Significant Carotid Disease Research Articles

An absent ophthalmic artery or carotid siphon signal on transcranial Doppler confirms the presence of severe ipsilateral internal carotid artery disease.

Transcranial Doppler ultrasound provides a useful adjunct to extracranial ultrasound in the diagnosis of carotid bifurcation disease. Previous studies have shown that collateral flow patterns and diminished flow velocities in the ipsilateral middle cerebral artery correlate with hemodynamically significant carotid disease. In a series of 7,054 carotid duplex and transcranial Doppler examinations, 12.5% (95% confidence interval [CI]: 8.7, 16.4) of 287 ophthalmic arteries ipsilateral to an apparent carotid occlusion had no detectable flow signal, compared with 0.5% (95% CI: 0.3, 0.7) of 6,767 ophthalmic arteries ipsilateral to a non-occluded carotid artery (p < 0.001). Carotid siphon signals were not detectable in 24.4% (95% CI: 19.4, 29.4) of arteries ipsilateral to the carotid occlusion, versus 1.0% (95% CI: 0.8, 1.3) ipsilateral to nonoccluded carotid arteries (p < 0.001). A significant number of absent ophthalmic artery and carotid siphon signals (5.7 and 8.7%, respectively) were also found in patients with 80 to 99% extracranial carotid stenosis. A subset of 216 studies with angiographic correlation confirmed the high association of these transcranial Doppler findings with severe stenosis or occlusion of the internal carotid artery. Primary ophthalmological disease or siphon occlusion did not explain these findings. An absent ophthalmic artery or carotid siphon signal on transcranial Doppler examination is believed to represent a failure to detect slow flow distal to severe carotid bifurcation lesions. As a sign of ipsilateral carotid occlusion, the sensitivities of absent ophthalmic artery and carotid siphon signals are quite low (12.5 and 24.4%, respectively). The high specificities of 99.5 and 99.0%, however, make these findings useful in confirming the diagnosis of presumptive carotid occlusion by carotid duplex ultrasound.

Evaluation and Treatment of Carotid Stenosis in Open-Heart Surgery Patients

Indications for identification and treatment of extracranial carotid artery disease in candidates for open-heart surgery (OHS) remain unsettled. We evaluated the efficacy of OPG-GEE screening and our nonrandomized use of carotid endarterectomy in 2312 OHS patients from 1975 to 1989. Data was analyzed using the χ2 squared and Fisher's exact tests. OPG was performed in 1602/2312 (69%) of the patients. OPG was positive in 122/1602 patients (7.6%) and negative in 1480/1602 (92.4%) patients. Of the patients with positive OPG, 31 patients had insignificant carotid bifurcation disease, 32 patients had total internal carotid artery occlusion, and 59 patients had operable carotid bifurcation lesions. Selective use of angiography identified an additional 8 patients with operable carotid bifurcation lesions (total 67, 33 symptomatic and 34 asymptomatic). Overall stroke rate for 2312 patients was 40/2312 (1.7%) [30 day mortality rate 60/ 2312 (3.2%)]. Stroke incidence was significantly increased (P < 0.01) in patients with a positive OPG, 8/122 (6.60%) vs those with negative OPG (23/1480, 1.6%). However, it was most marked in patients with operable bifurcation lesions (6/67, 9.0%). Stroke was not increased in patients with carotid occlusion or positive OPG without significant carotid bifurcation disease (2/63, 3.20%). Carotid endarterectomy in patients with operable bifurcation lesions was associated with a decreased (P < 0.05) stroke rate after OHS (1/44, 2.30% vs 5/23, 21.7%). Our data suggests identification of significant carotid disease and carotid endarterectomy will decrease stroke after OHS.

Carotid high-low flow ratio most accurately predicts significant stenosis.

