Generality
Aortic coarctation is the medical expression that indicates an abnormal narrowing along the initial part of the aorta, near the so-called arterial ligament.
Almost always of a congenital nature, the aortic coarctation subjects the heart of the patient to a greater effort than normal, in order to spread the blood beyond the narrowing; this effort can have several consequences, including: hypertension in the upper limbs combined with hypotension in the lower limbs, respiratory problems, slowing of growth, difficulty in eating, cyanosis and chest pain.
The diagnosis of aortic coarctation is based, generally, on the physical examination, on an echocardiogram and on a series of in-depth cardiac tests.
For those suffering from aortic coarctation, there is the possibility of repairing the vascular narrowing by surgery or an operation known as angioplasty with stenting .
Short review of the aorta
The aorta is the largest and most important artery in the human body.
Originating in the heart (to be precise from the left ventricle of the heart ), this fundamental arterial vessel is provided with numerous ramifications, through which it supplies every district of the human body with oxygenated blood, from the head to the lower limbs, passing through the limbs upper and trunk.
Analyzing it from the beginning, the aorta is didactically divided into two large consecutive sections: the thoracic aorta, occupying the anatomical portion of the thorax and including the three segments known as ascending aorta, aortic arch and descending aorta, and the abdominal aorta, located in the anatomical portion of the abdomen.
What is Aortic Coartation?
Aortic coarctation, or coarctation of the aorta, is a mostly congenital defect of the aorta, such that the latter presents an anomalous luminal narrowing in the vicinity of the so-called arterial ligament, ie the fibrous structure that unites the aortic arch to the pulmonary artery representing the post-natal residue of the fetal blood vessel known as the Botallo duct (or ductus arteriosus ).
For the avoidance of doubt, luminal narrowing means a reduction in the vascular lumen or, if preferred, of the vascular diameter .
What is the Botallo duct?
Present only during fetal life, the Botallo duct is the blood vessel that connects the pulmonary artery to the descending aorta and which serves to diffuse oxygenated blood towards the lower districts of the human body (abdominal organs and lower limbs).
The presence of the Botallo duct in the fetus is related to the inability of the child in the uterus to breathe and use the lungs to oxygenate the blood (at birth, with the disappearance of the arterial duct, the pulmonary artery becomes the artery that conveys oxygen-poor blood into the lungs).
The consequences
As it is an obstacle to blood flow, aortic coarctation involves a greater workload for the left ventricle of the heart, when the latter has to diffuse the oxygenated blood in the aorta. In fact, in order to carry the blood beyond the narrowing of the aorta, the left ventricle of the heart must generate a pressure greater than normal .
The whole situation described above is further complicated, when the aortic coarctation is severe: in this circumstance, despite the efforts of the left ventricle of the heart, the oxygenated blood struggles to overcome the aortic narrowing and the blood supply to the lower parts of the body human is compromised (remember that aortic coarctation localizes, at most, at the beginning of the descending aorta, ie the aortic portion that directs the oxygenated blood towards the abdomen and lower limbs).
Among the typical consequences of aortic coarctation, the difference in arterial pressure that is established between the upper part and the lower part of the body deserves a mention: superiorly, the arterial pressure is higher than normal, thanks to the work with greater pressure carried out from the heart; inferiorly, however, it is smaller than normal, due to the fact that the overcoming of the aortic narrowing subtracts pressure force from the blood pumped from the heart.
Epidemiology
It is difficult to accurately estimate the incidence of aortic coarctation in the general population, as this defect of the aorta can go unnoticed even throughout life, due to the possible lack of a related symptomatology.
Epidemiological studies concerning the spread of aortic coarctation in the two sexes have shown that male patients are twice as many female patients .
Causes
The causes of congenital aortic coarctation are unknown ; in other words, the factor - be it a genetic mutation or another type of event - that affects the normal fetal development of the aorta is not known.
Causes of non-congenital aortic coarctation
Aortic coarctation can also be a defect acquired throughout life (non-congenital aortic coarctation). In such situations, the possible cause may be:
- A traumatic injury to the thoracic aorta, such that the latter undergoes a narrowing;
- Atherosclerosis, that is the phenomenon of hardening of the arteries of medium and large caliber, combined by the formation of atheromas on the wall of these same vascular ducts;
- Takayasu arteritis, a vasculitis of autoimmune origin, which affects the major arteries such as the ascending aorta, the aortic arch, the branches of the aortic arch, the descending aorta, the pulmonary artery and its main branches.
