What Is Aorta?
The human heart consists of blood vessels that carry blood from the heart to other parts of the body and vice versa. Aorta is one such major vessel or artery, to be specific, that carries pure oxygenated blood from the heart to other parts of the body. It is the largest artery of the body. It measures an inch in diameter. The aorta continues its course from the heart, extends upwards towards the neck, and then continues down the abdomen to form an arch-shaped bend or curve known as the aortic arch.
What Does Aortic Arch Interruption Mean?
Aortic arch interruption or interrupted aortic arch is a structural defect of the heart which develops as a result of the incompletely formed aorta during fetal development. A discontinuity in the aortic arch occurs. A part of the aorta goes missing leaving a gap behind. This prevents the blood from the heart from flowing throughout the body. Surgery is the only treatment modality that can save the affected baby’s life.
Babies born with an interrupted aortic arch usually also have DiGeorge syndrome, a genetic disorder wherein the affected children have heart problems, decreased ability to resist viral infections, low blood calcium levels, cleft palate, kidney problems, abnormal facial features, and learning problems.
What Are the Types of Interrupted Aortic Arches?
Based on the site of aortic interruption, three types of aortic arch interruption exist,
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Type A - The interruption occurs beyond the left subclavian artery distal to it. Nearly 40 percent of babies born with aortic arch interruption have this type of interruption.
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Type B - In this type, the interruption occurs between the left subclavian artery and the left carotid artery. This is the most common type, and nearly 50% of babies with aortic arch interruption are born with this type.
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Type C - In this type, the interruption occurs between the brachiocephalic artery and the common carotid artery.
How Does Aortic Arch Interruption Develop?
During the fifth to seventh week of fetal development within the womb, some developmental disturbance results in faulty development of the aorta. This condition is hereditary, meaning it gets passed on from parents to their children.
Infants with interrupted aortic arch have a blocked aorta. Hence blood from the heart flows to other parts of the body through an opening called patent ductus arteriosus. This is a small blood vessel that permits the blood to bypass the baby’s fluid-filled lungs while the baby is in the womb. This patent ductus arteriosus usually closes on its own two days after birth. In babies with interrupted aortic arch, once the duct closes, blood from the heart can no longer reach other parts of the body leading to a sudden illness. This can cause the baby to suddenly become very ill. A drug called prostaglandin is given to the baby to keep the duct open until surgery is performed.
What Signs and Symptoms Do Infants With Aortic Arch Interruption Have?
Affected babies usually experience the following signs and symptoms:
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Fatigue.
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Weakness.
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Poor feeding.
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Rapid breathing.
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Grayish skin.
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A hole in the septum of the heart (atrial or ventricular septal defect).
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Low oxygen levels.
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Decreased urine output.
How Common Is Aortic Arch Interruption?
The condition is a rare one. It affects nearly 1.5 % of babies with congenital heart conditions. It is also said that the incidence is 2 cases per 100,000 live births.
How Is Interrupted Aortic Arch Diagnosed?
Even before the birth of the baby, the aortic arch interruption can be diagnosed with the help of prenatal ultrasound images.
Once the baby is born, until the closure of the patent ductus arteriosus, no symptoms occur. The duct closes within hours or days of birth, after which symptoms like weakness, poor feeding, grayish skin, cold feet, etc., develop based on which diagnosis is made. A heart murmur, increased heart rate, breathing rate, and liver enlargement might also be present. A pulse in the left arm or leg might be absent.
An echocardiogram helps confirm the diagnosis. Apart from this, heart catheterization oxygen saturation test, electrocardiogram, and chest X-rays are also performed by the physicians for diagnosis and treatment planning.
How Is Interrupted Aortic Arch Treated?
As soon as an interrupted aortic arch is diagnosed, treatment is immediate and vital. Though surgery is not performed immediately, it must be performed as soon as possible. Until then, a drug called Prostaglandin is given to keep the patent ductus arteriosus intact and prevent sudden cardiac collapse. This will help with the maintenance of continuous blood supply to other parts of the body (especially the lower part of the body) until surgical correction.
Surgery is performed to establish communication between the interrupted aortic arch. This is performed with the help of native arterial tissue, a homograph, or an autograph vascular patch. Along with this, if a hole is present (ventricular septal defect), it is also repaired with the help of a synthetic patch made up of polyester or polytetrafluoroethylene (ePTFE).
Are There Any Complications of Aortic Arch Interruption Surgery?
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At the site of surgery, a narrowing can develop over time. But this could be corrected with a procedure called balloon angioplasty.
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A condition called subaortic stenosis can occur, which needs a re-surgery.
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Those with corrected aortic arch interruption have the risk of bacterial endocarditis (inflammation of the heart due to bacteria in the bloodstream), especially with dental treatments, gastrointestinal and respiratory tract procedures. But such an incident can be prevented by taking prophylactic antibiotics before the procedure.
Can a Child With Aortic Arch Interruption Perform Normal Physical Activities After the Surgical Repair?
Children surgically corrected for aortic arch interruption are contraindicated from doing vigorous physical activities. But they can do activities and sports that do not require physical exertion. Also, they have to be aware of the fact that they need to take rest as and when required while performing physically exhausting tasks.
Conclusion:
Though a rare disease, aortic arch interruption is indeed life-threatening, requiring immediate surgical correction to save the life of the affected little one. Prenatal ultrasound scans are greatly beneficial in identifying one early, even before the birth of the child, letting the parents and the physician stay pre-prepared. Consult our specialist online to know more about the condition.