The Doppler quantitative carotid blood flow technique is a dynamic, physiologic tool that measures carotid blood flow, velocity, and vessel diameter. A high-low flow ratio that reflects variation in side-to-side carotid flow is calculated. We determined the accuracy of this method for the detection of carotid stenosis in 70 patients with cerebrovascular disease in whom cerebral angiography was the gold standard. The most sensitive measure proved to be high-low flow ratio, which was abnormal in 19 of 23 patients (82.6% sensitivity). The patients with high-grade stenosis had contralateral elevated flow compared with that of patients without high-grade stenosis and age-specific normal subjects. The quantitative carotid blood flow technique reflects compensatory alterations in flow produced by significant carotid disease, with an abnormal high-low flow ratio having the highest positive predictive value. This technique can be used independently to screen for carotid stenosis and as an adjuvant to carotid duplex scanning in the investigation of extracranial carotid disease.

Synchronous operation for ischemic cardiac and cerebrovascular disease: Early results and long-term follow-up

The late follow-up of 230 patients who underwent synchronous operation for extensive, obstructive extracranial and coronary artery disease from 1974 to 1989 was analyzed. Mean age at operation was 62.5 years; 161 patients (70%) were in New York Heart Association class III or IV, 185 (80%) had triple-vessel disease, and 67 (29%) had left main stem lesions of 50% or more. Previous myocardial infarctions were present in 132 patients (57%). Only 78 had normal left ventricular function. Included were 16 patients undergoing coronary reoperations, 17 patients with additional cardiac procedures, and 3 with synchronous pulmonary procedures. Symptomatic extracranial vascular disease or stabilized neurological deficits were present in 108 patients. Bilateral hemodynamically significant carotid disease was present in 91 patients and arch vessel lesions in 37. The hospital mortality in 8 patients (3.5%) was due to cardiac (n = 4), neurological (n = 1), or multiorgan failure (n = 3). Operative morbidity was mainly neurological (n = 20, 8.7%); 7 reversible deficits and 7 major strokes occurred, 2 reversible and 5 major strokes were related to the operated side(s), and 4 postoperative myocardial infarctions occurred. Actuarial survival at 5 years was 74% (± 3.3), at 10 years 54% (± 4.9), and at 15 years, 35% (± 6.6). This was mainly determined by late cardiac death (41/66). Ute morbidity was mainly attributable to cardiac causes rather than neurological causes. At 5 and 10 years, respectively, 72% and 44% of the patients were free of major cardiac and neurological events or death. Synchronous revascularization can be performed relatively safely. The long-term outcome is determined by the extent and severity of the cardiovascular disease.

Atherosclerosis of the ascending aorta and coronary artery bypass: Pathology, clinical correlates, and operative management

Analysis of 1735 patients who underwent coronary artery bypass grafting from January 1981 through December 1988 revealed 152 (8.8%) patients with mild (4.5%), moderate (2.2%), or severe (2.0%) atherosclerosis of the ascending aorta. Three distinct pathologic patterns were found. The prevalence of stroke in patients with the severe type of aortic disease prompted development of a new operative technique that has been used in 16 patients. It involves a "no-touch" technique of the ascending aorta whereupon the proximal saphenous vein anastomoses are performed end to side to internal mammary artery grafts. Ages ranged from 49 to 80 years (mean 68.9). The 16 patients had 62 distal artery and vein anastomoses and 26 proximal saphenous vein-internal mammary end-to-side anastomoses. Internal mammary artery free flows ranged from 130 to 420 ml/min. Two hospital deaths were unrelated to the technique. There have been no strokes or recurrences of angina. An inordinately high incidence of main left coronary disease (50%), significant carotid disease (79%), and abdominal aortic occlusive or aneurysm disease (93%) was discovered. Ascending aortic atherosclerosis must be suspected in all coronary bypass patients with associated significant carotid, abdominal aortic, and main left coronary artery disease, aortic wall irregularity on ascending aortic angiography, adhesions between the ascending aorta and its adventitia, pale appearance of the ascending aorta, and minimal bleeding of an aortic cannulation stab wound. A "no-touch" technique that avoids any manipulation of the ascending aorta and that uses the internal mammary arteries as the sole source of blood supply for coronary bypass is an effective method to prevent aortic clamp injury, "trash heart," or stroke from severe ascending aortic disease. Preoperative angiographic visualization of the ascending aorta of all patients undergoing coronary artery bypass is mandatory.

