Bilateral Vocal Fold Immobility

Introduction

Bilateral vocal fold immobility (BVFI) is an uncommon condition with potentially significant negative effects on breathing and quality of life. Patients usually have symptoms of airway obstruction, such as biphasic stridor and dyspnea, with a normal or nearly normal voice. This is in contrast to patients with unilateral vocal fold immobility, who usually complain of a breathy voice and aspiration. Etiologies of BVFI include immobility from both neurogenic causes (vocal fold paralysis) and mechanical fixation of the cricoarytenoid (CA) joints.

Neurogenic causes of bilateral vocal fold paralysis (BVFP) may be due to (1) iatrogenic injury to the recurrent laryngeal nerve (e.g., thyroidectomy, anterior cervical disc surgery, carotid endarterectomy, esophageal surgery, cardiac surgery, mediastinal surgery), (2) progressive neurologic disorders (e.g., amyotrophic lateral sclerosis, Shy-Drager syndrome, syringomyelia, Guillain-Barré syndrome), or (3) idiopathic causes.

Mechanical fixation of the CA joints causing BVFI may be due to (1) fixation of the CA joint secondary to radiation therapy, rheumatoid arthritis and other connective tissue disorders, benign infiltrative disorders such as amyloidosis, granulomatous diseases; (2) trauma; or (3) posterior glottic stenosis (PGS).

PGS is a common cause of BVFI. It is typically associated with intubation, although extraesophageal reflux disease may be a cofactor. The development of PGS is characterized by progressive airway obstruction, usually 4 to 8 weeks after extubation. Granulation tissue can cover the arytenoid cartilages and interarytenoid cleft. If this is observed, prompt débridement, steroid injection, and antacid treatment may be associated with less scar tissue formation and consequently less airway stenosis. Laryngeal balloon dilation may also have a therapeutic role in the acute or subacute setting.

Bogdasarian and Olsen developed a classification system for PGS that is useful to characterize the nature and severity of the posterior laryngeal stenosis. The least severe group of patients has an interarytenoid synechiae and posterior sinus tract. The next group includes those with a posterior glottic web that limits movement of the arytenoids, without fixation of the CA joints and no posterior sinus tract. The third group appears similar to the second; however, one CA joint is fixed. The most severe group and the most difficult to treat consists of patients with fixation of both CA joints ( Fig. 9.1 ).

Correctly identifying the cause of BVFI (neurogenic or mechanical) is critical in guiding treatment and shaping the expectations of both the patient and surgeon. The aim of treatment is to improve the airway while minimizing adverse effects on the voice.

Key Operative Learning Points

• Patients with BVFI secondary to mechanical fixation of the CA joints typically have more severe airway restriction and require more aggressive surgical enlargement of the glottis than patients with BVFP.

• Laryngeal electromyography (LEMG) is crucial in determining the presence of neurologic injury and may guide the surgeon in determining the operative side.

• Palpation of the arytenoid, either in the office or in the operating room, to confirm passive motion or immobility is critical information that helps guide treatment.

• Endoscopic techniques have replaced larger, more destructive surgery and have resulted in decreased morbidity.

• Granulation tissue formation is minimized by the use of perioperative antacid medications and the application of mitomycin-C to any mucosal defects.

• Only patients with realistic expectations of the balance between voice and airway improvement should undergo surgery to enlarge the glottic airway.

• Overly aggressive primary surgery will probably leave the patient with more severe breathy dysphonia and dysphagia than was necessary for airway improvement or decannulation.

• Posterior glottic airway surgery may worsen glottic protection during swallowing, thereby increasing the risk of aspiration.

• BVFP must be differentiated from PGS because the initial surgical options may be different.

• Exposure of arytenoid cartilage during transverse cordotomy may lead to the formation of granulation tissue and the need for further treatment.

Preoperative Period