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The U.S. Preventive Services Task Force recommends a single screening ultrasound for abdominal aortic aneurysm in males age 65 to 75 years who have a history of smoking. There is an estimated number needed to screen of approximately 850 people. It is unclear if screening is useful in women aged 65 to 75 who have smoked and they recommend against screening in women who have never smoked.
Repeat ultrasounds should be carried out in those who have an aortic size greater than 3.0 cm. In those whose aorta is between 3.0 and 3.9 cm this should be every three years, if between 4.0 and 4.4 cm every two year, and if between 4.5 and 5.4 cm every year.
In the United Kingdom one time screening is recommended in all males over 65 years of age. Australia has no guideline on screening.
Guidelines were issued in March 2010 for early detection of thoracic aortic disease, by the American College of Cardiology, the American Heart Association, and other groups. Among the recommendations:
- First-degree relatives of people with thoracic aortic aneurysm or dissection should have aortic imaging to identify asymptomatic disease.
- People with symptoms suggestive of thoracic aortic dissection should be routinely evaluated "to establish a pretest risk of disease that can then be used to guide diagnostic decisions."
- People diagnosed with Marfan syndrome should immediately have an echocardiogram to measure the aorta, and followed up 6 months later to check for aortic enlargement.
Unfortunately, coarctations can not be prevented because they are usually present at birth. The best thing for patients who are affected by coarctations is early detection. Some signs that can lead to a coarctation have been linked to pathologies such as Turner syndrome, bicuspid aortic valve, and other family heart conditions.
Screening for an aortic aneurysm so that it may be detected and treated prior to rupture is the best way to reduce the overall mortality of the disease. The most cost-efficient screening test is an abdominal aortic ultrasound study. Noting the results of several large, population-based screening trials, the US Centers for Medicare and Medicaid Services (CMS) now provides payment for one ultrasound study in male or female smokers aged 65 years or older ("SAAAVE Act").
Computed tomography angiography is a fast, noninvasive test that gives an accurate three-dimensional view of the aorta. These images are produced by taking rapid, thin-cut slices of the chest and abdomen, and combining them in the computer to create cross-sectional slices. To delineate the aorta to the accuracy necessary to make the proper diagnosis, an iodinated contrast material is injected into a peripheral vein. Contrast is injected and the scan performed using a bolus tracking method. This type of scan is timed to an injection to capture the contrast as it enters the aorta. The scan then follows the contrast as it flows though the vessel. It has a sensitivity of 96 to 100% and a specificity of 96 to 100%. Disadvantages include the need for iodinated contrast material and the inability to diagnose the site of the intimal tear.
A measurement of blood D-dimer level may be useful in diagnostic evaluation. A level less than 500 ng/ml may be considered evidence against a diagnosis of aortic dissection, although this guideline is only applicable in cases deemed "low risk" and within 24 hours of symptom onset. The American Heart Association does not advise using this test in making the diagnosis, as evidence is still tentative.
Previously, diagnosis was usually done through autopsy. Advances in imaging technologies allow for early detection and thus ample treatment and monitoring of the affected patient. A short-axis ultrasound of the aortic valve allows for the best view of the aortic valve, and gives a clear indication of the adduction pattern of the aortic valves.
If an “X” shape is seen, then the patient can be diagnosed with having a quadricuspid aortic valve. A transthoracic echocardiogram (TTE) indicates if there is an aortic regurgitation, but a 3-D transesophageal echocardiogram can give a better view of the aortic valve.
Multidetector coronary CT angiography has been indicated as a single competent diagnostic imaging tool capable of delineating valvular anatomy, severity of regurgitation, and high risk coronary problems. The typical method of treatment is through surgery such as aortic valve reconstruction surgery (AVRS) and aortic valve replacement, usually with a synthetic valve.
An abdominal aortic aneurysm is usually diagnosed by physical exam, ultrasound, or CT. Plain abdominal radiographs may show the outline of an aneurysm when its walls are calcified. However, this is the case in less than half of all aneurysms. Ultrasonography is used to screen for aneurysms and to determine the size of any present. Additionally, free peritoneal fluid can be detected. It is noninvasive and sensitive, but the presence of bowel gas or obesity may limit its usefulness. CT scan has a nearly 100% sensitivity for an aneurysm and is also useful in preoperative planning, detailing the anatomy and possibility for endovascular repair. In the case of suspected rupture, it can also reliably detect retroperitoneal fluid. Alternative less often used methods for visualization of an aneurysm include MRI and angiography.
