Coarctation of the Aorta
Coarctation of the aorta (COA) is a narrowing of the aorta, the main artery that carries blood from the heart to the body. This creates an obstruction of blood flow from the heart to the rest of the body and makes the heart work harder. Pressure also increases above the narrowing and that is why some patients may present with hypertension.
Coarctation occurs most commonly in a short portion of the aorta. However, in babies most of the aortic arch may be small (hypoplastic). Those patients with coarctation may also have other cardiac defects such as a bicuspid aortic valve, PDA, VSD, and others. A very small percentage of patients with coarctation can have other vessel abnormalities, including brain aneurysm. Some patients may not have any symptoms or significant narrowing until there is spontaneous closure of the PDA. A coarctation is common in patients with certain chromosomal abnormalities.
Sometimes the narrowing is mild and may not cause any symptoms. In these patients the coarctation may be detected due to hypertension (high blood pressure) or presence of a murmur or absent femoral pulses. In other cases, the aorta may be more constricted, placing significant strain on the heart. If the narrowing is severe, the ventricle may not be strong enough to perform the extra work resulting in congestive heart failure (CHF). The age in which the coarctation is detected depends on the severity of the narrowing. In approximately 50% of coarctation, the narrowing is severe enough to cause symptoms in the first week of life, when the PDA closes.
Infants with severe coarctation may develop severe symptoms and heart failure (CHF) including:
Poor weight gain
Poor feeding or tiring out
Rapid or labored breathing
Puffy eyes, face or extremities
Cool, pale or dusky skin
Older children and teens that have mild to moderate coarctation may complain of:
Shortness of breath, especially when exercising
Leg cramps after exercising or at night
Frequent nose bleeds
Dizziness or fainting
Chest pain, especially when exercising
Very cold legs and feet
Strong, throbbing headache
High blood pressure
Echocardiography is the most common test used to confirm a coarctation. And MRI or CT scan may be used in some patients if contemplating surgery. Cardiac catheterization is rarely necessary for diagnosis.
In a critically ill newborn the goals of management are to improve heart function and restore blood flow to the lower body. Babies are immediately transferred to a surgical center. In patients without significant coarctation surgical repair is usually done at 4 years of age, or earlier depending on the degree of obstruction, heart function and severity of symptoms. The most common surgical repair involves resection (removal) of the narrowed area (coarctation) with surgical re-anastomosis (reconnection) of the two normal ends to each other. In most cases the surgeon does not have to open the heart to repair a coarctation. It can be fixed through a small incision towards the back of the chest. It is considered a low-risk surgery. The outlook after surgery is favorable, but long-term follow-up is required.
In older children an alternative treatment may be catheter-based therapy. In selected cases the area of narrowing may be dilated with a balloon and/or stent, which is a tube made of metal meshwork, to keep the area open after the procedure. Balloon angioplasty and stenting is performed in the cardiac catheterization laboratory rather than an operating room and there is no real scar. During the procedure an interventional cardiologist inserts a tiny catheter into a blood vessel in the leg and uses a very thin wire to thread it up to the aorta. After establishing the diagnosis, a specialized catheter with a deflated balloon inside is advanced through the narrowing. The doctor then inflates the balloon, expanding the narrow spot. After the area has been widened the balloon is removed. The cardiologist may also implant a stent.
Balloon dilation and stenting as initial therapy for coarctation is somewhat controversial, especially in younger children. However, it is widely accepted as first-line treatment for recurrent coarctation following surgical repair with good results.
Heart surgery is a low-risk procedure. Potential complications are uncommon but there may be damage to vital organs, particularly the kidneys, spinal cord and aorta. The vocal cords and lymphatic drainage system may also be injured. Recurrence of coarctation at the area of repair is possible, even years following surgery. Recurrent coarctation is highest among newborns, occurring in about 20% of patients. Recurrent narrowing of the aorta is rare if the surgery is performed by age 3-4 years. Another concern after surgical repair is high blood pressure (hypertension). Usually the patient will be sent home on medication to treat high blood pressure for an undetermined amount of time.
Long-term follow-up with Dr. Villafañe is important as the patient may develop re-coarctation, dilation of the aorta (aneurysm), persistent hypertension and even aortic dissection. Another reason for continued follow-up is that many of these patients have other heart defects.
Patients with isolated coarctation and good surgical results lead a normal life and have no restrictions except for heavy weight lifting during the post-surgical period.