OVERVIEW
Aortitis is a chronic progressive nonspecific inflammation of the aorta and its major branches and pulmonary arteries, mainly causing stenosis or occlusion in different parts. Signs and symptoms are often atypical in pediatric patients, with nonspecific manifestations such as hypertension, fever, arthritis, and emaciation. In a few children, inflammation destroys the middle layer of the arterial wall, resulting in arterial dilatation or aneurysm. The clinical manifestations are different depending on the location of the lesion.
Etiology
The etiology of the disease is still unclear, and it is generally considered to be an autoimmune disease associated with infection. The majority of studies have linked the disease to tuberculosis, streptococcal, and viral infections and abnormal autoimmunity. Given the prevalence of the disease in young women, it is hypothesized that the onset of the disease is related to estrogen levels.
Symptoms
Clinical manifestations vary widely depending on the vessels involved. Some patients may have systemic symptoms such as fever, night sweats, lethargy, and poor appetite several weeks before the appearance of localized symptoms or signs, but they may also have an acute onset of the disease and come to the doctor with high blood pressure or even hypertensive encephalopathy.
According to the different blood vessels involved, there are local symptoms and signs of ischemia in different organs, such as headache, dizziness, syncope, fatigue of intermittent activities of the limbs, and so on. When local symptoms or signs appear, systemic symptoms may gradually decrease or disappear.
According to the results of angiography, there are five types: type I lesions involve the aortic arch and its branches, type IIa lesions involve the aortic arch and its branches, the ascending aorta; type IIb lesions involve the aortic arch and its branches, the ascending aorta, and the thoracic and descending aorta; type III lesions involve the thoracic and descending aorta, the abdominal aorta and/or renal arteries, and type IV lesions involve the abdominal aorta and/or renal arteries. Type V for Ⅱb plus Ⅳ type lesions involving the aortic arch and its branches, the carotid artery and cone artery stenosis or occlusion can cause different degrees of cerebral ischemia caused by dizziness, headache, vertigo, memory loss, unilateral or bilateral vision with black spots, hemorrhage in the fundus of the eye, visual acuity, vision loss, field of vision narrowing and even blindness. In a few patients, local ischemia produces nasal septum perforation, ulceration of the palate and auricle, tooth loss and facial atrophy. In severe cases, there are repeated fainting, convulsions, aphasia, hemiparesis or coma. Upper limb ischemia causes unilateral or bilateral limb weakness, numbness, coldness, soreness and even muscle atrophy. Involved arterial pulsation is weakened or disappeared, systolic murmur can be heard, and continuous vascular murmur due to collateral circulation can be occasionally heard. When the lesion involves the abdominal aorta and iliac arteries, lower limb weakness, soreness, cold skin and intermittent claudication may occur. Hypertension occurs when renal function is involved, especially the increase in diastolic blood pressure. Severe stenosis of the descending thoracic aorta can cause segmental hypertension with most of the blood discharged from the heart flowing to the upper limbs. In combination with pulmonary stenosis, palpitations, shortness of breath, angina pectoris and myocardial infarction may occur in a few children.
Examination
1. Increased erythrocyte sedimentation rate
Blood sedimentation rate is an important index to reflect the lesion activity of this disease, 43% of the patients have fast blood sedimentation rate, which can be as fast as 130mm/h. Most of the patients who have the disease for less than 10 years have fast blood sedimentation rate, while those who have the disease for more than 10 years tend to be stabilized, and their blood sedimentation rate is mostly back to normal.
2.C-reactive protein
C-reactive protein has the same clinical significance as blood sedimentation, and the positive rate is similar to that of blood sedimentation, which is an indicator of the lesion activity of the disease.
3. Anti-streptococcal hemolysin “O” test
The increase of this kind of antibody only indicates that the patient has been infected with hemolytic streptococcus recently, and half of the patients with this disease have positive or suspected positive reaction.
4. Blood tests
A small number of patients have increased white blood cell counts, but there is no obvious change in neutrophils. 1/3 of the patients have anemia, which is often mild.
5. Serum protein electrophoresis
There is often an increase in α1, α2 and γ globulin and a decrease in albumin.
