Takayasu’s arteritis

Findings

The MRA demonstrates focal stenoses of the right innominate artery, proximal right subclavian artery, and proximal left common carotid artery with post-stenotic dilatation. There is also marked narrowing of the right internal carotid artery and focal stenosis of the proximal left subclavian artery before the left vertebral, with reconstitution distal to the left vertebral. The CT angiogram again demonstrates segmental large vessel vascular stenoses and left common carotid fusiform aneurysm.

Differential Diagnosis:
- Takayasu's arteritis
- Temporal arteritis
- Atherosclerosis
- Syphilitic aortitis
- Fibromuscular dysplasia
- Idiopathic arteritis


Diagnosis: Takayasu’s arteritis


Key points

Defined as a granulomatous inflammation affecting predominately elastic arteries (aorta, main aorta branches, and pulmonary arteries). This is the only aortitis that causes stenosis or occlusion of the aorta.
Most commonly involves left subclavian, left common carotid, brachiocephalic trunk, renal arteries, celiac trunk, SMA, and pulmonary arteries.
Affects females more often than males (8:1). More often affects oriental persons aged 12-66.
For the first few months to years, the patient experiences a prepulseless phase that has fevers, sweats, myalgias, weight loss, and arthralgias, The pulseless phase then shows signs of limb ischemia and renovascular hypertension. Patients often have an ESR > 20 mm/hour.
Acutely there is granulomatous infiltration of the elastic fibers of the media that progresses to a fibrotic stage over weeks to months. The fibrosis leads to constriction from proliferation, thrombosis, and aneurysm formation.
Treat with steroids, and then angioplasty after active inflammation subsides.
Angiography (and CT angiography) may demonstrate wall thickening, stenoses, occlusions, luminal and mural calcium and thrombus deposition.

Classification
- Type I: is the classic pulseless type involving the subclavian, carotid, and brachiocephic trunk
- Type II: is a combination of types I and III
- Type III: is the atypical coarctation type involving the descending thoracic and abdominal aorta with major branches
- Type IV: is the dilated type with dilatation of the aortic length and its branches