Types of aortic coarctation
Depending on the site of the aortic narrowing, doctors distinguish aortic coarctation into three broad categories, which are:
- Pre-ductal aortic coarctation . This category includes all cases of coarctation of the aorta, in which the aortic narrowing localizes before the arterial ligament.
- Ductal aortic coarctation . This category includes all cases of coarctation of the aorta, in which the aortic narrowing is located at the arterial ligament.
- Post-ductal aortic coarctation . This category includes all cases of aortic coarctation, in which the narrowing of the aorta lies shortly after the arterial ligament.
Curiosity
Pre-ductal aortic coarctation is a congenital defect found in 5% of girls born with Turner syndrome .
The reasons for the association between pre-ductal aortic coarctation and Turner syndrome are unknown.
Symptoms and Complications
The degree of narrowing of the aorta plays a fundamental role on the characteristics of the symptomatology of aortic coarctation.
In fact, if the narrowing is slight, the aortic coarctation tends to lack symptoms even for the whole life of the patient; if, on the other hand, the narrowing is moderate or severe, it is always associated with a very precise symptomatology and from the first moments of life.
Below, the article reports a series of symptomatic case histories, distinguished according to the severity of the patient's shrinkage and age.
Mild aortic coarctation: possible symptoms in the child and in older patients
Recalling that its association with a symptomatology is infrequent, a slight aortic coarctation, in a small child, can cause:
- Weak breathing problems;
- Appetite decrease;
- Difficulty feeding;
- Growth slowdown.
In an adolescent and in an even more advanced age, however, it may be a reason for:
- Hypertension in the upper limbs and hypotension in the lower limbs;
- Dizziness;
- Dyspnoea;
- Syncope or pre-syncope;
- Chest pain;
- Sense of weakness;
- Leg cramps and intermittent claudication ;
- Nose blood;
- Headache.
Severe aortic coarctation: symptoms in the child
In a small child, severe aortic coarctation is always responsible for:
- Important respiratory problems;
- Cyanosis;
- Irritability;
- Profuse sweating;
- Serious inability to feed;
- Appetite decrease;
- Drastic slowdown in growth;
- Hypertension in the upper limbs (hypertension in the arms);
- Weak pulse in the lower limbs.
This complex and important symptomatology depends on the extreme workload to which the heart is subjected, in an attempt to pump oxygenated blood, and by the lack of blood perfusion towards the lower extremity of the body.
Complications in mild cases
At a later age and in the absence of adequate treatments, a mild aortic coarctation can determine a persistent state of hypertension in the upper parts of the body as well as the thickening of the muscular wall of the left ventricle ( left ventricular hypertrophy ); both of these phenomena are direct effects of the work at greater pressure carried out by the heart, with the intention of spreading the oxygenated blood beyond the narrowing of the aorta.
Complications in severe cases
In the absence of adequate therapy, severe aortic coarctation can result in numerous complications, some with a lethal outcome or otherwise highly debilitating.
The complications in question include:
- Heart failure;
- Stenosis of the aortic valve (aortic stenosis);
- Severe and persistent hypertension in the upper part of the body;
- Stroke;
- Premature coronary artery disease;
- Aortic dissection;
- Formation of a thoracic aortic aneurysm;
- Formation of a brain aneurysm;
- Cerebral hemorrhage;
- Renal failure and / or liver failure.
Associated conditions
For reasons that are still unclear, congenital aortic coarctation is often accompanied by congenital anomalies of the heart; in other words, most individuals who are born bearer of aortic coarctation also have one or more heart defects.
The heart defects in question are:
- The bicuspid aortic valve ;
- The patent ductus arteriosus (or patency of the ductus arteriosus );
- The patent foramen ovale ;
- Stenosis of the aortic valve ;
- The anomaly of the aortic valve that causes the so-called aortic regurgitation ;
- Mitral valve stenosis ;
- The anomaly of the mitral valve that causes the so-called mitral regurgitation .
Clearly, if present, these heart defects associate their symptoms with those of aortic coarctation.
Diagnosis
The possibility of diagnosing aortic coarctation depends on the presence of a correlated symptomatology. In fact, when aortic coarctation is asymptomatic, it is difficult to diagnose; while, when associated with a rich symptomatology, its identification is quite immediate.