6. Chest X-ray examination
(1) Cardiac changes 1/3 of patients have different degrees of cardiac enlargement, mostly mild left ventricular enlargement, severe enlargement is rare.
(2) Changes of thoracic aorta: the ascending aorta or the descending part of the arch is often bulging, protruding, dilated, or even aneurysmal dilatation, which may be the effect of hypertension or the manifestation of aortitis, and it is related to the type and scope of the lesion, and the descending aorta, especially the middle and lower part of the aorta becomes thin and inward, and the pulsation is weakened, which is an important indication for the extensive stenosis of the thoracic and descending aorta.
7. Electrocardiography
Half of the patients have left ventricular hypertrophy, left ventricular strain or high voltage, and a few have coronary artery insufficiency or myocardial infarction. Pulmonary hypertension caused by pulmonary stenosis may be manifested as right ventricular hypertrophy, and increased left ventricular afterload may partially mask the ECG features of right ventricular hypertrophy.
8. Fundus examination
The fundus of aphakia is a specific change of this disease, with an incidence of 14%, which can be divided into three phases: Phase 1 (vasodilatation phase), redness of optic nerve disk, dilatation of arterioles and veins, siltation, uneven venous lumen, capillary neonation, small hemorrhages, small hemangiomas, and normal irido-vitreous body; Phase 2 (anastomosis phase), pupil dilatation, disappearance of reaction, atrophy of iris, formation of retinal arteriolar anastomosis, and disappearance of peripheral vasculature Stage 3 (complication sign stage), manifested by cataract, retinal hemorrhage and detachment, etc.
9. Lung function test
Lung function changes are related to pulmonary stenosis and impaired pulmonary blood flow. Decreased ventilation is more common with bilateral impaired pulmonary blood flow, while diffusion dysfunction is rare, which is due to decreased pulmonary compliance caused by long-term impaired pulmonary blood flow, or cardiopulmonary function changes caused by pulmonary hypertension.
10. Hemogram
It can check the blood flow of the head and limbs, and can measure the diameter of the arterial lumen at the same time, which is valuable for diagnosis and understanding of the changes of the condition or post-surgery follow-up observation.
11. B-mode ultrasonography
It can detect stenosis or occlusion of the aorta and its main branches (carotid artery, subclavian artery, renal artery, etc.), but it is more difficult to detect its distal branches.
12. Radionuclide examination
99mTc-DTPA renography and mercaptopropionic acid stimulation test, when renal artery stenosis occurs, due to renal ischemia caused by renin system activity enhancement, angiotensin Ⅱ so that the glomerular glomerular artery contraction, glomerular filtration pressure increases, compensatory to maintain an appropriate glomerular filtration rate, taking mercaptopropionic acid 25mg, 1 hour after the re-examination of the renal camera, if there is renal artery stenosis exists, because the If renal artery stenosis exists, due to the fact that mercaptopropionic acid eliminates the contraction effect of angiotensin II on the small arteries of the glomerular arteries, the glomerular filtration rate decreases compared with that before taking the drug, and this is used to determine renal artery stenosis. The diagnostic positivity rate of this method is 96.3%, and specificity is 82.7%, which is significantly higher than that of the simple renal radiography (51.8%), and there is no difference in the specificity.
13.CT examination
Enhanced CT can show the lesions of some of the affected vessels and the edema of the wall of the affected vessels, which can help to determine whether the disease is active or not.
14. Angiography
(1) Digital subtraction angiography (DSA) is performed by injecting 76% pantethine glucosamine into the vein for imaging, which is a better screening method, easier to operate, less burden on the children, high contrast resolution, and can also show the lesions in the low-contrast area. Considering that aortitis is the most common cause of renal vascular hypertension, the head and arm arteries, carotid arteries, thoracic and abdominal aorta, renal arteries, iliac arteries and pulmonary arteries should be comprehensively examined during the imaging, and the examination has a greater diagnostic value of aortitis, which can generally replace renal arteriography, and it is also suitable for children in outpatient clinics. However, because of the unclear display of renal artery branch lesions, selective renal arteriography is still needed when necessary.
(2) Selective arteriography can directly show changes in the lumen of the affected vessels, the size of the diameter, whether the wall is smooth, and the extent and length of the affected vessels.
