Multi-slice computed tomography assessment of bronchial compression with absent pulmonary valve

Abstract

Background: Absent pulmonary valve is a rare cardiovascular anomaly that can result in profound tracheobronchial compression.

Objective: To demonstrate the advantage of multi-slice CT in diagnosing tracheobronchial compression, its severity as related to the adjacent dilated pulmonary arteries, and associated lung and cardiac lesions.

Materials and methods: We included children with absent pulmonary valve who were reviewed by multi-slice CT during a 17-year period. The number and locations of stenoses and lung lesions were noted and the severity of stenosis was categorized. The diameter of the pulmonary artery was measured and associated cardiac defects were demonstrated.

Results: Thirty-one children (14 girls and 17 boys) were included. Of these, 29 had ventricular septal defect and 2 had an intact ventricular septum. Twenty-nine children (94%) had tracheobronchial compression, judged to be mild in nine children (31%), moderate in 10 (34%) and severe in 10 (34%). The different locations of the stenosis (carina, main bronchi, lobar and segmental bronchi) were observed. And the number and location of lung lesions demonstrated that the right middle and left upper and lower lobes were often affected. The diameter of the pulmonary artery in these children was well above normal published values, and Spearman rank correlation analysis showed a correlation between the size of the pulmonary artery and the severity of the tracheobronchial stenosis. Nineteen children (61%) underwent surgery and 4 of these children had a multi-slice CT post-operative follow-up study.

Conclusion: Absent pulmonary valve can cause significant morbidity and mortality in children. Multi-slice CT can accurately depict areas of tracheobronchial compression, associated lung lesions and cardiac defects, helping to direct the surgeon.

Fig. 1

Multi-slice CT findings of severity of tracheobronchial compression. a Absent pulmonary valve with tetralogy of Fallot in a 7-year-old boy. The multi-slice CT coronal minimum-intensity projection demonstrates mild left bronchial compression (arrow). b Absent pulmonary valve syndrome with tetralogy of Fallot in a 4-month-old girl. Multi-slice CT coronal minimum-intensity projection reconstruction demonstrates moderate right and left bronchial compression (arrows). The two vertical black lines are part of an esophageal tube (arrowhead). c Absent pulmonary valve syndrome with tetralogy of Fallot in a 10-month-old girl. Multi-slice CT coronal minimum-intensity projection reconstruction demonstrates severe right tracheal bronchus stenosis and right bronchial compression and moderate left bronchus stenosis (arrows). Right middle lobar and lower lobar emphysema are present (arrowhead)

Fig. 2

Multi-slice CT findings of location of tracheobronchial compression. a Absent pulmonary valve syndrome with tetralogy of Fallot in a 10-month-old girl. Axial multi-slice CT image demonstrates carina and right main bronchus compression; the carina is shaped like an inverted “V” (arrowhead). Right upper lobar emphysema is present (arrow). b Absent pulmonary valve syndrome with tetralogy of Fallot in a 13-month-old boy. Multi-slice CT coronal minimum-intensity projection reconstruction demonstrates moderate left bronchial stenosis (arrow). c Absent pulmonary valve syndrome with tetralogy of Fallot in a 3-month-old boy. Multi-slice CT coronal minimum-intensity projection reconstruction demonstrates right intermediate bronchial stenosis (arrow) and right middle lobe obstructive emphysema (arrowhead)

Fig. 3

Multi-slice CT findings of absent pulmonary valve with or without ventricular septal defect and compressed bronchus. a Tetralogy of Fallot in a 4-month-old girl. Multi-slice CT axial-oblique maximum-intensity projection reconstruction demonstrates right and left pulmonary artery dilatation (arrows). Right and left main bronchi are inferior and posterior to the dilated right pulmonary artery. The left bronchus looks displaced posteriorly and compressed (arrowhead). b Absent pulmonary valve, intact ventricular septum and atrial septal defect in a 17-month-old girl. Multi-slice CT axial-oblique maximum-intensity projection reconstruction demonstrates main pulmonary artery and left pulmonary artery dilatation (arrows), which is markedly compressing the left bronchus (arrowhead). c Absent pulmonary valve syndrome with double-outlet right ventricle, ventricular septal defect, atrial septal defect and left superior vena cava in a 3-month-old boy. Multi-slice CT axial maximum-intensity projection reconstruction demonstrates a dilated right pulmonary artery (thin arrow) and hypoplastic left pulmonary artery (thick arrow). The proximal left bronchus looks compressed by the dilated right pulmonary artery (arrowhead)

Fig. 4

Absent pulmonary valve syndrome with tetralogy of Fallot in a 4-month-old boy. a Multi-slice CT axial and (b) coronal minimum-intensity projection CT images demonstrate carina (arrowhead in a) and left main bronchial compression (arrow in b). Note the obstructive emphysema in the left lung and right middle lobe (arrows in a). c, d Bronchoscopy demonstrates carina compression (arrow in c) and left main bronchus bronchomalacia (arrow in d). e Multi-slice CT coronal minimum-intensity projection reconstruction 3 months after surgery in the same child, take picture from different angle demonstrates an improved appearance of the left bronchus (arrow) and considerable improvement in the right middle lobe and left lung obstructive emphysema (arrowhead)