Teaching Case

A term female neonate with tracheomalacia following antenatal treatment of a left-sided congenital diaphragmatic hernia with fetal endoluminal tracheal occlusion (FETO) [1], presented to our department for pre-operative computed tomography (CT).

Computed tomography, focused on tracheal anatomy for endotracheal prosthesis tailoring, revealed the association of antenatally treated left diaphragmatic hernia, tracheomalacia and a right extra-pulmonary sequestration. The arterial blood supply of the sequestration arose from the abdominal aorta.

Congenital diaphragmatic hernia (CDH) is the most common cause of secondary pulmonary hypoplasia. It is left-sided in the vast majority of cases, while right-sided and bilateral forms are infrequent. Antenatal ultrasound can easily detect left-sided CDH, and magnetic resonance imaging (MRI) can improve the detection of and evaluate the extent of the defect. Prognosis is mainly related to the size of the herniation, the extent of which is best demonstrated with MRI. [2]
FETO is an antenatal therapeutic option for CDH, characterised by tracheal occlusion with a detachable balloon, which improves alveolar growth and vascular maturation. [1] This technique has improved the prognosis of these patients, but there are associated complications, mainly tracheomalacia typically presenting at birth. [3]
In the literature CDH has been described in association with other congenital anomalies, such as extra-lobar pulmonary sequestration [4], suggesting they could be ends of a common spectrum.
Bronchopulmonary foregut malformations (BPFMs) can be classified into three groups: bronchopulmonary anomalies, vascular anomalies, or a combination of both lung and vascular anomalies. Pulmonary sequestration is part of the combined anomaly group, and is the second BPFM most commonly observed antenatally. It is characterised by a portion of pulmonary parenchyma isolated from tracheobronchial tree and characterised by systemic arterial supply, mainly from the thoracic or abdominal aorta. It is classified as intra or extra-lobar, depending on whether the pleural investment is shared with normal lung in intra-lobar pulmonary sequestrations, or whether the sequestration has its own pleural investment, as in extra-lobar pulmonary sequestrations, and on whether the venous drainage is to the pulmonary or systemic veins respectively. Antenatal ultrasound and MRI can detect the presence of the sequestration and the feeding artery, as can postnatal CT.
This case underlines the potential coexistence of congenital malformations and potential complications associated with FETO.
Antenatal and postnatal imaging play a pivotal role in the management of these patients, especially when potentially treatable.