| Takayasu's arteritis | |
|---|---|
| Classification and external resources | |
| ICD-10 | M31.4 |
| ICD-9 | 446.7 |
| OMIM | 207600 |
| DiseasesDB | 12879 |
| MedlinePlus | 001250 |
| eMedicine | med/2232 ped/1956 neuro/361 radio/51 |
| MeSH | D013625 |
Takayasu's arteritis (also known as "aortic arch syndrome", "nonspecific aortoarteritis" and the "pulseless disease"[1]:841) is a form of large vessel granulomatous vasculitis[2] with massive intimal fibrosis and vascular narrowing affecting often young or middle-aged women of Asian descent. It mainly affects the aorta (the main blood vessel leaving the heart) and its branches, as well as the pulmonary arteries. Females are about 8-9 times more likely to be affected than males.[2][3] Patients often notice the disease symptoms between 15 and 30 years of age. In the Western world, atherosclerosis is a more frequent cause of obstruction of the aortic arch vessels than Takayasu's arteritis. Takayasu's arteritis is similar to other forms of vasculitis, including giant cell arteritis.[2] Due to obstruction of the main branches of the aorta, including the left common carotid artery, the brachiocephalic artery, and the left subclavian artery, Takayasu's arteritis can present as pulseless upper extremities (arms, hands, and wrists with weak or absent pulses on the physical examination) which may be why it is also commonly referred to as the "pulseless disease."
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Although its etiology is unknown, the condition is characterized by segmental and patchy granulomatous inflammation of the aorta and its major derivative branches. This inflammation leads to arterial stenosis, thrombosis, and aneurysms.[3] There is also irregular fibrosis of the blood vessels due to chronic vasculitis leading to sometimes massive intimal fibrosis (fibrosis of the inner section of the blood vessels).[4] Prominent narrowing due to inflammation, granuloma, and fibrosis is often seen in arterial studies such as Magnetic resonance angiography (MRA), computed tomography angiography (CTA), or arterial angiography (DSA).
Some patients develop an initial "inflammatory phase" characterized by systemic illness with symptoms of malaise, fever, night sweats, weight loss, arthralgia, and fatigue. There is also often anemia and marked elevation of the ESR or C-reactive protein (nonspecific markers of inflammation). The initial "inflammatory phase" is often followed by a secondary "pulseless phase."[2] The "pulseless phase" is characterized by vascular insufficiency from intimal narrowing of the vessels manifesting as arm or leg claudication, renal artery stenosis causing hypertension, and neurological manifestations due to decreased blood flow to the brain.[2] Of note is the function of renal artery stenosis in causation of high blood pressure: Normally perfused kidneys produce proportionate amount of a substance called renin. Stenosis of the renal arteries, causes hypoperfusion (decreased blood flow) of the juxtaglomerular apparatus, resulting in exaggerated secretion of renin, and high blood levels of aldosterone, eventually leading to water and salt retention and high blood pressure. The neurological symptoms of the disease vary depending on the degree, and the nature of the blood vessel obstruction and can range from lightheadedness, to seizures in severe cases. One rare but important feature of the Takayasu's arteritis is ocular involvement in form of visual field defects, vision loss, or retinal hemorrhage[4][5] Some patients with Takayasu's arteritis may present with only late vascular changes, without an antecedent systemic illness. In the late stage, weakness of the arterial walls may give rise to localized aneurysms. As with all aneurysms, possibility of rupture and vascular bleeding is existent and requires monitoring. Raynaud's phenomenon is commonly found in this disease, mainly due to decreased circulation of the blood to the arms.
The great majority of patients with Takayasu’s arteritis respond to steroids such as prednisone. The usual starting dose is approximately 1 milligram per kilogram of the body weight per day (for most people, this is approximately 60 milligrams a day). Because of the significant side effects of long-term high–dose prednisone use, the starting dose is tapered over several weeks to a dose that the physician feels is tolerable for the patient.
Surgical options may need to be explored for patients who do not respond to steroids. Re-perfusion of tissue can be achieved by large vessel reconstructive surgery such as bypass grafting. Grafting autologous tissue has the highest rates of success. Percutaneous transluminal coronary angioplasty (PTCA) is not as effective in the long term but has fewer risks.
The first case of Takayasu’s arteritis was described in 1908 by a Japanese opthalmologist, Mikito Takayasu at the Annual Meeting of the Japan Ophthalmology Society.[6][7] Takayasu described a peculiar "wreathlike" appearance of the blood vessels in the back of the eye (retina). Two Japanese physicians at the same meeting (Drs. Onishi and Kagoshima) also reported similar eye findings in patients whose wrist pulses were absent. It is now known that the blood vessel malformations that occur in the retina are an angiogenic response to the arterial narrowings in the neck, and that the absence of pulses noted in some patients occurs because of narrowings of the blood vessels to the arms. The eye findings described by Takayasu are rarely seen in patients from North America and British Columbia[reference missing].
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