Diagnostic value of the static laryngeal image in laryngomalacia type 1, 2 and 3

Introduction Laryngomalacia (LM) is best diagnosed by endoscopy under spontaneous respiration. A typical characteristic is the inspiratory collapse of the supraglottic structures, causing inspiratory stridor. Still, the clinical classification of LM and a substantial majority of the theories about the pathogenesis of LM are anatomically based.

Methods The aim of the present study was to compare the static endoscopic picture in apnea in infants and toddlers with LM and the dynamic endoscopic appearance under preserved spontaneous breathing. In 10 consecutive pediatric patients with clinical signs of LM (age 2m-2y) endoscopic evaluation of the larynx was performed in apnea and under spontaneous respiration during drug-induced sleep endoscopy. For the direct laryngoscopy, a Macintosh laryngoscope was used together with a conventional 70o rigid endoscope. In 2 patients additional flexible nasolaryngoscopy was used.

Results In type 1 and 2 or overlapping 1/2 LM the static endoscopic picture is fully comparable to the dynamic one – diagnosis is possible even during routine laryngoscopy in apnea. In LM type 3 the static picture appeared normal and only the dynamic one revealed the typical posterior collapse of the epiglottis. In LM type 3 direct laryngoscopy with no spontaneous respiration would result in false-negative findings.

Conclusion The diagnosis LM is based on the combination of clinical symptoms and specific dynamic endoscopic findings. Yet the anatomic theories about LM suggest the presence of specific structural abnormalities. The static appearance of LM larynx on direct laryngoscopy differs from normal anatomy in type 1 and 2 LM and may have diagnostic value. In type 3 LM the anatomically normal larynx on static endoscopy could not rule out the diagnosis.

Publication History

Article published online:
10 June 2020