What Is An Aortic Arch?Before proceeding to know what an aortic arch is, it is necessary first to understand the whole aorta’s anatomy. The aorta is responsible for transporting oxygen-rich blood to different parts of the body, after starting from the aortic valve, the ascending aorta winds towards the head, which becomes the aortic arch. It is also regarded as a transverse aorta because of its rainbow shape over the heart’s superior aspect. This aortic arch then moves in an inferior direction through the chest and abdomen. At the left subclavian artery, the aortic arch becomes the thoracic aorta. Following the thoracic aorta, there is the abdominal aorta.
Aortic CoarctationAortic coarctation generally refers to the narrowing or compression of the aortic arch or the entire aorta. The heart consists of the left and right atrium, right and left ventricle, the pulmonary artery, which leads the right ventricle to the lungs, and the aorta that goes into the body.
Types Of Aortic CoarctationThere are two different types of aortic coarctation to be familiar with
- Infantile Pediatric Form: The infant form of aortic coarctation amounts for up to 70% of the total cases. The coarctation generally occurs after the aortic arch, which branches off to the upper extremities and into the head, and prior to the ductus arteriosus. The ductus arterioles only appear during fetal development and usually close after birth. However, in cases of infant coarctation, this ductus arteriosus remains open (patent), and the lower half of the body will suffer from cyanosis.
- Adult Form: In the adult form, the coarctation appears after the ductus but is not associated with a patent ductus arteriosus. As a result, the lower body will NOT suffer from cyanosis in cases of Adult Aortic Coarctation. However, there will be more blood supply to the upper half of the body in the adult form and less blood supply to the lower. This will result in hypertension in the upper half and hypotension in the lower half.
TreatmentThe treatment against the aortic coarctation varies depending on how extensive the coarctation is. In its most usual form where the coarctation is very discreet and is restricted to the area of the aorta when it starts traveling downwards, this can be treated with either balloons or catheters through the groin or through an incision in the left side of the chest and surgically removing the narrowed portion of the aorta. There are multiple options available for treatment against aortic coarctation. In balloon dilation, a tiny balloon is used to widen the aorta as well as having the narrowed area of the aorta surgically removed, which corrects hypertension. In its most extreme form, when a large of the aorta has narrowed, and there is inadequate blood flow, this traditionally requires a more extensive surgery from the front of the chest while connecting the subject to a heart-lung machine. The exact type of therapy needed depends on the age, the extent of the lesion, and the expertise to deal with different conditions in the individual hospital. Also, surgery can be performed in asymptomatic patients to eliminate the compression of the trachea and the esophagus. For a double aortic-arch repair, the left arch is typically divided along with an adductor ligament. In cases of vascular ring repair, surgery required division of the ductal ligament.
Interrupted Aortic Arch Developmental DefectsIn the early stages of fetal development, two aortic arches come from the heat, ascend upward, and then gradually descend into the heart, merging together to form a single aorta. As the heart develops, the right-sided arch slowly disappears, leaving the left-sided arch to drop upward and continue to the descending aorta located behind the heart. The naturally developed left-sided aorta is located immediately in front of the trachea and the esophagus. However, a vascular ring is a defect in which the arch vessels encircle the trachea and the esophagus and is usually caused by the abnormal development of the aortic arch. If both arches stay open, it is termed a double-aortic arch, and these two arches surround the trachea and the esophagus, leading to narrowing or compression of the aorta or the aortic structure, eventually causing difficulties in breathing and feeding. In yet another form of the interrupted aortic arch, the left-sided arch disappears while the right-sided arch remains open, causing the vascular ring’s formation.
Aortic Coarctation RecoveryOnce the aortic coarctation is done and taken care of successfully, the patients still need to follow-up with their respective cardiologists routinely in order to ensure that the aorta continues to grow. A subset of patients who undergo aortic coarctation repair either surgically or with the balloon often require additional procedures to open up the scar tissue and ensure that the aorta grows subsequently. In terms of long-term outcomes, a small subset of patients tends to have high blood pressure that might need medications for a prolonged time to ensure that their blood pressure remains under control. Apart from the above-mentioned subset of patients, most people who undergo an aortic coarctation can have a relatively average life expectancy without any restrictions on their activities in the long term whatsoever.
Interrupted Aortic Arch: Survival RateWith the rapid evolution of science and technology, the medical field has received a considerable boost. Over the past few years, patients’ survival rate from interrupted aortic arch has leaped from 65% to almost 90%. However, the narrowing can reappear at some sites over the years but can be treated with balloon angioplasty.
Signs and symptoms of poor perfusion or congestive heart failure may develop when the ductus arteriosus begins to close, usually within the first day or two after birth
The vessels before the coarctation see a higher amount of blood pressure compared to those after. This coarctation can sometimes be detected by fluctuating blood pressures in the arms and legs. The degree to which the aortic arch has narrowed usually is the deciding factor in determining how soon the patient should undergo treatment. Some traditional symptoms of aortic coarctation include high BP, chest pains, fastened heartbeat, breathing difficulty, fatigue, headaches, muscle weakness, nosebleeds, leg cramps, cold feet, and so on.
In cases of infantile coarctation, the baby's skin may turn blue/gray in places where there is an insufficient supply of blood. Babies born with prior heart ailments are also prone to the interrupted aortic arch.
NOTE: Coarctation of the aorta is a rare heart condition and isn't often detected until adulthood. However, a high BP amongst adults could be an indication of aortic coarctation.
The infant may develop weakness, fatigue, poor feeding, rapid breathing, fast heart rate, or low oxygen levels, particularly when measured in the legs and feet.
This condition can worsen and lead to shock. The infant will then be pale, mottled and cool. The infant will likely have decreased urine output and poor pulses, especially in the lower extremities.
Interrupted aortic arch is thought to be a result of faulty development of the aortic arch system during the fifth to seventh week of fetal development. This defect is almost always associated with a large ventricular septal defect (VSD).
Patients with interrupted aortic arch often have a chromosomal abnormality called DiGeorge syndrome.