Pediatric Coarctation of the Aorta

Coarctation (pronounced ko-ärk-'ta-shun) comes from the Latin term for “constrict.”

Coarctation is a narrowing of the aorta, which is the main vessel that carries blood to the body. Shaped like a candy cane, the aorta leaves the heart and moves up toward the head, makes a 180-degree curve in the upper chest, and then goes down the chest and into the abdomen. During the curve, the aorta gives off three large branches to supply the head, neck and arms with blood. Coarctation of aorta is a pinching at the point in the upper chest where the aorta is just starting to move down to the lower body, just past the third branch to the arms.

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It is not completely understood why some people develop a coarctation and others do not. What is widely accepted is that the coarctation typically develops in the area of the ductus arteriosus. This is a blood vessel that is present in fetal circulation and typically closes off after birth. When the ductus arteriosus constricts, it often can cause narrowing of the aorta at the point where they are connected. This narrowing is what develops into the coarctation.

Coarctation of the aorta may occur as an isolated defect, but commonly occurs along with other heart defects. The most common defect associated with coarctation is a hole between the two main pumping chambers of the heart, known as a ventricular septal defect. The presence of another defect may greatly impact the treatment of the coarctation.

In a recent study in Atlanta, the U.S. Centers for Disease Control and Prevention (CDC) has estimated that about four out of every 10,000 babies born have coarctation of aorta.

Coarctation may be diagnosed during pregnancy with a fetal echocardiogram, which is a specialized ultrasound of the fetal heart. The affiliated physicians in the Fetal Cardiology Program at The Fetal Center will confirm a coarctation of the aorta diagnosis and prepare a delivery plan for both mom and baby. A multidisciplinary team of specialists will also develop the baby's immediate care plan following delivery.

If coarctation is not diagnosed in utero, and suspicion of a heart defect occurs after the baby is born, a pediatrician will refer the patient to a pediatric cardiologist or neonatologist to determine the diagnosis.

A mild to moderate coarctation may have no symptoms at all. Doctors may discover it soon after birth or several years later (and, more rarely, in early adulthood) by hearing a murmur in the area and also noting differing pulses and blood pressures in the upper and lower body. Since the narrowed portion occurs just past the third branch to the arms, blood pressure may be higher in the arms than in the legs. Clues to severe coarctations include pale skin, irritability, poor growth, heavy sweating, difficulty breathing and cold feet or legs.

The following tests may be utilized to find more details:

• Pulse oximetry is a small and painless monitoring device placed on a finger or toe to reveal the oxygen level in the blood. In a newborn, the oxygen level may drop with a coarctation.
• An echocardiogram (ECHO) uses sound waves (ultrasound) to produce images on a screen of the heart and blood vessels in action. These reveal whether the heart is pumping properly.
• An electrocardiogram (EKG or ECG), a painless exam, checks the heart’s electrical action that may reveal enlargement from the heart working harder in the presence of a coarctation.
• Chest X-rays create images of the heart and lungs to detect abnormalities. It can detect heart enlargement, and in older patients, can reveal enlarged blood vessels that are circumventing the coarctation.
• A cardiac MRI (magnetic resonance imaging) uses radio waves, magnets and a computer to form three-dimensional images of the heart, which can reveal structural abnormalities in detail.
• Cardiac catheterization involves a thin, long tube that is inserted into a blood vessel and guided into an artery or vein in the heart. Through the procedure, the heart’s direct pressure and blood flow measurements can be obtained. Coarctation may also be treated in the catheterization laboratory, depending on the nature of the coarctation and the age/size of the patient.

No matter the child’s age, a narrowed aorta must be fixed. Having to squeeze blood through this narrowed area is an extra stress on the heart, so it is usually recommended that children with mild to moderate coarctations have surgery to widen the blood vessel. In severe cases, which usually occur in the newborn period, there is not enough blood that can get through the narrowed portion to keep the lower part of the body healthy. These babies may need urgent surgery to fix their coarctation.

Surgery for coarctation of aorta involves widening the narrowed portion and is usually done through an incision in the left side of the chest (called a thoracotomy), although there are occasions when it may be done through a vertical incision in the front of the chest (sternotomy).

