Impact of Surgical Diaphragmatic Repair on Central Airway Shape in Neonatal Congenital Diaphragmatic Hernia.

RATIONALE: Neonates with congenital diaphragmatic hernia (CDH) frequently experience central airway abnormalities, including tracheobronchomalacia, which persist post-surgical repair. However, these complications often remain underdiagnosed due to reliance on symptomatic evaluation and limited use of bronchoscopy. Ultrashort echo time (UTE) magnetic resonance imaging (MRI) offers a non-invasive, three-dimensional method to assess airway dynamics and evaluate tracheobronchomalacia.

OBJECTIVES

To quantify changes in central airway morphology and dynamics before and after surgical diaphragmatic repair in neonates with CDH using UTE MRI.

METHODS

This study examined neonates with CDH admitted between 2015 and 2020 who underwent both pre- and post-surgical UTE MRI. Airway dynamics were assessed using respiratory-gated radial three-dimensional UTE images at four breathing phases. Three-dimensional airway surfaces were generated from the cricoid to the main bronchi. Changes from pre- to post-surgery in cross-sectional areas, dynamic collapse, and eccentricity index were analyzed.

RESULTS

Six neonates with left-sided CDH were included. Following surgery, tracheal minimum eccentricity index at end expiration decreased significantly (0.68 ± 0.06 to 0.53 ± 0.15, p = 0.023), indicating increased collapse. The ipsilateral bronchus demonstrated similar changes, with eccentricity index decreasing significantly from 0.65 ± 0.04 to 0.55 ± 0.11 (p = 0.048), while the contralateral bronchus remained stable. Mean tracheal cross-sectional area decreased from 22.7 ± 6.1 mm² to 19.1 ± 3.1 mm² (p = 0.115), while dynamic motion increased from 21 ± 7% to 40 ± 15% (p = 0.055).

CONCLUSIONS

Neonates with CDH have significant central airway abnormalities pre-surgery, which persists and may worsen post-repair, particularly in the trachea and ipsilateral bronchus. These findings suggest tracheobronchomalacia is an underrecognized component of CDH. Integrating airway assessment into surgical planning could improve post-operative outcomes.