Variability of doppler ophthalmic pressure index with occlusive carotid artery disease

To evaluate day-to-day variability of Doppler ophthalmic pressure index by means of the ophthalmomanometry-Doppler technique, bilateral ophthalmic artery pressure and indirect systemic blood pressure determinations were repeated within 1 month in 40 patients with clinically stable occlusive carotid disease. No difference in Doppler ophthalmic pressure and calculated pressure index between both days could be demonstrated. The standard deviation of differences in ophthalmic pressure index between first and second day measurements was 0.04. Correlation between bilateral ophthalmic pressure index measurements on both days was high (r = 0.93, n = 80). It is concluded that individual Doppler ophthalmic pressure index must change at least 0.08 before it can be considered significant. In 37 patients with occlusive carotid artery disease (>60% diameter reduction) undergoing 38 endarterectomies, Doppler ophthalmic pressure index was evaluated before and after surgery. Mean ± SD ipsilateral Doppler ophthalmic pressure index increased from 0.59 ± 0.07 to 0.71 ± 0.05 (p < 0.001) after endarterectomy. In 12 patients with significant bilateral occlusive carotid disease, mean ± SD contralateral Doppler ophthalmic pressure index increased from 0.54 ± 0.05 to 0.61 ± 0.06 (p < 0.02), whereas contralateral pressure index in patients with unilateral disease showed no change (0.71 vs 0.71) after ipsilateral endarterectomy. These results indicate that carotid endarterectomy not only normalizes ipsilateral Doppler ophthalmic pressure index but also improves contralateral Doppler ophthalmic pressure index provided significant bilateral occlusive carotid disease is present.

Variability of Doppler ophthalmic pressure index with occlusive carotid artery disease

To evaluate day-to-day variability of Doppler ophthalmic pressure index by means of the ophthalmomanometry-Doppler technique, bilateral ophthalmic artery pressure and indirect systemic blood pressure determinations were repeated within 1 month in 40 patients with clinically stable occlusive carotid disease. No difference in Doppler ophthalmic pressure and calculated pressure index between both days could be demonstrated. The standard deviation of differences in ophthalmic pressure index between first and second day measurements was 0.04. Correlation between bilateral ophthalmic pressure index measurements on both days was high (r = 0.93, n = 80). It is concluded that individual Doppler ophthalmic pressure index must change at least 0.08 before it can be considered significant. In 37 patients with occlusive carotid artery disease (greater than 60% diameter reduction) undergoing 38 endarterectomies, Doppler ophthalmic pressure index was evaluated before and after surgery. Mean +/- SD ipsilateral Doppler ophthalmic pressure index increased from 0.59 +/- 0.07 to 0.71 +/- 0.05 (p less than 0.001) after endarterectomy. In 12 patients with significant bilateral occlusive carotid disease, mean +/- SD contralateral Doppler ophthalmic pressure index increased from 0.54 +/- 0.05 to 0.61 +/- 0.06 (p less than 0.02), whereas contralateral pressure index in patients with unilateral disease showed no change (0.71 vs 0.71) after ipsilateral endarterectomy. These results indicate that carotid endarterectomy not only normalizes ipsilateral Doppler ophthalmic pressure index but also improves contralateral Doppler ophthalmic pressure index provided significant bilateral occlusive carotid disease is present.

Anterior cerebral artery velocity changes in disease of the middle cerebral artery stem.