The surgical repair can be done in one of two ways:

• Narrowed segment is cut out - there is enough "give" in the aorta to put the two good ends back together.
• Incision is made along the length of the narrowed segment and a patch is placed to widen it.

Neither method has proved to be superior to the other. The particular technique is chosen by the surgeon based on the characteristics of that individual coarctation as well as his/her personal experience or preference.

The complication rate from surgery is low, and the narrowing can usually be widened satisfactorily. Whichever technique is used, approximately 5% of patients will redevelop narrowing in that area over the first few months to years. It is also possible that the high blood pressure, which many of these children have before surgery, may not go away after surgery. The reasons for this are unclear.

Cardiac Catheterization:

Some patients with coarctation (or a coarctation that came back after surgery) can have the coarctation repaired by stretching it with a balloon. This procedure is done in the cardiac catheterization room and does not involve open surgery. Your cardiologist and surgeon will be able to help guide you as to whether this is a possibility.

What Are the Long-Term Effects?

Most symptoms resolve after the operation. The complication rate is low, and the narrowing usually can be widened satisfactorily. Many children will require anti-hypertensive medications to control high blood pressure for the first few months after surgery. There is also an increased incidence of high blood pressure in adults that had coarctation repairs as infants and children.

As a child grows, a coarctation may reoccur. In rare cases, an aortic aneurysm (a localized enlargement of an artery caused by a weakened arterial wall) may be suspected, and a CT scan (a more detailed form of three-dimensional X-ray known as computed tomography) may be ordered.

If coarctation reoccurs after surgery, the primary treatment is with heart catheterization where a balloon can be used to restretch the area (angioplasty), or a stent can be implanted to maintain open the constricted site.

What Follow-Up Care Is Needed?

A cardiologist should monitor the child regularly to make sure blood pressure is normal and no further health conditions arise. Periodic electrocardiograms and echocardiograms may be needed.

Some children will need blood-pressure-lowering medications long-term after surgery.

At Children’s Heart Institute at Children’s Memorial Hermann Hospital, patients with congenital or acquired heart disorders receive hands-on specialized care 24/7 from a team of affiliated physicians and specialty-trained nurses who aim to deliver the best possible outcomes.

Children’s Memorial Hermann Hospital was named one of the top children's hospitals nationally in Cardiology & Heart Surgery by U.S. News & World Report. In addition, Children’s Heart Institute is among the top congenital heart surgery programs in North America for patient care and outcomes, according to the Fall 2019 Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database Report of 118 STS participating programs.

In collaboration with various subspecialties, the affiliated team provides comprehensive care for newborns, children and adolescents, with the ability to transition into adult congenital cardiac care. Team members have the experience and skills necessary to offer innovative treatment methods and specialized services, including, but not limited to:

• Biventricular repairs and biventricular conversions
• Congenital heart optimization
• Full repairs for complex congenital heart defects in newborns
• Hybrid catheterization and surgical procedures
• Minimally invasive transcatheter pulmonary valve (TPV) therapy
• Minimally invasive repairs
• Treatment for adult congenital heart disease
• Valve repairs and preservation

With the Level IV Neonatal Intensive Care Unit (NICU) and a dedicated Children’s Heart Institute Intensive Care Unit at Children’s Memorial Hermann Hospital, critical heart patients have access to quality, specialized care. By utilizing state-of-the-art techniques, the team at Children’s Heart Institute strives to offer patients with the most complex problems the greatest opportunity for a normal life.

If you have any questions, use the online tool below to help us connect with you. To refer a patient or schedule an appointment, please contact our clinic using the information below.

• Pediatric Cardiology Clinic
  The University of Texas Health Science Center Professional Building
  6410 Fannin, Suite 370
  Houston, TX 77030
  Phone: (713) 486-6755 (Appointment Line)
   
• Pediatric and Congenital Heart Surgery Clinic
  The University of Texas Health Science Center Professional Building
  6410 Fannin, Suite 370
  Houston, TX 77030
  Phone: (713) 500-5746
  CMHH-Heart@memorialhermann.org

The Children’s Heart Institute is a collaboration between the affiliated physicians at McGovern Medical School at UTHealth Houston and Children’s Memorial Hermann Hospital. Typically, patients are seen on an outpatient basis at a UT Physicians clinic with all inpatient procedures performed at Children’s Memorial Hermann Hospital.