The most accurate diagnostic test with the lowest morbidity in the diagnosis of renal artery stenosis is:
MRA has the advantage of not requiring iodinated contrast agents to provide vessel opacification (see Fig. below). Gadolinium is used as a contrast agent for MRA studies, and because it is generally not nephrotoxic, it can be used in patients with elevated creatinine.
Magnetic resonance angiogram (MRA) of aortic arch and carotid arteries. This study can provide a three-d imensional analysis of vascular structure such as aortic arch branches, carotid and vertebral arteries.
The risk of a recurrent ipsilateral stroke in patients with severe carotid stenosis is approximately
Currently, most stroke neurologists prescribe both aspirin and clopidogrel for secondary stroke prevention in patients who have experienced a transient ischemic attack (TIA) or stroke. In patients with symptomatic carotid stenosis, the degree of stenosis appears to be the most important predictor in determining risk for an ipsilateral stroke. The risk of a recurrent ipsilateral stroke in patients with severe carotid stenosis approaches 40%.
Which of the following statements concerning carotid body tumors is true?
The carotid body originates from the third branchial arch and from neuroectodermal-derived neural crest lineage. The normal carotid body is located in the adventitia or periadventitial tissue at the bifurcation of the common carotid artery (Fig. below). The gland is innervated by the glossopharyngeal nerve. Its blood supply is derived predominantly from the external carotid artery but can also come from the vertebral artery. Carotid body tumor is a rare lesion of the neuroendocrine system. Other glands of neural crest origin are seen in the neck, parapharyngeal spaces, mediastinum, retroperitoneum, and adrenal medulla. Tumors involving these structures have been referred to as paraganglioma, glomus tumor, or chemodectoma. Approximately 5 to 7% of carotid body tumors are malignant. Although chronic hypoxemia has been invoked as a stimulus for hyperplasia of carotid body, approximately 35% of carotid body tumors are hereditary. The risk of malignancy is greatest in young patients with familial tumors.
A. Carotid body tumor (arrow) located adjacent to the carotid bulb. B. Following periadventitial dissection, the carotid body tumor is removed.
The following are major risk factors associated with carotid stenosis disease progression EXCEPT:
The presence of or progression to a greater than 80% stenosis correlated highly with either the development of a total occlusion of the internal carotid artery or new symptoms. The major risk factors associated with disease progression were cigarette smoking, diabetes mellitus, and age. This study supported the contention that it is prudent to follow a conservative course in the management of asymptomatic patients presenting with a cervical bruit.
Rest pain seen with occlusive peripheral vascular disease in the lower extremity most commonly occurs in
Progression of the underlying atherosclerotic process is more likely to occur in patients with diabetes, those who continue to smoke, and those who fail to modify their atherosclerotic risk factors. In comparison, rest pain is constant, and usually occurs in the forefoot across the metatarsophalangeal joint. It is worse at night and requires placing the foot in a dependent position to improve symptoms
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