Improved Imaging of Carotid Artery Bifurcation Using Helical Computed Tomographic Angiography

Although duplex scan and magnetic resonance angiography (MRA) provide reliable and noninvasive tests for detecting extracranial carotid artery disease, they sometimes fail to differentiate between high-grade stenosis and total carotid occlusion. Helical computed tomographic angiography (CTA) is a safe, noninvasive technique that allows the rapid acquisition of data that can be reconstructed into two- and three-dimensional images. Axial images can be magnified and provide a cross-sectional view of the carotid vessel and the atherosclerotic plaque. Maximal intensity projection technique allows data to be reconstructed into images that closely resemble conventional arteriograms. Helical CTA has previously been shown to have a diagnostic accuracy approaching 90%. We present two case reports demonstrating the utility of helical CTA in carotid artery imaging when duplex scan and MRA results are ambiguous. These cases illustrate improved carotid imaging with helical CTA. Duplex scan results are unreliable in the presence of thick calcified plaques, and severe stenoses can be misread as occlusion by duplex and MRA due to low blood flow. Thus, helical CT angiography should be considered as a confirmatory test, before arteriography, when duplex scan or MRA results are equivocal.     

Asymptomatic carotid bruit in patients who undergo coronary artery surgery

The clinical significance of the presence of carotid bruit was evaluated in 643 patients who underwent coronary artery surgery alone or in combination with other cardiac procedures. Carotid bruit was heard in 31 patients (5%) who were neurologically asymptomatic. All of them underwent coronary artery surgery without additional carotid procedures, and none of them developed neurological deficits during the postoperative period. Of the remaining 612 patients, 18 were identified as having a history of focal neurological disorders, and 9 of them had carotid bruit. All were analyzed by means of noninvasive tests and angiography. Five underwent carotid endarterectomy prior to (2 patients) and simultaneously with (3 patients) a coronary bypass procedure. Seven patients developed neurological deficits postoperatively. Most of the deficits were not lateralized or focal but diffuse, which suggests global cerebral ischemia not related to carotid disease. Only 1 patient had proven carotid obstructive disease and underwent successful carotid thrombendarterectomy 10 days postoperatively. This study, although based on limited material, supports the hypothesis that patients with asymptomatic carotid bruit can safely undergo coronary artery surgery. In the group of patients without neurological symptomatology, postoperative neurological deficits were rarely caused by occlusive carotid disease. However, patients with asymptomatic carotid bruit should be closely followed with the goal of identifying those who are at risk of developing neurological deficits.     

Evaluation of the extracranial carotid arteries: correlation of magnetic resonance angiography, duplex ultrasonography, and conventional angiography

We compared duplex scanning, "bright blood" and "black blood" magnetic resonance angiography, and conventional angiography for evaluation of the extracranial carotid arteries. All three methods were applied to 39 vessels in 20 patients. Duplex scanning was inaccurate when compared to conventional angiography in six instances. In three instances the degree of stenosis was overgraded by the scanner, and in three cases the stenosis was undergraded. Magnetic resonance angiography was inaccurate when compared to conventional angiography in three instances. In all cases magnetic resonance angiography overgraded the degree of stenosis. By use of a greater than 70% stenosis as a positive study, the sensitivity of magnetic resonance angiography was 100% and the specificity 92%. With use of the same criteria, the sensitivity of duplex scanning was 86%, and specificity was 84%. In those evaluations where the results of the magnetic resonance angiography and duplex scanning were in agreement, the correlation with conventional angiography was 100%. We conclude that magnetic resonance angiography is an alternative means to duplex scanning for noninvasive carotid imaging. A combination of bright and black blood magnetic resonance angiography is precise in delineating lesions of the extracranial carotid artery and may ultimately eliminate the need for conventional angiography in the evaluation of carotid stenosis.     

Current status in cervical carotid artery stent placement

Aim of this paper is to provide background information and the latest developments and studies pertaining to carotid artery stent placement in the treatment of carotid artery occlusive disease. A review of current literature combined with personal experience in the field of carotid stenting is presented. Endovascular stent placement for carotid artery occlusive disease is evolving from its initial controversial position to that of an alternative treatment of extracranial carotid artery disease. The high technical success (98-99%) as well as the relatively few complications makes carotid stenting a substitute for carotid endarterectomy for symptomatic patients and especially those with high medical comorbidities. With the advent of distal embolic protection, the complication rates for carotid stenting have decreased by approximately 50% to 2-4% for most major centers. Hence, with improved technology, carotid stenting is becoming an option for asymptomatic patients, especially those with high surgical risk. Early results for patency and neurological follow-up have also been encouraging. When we first began performing carotid stenting in 1995, we used a mixture of peripheral and coronary techniques. As stent design, guide catheters and cerebral protection devices have become dedicated and sophisticated, the technical success, patency and complication rates have improved. Carotid stenting will increase in application in the future especially among high surgical-risk patients with symptomatic and asymptomatic carotid occlusive disease.     

