple roles in nasal physiology:

• Airflow regulation: Functions as a vasoactive structure that modulates airflow at the nasal valve 3
• Secretory function: Rich glandular content suggests significant role in humidification and conditioning of inspired air 3
• Dynamic structure: Varies in size over time, correlating with inferior turbinate changes during the nasal cycle (r=0.35, p=0.04) 5
• Allergen filtration: Contributes to filtering inhaled particles; removal decreases septal deposition of Artemisia pollen from 30.70% to 22.79% while increasing lower airway deposition from 17.00% to 24.12% 4

Clinical Significance

NSB hypertrophy can cause anatomic nasal obstruction, particularly at the critical internal nasal valve region. Imaging studies demonstrate that enlarged NSB correlates with nasal disease symptoms 2. The structure's location makes it clinically relevant when evaluating anterior nasal obstruction that doesn't respond to medical management.

Surgical Approach: Coblation NSB Reduction

Coblation NSB reduction is the preferred surgical technique based on the highest quality available evidence 1. This approach offers several advantages:

Technique Details

• Access: Performed endoscopically under local or general anesthesia
• Method: Controlled ablation of NSB tissue using coblation technology
• Target: Patients with abnormally thickened NSB (mean maximal width ≥16.4±2.2 mm on CT) 1

Clinical Outcomes

The evidence demonstrates significant improvement:

• Subjective improvement: Visual analog scale scores for nasal obstruction decreased from 7.63±0.99 preoperatively to:

  • 3.88±0.92 at 3 months
  • 4.16±0.78 at 6 months
  • 4.63±0.69 at 1 year 1

• Patient satisfaction: 75% (6/8 patients) satisfied at 1-year follow-up 1

Important Caveats

Long-term outcomes beyond 1 year remain unproven 2. The gradual increase in obstruction scores from 3 months to 1 year (3.88 to 4.63) suggests possible tissue regrowth or adaptation, warranting careful patient counseling about realistic expectations.

Alternative Considerations

While the provided guidelines [6-7] extensively discuss septal deviation and turbinate hypertrophy management, they do not specifically address NSB surgery. The NSB is distinct from:

• Septal deviation: Managed with septoplasty (77% subjective improvement) 6
• Inferior turbinate hypertrophy: Treated with various reduction techniques including radiofrequency, submucosal resection, or turbinoplasty 6

The NSB should not be confused with these structures, as it has unique histology and function 3.

Clinical Decision Algorithm

1. Identify NSB hypertrophy: Measure NSB width on coronal CT imaging; consider abnormal if >16 mm 1
2. Confirm contribution to obstruction: Use nasal endoscopy to visualize NSB at internal valve; assess with topical decongestant response
3. Exclude other causes: Rule out septal deviation, turbinate hypertrophy, and valve collapse as primary contributors
4. Surgical candidacy: Offer coblation NSB reduction for patients with documented NSB hypertrophy causing valve obstruction refractory to medical management
5. Counsel appropriately: Inform patients that improvement may diminish over time and long-term data are limited

Critical Pitfall

Excessive septal cartilage resection during traditional septoplasty can create "flagging septum", where loss of central support disrupts the normal septum-turbinate interaction during the nasal cycle, paradoxically worsening obstruction symptoms 8. This underscores the importance of tissue-preserving techniques and recognizing the NSB as a distinct structure requiring targeted intervention rather than broad septal resection.