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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.
Because of the varying symptoms and signs of aortic dissection depending on the initial intimal tear and the extent of the dissection, the proper diagnosis is sometimes difficult to make.
While taking a good history from the individual may be strongly suggestive of an aortic dissection, the diagnosis cannot always be made by history and physical signs alone. Often, the diagnosis is made by visualization of the intimal flap on a diagnostic imaging test. Common tests used to diagnose an aortic dissection include a CT scan of the chest with iodinated contrast material and a transesophageal echocardiogram. The proximity of the aorta to the esophagus allows the use of higher-frequency ultrasound for better anatomical images. Other tests that may be used include an aortogram or magnetic resonance angiogram of the aorta. Each of these tests has pros and cons, and they do not have equal sensitivities and specificities in the diagnosis of aortic dissection.
In general, the imaging technique chosen is based on the pretest likelihood of the diagnosis, availability of the testing modality, patient stability, and the sensitivity and specificity of the test.
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.
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.
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.
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.
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.
"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.
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.
Right-sided aortic arch is rare, with a prevalence among adults of about 0.01%.
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").
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.
Hypertension is defined when a patient's blood pressure in the arm exceeds 140/90 mmHg under normal conditions. This is a severe problem for the heart and can cause many other complications. In a study of 120 coarctation repair recipients done in Groningen, The Netherlands, twenty-nine patients (25%) experienced hypertension in the later years of life due to the repair. While hypertension has many different factors that lead to this stage of blood pressure, people who have had a coarctation repair — regardless of the age at which the operation was performed — are at much higher risk than the general public of hypertension later in life. Undetected chronic hypertension can lead to sudden death among coarctation repair patients, at higher rates as time progresses.
Angioplasty is a procedure done to dilate an abnormally narrow section of a blood vessel to allow better blood flow. This is done in a cardiac catheterization laboratory. Typically taking two to three hours, the procedure may take longer but usually patients are able to leave the hospital the same day. After a coarctation repair 20-60% of infant patients may experience reoccurring stenosis at the site of the original operation. This can be fixed by either another coarctectomy.
Coronary artery disease (CAD) is a major issue for patients who have undergone a coarctation repair. Many years after the procedure is done, heart disease not only has an increased chance of affecting coarctation patients, but also progresses through the levels of severity at an alarmingly increased rate. In a study conducted by Mare Cohen, MD, et al., one fourth of the patients who experienced a coarctation died of heart disease, some at a relatively young age.
Clinical criteria are used in most studies when defining recurrence of coarctation (recoarctation) when blood pressure is at a difference of >20 mmHg between the lower and upper limbs. This procedure is most common in infant patients and is uncommon in adult patients. In a study conducted by Koller et al., 10.8% of infant patients underwent recoarctations at less than two years of age while another 3.1% of older children received a recoarctation.
People who have had a coarctation of the aorta are likely to have bicuspid aortic valve disease. Between 20% and 85% of patients are affected with this disease. Bicuspid aortic valve disease is a big contributor to cardiac failure, which in turn makes up roughly 20% of late deaths to coarctation patients.
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.
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.
Although the current standard of determining rupture risk is based on maximum diameter, it is known that smaller AAAs that fall below this threshold (diameter5.5 cm) may remain stable. In one report, it was shown that 10–24% of ruptured AAAs were less than 5 cm in diameter. It has also been reported that of 473 non-repaired AAAs examined from autopsy reports, there were 118 cases of rupture, 13% of which were less than 5 cm in diameter. This study also showed that 60% of the AAAs greater than 5 cm (including 54% of those AAAs between 7.1 and 10 cm) never experienced rupture. Vorp "et al." later deduced from the findings of Darling "et al." that if the maximum diameter criterion were followed for the 473 subjects, only 7% (34/473) of cases would have succumbed to rupture prior to surgical intervention as the diameter was less than 5 cm, with 25% (116/473) of cases possibly undergoing unnecessary surgery since these AAAs may never have ruptured.
Alternative methods of rupture assessment have been recently reported. The majority of these approaches involve the numerical analysis of AAAs using the common engineering technique of the finite element method (FEM) to determine the wall stress distributions. Recent reports have shown that these stress distributions have been shown to correlate to the overall geometry of the AAA rather than solely to the maximum diameter. It is also known that wall stress alone does not completely govern failure as an AAA will usually rupture when the wall stress exceeds the wall strength. In light of this, rupture assessment may be more accurate if both the patient-specific wall stress is coupled together with patient-specific wall strength. A non-invasive method of determining patient-dependent wall strength was recently reported, with more traditional approaches to strength determination via tensile testing performed by other researchers in the field. Some of the more recently proposed AAA rupture-risk assessment methods include: AAA wall stress; AAA expansion rate; degree of asymmetry; presence of intraluminal thrombus (ILT); a rupture potential index (RPI); a finite element analysis rupture index (FEARI); biomechanical factors coupled with computer analysis; growth of ILT; geometrical parameters of the AAA; and also a method of determining AAA growth and rupture based on mathematical models.
The post-operative mortality for an already ruptured AAA has slowly decreased over several decades but remains higher than 40%. However, if the AAA is surgically repaired before rupture, the post-operative mortality rate is substantially lower: approximately 1-6%.
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.
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.
Currently, there is controversy over whether or not inheritance truly plays a role in FAD, and if so which gene it acts upon. FAD does not come from strictly one predisposing factor, such as hypertension. It is suggested that the combination of environmental factors along with genetics may contribute to causing FAD. Before newer and more effective cures and therapies can be developed, first the specific gene mutation must be identified. Until such a gene is determined, scientists say patient education, and physician awareness is vital. Currently scientists have found animal models to be beneficial in understanding the pathology behind FAD. In the future there is hope to develop drugs that will better support and strengthen the aortic wall. Endovascular methods of treatment are becoming increasingly popular, and scientists hope to use this technique in both acute and chronic cases.
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.
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).
Quadricuspid aortic valves are very rare cardiac valvular anomalies with a prevalence of 0.013% to 0.043% of cardiac cases and a prevalence of 1 in 6000 patients that undertake aortic valve surgery. There is a slight male predominance in all of the cases, and the mean age is 50.7.
During pregnancy, prenatal ultrasound may reveal the abnormal course of the arch. On chest radiography, a right-sided aortic arch is visualized by the aortic knob (the prominent shadow of the aortic arch) that is located right from the sternum instead of left. Complex lesions are often assessed by MRI or CT.
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.
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.