Carotid Artery Stenosis—Hemodynamic Significance and Clinical Course

Abstract

Two hundred fifteen patients with a history of either stroke, transient ischemic attack (TIA), or asymptomatic carotid bruit underwent noninvasive carotid artery testing using oculopneumoplethysmography. Of patients with hemodynamically significant stenosis, 51 (40.8%) underwent endarterectomy, and 74 (59.2%) were treated nonoperatively. The incidence of stroke in the nonoperated group was 12/74 (16.2%) compared with only 1/51 (1.9%) in the operated group. Similarly, recurrent TIA occurred in 29/74 (39.2%) of the nonoperated group vs 9/51 (17.6%) of the operated. In nonhemodynamically significant carotid stenosis, the risk of cerebrovascular death and stroke was exceedingly low: 2/90 (2.2%). Patients with hemodynamically significant stenosis treated nonoperatively have a greater risk of cerebrovascular death, stroke, and TIA than patients treated with carotid endarterectomy.

Ultrasound examination of carotid and vertebral arteries

“…In general, this is assumed when the cross-sectional area is reduced by 75 % or more [36]. Here, the degree of stenosis correlates with stroke incidence [37]. Critical appraisals are currently looking at how strictly risk assessment in carotid stenoses should focus on the degree of stenosis [38].…”

Ischemic Cerebrovascular Complications of Pregnancy

“…141,111 For patients who experience multiple transient ischemic attacks or increasing frequency or duration of transient ischemic attacks but who are not surgical candidates, the recommendation is for intravenous heparin during the first two weeks after the most recent transient ischemic attack and subcutaneous self-administered heparin for two to six weeks thereafter. 31,[149][150][151] In general, warfarin is to be avoided during pregnancy, particularly during the first trimester, because of the increased risk of teratogenic complications and fetal wastage with such therapy.…”

“…141 Microneurosurgical extracranial-intracranial bypass may be useful in patients with minimal neurologic deficit due to internal carotid artery occlusion, siphon stenosis, or stenosis or occlusion of the 'middle cerebral artery with poor collateral circulation."' Recently, such procedures have been applied to the posterior circulation also."'…”

“…The neurovascular examination, supplemented by direct and indirect noninvasive studies of the carotid system, may aid in making a decision regarding angiography. Patients with underlying pressure-significant lesions of the internal carotid system are at high risk for subsequent cerebral infarction,141,142 and these patients should undergo cerebral angiography if they are in a low-risk surgic Al category. Patients with normal findings on indirect noninvasive studies (that is, lack of pressure-significant lesions of the internal carotid system) but abnormal or questionably Abnormal findings on direct noninvasive studies may benefit from intravenous digital subtraction angiography 141,144 to help determine the nature of any underlying lesions of the carotid system without the risk of cerebral arteriography.…”

“…Patients with normal findings on indirect noninvasive studies (that is, lack of pressure-significant lesions of the internal carotid system) but abnormal or questionably Abnormal findings on direct noninvasive studies may benefit from intravenous digital subtraction angiography 141,144 to help determine the nature of any underlying lesions of the carotid system without the risk of cerebral arteriography. If the findings from both indirect and direct noninvasive studies are normal, no further radiologic procedures are recommended.Patients with transient ischemic attacks of the carotid system and pressure-significant atherosclerotic stenosis or severe ulceration in a surgically accessible ipsilateral carotid lesion are usually advised to undergo endarterectomy if there is a surgeon available who is capable of operating with low morbidity and mortality 141. 146 Angiography is generally not performed on patients with vertebrobasilar transient ischemic attacks except in unusual circumstances; in these patients, medical treatment is instituted.…”