Residency · Residency · Otolaryngology
Laryngotracheal Stenosis: Evaluation and Management
Overview
Laryngotracheal stenosis (LTS) refers to narrowing of the airway at the level of the subglottis or trachea. It is a challenging condition that can significantly impact breathing, voice, and quality of life. Post-intubation injury remains the most common etiology, but idiopathic subglottic stenosis and autoimmune-related stenosis are increasingly recognized. Management ranges from endoscopic dilation to open airway reconstruction, depending on the severity and etiology.
Etiology
Acquired
Post-intubation (most common overall): mucosal ischemia from cuff pressure, duration of intubation, tube size, traumatic intubation. Post-tracheotomy: stomal granulation, suprastomal collapse, A-frame deformity. Autoimmune/inflammatory: granulomatosis with polyangiitis (GPA/Wegener), sarcoidosis, relapsing polychondritis, amyloidosis, IgG4-related disease. Idiopathic subglottic stenosis (iSGS): predominantly affects women (90%); age 30-50; no identifiable cause; limited to the subglottis; ECM fibroproliferation. Radiation-induced: late fibrosis after laryngeal or thyroid radiation. Infectious: tuberculosis, fungal, bacterial tracheitis. Traumatic: blunt/penetrating laryngeal trauma, caustic ingestion. Gastroesophageal reflux: debated as contributory factor.
Congenital
Subglottic stenosis: most common congenital laryngeal anomaly requiring treatment. Complete tracheal rings (stove-pipe trachea), Associated with Down syndrome, CHARGE syndrome.
Classification
Myer-Cotton Grading (Subglottic Stenosis)
Based on percentage of airway obstruction measured endoscopically.
| Grade | Obstruction | Description |
|---|---|---|
| I | 0-50% | Mild narrowing |
| II | 51-70% | Moderate narrowing |
| III | 71-99% | Severe narrowing (pinhole lumen) |
| IV | 100% | No detectable lumen (complete) |
Grade I: 0-50% obstruction. Grade II: 51-70% obstruction. Grade III: 71-99% obstruction. Grade IV: no detectable lumen (complete obstruction).
McCaffrey Classification (Tracheal Stenosis)
Based on the anatomic site and length of stenosis. Stage 1: subglottic or tracheal, <1 cm length. Stage 2: subglottic, >1 cm length. Stage 3: subglottic extending into upper trachea. Stage 4: involving the glottis with vocal fold fixation.
Additional Descriptors
Location: glottic, subglottic, tracheal, or combination. Length: short segment (<1 cm) vs. long segment. Morphology: web-like (thin), cicatricial (mature scar), cartilaginous collapse. Vocal fold mobility: fixed vs. mobile (critical for surgical planning).
Evaluation
Symptoms
Dyspnea on exertion (early); stridor (advanced), Biphasic stridor suggests subglottic/tracheal level, Exercise intolerance often misdiagnosed as asthma, Voice changes if glottic involvement, Recurrent respiratory infections.
Diagnostic Workup
Flexible laryngoscopy: assess supraglottis, glottis, vocal fold mobility, subglottic region. CT neck/chest: define stenosis location, length, and relationship to adjacent structures; 3D reconstruction helpful for surgical planning. Direct laryngoscopy and bronchoscopy: gold standard for assessment; performed under general anesthesia; allows sizing of the airway (endotracheal tubes or bronchoscopes). Pulmonary function tests: flattening of the inspiratory limb (variable extrathoracic obstruction) or both limbs (fixed obstruction) on flow-volume loop. Laboratory: ANCA (GPA), ACE level (sarcoidosis), ESR/CRP, anti-collagen II antibodies (relapsing polychondritis). Biopsy: if autoimmune or infectious etiology suspected; avoid biopsy of subglottic mucosa unless necessary (may worsen stenosis).
Endoscopic Management
Balloon Dilation
First-line for soft, web-like stenosis (thin scar), Radial force distributes pressure evenly, Can be performed awake or under general anesthesia, Particularly effective for idiopathic subglottic stenosis. Often requires repeated dilations; many patients managed long-term with serial dilations.
Laser Treatment
CO2 laser: radial incisions through scar (cross-hatch pattern). KTP or thulium laser: hemostatic; useful for vascular granulation tissue. Laser + dilation: combination approach for thicker scar. Risk of restenosis; avoid circumferential mucosal injury (promotes scar contracture).
Adjunctive Medical Therapy
Mitomycin C: topical application (0.4-1 mg/mL) after dilation or laser; inhibits fibroblast proliferation; controversial efficacy. Intralesional corticosteroid injection: triamcinolone (40 mg/mL) injected into the scar; reduces inflammation and fibrosis. Systemic steroids: short course perioperatively. Anti-reflux therapy: PPI if reflux suspected as contributory factor. Immunosuppression: for autoimmune-related stenosis (GPA, relapsing polychondritis) -- critical to medical management.
Endoscopic Limitations
Circumferential scar >1 cm: high recurrence with endoscopic approaches alone. Cartilaginous collapse: not amenable to dilation. Glottic involvement with vocal fold fixation: requires open approach. Multiple failed endoscopic procedures: consider open reconstruction.
Open Surgical Management
Cricotracheal Resection (CTR)
Gold standard for subglottic stenosis (Grade III-IV), Anterior cricoid arch resected; stenotic segment excised. Trachea anastomosed to the remaining cricoid/thyroid cartilage. Decannulation rate: 90-95%. Single-stage procedure (no stenting required in most cases). Requires preservation of at least one functioning RLN, Higher morbidity than endoscopic approaches; risk to RLN.
