Different laryngeal dimensions and proportions in normal pediatric larynxes and laryngomalacia

The dynamic endoscopic picture of severe laryngomalacia (LM) is distinctive, but the criteria for differentiation between normal anatomy, borderline conditions and LM have not been established yet. Our aim is to evaluate morphometric endoscopic criteria of the larynxes in newborns and toddlers with LM and without noticeable laryngeal pathology.

Infants and toddlers subjected to general anesthesia with intubation for other reasons were included. During routine laryngoscopy for intubation endoscopic pictures and video sequences were recorded in an uniform manner. A total of 24 patients (20 with normal anatomy; 4 with LM) were evaluated A Macintosh laryngoscope with a raster scale attached to the blade was used. In each case, the raster was captured both with the larynx (subsequently serving as a measurement unit) and separately with the optical system mounted on a stand (distortion correction template). After correction of the barrel distortion of selected images and contouring of the supraglottic and glottic floor, analysis of 4 laryngeal proportions and 11 dimensions was performed.

The antero-posterior/transverse supraglottic diameter ratio is 1,47 ± 0,74 in norm and 2,56 ± 0,53 in LM. The epiglottic edge width/epiglottic intlet ratio is < 1 (0,44 ± 0,13) in norm and > 1 (1,18 ± 0,19) in LM. The epiglottic inlet/transverse supraglottic diameter ratio is 0,43 ± 0,11 in norm and 0,26 ± 0,05 in LM.

In LM the antero-posterior supraglottic diameter is longer, the inlet of the epiglottis is thinner than its upper edge width and relatively thinner than the transverse supraglottic diameter in comparison to the normal larynx. In LM the supraglottis has specific static proportions, which may serve as diagnostic criteria for LM during routine laryngoscopy in apnea.

Publikationsverlauf

Publikationsdatum:
23. April 2019 (online)