Tracheal Stenosis

Definition

Etiology

Acquired (most common)

Congenital

Malignant

Clinical Presentation

• Dyspnea on exertion (progressive)
• Stridor (inspiratory or biphasic)
• Cough and wheezing
• Obstructive pneumonia in severe cases
• Dysphonia and dysphagia if subglottic involvement

Key pitfall: Tracheal stenosis is frequently misdiagnosed as adult-onset asthma, and patients are often started on steroids before the correct diagnosis is made. - Current Surgical Therapy 14e

Diagnosis

1. Flow-volume loop / spirometry - flattening of the inspiratory and/or expiratory limb suggests fixed obstruction; helps identify critical stenosis
2. High-resolution CT with 3D reconstruction - preferred imaging; defines location, length, configuration, relationship to surrounding structures, and wall thickness
3. Flexible bronchoscopy - gold standard for characterizing stenosis, assessing mucosa, and directing therapy
4. Rigid bronchoscopy (in the OR) - best for measuring stenosis length, assessing mucosal quality, and allowing simultaneous dilation
5. Laryngoscopy - to evaluate vocal fold mobility and subglottic extension
6. Soft tissue neck radiograph - can show location/extent of subglottic/upper tracheal lesion

Classification of Stenosis

• Location: Subglottic, upper tracheal, mid-tracheal, lower tracheal
• Morphology:
  • Cicatricial/membranous (fibrous with intact cartilage)
  • Anterior wall collapse (cartilage destruction)
  • Complete stenosis
• Length: <1 cm (simple) vs >1 cm (complex)
• Associated malacia: Present or absent

Management

Endoscopic / Bronchoscopic Interventions (simple stenosis, or bridge to surgery)

• Rigid bronchoscopic dilation - preferred; graduated pediatric-to-adult bronchoscopes serially dilate the stricture. Racemic epinephrine + steroids given for 24-48 h after to minimize edema.
• Balloon dilation - alternative for thin band stenosis or poor surgical candidates
• Radial incisions + dilation - electrocautery or laser (CO₂) radial cuts followed by dilation
• CO₂ laser excision - particularly useful for cicatricial stenosis; avoids tracheostomy; staged if circumferential (2-4 weeks apart to avoid restenosis)
• Local adjuncts: Intralesional mitomycin-C, corticosteroid injections have been studied as adjuncts to endoscopic interventions
• Silicone stent - for patients ineligible for or awaiting surgery; NOT expanding metal stents (risk of granulation tissue and erosion)

Surgical Management (complex stenosis, recurrent simple stenosis)

• Indications: Any patient with airway stenosis from tracheal injury who is a surgical candidate
• Contraindications:
  • Absolute: Non-reconstructible airway (excessive length of damage), severe comorbidities, prolonged need for mechanical ventilation
  • Relative: Prior radiation, active mucosal inflammation, active steroid use (must be weaned 2-4 weeks before surgery), purulent secretions
• Length limit: Up to ~4-6 cm can be safely resected; high subglottic location limits surgical options
• Anesthesia: Total intravenous anesthesia (TIVA) with remifentanil and propofol is preferred; maintains spontaneous ventilation for critical stenosis
• Technique: Meticulous lateral tracheal dissection (≤1 cm circumferentially) to preserve segmental blood supply from the inferior thyroid artery; recurrent laryngeal nerves protected in the tracheoesophageal groove; anastomosis with interrupted 4-0 Vicryl sutures (knots outside); neck kept flexed postoperatively ("guardian suture") to reduce anastomotic tension
• Laryngotracheoplasty or cricotracheal resection for subglottic involvement
• Montgomery T-tube for complex multi-site stenosis or poor surgical candidates needing long-term stenting

Inflammatory/Autoimmune Stenosis

Malignant Tracheal Stenosis

• Localized: Surgical resection (5-year survival 39-79% for squamous; adenoid cystic carcinoma - complete resection is more important than nodal staging)
• Unresectable: Chemoradiation (SqCC); radiation alone (adenoid cystic)
• Palliative: Stenting, laser debulking for critical obstruction

Postoperative Care

• Neck flexion maintained for ~1 week via "guardian suture" (chin-to-chest suture)
• Avoid neck hyperextension
• Racemic epinephrine + steroids for post-dilation edema
• Voice/swallowing assessment (VHI, DHI questionnaires) as baseline and follow-up

Recent Evidence (2024)

• A 2024 systematic review and meta-analysis (PMID 39263927) identified key risk factors for tracheal stenosis, including intubation duration and cuff management.
• A 2024 systematic review on tracheal resection (PMID 39254596) confirmed resection and anastomosis as the gold standard for postintubation stenosis.
• A 2024 meta-analysis (PMID 38967672) on local adjuncts (mitomycin-C, steroids) to endoscopic interventions for benign laryngotracheal stenosis found benefit in reducing recurrence rates.
• A 2024 systematic review on slide tracheoplasty (PMID 38885545) for congenital tracheal stenosis demonstrated excellent outcomes.

Intratympanic Gentamicin Injection (IT-G)

Introduction

Mechanism of Action

• Binds NMDA receptors → excitotoxic vestibular hair cell damage
• Generates reactive oxygen species (ROS) → oxidative injury to type I vestibular hair cells (predominantly in the cristae and maculae)
• Destroys vestibular hair cell function → partial or complete chemolabyrinthectomy (also called "partial chemical labyrinthectomy")
• After ablation, the Meniere's disease vertigo attacks are no longer detected or provoke nystagmus, so the patient stops experiencing rotational vertigo

Indications

1. Refractory unilateral Meniere's disease - failure of medical management (dietary sodium restriction, diuretics, betahistine)
2. After failed intratympanic dexamethasone (preferred first intratympanic agent)
3. Tumarkin drop attacks (otolithic crises) - particularly effective in this setting
4. "End-stage" Meniere's disease with disabling vertigo in an ear with significantly impaired hearing (where hearing preservation is less of a concern)

Place in stepwise management: IT-dexamethasone is offered first (Grade A recommendation, 80% long-term vertigo control, no hearing risk). IT-gentamicin is offered when dexamethasone fails (Grade A recommendation). - Scott-Brown's Otorhinolaryngology

Contraindications

• Bilateral Meniere's disease (relative - risk of bilateral vestibular loss causing oscillopsia/chronic imbalance)
• Only-hearing or better-hearing ear
• Active middle ear infection / perforated tympanic membrane (relative)
• Patients unable to undergo vestibular compensation (severe neurological comorbidity)

Preparation and Technique

Dosing Schedules

Efficacy

• Vertigo control (Class A + B): 87.5% (Huon et al. 2012 meta-analysis); 93.5% at 2-year follow-up in one RCT
• vs. IT-dexamethasone: Gentamicin superior for vertigo control (93.5% vs. 61% in a 2012 RCT)
• Drop attacks (Tumarkin crises): Effective - specifically noted in guidelines as an indication
• vs. vestibular nerve section: Comparable results (vestibular neurectomy ~90% vs. IT-G ~66-90% depending on protocol)

Complications

With modern titration protocols, the risk of clinically significant hearing loss is comparable to the natural history of Meniere's disease itself. - Cummings Otolaryngology

Monitoring After Injection

• Head thrust test / video head impulse test (vHIT): Peripheral vestibular deficit evident after even a single dose - key objective marker of successful ablation
• Ice water caloric testing: Complete ablation of caloric response is NOT required for vertigo control; targeting complete ablation leads to unnecessary hearing loss
• Audiogram at each visit
• Patient diary of vertigo attacks (AAO-HNS classification)

Position vs. Other Ablative Options