Laryngotracheal Reconstruction (LTR)
Expansion of the subglottic airway using cartilage grafts (costal cartilage). Anterior graft: placed in anterior cricoid split; widens the anterior-posterior dimension. Posterior graft: placed in posterior cricoid split; widens the transverse dimension (used when posterior stenosis or posterior glottic stenosis present). Single-stage (no tracheotomy or decannulation at same procedure) or double-stage (stent placed, tracheotomy maintained). More commonly used in pediatric LTS. Decannulation rate: 85-95%.
Tracheal Resection and Anastomosis
For isolated tracheal stenosis. Resection of the stenotic segment; primary end-to-end anastomosis. Up to 50% of the trachea can be resected (approximately 6 cm) with release maneuvers. Suprahyoid release (Montgomery): drops the larynx to reduce anastomotic tension. Decannulation rate: >95%.
Posterior Glottic Stenosis
May coexist with subglottic stenosis (especially post-intubation). Bogdasarian-Olson classification (Types I-IV). Endoscopic: laser lysis of interarytenoid scar. Open: posterior cricoid split with costal cartilage graft. May require arytenoidectomy or arytenoid lateralization for fixed vocal folds.
Idiopathic Subglottic Stenosis (iSGS)
Predominantly Caucasian women, ages 30-50. Estrogen receptor expression in scar tissue may play a role. Limited to the subglottis (1-3 cm below the vocal folds). Many patients managed long-term with serial endoscopic dilations (every 6-24 months). Cricotracheal resection is curative in most cases but carries surgical risk. North American Airway Collaborative (NoAAC): multicenter research effort for standardized outcomes. Intralesional steroid injection + dilation: first-line endoscopic approach.
<image>Endoscopic grading of subglottic stenosis (Myer-Cotton classification). Four panels showing bronchoscopic views of the subglottis. Grade I: mild narrowing with >50% of the lumen patent. Grade II: moderate narrowing with 30-50% of the lumen patent. Grade III: severe narrowing with only a pinhole lumen visible (1-30% patent). Grade IV: complete obstruction with no visible lumen. Each panel includes an adjacent cross-sectional diagram showing the percentage of airway obstruction relative to a normal subglottic lumen, with the stenotic scar tissue highlighted.</image>
<image>Cricotracheal resection surgical technique. Step-by-step illustration showing: (1) Anterior neck incision and exposure of the laryngotracheal framework. (2) Identification of the stenotic segment with the cricoid arch anteriorly. (3) Resection of the anterior cricoid arch and stenotic tracheal segment while preserving the posterior cricoid plate and recurrent laryngeal nerves. (4) Mobilization of the distal trachea with release maneuvers. (5) Thyrotracheal anastomosis with interrupted absorbable sutures. Cross-sectional insets show the airway lumen before and after resection. Labels indicate the recurrent laryngeal nerves, preserved posterior cricoid plate, and anastomotic suture line.</image>
<image>Algorithm for management of laryngotracheal stenosis. Flowchart begins with symptomatic airway stenosis, proceeds through endoscopic assessment and grading (Myer-Cotton). Grade I-II with thin web directs to endoscopic dilation with adjuncts (steroids, mitomycin C). Grade III-IV or failed endoscopic management branches to open surgical options: cricotracheal resection for subglottic stenosis, tracheal resection-anastomosis for tracheal stenosis, and laryngotracheal reconstruction for combined or pediatric cases. Autoimmune etiology sidebranch emphasizes immunosuppressive therapy as primary treatment with endoscopic procedures for acute airway compromise. Decision points include assessment of scar maturity, vocal fold mobility, and length of stenosis.</image>
Clinical Pearls
Subglottic stenosis is frequently misdiagnosed as refractory asthma; a fixed or flattened inspiratory loop on flow-volume testing should prompt endoscopic evaluation. Idiopathic subglottic stenosis overwhelmingly affects women; the etiology remains unknown but estrogen receptor positivity in scar tissue suggests a hormonal component. Always rule out autoimmune etiologies (GPA, relapsing polychondritis, sarcoidosis) before proceeding with surgery; immunosuppression may be the primary treatment and surgical intervention without medical control leads to recurrence. Avoid circumferential mucosal injury during endoscopic treatment; loss of more than one-third of the mucosal circumference promotes cicatricial contracture and worsens stenosis. Cricotracheal resection has a 90-95% decannulation rate and is the definitive treatment for mature, high-grade subglottic stenosis; however, many patients with iSGS can be managed long-term with serial dilations every 6-24 months. Always assess vocal fold mobility before open reconstruction; posterior glottic stenosis with vocal fold fixation requires specific surgical strategies (posterior graft, arytenoidectomy).
References
- Myer CM, O'Connor DM, Cotton RT. "Proposed grading system for subglottic stenosis based on endotracheal tube sizes." Ann Otol Rhinol Laryngol. 1994;103(4 Pt 1):319-323.
- Gelbard A, Francis DO, Sandulache VC, Simmons JC, Donovan DT, Ongkasuwan J. "Causes and consequences of adult laryngotracheal stenosis." Laryngoscope. 2015;125(5):1137-1143.
- Liberman M, Mathisen DJ. "Tracheal tumors and strictures: surgical treatment and results." Semin Thorac Cardiovasc Surg. 2009;21(3):280-289.
- Aravena C, Almeida FA, Mukhopadhyay S, et al. "Idiopathic subglottic stenosis: a review." J Thorac Dis. 2020;12(3):1100-1111.
