A New Approach to Treating Bilateral Vocal Fold Paralysis

Bilateral vocal fold paralysis (BVFP) affects less than 1 infant per million births annually. Symptoms are biphasic stridor, slow weight gain or failure to thrive, or respiratory distress. The signs can present at birth or increase 4–6 weeks after birth.

The etiology of BVFP can be congenital or acquired. Acquired is usually associated with an underlying congenital anomaly, such as Arnold-Chiari malformation, hydrocephalus, intraventricular hemorrhage, or even subglottic web1.

About 50% of children with BVFP may not require any surgical intervention, with spontaneous movement returning after 12 months1,2. The other 50% — whose respiratory symptoms are significant and who suffer from failure to thrive and respiratory decompensation — require a surgical intervention.

A new surgical treatment approach

Previously, the only surgical option available for this type of patient was to place a tracheostomy, allow the child to grow, and perform a posterior costal cricoid graft laryngoplasty to augment the airway, a vocal cord lateralization, CO2 laser cordotomy, or artytenoidectomy procedure.

However, a new approach — endoscopic laryngoplasty of anterior-posterior cricoid split with balloon dilation — has evolved with possible avoidance of a tracheostomy for BVFP. For optimal success, the patient should have minimal reflux or well-managed reflux (normal impedance, no laryngeal edema or cobblestoning, and no inflammation or eosinophilic esophagitis on esophagogastroduodenoscopy [EGD]), no pulmonary or cardiac issues, and the vocal cords should not be fixed upon palpation with micro-instruments.

The workup includes:

• Flexible laryngoscopy while the child is awake to see dynamic motion of the upper airway, including movement of the vocal folds and position of the vocal cord, as well as if there are other causes for the stridor, such as laryngomalacia
• Videofluorographic swallowing study (VFSS) to look at the swallowing mechanism
• MRI of the brain to rule out any congenital anomalies such as Chiari malformation
• EGD and impedance probe to rule out reflux and if present, maximize therapy to reduce laryngopharyngeal reflux (LPR) that could affect the surgical site

Endoscopic laryngoplasty of anterior-posterior cricoid split with balloon dilation

After induction of general anesthesia, a microlaryngoscopy and bronchoscopy is performed to confirm BVFP with very limited but only passive mobility of the vocal cords. The vocal cords should be easily moved apart when palpated with a micro-instrument. The larynx, subglottis, trachea, and bronchi are evaluated to confirm that there is no evidence of inflammation, edema, or reflux compromising the airway (Figures 1 and 2). An intravenous anesthetic agent is used.

The patient is then intubated and placed into laryngeal suspension for easy, endoscopic access. A knife is used to carefully incise the posterior cricoid plate entirely. The split is diffracted at the incision with a spreading instrument to widen the glottic aperture. Next, an anterior cricoid split is performed, first using a knife to make an incision in the cartilage, and then putting gentle pressure on the anterior arch of the cricoid (on the surface of the neck) to split through it completely. This further widens the airway (Figure 3).

The airway size is then assessed by using the outer diameter of endotracheal tubes as a guide. Airway balloon catheters are then used to serially dilate the airway to markedly improve the glottic aperture (Figure 4). The endotracheal tube is replaced in between dilations to provide ventilation and maintain oxygenation.

Once the airway has been adequately enlarged in this fashion, the patient is intubated nasally with an endotracheal tube that is a half size larger than what is age appropriate2, using a fiberoptic bronchoscope to both place and confirm position. The endotracheal tube is sutured to the nasal septum in addition to taping it in place. A nasogastric feeding tube is also placed prior to leaving the operating room.

The patient is kept intubated for 1–2 weeks to allow the airway to heal. A repeat microlaryngoscopy and bronchoscopy is performed just prior to extubation in order to assess the healing process.

References

1. Ada M, Isildak H, Saritzal G. Congenital vocal cord paralysis. J Craniofacial Surgery. 2010;21(1): 273–274. 
2. Rutter MJ, Hart CK, Alarcon A, Daniel SJ, Parikh SR, Balakrishnan K, Lam D, Johnson K, Sidell DR. Endoscopic anterior-posterior cricoid split for pediatric bilateral vocal fold paralysis. Laryngoscope. 2018;128(1):257–263.