Transcranial Doppler ultrasonography can map the changes in blood velocity that result from stenosis or occlusion of the middle cerebral artery. To evaluate patterns of collateral blood flow in disease of the middle cerebral artery stem, we used both cerebral angiography and transcranial Doppler ultrasonography to study the systolic blood velocities in both anterior cerebral arteries in 10 consecutive patients with middle cerebral artery stenosis or occlusion. Five patients had no evidence of hemodynamically significant carotid disease and good-quality measurements of systolic velocity in each anterior cerebral artery. Two of the five patients had middle cerebral artery stem stenosis and the other three had occlusion. The ratios of mean blood velocity in the normal compared with the abnormal side for the five patients (mean 1.34 +/- 0.23, range 1.15-1.74) were significantly higher than ratios for 10 controls (mean 1.04 +/- 0.12, range 0.76 +/- 1.19) using an unpaired t test (t = 3.492, 0.0005 less than p less than 0.005). Our results suggest that transcranial Doppler ultrasound measurements of anterior cerebral artery blood velocity may be a useful index of collateral blood flow from the anterior cerebral artery territory into the middle cerebral artery territory. Changes in mean velocity ratio may document the evolution and adequacy of collateral blood flow over the cerebral convexity in middle cerebral artery stem disease. In addition, the changes in anterior cerebral artery blood velocity appear to be an important corroborative finding for middle cerebral artery stem occlusion.

Risk factors for extracranial internal or common carotid arterial disease in persons aged 60 years and older

Systolic and diastolic hypertension, diabetes mellitus and cigarette smoking are risk factors for atherothrombotic brain infarction. 1–6 The relation of abnormal serum lipids and obesity to atherothrombotic brain infarction is unclear. 1,2,5–7 We reported in a retrospective study of 535 elderly patients that risk factors for atherothrombotic brain infarction were systolic or diastolic hypertension and diabetes mellitus in both elderly men and women and cigarette smoking in elderly men. 5 We demonstrated in a prospective study of 708 elderly patients that at 3-year follow-up, risk factors for new atherothrombotic brain infarction were systolic or diastolic hypertension and diabetes mellitus in both elderly men and women, cigarette smoking in elderly men and obesity in elderly women. 6 We also reported that 64 of 478 unselected elderly patients ( 13%) in a long-term health care facility had 40 to 100% luminal diameter narrowing of an extracranial internal or common carotid artery diagnosed by carotid duplex ultrasonography. 8 We now report correlations of coronary risk factors with significant extracranial carotid disease (ECD) diagnosed by carotid duplex ultrasonography.

Should we perform carotid endarterectomy synchronously with cardiac surgical procedures?

From Jan. 1, 1979 through July 31, 1987, 63 patients had carotid endarterectomy (CEA) concurrently with cardiac surgical procedures including coronary artery bypass grafting (CABG) in 61, CABG plus mitral value replacement in one, and aortic valve replacement in one. Among the 62 patients having CABG, unstable angina had been present in 36 (58%), left main coronary artery disease in 21 (34%), and both unstable angina and left main coronary artery disease in 13 (21%). Indications for carotid surgery included previous stroke, amaurosis fugax, or hemispheric transient ischemic attacks (TIAs) in 33 patients (52%); bilaterally significant carotid disease was noted in 48% of the patients. Major neurologic complications occurred in three patients (4.8%), including perioperative stroke in two (3.2%) (fatal in one) and a TIA in a third patient. Bilateral carotid lesions, a contralateral total carotid occlusion, previous cerebrovascular symptoms, and intraaortic balloon pump support did not increase neurologic risk. Seven patients died postoperatively (11%). The mortality rate was 2.8% in patients younger than 65 years vs 22% in patients 65 years or older, 19% in patients with left main coronary artery disease vs 7.3% in patients without, 13.3% in men vs 5.6% in women, 25% in patients with a history of congestive heart failure vs 7.8% in patients without failure, and 6.2% in patients with unilateral carotid disease, 17% in patients with bilateral carotid disease, and 23% in patients with bilateral disease including a contralateral carotid occlusion. A mortality predictive index (MPI) was developed to summarize individual risk for a fatal outcome. Survivors had a mean MPI of 1.98 vs 3.30 for those who died. The mortality rate was 2.4% in patients with an MPI of 0 to 2 vs 29% for those with an index of 3 to 5. In elderly cardiac surgical patients and those with an MPI of 3 or greater, the risks of operation may outweigh the potential benefits of synchronous CEA.

