Fetopathology and developmental pathology of the embryo and fetus: Coarctation of the aorta

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Coarctation of the aorta

Classification

Coarctation is congenital narrowing of the aorta just distal to the origin of the left subclavian artery

two variants:
- true coarctation: local, short narrowing of the aortic arch. According to the relationship between the coarctation and the inserction of the ductus arteriosus or ligamentum arteriosum preductal, juxtaductal and postductal variants are distinguished.
- tubular hypoplasia: narrowing of the long preductal segment of the aortic arch between the left subclavian artery and the ductus (the aortic isthmus). In extreme coarctation the entire trasverse aortic arch may be hypoplastic. Tubular hypoplasia is the variant seen commonly in fetuses

Coarctation of the aorta may be an isolated defect but is frequenly associated with other cardiac malformations: bicuspid aortic valve, patent ductus arteriosus, ventricular septal defect, mitral valve anomalies, tricuspid atresia etc.

Clinical signs

symptoms of severe and progressive left heart failure occur in first days of life with closure of the ductus (there is an acute increse in afterload to the left ventricle)
in less severe obstruction there is time for compensatory mechanisms to develope: left ventricle hypertrophy, collateral vessels bypassing the obstruction
typical finding is diminished blood pressure and pulses in femoral arteries compared to upper extremities. Note: the pulse in lower extremities is palpable in infants with patent ductus.
surgical therapy: resection of the narrowed segment and end to end anastomosis. Subclavian flap aortoplasty is used in tubular hypoplasia
coarctation of the aorta is often associated with Turner syndrome

Pictures

Scheme of coarctation of the aorta: Coarctation of the aorta, Macro, autopsy (72718)