An aneurysm ruptures if the mechanical stress (tension per area) exceeds the local wall strength; consequently, peak wall stress (PWS) and peak wall rupture risk (PWRR) have been found to be more reliable parameters than diameter to assess AAA rupture risk. Medical software allows computing these rupture risk indices from standard clinical CT data and provides a patient-specific AAA rupture risk diagnosis. This type of biomechanical approach has been shown to accurately predict the location of AAA rupture.
Thoracic abdominal aneurysm is defined as a diameter exceeding the following cutoff:
- 4.5 cm in the United States
- 4.0 cm in South Korea
A diameter of 3.5 cm is generally considered dilated. However, average values vary with age and size of the reference population, as well as different segments of the aorta.
A bicuspid aortic valve can be associated with a heart murmur located at the right second intercostal space. Often there will be differences in blood pressures between upper and lower extremities. The diagnosis can be assisted with echocardiography or magnetic resonance imaging (MRI). Four-dimensional magnetic resonance imaging (4D MRI) is a technique that defines blood flow characteristics and patterns throughout the vessels, across valves, and in compartments of the heart. Four-dimensional imaging enables accurate visualizations of blood flow patterns in a three-dimensional (3D) spatial volume, as well as in a fourth temporal dimension. Current 4D MRI systems produces high-resolution images of blood flow in just a single scan session.
A chest X-ray can also assist in the diagnosis and provide clues as to the severity of the disease, showing the degree of calcification of the valve, and in a chronic condition, an enlarged left ventricle and atrium.
"Prenatal diagnosis (fetal ultrasound):"
Today the diagnosis of double aortic arch can be obtained in-utero in experienced centers. Scheduled repair soon after birth in symptomatic patients can relieve tracheal compression early and therefore potentially prevent the development of severe tracheomalacia.
"Chest X-ray:"
Plain chest x-rays of patients with double aortic arch may appear normal (often) or show a dominant right aortic arch or two aortic arches . There might be evidence of tracheal deviation and/or compression. Sometimes patients present with radiologic findings of pneumonia.
"Barium swallow (esophagraphy):"
Historically the esophagram used to be the gold standard for diagnosis of double aortic arch. In patients with double aortic arch the esophagus shows left- and right-sided indentations from the vascular compression. Due to the blood-pressure related movement of the aorta and the two arches, moving images of the barium-filled esophagus can demonstrate the typical pulsatile nature of the obstruction. The indentation from a dominant right arch is usually deeper and higher compared to the dent from the left arch.
"Bronchoscopy:"
Although bronchoscopy is not routinely done in patients with suspected or confirmed double aortic arch, it can visualize sites and severity of pulsatile tracheal compression.
"Echocardiography:"
In babies under the age of 12 months, echocardiography is considered to be sensitive and specific in making the diagnosis of double aortic arch when both arches are open. Non-perfused elements of other types of vascular rings (e.g. left arch with atretic (closed) end) or the ligamentum arteriosum might be difficult to visualize by echocardiography.
"Computed tomography (CT):"
Computed tomography after application of contrast media is usually diagnostically accurate. It shows the relationship of the arches to the trachea and bronchi.
"Magnetic resonance imaging (MRI):"
Magnetic resonance imaging provides excellent images of the trachea and surrounding vascular structures and has the advantage of not using radiation for imaging compared to Computed tomography.
"Cardiac catherization/aortography:"
Today patients with double aortic arch usually only undergo cardiac catherization to evaluate the hemodynamics and anatomy of associated congenital cardiac defects. Through a catheter in the ascending aorta contrast media is injected and the resulting aortography may be used to delineate the anatomy of the double aortic arch including sites of narrowing in the left aortic arch. Aortography can also be used to visualize the origin of all head and arm vessels originating from the two arches.
BAV may become calcified later in life, which may lead to varying degrees of severity of aortic stenosis that will manifest as murmurs. If the leaflets do not close correctly, aortic regurgitation can occur. If these become severe enough, they may require heart surgery.The heart is put under more stress in order to either pump more blood through a stenotic valve or attempt to circulate regurgitation blood through a leaking valve.