Simultaneous extensive extracranial and coronary revascularization. Long-term follow-up up to 13 years.

Simultaneous surgery for extensive extracranial and coronary revascularization was performed in 168 patients (mean age 61 years), from 1974 up to June 1987; 116 patients (69%) were in NYHA class III or IV, 133 (79%) had triple vessel disease and 51 (30%) had left main stem lesions. One or more previous myocardial infarctions were present in 96 patients (57%); normal preoperative left ventricular function was present in only 35%. In 22 cases, additional cardiac procedures were performed. Symptomatic extracranial disease was present in 76 patients (45%), arch vessel surgery was performed in 29 (17%) and bilateral haemodynamically significant carotid disease was present in 58 (35%). Operative mortality (3%) was mainly cardiac and operative morbidity mainly neurological (7%). Actuarial survival at 5 years (75%) and 10 years (57%) was mainly determined by the cardiac survival (87% at 5 years and 70% at 10 years), while neurological follow-up deaths were rare (neurological survival 97% at 5 years and 91% at 10 years). Late morbidity was more cardiac than neurologically determined; actuarial curves showed 72% to be free of all serious events or death at 5 years, and 47% at 10 years.

The risk of stroke in patients with asymptomatic carotid stenosis undergoing cardiac surgery: A follow-up study

During a 7-year period, 4047 patients underwent a battery of noninvasive carotid tests before cardiac surgery. Two thirds of the patients with abnormal studies underwent carotid angiography. One hundred fifty-three patients (3.8%) had significant carotid disease, narrowing the luminal diameter by greater than 50%. The incidence of transient ischemic attack or cerebrovascular accident following cardiac surgery was 1.9% in those patients with no carotid disease and 9.2% in those patients with carotid lesions. The incidence of transient ischemic attack or cerebrovascular accident in 32 patients with inoperable (occluded) carotid vessels was 15.6% and in 121 patients with operable (stenotic) lesions was 7.4%. In the group of patients with stenosis, 57 patients underwent carotid operation with an 8.8% incidence of neurologic deficit. During the last 112 years, no patient with asymptomatic carotid stenosis underwent simultaneous carotid and coronary surgery. Four of 64 patients with combined lesions but no carotid surgery (6.3%) had a neurologic deficit, one of which was severe and permanent. The highest incidence of neurologic dysfunction occurred in patients with unilateral occlusions and contralateral stenosis. Four of 12 patients in this group had a deficit (three of seven patients underwent operation; one of five did not), one of which was permanent. The operative mortality rate after cardiac surgery was three times higher in patients with carotid disease than in those patients with normal carotid arteries. Combined carotid and coronary surgery is currently reserved for patients with neurologic symptoms and severe cardiac disease.

Embolic lesions from the subclavian artery causing transient vertebrobasilar insufficiency

Thirteen patients with transient vertebrobasilar insufficiency caused by emboli from a proximal subclavian artery lesion were treated over a 5-year period. This group was characterized by the absence of significant carotid disease (12 of 13 patients) and equal arm pressures bilaterally in most patients (8 of 13 patients). An isolated supraclavicular bruit (12 of 13 patients) and a history of ipsilateral digital ischemia (5 of 13 patients) were common. Arch angiography demonstrated proximal subclavian lesions in 12 patients, with obvious ulcerations in 10 cases and thrombus in an old carotid-subclavian bypass graft in one case. Surgery directed at removal or exclusion of the lesion was successful in all cases. Isolated lesions in the subclavian artery can be a source of emboli into the vertebrobasilar circulation. These lesions are effectively treated by exclusion and vascular reconstruction.

