Aortitis

AORTITIS

The aorta, which is the main trunk of the arterial system, is divided into the ascending aorta (5 cm [2 inches] in diameter, contained in the pericardium), the aortic arch (extending upward, backward, and downward), and the descending aorta. The tho-racic aorta is above the diaphragm; the abdominal aorta is below the diaphragm. The abdominal aorta is further designated as suprarenal (above renal artery level), perirenal level (at renal artery level), and infrarenal (below renal artery level).

Aortitis is inflammation of the aorta, particularly of the aor-tic arch. Two types are known to occur: Takayasu’s disease and syphilitic aortitis. Takayasu’s disease, or occlusive thromboaor-topathy, is uncommon; today, syphilitic aortitis is rare.

Takayasu’s disease, a chronic inflammatory disease of the aor-tic arch and its branches, primarily affects young or middle-aged women and is more common in those of Asian descent. It is nonatherosclerotic; the exact pathologic mechanism is unknown but thought to be immune complex mediated. It progresses from a systemic inflammation with localized arteritis to end-organ is-chemia because of large vessel stenosis or obstruction. Magnetic resonance angiography, CT, duplex ultrasonography, or arteri-ography is used to diagnose and evaluate the lesions, which are typ-ically long, smooth areas of narrowing with or without aneurysms. In the early stages, the disease may respond to corticosteroids, and patients may benefit from the addition of cytotoxic immuno-suppressive agents (Strider et al., 1996). Selective PTA and sur-gical revascularization may be performed after suppression of the systemic vascular inflammation.