One of the most notable associations with BAV is the tendency for these patients to present with ascending aortic aneurysmal lesions.
The extracellular matrix of the aorta in patients with BAV shows marked deviations from that of the normal tricuspid aortic valve.
It is currently believed that an increase in the ratio of MMP2 (Matrix Metalloproteinases 2) to TIMP1 (Tissue Inhibitor Metalloproteinases 1) may be responsible for the abnormal degradation of the valve matrix and therefore lead to aortic dissection and aneurysm. However, other studies have also shown MMP9 involvement with no differences in TIMP expression. The size of the proximal aorta should be evaluated carefully during the workup. The initial diameter of the aorta should be noted and annual evaluation with CT scan, or MRI to avoid ionizing radiation, should be recommended to the patient; the examination should be conducted more frequently if a change in aortic diameter is seen. From this monitoring, the type of surgery that should be offered to the patient can be determined based on the change in size of the aorta.
Coarctation of the aorta (a congenital narrowing in the region of the ductus arteriosus) has also been associated with BAV.
Since the cause of FAD has not been genetically pinpointed, the only way to diagnose FAD is through the examination of phenotypic variations in the aorta. Usually echocardiography is used to take measurements of the aortic root as well as transesophageal echocardiography. Biomarkers lend a quick way to diagnose dissection when time is of the essence. These have the ability to relay the levels of smooth muscle mysosin heavy chain protein present, which is released from damaged aortic tissue.
There are two types of FAD; groups A and B. Normally if any area of the ascending aorta is involved in the dissection this is considered group A. If the dissection occurs within the descending aorta this is classified in group B. These two groups can than be broken down into three classes of FAD: Type 1, Type 2 and Type 3. Group A consists of Types 1 and 2, whereas Group B consists only of Type 3. Type 1 encompasses dissection in the distal ascending aorta closest to the heart, not including the aortic arch. Type 2 refers to dissection of the ascending aorta, closer to and including the aortic arch. Type 3 refers to the descending thoracic and abdominal aorta.
Group A dissections are the more serious of the two due to the location of the dissection in the ascending aorta, which leads to a higher risk of congestive heart failure and pericardium and/or aortic valve rupture. Individuals also tend to be predisposed to type A if they do have Marfans or Elhers-Danlos syndromes. These contribute to a higher fatality rate in group A dissection if immediate surgery is not performed. The most common corrective surgeries are actual aortic valve replacement and coronary artery bypass. The five year survival rate after surgery is a successful 70.4% due to vigilant monthly physical exams and chest x-rays to monitor progress. Group B dissections typically have a higher surgery mortality rate and are therefore not good candidates. Instead medical management is the common response to treating and keeping dissections of the descending aorta under control.
In adults and children found to have coarctation, 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. In some cases angioplasty can be performed to dilate the narrowed artery, with or without the placement of a stent graft.
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.
The long term outcome is very good. Some patients may, however, develop narrowing (stenosis) or dilatation at the previous coarctation site. All patients with unrepaired or repaired aortic coarctation require follow up in specialized Congenital Heart Disease centers.
Cardiac chamber catheterization provides a definitive diagnosis, indicating severe stenosis in valve area of <1.0 cm (normally about 3 cm). It can directly measure the pressure on both sides of the aortic valve. The pressure gradient may be used as a decision point for treatment. It is useful in symptomatic people before surgery. The standard for diagnosis of aortic stenosis is noninvasive testing with echocardiography. Cardiac catheterization is reserved for cases in which there is discrepancy between the clinical picture and non-invasive testing, due to risks inherent to crossing the aortic valve such as stroke.
Fetal aortic valve stenosis can be diagnosed by echocardiography before birth. The diagnostic features include a poorly contracting left ventricle, aortic valve thickening/restriction, a varying degree of left ventricular hypertrophy and abnormal Doppler flow characteristics in the left heart. There may be little or no detectable flow into or out of the left side of the heart.
There are two screening periods, one during the first trimester and the other during the second trimester. Fetal aortic stenosis is typically detected between 18 and 24 weeks gestation. This early detection is important because it allows for parents to be counseled in a timely and rational manner, allowing for discussion of prognosis and possible outcomes. Another reason for this crucial early detection is because it allows for postnatal management planning.