(3) Coronary arteriography In recent years, the involvement of coronary arteries in this disease has been emphasized, and the incidence of coronary artery involvement is 9% to 10%.
Diagnosis
Hypertension, pulseless or weak pulse and vascular murmur are the main clinical manifestations of this disease. Multiple aortitis should be considered when a child with unexplained hypertension develops fever, arthralgia and accelerated blood sedimentation. Whenever a girl around 10 years of age develops persistent fever of unknown origin, she should be examined for large arterial pulsations in various parts of the body, measure blood pressure in the extremities and auscultate for vascular murmurs. The vascular murmur of the lesion site is helpful in the diagnosis of the disease, and is often heard in the abdomen, supraclavicular recess, suprasternal recess, external line of sternocleidomastoid muscle, and the lumbar back, which is mostly continuous, and sometimes tremor can be touched. The vascular murmur is associated with stenosis, vessel wall opacities, and the formation of collateral circulation, and angiography can be used to determine the location and extent of the lesion.
In the past, the diagnosis of aortitis in children followed the classification criteria of the American College of Rheumatology in 1990, and the diagnosis could be made if three of the following six items were met: (1) the age of onset of the disease was less than 40 years old; (2) intermittent dyskinesia of the limbs; (3) diminished brachial arterial pulses; (4) the difference in systolic blood pressure between the upper limbs of the two limbs was more than 10 mm Hg; (5) murmur of the aorta or subclavian artery; (6) the arterial vascular abnormality was not caused by atherosclerosis or fibromuscular dysplasia. abnormalities on angiography.
However, since the manifestations in children and adults are not the same, a revised criterion was proposed in 2008: angiographic abnormalities of the aorta and its branches, and aneurysm or dilatation of the pulmonary artery are required, along with any of the following five criteria: (1) diminished or absent pulse; (2) abnormal blood pressure differences in the extremities; (3) vascular murmurs; (4) hypertension; and (5) elevated markers of acute inflammatory response (ESR, CRP). Angiography includes conventional angiography (DSA), computed tomography angiography (CTA), and magnetic resonance angiography (MRA), with non-invasive CTA and MRA being more commonly used.
Treatment
1. Adrenocorticotropic hormone
Appropriate treatment is very important to prevent irreversible vascular damage. Glucocorticosteroids are the most basic drugs, and the remission rate of hormones alone is about 60%. Early use of glucocorticosteroids can effectively inhibit systemic symptoms, alleviate arterial stenosis and control disease progression, but the efficacy is poorer if fibrosis and embolism have already occurred. In general, early oral prednisone is given in sufficient quantity, and in the acute stage, it can be taken in divided doses to achieve better anti-inflammatory effect, but in mild cases and after remission, it should be changed to be taken in the morning in order to reduce the side effects, and it should be gradually reduced to a small dose to maintain it after the inflammatory indexes are under control. Critically ill patients can be given high-dose methylprednisolone shock therapy in the early stage. The duration of treatment should be 1~1.5 years or at least 6 months.
2. Immunosuppressant
It is suitable for those who are ineffective in glucocorticoid (about 30%) or whose disease recurs after glucocorticoid dosage is reduced. Since 46% to 84% of patients will eventually require a combination of glucocorticosteroids and immunosuppressants. It is recommended that glucocorticoids and immunosuppressants be combined as early as possible in patients with severe symptoms, extensive lesions, and markedly elevated inflammatory markers. Commonly used immunosuppressive agents include methotrexate, cyclophosphamide and azathioprine. In recent years, the use of morphine macrolide (MMF), cyclosporine (CsA), and tacrolimus have shown positive results.
3.Symptomatic treatment
Actively control hypertension and apply antiplatelet aggregation drugs (aspirin, dipyridamole).
4. Infection control
If tuberculosis or other infections exist, treatment should be given at the same time.
5. Interventional and surgical treatment
If the patient is in chronic quiescent stage and the obstructive symptoms seriously affect the function, surgical treatment can be carried out according to the situation, for example, revascularization of the obstructed or narrowed area, bypass grafting, aneurysm resection, aortic valve replacement and so on.