Examinations for diagnosis
In general, the examination procedure for the diagnosis of aortic coarctation (ie for the detection of aortic coarctation) begins with an accurate physical examination ; therefore, it continues with an echocardiogram and ends with a series of in-depth tests, which could include the electrocardiogram, chest X-ray, nuclear magnetic resonance in the chest, chest CT and cardiac catheterization .
EXAMINATION OBJECTIVE
In a context of aortic coarctation, an accurate physical examination must include, in addition to a careful analysis of the symptoms exhibited by the patient, the measurement of the wrist at the level of the lower limbs, the comparison between the arterial pressure at the arm level and the arterial pressure at the level of the lower limbs, and finally the cardiac auscultation.
| Physical examination: fundamental elements for the diagnosis of aortic coarctation |
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ECHOCARDIOGRAM
The echocardiogram is a diagnostic test that, by means of an ultrasound probe, allows the visualization on a monitor of the heart, the blood vessels associated with the heart (including the aorta) and the blood flow inside the cardiac cavities.
In a context of aortic coarctation, the echocardiogram represents the diagnostic confirmation investigation, as it allows to highlight quite clearly the presence of a narrowing along the first tracts of the aorta.
It should be added that the echocardiogram allows the identification of those cardiac abnormalities reported above and often combined with aortic coarctation.
Is there a possibility of prenatal diagnosis?
Currently, unfortunately, there is no diagnostic test for prenatal identification (ie before birth) of aortic coarctation.
Diagnosis of asymptomatic cases
In asymptomatic cases, the diagnosis of aortic coarctation often occurs by pure chance, during cardiac checks performed for quite different reasons.
Therapy
With the aim of canceling shrinkage, the treatment of aortic coarctation depends on two factors, which are: the patient 's age and the severity of narrowing at the level of the aorta.
Possible therapeutic approaches for resolving coarctation include several surgical procedures and an operation known as angioplasty with stenting .
Surgery: possible interventions
In the list of surgical procedures that can be adopted for the purpose of canceling aortic coarctation, include:
- The resection of the coarctated tract (ie restricted), followed by the termino-terminal anastomosis .
It consists in the elimination, through resection, of the restricted aorta segment and in the subsequent work of connecting the two ends resulting from the aforementioned resection (so as to restore continuity to the aortic duct).
- The aortoplasty with left subclavian artery flap . It involves the reconstruction of the aorta through a modification of the left subclavian artery.
- The installation of a bypass . It consists in the grafting of a "new" vascular segment, in order to circumvent the obstacle represented by the narrowing.
- Aortoplasty with patch . It involves an incision of the aorta in correspondence of the narrowing, followed by the insertion of a sort of patch in order to enlarge the aorta.
In general, the aforementioned patch is made of synthetic material.
Angioplasty with stenting
Angioplasty is the medical procedure that allows you to eliminate or, at least, reduce the narrowing or narrowing of a blood vessel, by using a particular catheter.
Stenting, on the other hand, consists in placing a metal prosthesis ( stent ) inside a blood vessel previously occluded and reopened by angioplasty, in order to keep it patent over time and avoid second occlusions.
As can be guessed, in the presence of aortic coarctation, angioplasty with stenting has as its object the segment of the aorta in which the shrinkage resides.
Are there drugs for aortic coarctation?
Before and in some cases even after surgical treatment or stenting angioplasty, the carrier (or former carrier) of an aortic coarctation may need to follow a drug therapy to control hypertension (hypotensive drugs).
Did you know that ...
Unfortunately, for some former carriers of aortic coarctation, hypotensive treatment may need to last for years, if not for life.
Advice for the post-treatment phase
Even when the treatment was 100% efficient, the former carrier of aortic coarctation should:
- Undergo periodic medical checks in order to monitor the situation;
- Practice physical exercise regularly and according to what its possibilities are;
- Take all possible precautions against endocarditis.
Prognosis
The prognosis in the presence of aortic coarctation varies from patient to patient, based on:
- The severity of the shrinkage. A more severe narrowing is complex to treat and may recur later (recurrence);
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- Early diagnosis. A delayed aortic coarctation may have already seriously compromised heart health at the time of therapy.
Prevention
Unfortunately, there is no prevention of aortic coarctation.
