Crescendo TIAs refers to a syndrome comprising repeated TIAs within:
TIA is a focal loss of neurologic function, lasting for less than 24 hours. Crescendo TIAs refer to a syndrome comprising repeated TIAs within a short period of time that is characterized by complete neurologic recovery in between. At a minimum, the term should probably be reserved for those with either daily events or multiple resolving attacks within 24 hours. Hemodynamic TIAs represent focal cerebral events that are aggravated by exercise or hemodynamic stress and typically occur after short bursts of physical activity, postprandially, or after getting out of a hot bath. It is implied that these are due to severe extracranial disease and poor intracranial collateral recruitment. Reversible ischemic neurologic deficits refer to ischemic focal neurologic symptoms lasting longer than 24 hours but resolving within 3 weeks. When a neurologic deficit lasts longer than 3 weeks, it is considered a completed stroke. Stroke in evolution refers to progressive worsening of the neurologic deficit, either linearly over a 24-hour period or interspersed with transient periods of stabilization and/or partial clinical improvement.
Late postoperative complications of aortobifemoral bypass grafting include all of the following EXCEPT:
Perioperative complications of aortobifemoral bypass grafting:
The best diagnostic imaging modality for identifying lower extremity occlusive disease is:
Contrast angiography remains the gold standard imaging study. Using contrast angiography, interventionists can locate and size the anatomic significant lesions and measure the pressure gradient across the lesion, as well as plan for potential intervention. Angiography is, however, semi-invasive and should be confined to patients for whom surgical or percutaneous intervention is contemplated. Patients with borderline renal function may need to have alternate contrast agents, such as gadolinium or carbon dioxide, to avoid contrast-induced nephrotoxicity.
According to the Fontaine classification system for lower extremity occlusive disease
The Fontaine classification uses four stages:
The most common source of distal emboli is:
The heart is the most common source of distal emboli, which accounts for more than 90% of peripheral arterial embolic events. Atrial fibrillation is the most common source. Sudden cardioversion results in the dilated noncontractile atrial appendage regaining contractile activity, which can dislodge the contained thrombus. Other cardiac sources include mural thrombus overlying a myocardial infarction or thrombus forming within a dilated left ventricular aneurysm. Mural thrombi can also develop within a ventricle dilated by cardiomyopathy. Emboli that arise from a ventricular aneurysm or from a dilated cardiomyopathy can be very large and can lodge at the aortic bifurcation (saddle embolus), thus rendering both legs ischemic. Diseased valves are another source of distal embolization. Historically, this occurred as a result of rheumatic heart disease. Currently, subacute endocarditis and acute bacterial endocarditis are the more common causes. Infected emboli can seed the recipient vessel wall, creating mycotic aneurysms.
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