Anatomy Pelvis Head Neck · Year 1 · from Anatomy Pelvis Head Neck
Case 2: Bilateral Vocal Fold Paralysis with Airway Compromise
Patient Demographics
- Age: 62 years old
- Sex: Male
- Occupation: Retired engineer
Chief Complaint
Progressive shortness of breath and noisy breathing since neck surgery.
History of Present Illness
The patient underwent a completion thyroidectomy for recurrent thyroid cancer 3 days ago. He notes that his voice is remarkably normal but has developed progressive inspiratory stridor and shortness of breath, especially with exertion. He denies dysphagia or aspiration. His breathing difficulty has worsened despite nebulizer treatments. He becomes dyspneic with minimal activity and has noticed that his breathing sounds "squeaky" or "whistling."
Physical Examination
- Vitals: HR 98 bpm, BP 148/92 mmHg, RR 26, SpO2 91% on room air, improving to 94% on 4L nasal cannula
- General: Anxious, using accessory muscles of respiration
- Neck: Well-healed incisions from current and prior surgeries
- Respiratory: Biphasic stridor (both inspiratory and expiratory), no wheezing
- Voice: Surprisingly normal in quality, though weak
- Flexible laryngoscopy: Both vocal folds immobile in the paramedian position; narrow glottic aperture; no mucosal lesion
Diagnosis
Bilateral recurrent laryngeal nerve palsy with critical airway narrowing.
Anatomical Correlation
Bilateral RLN injury is a surgical emergency because both vocal folds are paralyzed in the paramedian position, leaving only a narrow glottic aperture for breathing. The voice may be paradoxically preserved because the vocal folds can still come together, but the airway is critically compromised because neither fold can abduct. The posterior cricoarytenoid muscles, which abduct the vocal folds during inspiration, are both paralyzed. This is in contrast to unilateral injury, where the contralateral functioning fold can approximate the paralyzed fold for phonation but leaves a sufficient airway. The cricoid cartilage is the only complete cartilaginous ring in the airway, forming the narrowest fixed point of the adult airway at the level of C6. In bilateral vocal fold paralysis, the rima glottidis becomes the critically narrowed segment. Stridor is biphasic because both inspiration and expiration are obstructed by the immobile folds.
Treatment
- Emergent airway management: Intubation (may be difficult due to narrowed glottis) or surgical airway
- Tracheostomy: Required in most cases of bilateral vocal fold paralysis
- Long-term airway options:
- Posterior cordotomy (laser incision of one vocal fold)
- Arytenoidectomy (removal of one arytenoid cartilage)
- Both procedures sacrifice voice quality for improved airway
- Future reinnervation procedures: Experimental approaches to restore abduction