| Aortic coarctation | |
|---|---|
| Classification and external resources | |
Aortic coarctation. A. 'Black-blood' oblique sagittal view showing discrete, tight coarctation at the aortic isthmus (arrow). B. 3D, contrast-enhanced CT angiogram showing mildly narrowed bare metal stent (arrow) that partially overlies the left subclavian artery origin. The arrowhead shows a subtle pseudo-aneurysm at the distal end of the stent. C. 3D, contrast-enhanced MR angiogram showing aortic arch hypoplasia and coarctation with a 'jump' by-pass graft posteriorly (arrow). D. 3D, contrast-enhanced MR angiogram showing large pseudo-aneurysm (arrowhead) after previous patch angioplasty repair. The true lumen is shown posteriorly (arrow). |
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| ICD-10 | Q25.1 |
| ICD-9 | 747.10 |
| OMIM | 120000 |
| DiseasesDB | 2876 |
| eMedicine | med/154 |
| MeSH | D001017 |
Coarctation of the aorta, or aortic coarctation, is a congenital condition whereby the aorta narrows in the area where the ductus arteriosus (ligamentum arteriosum after regression) inserts.
Contents |
There are three types:[1]
In mild cases, children may show no signs or symptoms at first and their condition may not be diagnosed until later in life. Some children born with coarctation of the aorta have other heart defects, too, such as aortic stenosis, ventricular septal defect, patent ductus arteriosus or mitral valve abnormalities.
Coarctation is about twice as common in boys as it is in girls. It’s common in girls who have Turner syndrome.
Symptoms may be absent with mild narrowings (coarctation). When present, they include: difficulty breathing, poor appetite or trouble feeding, failure to thrive. Later on, children may develop symptoms related to problems with blood flow and an enlarged heart. They may experience dizziness or shortness of breath, faint or near-fainting episodes, chest pain, abnormal tiredness or fatigue, headaches, or nosebleeds. They may have cold legs and feet or have pain in their legs with exercise (intermittent claudication).
In more severe cases, where severe coarctations, babies may develop serious problems soon after birth because not enough blood can get through the aorta to the rest of their body. Arterial hypertension in the arms with normal to low blood pressure in the lower extremities is classic. Poor peripheral pulses in the legs and a weak femoral artery pulse may be found in severe cases.
The coarctation typically occurs after the left subclavian artery. However, if situated before it, blood flow to the left arm is compromised and asynchronous or radial pulses of different "strength" may be detected (normal on the right arm, weak or delayed on the left). In these cases, a difference between the normal radial pulse in the right arm and the delayed femoral pulse in the legs (either side) may be apparent, whilst no such delay would be appreciated with palpation of both delayed left arm and either femoral pulses. On the other hand, a coarctation occurring after the left subclavian artery will produce synchronous radial pulses, but radial-femoral delay will be present under palpation in either arm (both arm pulses are normal compared to the delayed leg pulses).
With imaging, resorption of the lower part of the ribs may be seen, due to increased blood flow over the neurovascular bundle that runs there. Post-stenotic dilation of the aorta results in a classic 'figure 3 sign' on x-ray. The characteristic bulging of the sign is caused by dilatation of the aorta due to an indrawing of the aortic wall at the site of cervical rib obstruction, with consequent post-stenotic dilation. This physiology results in the '3' image for which the sign is named.[5][6][7] When the esophagus is filled with barium, a reverse 3 or E sign is often seen and represents a mirror image of the areas of prestenotic and poststenotic dilatation.[8]
Coarctation of the aorta can be accurately diagnosed with magnetic resonance angiography. In teenagers and adults echocardiograms may not be conclusive. In adults with untreated coarctation blood often reaches the lower body through collaterals, e.g. internal thoracic arteries via. the subclavian arteries. Those can be seen on MR, CT or angiography. An untreated coarctation may also result in hypertrophy of the left ventricle.
coarctation of the aorta by CMR
A case of coarctation of the aorta was published in the New England Journal of Medicine in 2007 employing chest radiography and magnetic resonance images.[9]
A case of long-standing misdiagnosed coarctation of the aorta in an adult was described in the New York Times Magazine.[10]
Therapy/Treatment is conservative if asymptomatic, but may require surgical resection of the narrow segment if there is arterial hypertension. The first operations to treat coarctation were carried out by Clarence Crafoord in Sweden in 1944.[11] In some cases angioplasty can be performed to dilate the narrowed artery. If the coarctation is left untreated, arterial hypertension may become permanent due to irreversible changes in some organs (such as the kidney).
For fetuses at high risk for developing coarctation, a novel experimental treatment approach is being investigated, wherein the mother inhales 45% oxygen three times a day (3 x 3–4 hours) beyond 34 weeks of gestation. The oxygen is transferred via the placenta to the fetus and results in dilatation of the fetal lung vessels. As a consequence, the flow of blood through the fetal circulatory system increases, including that through the underdeveloped arch. In suitable fetuses, marked increases in aortic arch dimensions have been observed over treatment periods of about two to three weeks[12] COMPLICATIONS:1-left venticular failure 2-aortic dissection 3-cerebral hemorrhage 4-progressive aortic regurgitation or stenosis
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