ACE Question

Which of the following associated cardiovascular anomalies is MOST likely to be found in a 15-year-old boy presenting for angiographic balloon dilatation and stenting of aortic coarctation?

• (A) Bicuspid aortic valve
• (B) Tetralogy of Fallot
• (C) Vascular ring

Coarctation of the aorta is a congenital defect most often diagnosed early in life. If severe and concurrent with closure of the ductus arteriosus, an undiagnosed neonate can present in cardiogenic shock. Many such coarctations are diagnosed during fetal echocardiography. In this instance, surgical repair is performed shortly after birth and prior to complete closure of the ductus arteriosus. In neonates, restenosis is less likely after surgical repair than after balloon angioplasty.

The anatomic location of the aortic coarctation is defined as preductal, juxtaductal, or postductal. It occurs in males about 1.5 times more frequently than females. When diagnosed later in life, aortic coarctation can be associated with right upper extremity hypertension, headache, epistaxis, or heart failure. Associated congenital cardiac lesions include bicuspid aortic valve (80%), patent ductus arteriosus (50%), and, less frequently, ventricular septal defects, atrioventricular septal defects, and other left-sided cardiac lesions. Neither vascular ring (branches of the aorta entrapping the trachea) nor Tetralogy of Fallot has been associated with aortic coarctation.

When diagnosis of aortic coarctation is delayed, collateral circulation can develop (Figure 1). Anastomotic connections between the internal thoracic and subclavian arteries, thyrocervical trunks, and vertebral and anterior spinal arteries provide blood flow to the descending aorta, thus the lower body. Patients with robust collateral flow may have minimal decrease or delay in lower extremity pulses. Delayed diagnosis is also associated with postrepair persistence of hypertension, coronary artery disease, and stroke. Without treatment, the mortality rate at age 43 years is reported to be 75%.

In adult and older pediatric patients, the accepted initial treatment of discrete aortic coarctation is balloon angioplasty and stenting (Figure 2). Sequelae and complications include restenosis (especially in younger patients who are still growing), aneurysm formation, aortic dissection, stent migration, balloon rupture, femoral artery injury, and stroke.