takayasu arteritis - shasan

[ArchivalUser]

description please??sym,diagn,rx,

[ArchivalUser]

from Harrison:

Takayasu's Arteritis

Definition

Takayasu's arteritis is an inflammatory and stenotic disease of medium- and large-sized arteries characterized by a strong predilection for the aortic arch and its branches. For this reason, it is often referred to as the aortic arch syndrome.

Incidence and Prevalence

Takayasu's arteritis is an uncommon disease with an estimated annual incidence rate of 1.2“2.6 cases per million. It is most prevalent in adolescent girls and young women. Although it is more common in Asia, it is neither racially nor geographically restricted.

Pathology and Pathogenesis

The disease involves medium- and large-sized arteries, with a strong predilection for the aortic arch and its branches; the pulmonary artery may also be involved. The most commonly affected arteries seen by angiography are listed in Table 319-6. The involvement of the major branches of the aorta is much more marked at their origin than distally. The disease is a panarteritis with inflammatory mononuclear cell infiltrates and occasionally giant cells. There are marked intimal proliferation and fibrosis, scarring and vascularization of the media, and disruption and degeneration of the elastic lamina. Narrowing of the lumen occurs with or without thrombosis. The vasa vasorum are frequently involved. Pathologic changes in various organs reflect the compromise of blood flow through the involved vessels.


Immunopathogenic mechanisms, the precise nature of which is uncertain, are suspected in this disease. As with several of the vasculitis syndromes, circulating immune complexes have been demonstrated, but their pathogenic significance is unclear.

Clinical and Laboratory Manifestations

Takayasu's arteritis is a systemic disease with generalized as well as vascular symptoms. The generalized symptoms include malaise, fever, night sweats, arthralgias, anorexia, and weight loss, which may occur months before vessel involvement is apparent. These symptoms may merge into those related to vascular compromise and organ ischemia. Pulses are commonly absent in the involved vessels, particularly the subclavian artery. The frequency of arteriographic abnormalities and the potentially associated clinical manifestations are listed in Table 319-6. Hypertension occurs in 32 to 93% of patients and contributes to renal, cardiac, and cerebral injury.

Characteristic laboratory findings include an elevated ESR, mild anemia, and elevated immunoglobulin levels.

Diagnosis

The diagnosis of Takayasu's arteritis should be suspected strongly in a young woman who develops a decrease or absence of peripheral pulses, discrepancies in blood pressure, and arterial bruits. The diagnosis is confirmed by the characteristic pattern on arteriography, which includes irregular vessel walls, stenosis, poststenotic dilatation, aneurysm formation, occlusion, and evidence of increased collateral circulation. Complete aortic arteriography by catheter-directed dye arteriography or magnetic resonance arteriography should be obtained, in order to fully delineate the distribution and degree of arterial disease. Histopathologic demonstration of inflamed vessels adds confirmatory data; however, tissue is rarely readily available for examination.

Takayasu's Arteritis: Treatment

The long-term outcome of patients with Takayasu's arteritis has varied widely between studies. Although two North American reports found overall survival to be 94%, the 5-year mortality rate from other studies has ranged from 0“35%. Disease-related mortality most often occurs from congestive heart failure, cerebrovascular events, myocardial infarction, aneurysm rupture, or renal failure. Even in the absence of life-threatening disease Takayasu's arteritis can be associated with significant morbidity. The course of the disease is variable, and although spontaneous remissions may occur, Takayasu's arteritis is most often chronic and relapsing. Although glucocorticoid therapy in doses of 40“60 mg prednisone per day alleviates symptoms, there are no convincing studies that indicate that they increase survival. The combination of glucocorticoid therapy for acute signs and symptoms and an aggressive surgical and/or angioplastic approach to stenosed vessels has markedly improved outcome and decreased morbidity by lessening the risk of stroke, correcting hypertension due to renal artery stenosis, and improving blood flow to ischemic viscera and limbs. Unless it is urgently required, surgical correction of stenosed arteries should be undertaken only when the vascular inflammatory process is well controlled with medical therapy. In individuals who are refractory to or unable to taper glucocorticoids, methotrexate in doses up to 25 mg per week has yielded encouraging results.

[ArchivalUser]

thanks triplehelix.....