Embolic lesions from the subclavian artery causing transient vertebrobasilar insufficiency.

Thirteen patients with transient vertebrobasilar insufficiency caused by emboli from a proximal subclavian artery lesion were treated over a 5-year period. This group was characterized by the absence of significant carotid disease (12 of 13 patients) and equal arm pressures bilaterally in most patients (8 of 13 patients). An isolated supraclavicular bruit (12 of 13 patients) and a history of ipsilateral digital ischemia (5 of 13 patients) were common. Arch angiography demonstrated proximal subclavian lesions in 12 patients, with obvious ulcerations in 10 cases and thrombus in an old carotid-subclavian bypass graft in one case. Surgery directed at removal or exclusion of the lesion was successful in all cases. Isolated lesions in the subclavian artery can be a source of emboli into the vertebrobasilar circulation. These lesions are effectively treated by exclusion and vascular reconstruction.

Evaluation of the vertebral arteries with duplex sonography.

Using duplex sonography, we have routinely evaluated the vertebral arteries as part of the carotid artery examination in 453 consecutive patients over a 6-month period. Sixty-two of these 906 vessels could not be adequately evaluated, primarily because these vessels lay too deep within the vertebral structures, resulting in a technical failure rate of 6.8%. For the remaining 844 vessels, 74.4% were considered normal by Doppler flowmeter spectral analysis. Angiographic correlation was available for 224 vessels; of 155 judged normal by duplex sonography, 144 (93%) were shown to be normal or have only mild atherosclerotic disease. Eleven vessels were considered either occluded or to have severe disease by duplex sonography, and angiography showed this to be the case in 10 (91%) vessels. Unusually strong vertebral artery flow was associated with hemodynamically significant carotid or contralateral vertebral atherosclerotic disease or subclavian steal 82% of the time. Twelve cases of subclavian steal, only one of which was symptomatic, were identified by duplex sonography; four of these were confirmed by angiography. Angiographic correlation was available for 229 vessels in which duplex evaluation showed vertebral artery flow to be moderately damped. In 11 of these (38%), angiography showed greater than 50% stenosis. Angiography judged the remaining 18 vessels in this group normal; these vessels may represent a small subgroup of patients with normal anatomy or only mild atherosclerotic disease, but with hemodynamic dysfunction that can be identified with the duplex technique.

Evaluation of the vertebral arteries with duplex sonography

Using duplex sonography, we have routinely evaluated the vertebral arteries as part of the carotid artery examination in 453 consecutive patients over a 6-month period. Sixty-two of these 906 vessels could not be adequately evaluated, primarily because these vessels lay too deep within the vertebral structures, resulting in a technical failure rate of 6.8%. For the remaining 844 vessels, 74.4% were considered normal by Doppler flowmeter spectral analysis. Angiographic correlation was available for 224 vessels; of 155 judged normal by duplex sonography, 144 (93%) were shown to be normal or have only mild atherosclerotic disease. Eleven vessels were considered either occluded or to have severe disease by duplex sonography, and angiography showed this to be the case in 10 (91%) vessels. Unusually strong vertebral artery flow was associated with hemodynamically significant carotid or contralateral vertebral atherosclerotic disease or subclavian steal 82% of the time. Twelve cases of subclavian steal, only one of which was symptomatic, were identified by duplex sonography; four of these were confirmed by angiography. Angiographic correlation was available for 229 vessels in which duplex evaluation showed vertebral artery flow to be moderately damped. In 11 of these (38%), angiography showed greater than 50% stenosis. Angiography judged the remaining 18 vessels in this group normal; these vessels may represent a small subgroup of patients with normal anatomy or only mild atherosclerotic disease, but with hemodynamic dysfunction that can be identified with the duplex technique.

