- Patient history, including prematurity, history of intubation, feeding history, prior airway surgery, and other medical conditions.
- Physical examination, including weight, stridor, voice quality and cry, craniofacial abnormalities, pulmonary status, and cardiac status.
The following tests are diagnostic:
- Posteroanterior and lateral neck and chest x-rays
- Computed tomography and magnetic resonance imaging
- Flexible laryngoscopy
- Rigid endoscopy and microlaryngoscopy
Advances in care of premature infants in the last few decades have resulted in increased survival rates and a new population of patients with a history of prolonged intubation. A proportion of these patients develop subglottic stenosis up to 8%, according to some reports. Further advances in endotracheal tube and ventilation management in the last 30 y have decreased the incidence of subglottic stenosis in the neonatal population to <1%. A second population of infants born with congenital subglottic stenosis has remained stable at approximately 5%. These patients provide some of the greatest diagnostic and management challenges for the otolaryngologist.
Other airway abnormalities—both congenital and iatrogenic—including laryngomalacia, vocal fold paralysis, and supraglottic and glottic stenosis, have prompted otolaryngologists to continue to refine surgical airway reconstruction techniques. These techniques are becoming further advanced with the advent of endoscopic minimally invasive surgical procedures including robotic assisted endoscopic airway reconstruction on the horizon.
. The problem of pediatric laryngotracheal stenosis: a clinical and experimental study on the efficacy of autogenous cartilaginous grafts placed between the vertically divided halves of the posterior lamina of the cricoid cartilage. Laryngoscope.
(Comprehensive review of the history of subglottic stenosis diagnosis and management.)
Faust R, Rahbar R. Robotic surgical technique for pediatric laryngotracheal reconstruction. Otolaryngol Clin N Am. 2008;41:1045. (Description of applications of robotic surgery for airway reconstruction.)
Walner DL, Loewen MS, Kimura RE. Neonatal subglottic stenosis: incidence and trends. Laryngoscope.
(Review of the incidence trends of neonatal subglottic stenosis revealing improvement over the last three decades.)
The incidence of congenital subglottic stenosis is approximately 5%. The cricoid cartilage develops abnormally and may be elliptical or flattened in shape, causing cartilaginous stenosis. The remainder of subglottic stenosis is considered to be iatrogenic—airway intubation with large tube size relative to airway diameter and duration of intubation both playing roles. Host factors also play a significant role, however, because some children intubated for a very short time develop subglottic stenosis, whereas others with a prolonged intubation history do not.
Acquired subglottic stenosis more often involves soft tissue stenosis in contrast to the congenital form, which results in cartilaginous stenosis. Pressure is considered to play a role, causing initial mucosal edema and inflammation with subsequent ulceration and finally fibrosis (Figure 40–1). Other factors may exacerbate stenosis development such as gastroesophageal reflux disease (GERD) and infection. The characterization of stenosis during diagnostic endoscopy, including the location, severity, and length of the stenosis, is extremely important and helps to direct management options and predict outcomes.