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

Area of Science:

• Pediatric Surgery
• Radiology
• Neonatal Medicine

Background:

• Neonates with congenital diaphragmatic hernia (CDH) frequently exhibit central airway abnormalities, such as tracheobronchomalacia, which can persist post-surgical repair.
• These airway complications are often underdiagnosed due to reliance on symptomatic evaluation and limited use of bronchoscopy.
• Ultrashort echo time (UTE) magnetic resonance imaging (MRI) provides a non-invasive, 3D method for assessing airway dynamics and evaluating tracheobronchomalacia.

Purpose of the Study:

• To quantify changes in central airway morphology and dynamics before and after surgical diaphragmatic repair in neonates with CDH using UTE MRI.
• To assess the utility of UTE MRI in identifying and characterizing airway abnormalities in neonates with CDH.

Main Methods:

• Retrospective analysis of neonates with CDH who underwent pre- and post-surgical UTE MRI between 2015 and 2020.
• Respiratory-gated radial 3D UTE images acquired at four breathing phases to assess airway dynamics.
• Generation of 3D airway surfaces from the cricoid to the main bronchi for analysis of cross-sectional areas, dynamic collapse, and eccentricity index.

Main Results:

• Six neonates with left-sided CDH were included in the study.
• Post-surgery, a significant decrease in tracheal minimum eccentricity index (indicating increased collapse) was observed (0.68 to 0.53, p=0.023).
• The ipsilateral bronchus also showed significant changes with decreased eccentricity index (0.65 to 0.55, p=0.048), while the contralateral bronchus remained stable. Tracheal cross-sectional area decreased, and dynamic motion increased post-surgery.

Conclusions:

• Neonates with CDH exhibit significant central airway abnormalities pre-surgery that persist or worsen post-repair, particularly in the trachea and ipsilateral bronchus.
• These findings highlight tracheobronchomalacia as an underrecognized component of CDH.
• Integrating airway assessment into surgical planning may improve post-operative outcomes for neonates with CDH.