Symptoms and Signs of Carotid Territory Transient Cerebral Ischaemia

In 400 patients referred for non-invasive vascular assessment by ultrasono graphy, 29% of 214 with transient ischaemic attacks, 25% of 44 with reversible ischaemic neurological deficits and 28% of 46 with recovered stroke had signifi cant extracranial internal carotid artery disease. For amaurosis fugax, 65% of 74 patients had significant disease. Both cerebral and ocular symptoms of simi lar laterality with respect to one carotid occurred together in 22 patients, of whom 86% had significant internal carotid disease. Bruit was heard in 29% of carotids in 200 symptomatic patients. Only 45% of bruits were associated with significant internal carotid disease. The external carotid alone was shown to be the source of cervical murmur in a significant number of patients.

Indirect assessment of carotid occlusive disease by ocular pneumoplethysmography. 500 mm Hg vacuum pressure measurements and ocular pulse timing.

The interpretation and diagnostic value of the ophthalmic artery pressure measurement and ocular pulse timing modes of the 500 mm Hg vacuum OPG-Gee ocular pneumoplethysmograph were evaluated in 65 patients who underwent aortic arch and cerebral arteriography. Data analysis revealed the OPG-Gee differential tracing which electronically compares and amplifies differences between the right and left eye pulse waveforms to be of little value. In predicting the presence of a greater than or equal to 50 percent diameter unilateral stenosis, an eye-eye pulse interval of greater than 15 msec was 82 percent accurate, a greater than or equal to 5 mm Hg ophthalmic artery pressure difference was 77 percent accurate and when combined these two criteria were 84 percent accurate. Neither of the criteria intended to detect bilateral carotid lesions, eye-ear pulse interval nor ophthalmic/brachial pressure index, were reliable. Ocular pulse timing was found to be highly specific but insensitive to hemodynamically significant carotid disease. OPG-Gee pressure determinations were more sensitive but lacked specificity. In combination, these criteria allowed identification of unilateral hemodynamically significant lesions with a sensitivity of 83 percent and a specificity of 86 percent. If used to detect more severe degrees of arteriographic stenosis, 60 and 70 percent diameter reduction, the overall diagnostic accuracy of these techniques was not improved. These results do not justify the use of the OPG-Gee instrument as a single noninvasive test for carotid arterial disease.

Hemodynamics of the carotid-artery circulation in the elderly "dizzy" patient.

One hundred and one consecutive patients complaining of dizziness were assessed by noninvasive carotid-artery testing, including oculoplethysmography, supraorbital directional Doppler and direct carotid flow Doppler. Hemodynamically significant carotid disease was found in 8 of 34 patients with the nonspecific complaint of "lightheadedness," in 4 of 21 patients with syncope, in 3 of 12 patients with vertebrobasilar insufficiency, and in 7 of 27 patients with associated focal cerebral signs or symptoms. None of 7 patients with vertigo alone were affected. In summary, 21 of the 101 patients with dizziness had hemodynamically significant obstruction to flow in the carotid-artery circulation. These findings suggest that in a fairly large proportion of patients complaining of dizziness, the symptoms may be the result of decreased cerebral perfusion due to carotid-artery occlusive disease. In these patients, noninvasive carotid-artery testing appears to be useful in identifying those with significant obstruction to blood flow in the carotid-artery circulation.

Retinal artery emboli. Indications for angiography and carotid endarterectomy.

Six patients with ocular symptoms were referred by the Eye Service to the Vascular Service because of the presence of cholesterol emboli on fundoscopic examination of the retinal arteries. None of the six patients had classic intermittent retinal or cerebral ischemic attacks. Four-vessel aortic arch arteriogram was suggested and significant ipsilateral carotid disease was found in all patients. Four patients underwent carotid endarterectomy, with removal of ulcerated plaques from the carotid bifurcation. Two patients had total occlusion of the ipsilateral internal carotid artery and therefore were not operative candidates. The presence of retinal cholesterol emboli is an indication for extracranial arteriography. When ipsilateral ulcerative disease is found, carotid endarterectomy is indicated regardless of the symptoms.