79: Coarctation of the Aorta and Interrupted Aortic Arch

Coarctation of the aorta (CoA)

• Introduction

  • CoA is defined as a hemodynamically significant narrowing of the aorta. It occurs in about 4 in 10,000 births and accounts for more than 5 percent of congenital heart defects.

• Clinical features

  • CoA presents as a spectrum of disease, ranging from neonatal ductal dependence to newly diagnosed, previously unrecognized, long-standing hypertension in an adult. One-third of neonates have an isolated CoA, one-third a ventricular septal defect (VSD), and one-third have complex congenital heart disease. A bicuspid aortic valve is present in 50 percent. Up to 80 percent of neonates with hypoplastic left heart syndrome have a CoA.

• Diagnosis

  • Echocardiography is the diagnostic modality of choice in neonates. In older patients, computed tomography, magnetic resonance imaging and angiography are employed.

• Treatment

  • Surgical treatment is preferred, with several techniques available. The choice of procedure depends on the anatomy of the aorta and associated anomalies. Native CoA balloon angioplasty is possible but has decreased long-term success in neonates; its use is perhaps of better application in desperately ill neonates and older children and recoarctation. Endovascular stents have emerged as a possible alternative to surgery, but long-term data are not available.

• Results

  • Surgical repair of isolated CoA in the neonatal period can be accomplished with minimal morbidity and mortality, whereas the results of repair of CoA in association with complex congenital heart disease vary according to the dominant cardiac pathology and patient-related variables. Recoarctation occurs in up to 30 percent of patients corrected in the neonatal period, with a similar incidence despite the different techniques utilized. Late hypertension is common in patients operated later in life and is partly responsible for the slightly decreased long-term survival of this patient population.

Interrupted aortic arch (IAA)

• Morphology

  • In this condition there is anatomic lack of continuity in the aortic arch, classified according to the site of occurrence into type A (distal to left subclavian), type B (between the left common carotid and subclavian), and type C (just distal to the innominate artery). Type B is most common and is associated with thymic agenesis and 22q11 microdeletion. The prevalence of IAA is 0.003 per 1000 live births. A VSD is nearly always present. Bicuspid aortic valve is found in 50 percent of infants, with left ventricular outflow tract obstruction (LVOTO) often seen because of hypoplasia of the aortic root or posterior malalignment of the infundibular septum.

• Clinical features

  • In newborns not prenatally diagnosed, presentation is rapid because of ductal closure and resulting visceral hypoperfusion and shock. Peripheral pulses vary according to the site of interruption and there is variable pulmonary overcirculation. Median time of death if untreated is between 4 and 10 days from birth, with 75 percent mortality within 1 year.

• Diagnosis

  • Echocardiography is the diagnostic modality of choice in neonates. In more complex anomalies, computed tomography, magnetic resonance imaging, and angiography are employed.

• Treatment

  • Surgical treatment follows a brief period of stabilization with prostaglandin (PGE1) infusion and restoration of ...