Mortality from aortic rupture is up to 90%. 65–75% of patients die before they arrive at hospital and up to 90% die before they reach the operating room.
The risk of aneurysm enlargement may be diminished with attention to the patient's blood pressure, smoking and cholesterol levels. There have been proposals to introduce ultrasound scans as a screening tool for those most at risk: men over the age of 65. The tetracycline antibiotic doxycycline is currently being investigated for use as a potential drug in the prevention of aortic aneurysm due to its metalloproteinase inhibitor and collagen stabilizing properties. In contrast, fluoroquinolones antibiotics are being investigated as a potential contributor to aortic aneurysms, given their tendency to break down collagen fibrils.
Anacetrapib is a cholesteryl ester transfer protein inhibitor that raises high-density lipoprotein (HDL) cholesterol and reduces low-density lipoprotein (LDL) cholesterol.
Anacetrapib reduces progression of atherosclerosis, mainly by reducing non-HDL-cholesterol, improves lesion stability and adds to the beneficial effects of atorvastatin
Elevating the amount of HDL cholesterol in the abdominal area of the aortic artery in mice both reduced the size of aneurysms that had already grown and prevented abdominal aortic aneurysms from forming at all. In short, raising HDL cholesterol is beneficial because it induces programmed cell death. The walls of a failing aorta are replaced and strengthened. New lesions should not form at all when using this drug.
Medical therapy of aneurysm of the aortic sinus includes blood pressure control through the use of drugs, such as beta blockers.
Another approach is surgical repair. The determination to perform surgery is usually based upon the diameter of the aortic root (with 5 centimeters being a rule of thumb - a normal size is 2-3 centimeters) and the rate of increase in its size (as determined through repeated echocardiography).
Diagnosis is often suspected in patients "in extremis" (close to death) with abdominal trauma or with relevant risk-factors. Diagnosis is confirmed quickly in the Emergency room by ultrasound or CT scan.
Treatment consists of open heart surgery soon after birth. Awaiting surgery, prostaglandin can be administered to keep the ductus arteriosus open, thereby allowing blood flow to the lower body. Failure to treat the condition yields a mortality rate of 90% at a median age of 4 days.
Surgical correction is indicated in all double aortic arch patients with obstructive symptoms (stridor, wheezing, pulmonary infections, poor feeding with choking). If symptoms are absent a conservative approach (watchful waiting) can be reasonable. Children with very mild symptoms may outgrow their symptoms but need regular follow-up.
Right-sided aortic arch is rare, with a prevalence among adults of about 0.01%.
Aortic aneurysms are often discovered during an X-ray, ultrasound, or echocardiogram done for other reasons. IAA may also be found during a routine physical exam by feeling for bulges in the abdominal area. If your doctor thinks you might have an aortic aneurysm, you will likely have a medical history and physical exam. You might have further tests to locate the aneurysm.
When an aneurysm is suspected or diagnosed, it is important to:
- Pinpoint the location of the aneurysm.
- Estimate its size.
- Find out how fast it is growing.
- Find out whether other blood vessels are involved.
- See if there are blood clots or inflammation.
Tests to help find out the location, size, and rate of growth of an aneurysm include:
- Abdominal ultrasound - This imaging allows the doctor to observe growth of the aneurysm. If the aneurysm is large, a monitoring ultrasound may need to occur every 6 to 12 months. If the aneurysm is small, monitoring may occur every 2 to 3 years.
- Computed tomography (CT) and magnetic resonance angiogram (MRA) - These imaging techniques give a more detailed view of the aneurysm. These techniques may be used to gather information about aneurysm's relation to the blood vessels of the kidney or other organs. Your doctor needs this information especially before surgery. CT is used to watch the growth of a thoracic aortic aneurysm.
- Echocardiogram - This ultrasound exam is used to study the heart. A transthoracic echocardiogram (TTE) or a transesophageal echocardiogram (TEE) may also be done to further diagnose thoracic aortic aneurysm.
- Angiogram - An angiogram can help your doctor identify the size of the aneurysm and also examine if there are any aortic dissections, blood clots, or other blood vessel involvement.