What Are the Most Common Indications for Which Laryngotracheal Reconstruction (LTR) Is Performed?

An LTR is performed in cases of acquired or congenital subglottic stenosis.

What Is Subglottic Stenosis (SGS)?

Subglottic stenosis is narrowing of the airway between the lower border of the cricoid cartilage and extending up to below the vocal folds (Figure 33.1).

Figure 33.1 Schematic demonstrating the relationship between the vocal cords and cricoid cartilage

The most rigid and unyielding part of the airway is the cricoid cartilage.

What Are the Causes of Acquired SGS?

Trauma to the subglottis is the primary cause of acquired subglottic stenosis (SGS), most commonly resulting from prolonged or traumatic endotracheal intubation.

Prolonged intubation or intubation with an over-sized tube or overinflated endotracheal cuff increases the risk of developing SGS, especially in the presence of underlying congenital anomalies.

Risk of developing SGS is increased in the presence of inflammatory conditions, such as persistent gastroesophageal reflux.

The incidence of SGS in intubated neonates is reported to be 0–2% although most neonates can tolerate long periods of intubation without injury to the subglottis (in stark contrast to adults).

What Are the Causes of Congenital SGS?

Congenital subglottic stenosis is a rare birth defect due to incomplete recanalization of the laryngotracheal tube during gestation and is frequently associated with other congenital head and neck lesions and syndromes including: 22q11 deletion, Down syndrome, and CHARGE syndrome.

What Are the Symptoms and Signs of SGS?

Signs of SGS include “noisy breathing” or stridor, respiratory distress, history of recurrent croup, and exercise intolerance. Stridor in SGS is biphasic because of fixed narrowing of the extra-thoracic airway. This is in contrast to inspiratory stridor, characteristic of supraglottic pathology, and expiratory stridor, characteristic of intrathoracic pathology.

What Is the Myer–Cotton Grading Scale for Determination of Severity of SGS?

The stenosis is based on age-appropriate airway size and degree of narrowing.

Mild stenoses (grades 1 and 2) are usually managed nonoperatively, whereas more severe stenoses (grades 3 and 4) often require surgical intervention (Figure 33.2).

Figure 33.2 Myer–Cotton grading system for degree of subglottic stenosis

How Is the Airway Size Determined?

The airway is sized during suspension laryngoscopy. Under direct vision, the otolaryngologist places an uncuffed endotracheal tube through the vocal cords. A leak test is performed during which the insufflation is maintained at increasing pressures (e.g. 5, 10, 15 c H₂O) until a leak is visible under direct vision. The outer diameter of the uncuffed endotracheal tube determines the airway size. The largest tube that can be placed with an air leak less than 20 cm of water is recorded for staging.