Discussion
APVS includes rudimentary, dysplastic, or absent pulmonary valve
leaflets, dilated main pulmonary artery with or without dilation of its
branches, to-and-fro flow at the site of the absent pulmonary valve, and
systolic pressure gradient across the narrowed pulmonary valve1. APVS is a rare variant of ToF, which accounts for
approximately 3–6% of patients with ToF 2.
L-TGA is also rare, with a published incidence ranging from 0.02 to 0.07
per 1000 births 3. The most common anatomic cardiac
abnormalities with L-TGA include ventricular septal defect, pulmonary
stenosis, and abnormalities of the tricuspid valve 3.
A dilated pulmonary artery with APVS can compress the tracheobronchial
tree and the esophagus, which is a significant indicator of poor
postnatal prognosis 4. One study showed that complete
repair with a valved conduit and reduction pulmonary arterioplasty can
help improve tracheomalacia 5. Although most patients
might require pulmonary arterioplasty, it is still controversial whether
a pulmonary valve or a valved/unvalved conduit should be inserted and
how the degree of size reduction of the pulmonary artery should be
determined. The standard medical therapy for tracheomalacia is
positive-pressure ventilation with or without a tracheostomy5. We performed anatomical left ventricle to pulmonary
artery shunt with a bicuspid conduit made of polytetrafluoroethylene,
which has excellent biocompatibility and low antigenicity6. Our patient required tracheostomy and positive
pressure ventilation from birth till the age of one year. The anatomical
left ventricle instead of the right ejected blood to the pulmonary
artery directly because of cTGA. This, along with aortic valve stenosis,
could lead to pulmonary over circulation and dilate the pulmonary artery
easily. Therefore, the complex of APVS, cTGA, and aortic stenosis might
cause pulmonary artery dilation and tracheomalacia more easily than APVS
with TOF.