Balloon dilatation of pediatric subglottic laryngeal stenosis during the artificial apneic pause: experience in 5 children

Quantitative Evaluation of Subglottic Stenosis Using Ultrashort Echo Time MRI in a Rabbit Model

OBJECTIVE/HYPOTHESIS

To assess the ability of ultra-short echo time (UTE)-MRI to detect subglottic stenosis (SGS) and evaluate response to balloon dilation. To correlate measurements from UTE-MRI with endotracheal-tube (ETT)-sizing and to investigate whether SGS causes change in airway dynamics.

STUDY DESIGN

Animal research study.

METHODS

Eight adult New-Zealand white rabbits were used as they approximate neonatal airway-size. The airways were measured using ETT-sizing and 3D UTE-MRI at baseline, 2 weeks post-cauterization induced SGS injury, and post-balloon dilation treatment. UTE-MR images were acquired to determine airway anatomy and motion. Airways were segmented from MR images. Cross-sectional area (CSA), major and minor diameters (D_major and D_minor ), and eccentricity were measured.

RESULTS

Post-injury CSA at SGS was significantly reduced (mean 38%) compared to baseline (P = .003) using UTE-MRI. ETT-sizing correlated significantly with MRI-measured CSA at the SGS location (r = 0.6; P < .01), particularly at the post-injury timepoint (r = 0.93; P < .01). Outer diameter from ETT-sizing (OD) correlated significantly with D_major (r = 0.63; P < .01) from UTE-MRI at the SGS location, especially for the post-injury timepoint (r = 0.91; P < .01). Mean CSA of upper trachea did not change significantly between end-expiration and end-inspiration at any timepoint (all P > .05). Eccentricity of the upper trachea increased significantly post-balloon dilation (P < .05).

CONCLUSIONS

UTE-MRI successfully detected SGS and treatment response in the rabbit model, with good correlation to ETT-sizing. Balloon dilation increased CSA at SGS, but not to baseline values. SGS did not alter dynamic motion for the trachea in this rabbit model; however, tracheas were significantly eccentric post-balloon dilation. UTE-MRI can detect SGS without sedation or ionizing radiation and may be a non-invasive alternative to ETT-sizing.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E1971-E1979, 2021.

Ongoing Laryngeal Stenosis: Conservative Management and Alternatives to Tracheostomy

Background: Following tracheal intubation, some children may develop stridor, which is an indication of an obstructive lesion in the airway, such as an ongoing laryngeal stenosis (LS). This review focuses on evaluation of stridor and possible endoscopic predictors of progression to LS and, once post-intubation acute lesions are established, therapeutic choices to manage this disorder in avoidance of tracheostomy. Tracheostomy, due to its inherent increased morbidity, mortality and influence on social stigma, should be viewed only as a last resort. In this article, available conservative and alternative therapies for ongoing LS are thoroughly reviewed. Methods: A systematic review concerning randomized clinical trials and prospective studies on treatment modalities for LS was performed. A search strategy was developed for MEDLINE comprising terms related to disease, intervention and population. Title and abstract from captured references were peer-reviewed for eligibility. Selected studies full-texts were peer-reviewed and the results were compiled in a structured and narrative review. Stridor evaluation and post-extubation acute lesion classification were studied. Treatments such as balloon dilation, rigid dilation, corticosteroid-coated small tube intubation, and corticosteroid nebulization were described and evidence supporting their usage was discussed.