An assessment of carotid phonoangiography and oculoplethysmography in the detection of carotid artery stenosis

Carotid phonoangiography (CPA) and oculophlethysmography (OPG) examinations for the detection of extracranial carotid occlusive disease were performed in 308 patients, 103 of whom underwent arch angiography. When correlated with angiographic findings, the overall accuracy of CPA/OPG was 86 per cent. There were 4 per cent false-positive and 9.6 per cent false-negative results, and these were further analyzed. Significant carotid bruits demonstrated by CPA strongly suggested the presence of appreciable carotid stenosis. Noninvasive CPA/OPG is an excellent diagnostic tool in patients with nonhemispheric symptoms, in those with asymptomatic bruits, as a screening procedure in potential stroke victims, and for follow-up after carotid endarterectomy. Caution is advised in relying on this and other noninvasive technics as the sole method for recommending angiography and operative treatment in symptomatic patients.     

Supraorbital photoplethysmography. Simple,accurate screening for carotid occlusive disease

A technique of supraorbital photoplethys-mography has been developed for rapid noninvasive assessment of significant obstruction of the extracranial internal carotid artery. Photopulse pickups over each supraorbital and frontal artery permit recording of pulsation and the effect of compression of all major branches of the external carotid artery and each common carotid artery. Studies were performed on each carotid artery of 76 consecutive patients under-going contrast arteriography for suspected cerebrovascular disease. Supraorbital PPG correctly identified all 20 occluded internal carotid arteries, all 16 arteries with significant (≥50%) stenosis and 10 of 44 vessels with <50% stenosis. There were only eight (7.3%) false positive studies in the remaining 110 patients with normal or insignificantly stenotic carotid arteries. We feel that this simple plethysmographic technique, which requires no ocular anesthesia or risk of ocular injury, may prove to be a useful noninvasive technique to screen patients for significant carotid artery occlusive disease.     

Noninvasive screening for asymptomatic carotid artery disease prior to cardiac operation. Experience with 500 patients

Five hundred patients scheduled for cardiac operations underwent preoperative screening for asymptomatic carotid artery disease by means of the Gee ocular pneumoplethysmograph (OPG). Only patients with abnormal OPG measurements (5 mm Hg difference or greater in ophthalmic artery pressures or 0.69 or less ophthalmic artery/brachial artery pressure ratio) had cerebral angiography regardless of the presence or absence of a carotid bruit. Thirty-two patients (6.4%) were found to have carotid bruits. Nine patients had abnormal OPG measurements. Cerebral angiograms disclosed that six of these patients had significant (greater than 50%) carotid artery stenosis, and endarterectomy was performed prior to cardiac operation without incident. Nine other patients without carotid bruits had abnormal OPG measurements, and they also underwent cerebral angiography. Angiograms revealed significant carotid artery stenosis in three patients and prophylactic endarterectomy was performed. Twenty-three patients with carotid artery bruits and normal OPG measurements did not have cerebral angiography prior to the cardiac procedure. The incidence of stroke in this series of 500 patients was 0.4% (two patients). The clinical management of patients with asymptomatic carotid artery disease and coronary artery disease was facilitated by the use of noninvasive screening for the evaluation of carotid artery bruits. Patients with hemodynamically insignificant carotid disease, verified by OPG measurements, can be spared the risk and cost of cerebral angiography. Patients without clinical signs of carotid artery disease can also be identified.     

Correlation of transcranial Doppler and noninvasive tests with angiography in the evaluation of extracranial carotid disease

To evaluate the usefulness of transcranial Doppler sonography in determining severity of extracranial carotid disease, we compared transcranial Doppler, ocular pneumoplethysmography, Doppler spectral analysis, and duplex scanning data to information derived from cerebral angiography. Fifty-one consecutive patients with unilateral extracranial internal carotid artery stenosis or occlusion were selected. Transcranial Doppler indexes included the peak systolic flow velocity in the middle cerebral artery ipsilateral to the stenosed internal carotid artery (iMCAFV), the difference between the peak systolic flow velocities in the middle cerebral artery ipsilateral and contralateral to the stenosed internal carotid artery (dMCAFV), and the peak systolic flow velocity in the anterior cerebral artery contralateral to the stenosed internal carotid artery (cACAFV). The minimal residual lumen determined angiographically was used as the index of internal carotid artery stenosis. Linear regression analysis with minimal residual lumen as the dependent variable and transcranial Doppler and noninvasive tests as independent variables showed the following correlation coefficients: (1) dMCAFV and cACAFV, R2 = 0.3170; (2) ocular pneumoplethysmography, R2 = 0.4798; (3) dMCAFV, cACAFV, delta ocular pneumoplethysmography, duplex scanning, and spectral analysis R2 = 0.6382; (4) ocular pneumoplethysmography, duplex scanning, and spectral analysis, R2 = 0.6491; (5) iMCAFV, no association. These results were supported by sensitivity and specificity as well as bivariate analysis. We conclude that transcranial Doppler did not significantly add to the information obtained by our noninvasive battery of tests in the evaluation of unilateral extracranial carotid disease.     

Carotid endarterectomy based on duplex ultrasound in patients with and without hemispheric symptoms

Carotid endarterectomy is the most commonly performed vascular procedure. This retrospective study was conducted to determine the efficacy of duplex imaging as the sole diagnostic study for preoperative evaluation of symptomatic and asymptomatic patients who underwent carotid endarterectomy. We conducted a retrospective case series analysis in a community teaching hospital. From January 1994 to September 1998, 316 patients underwent carotid endarterectomy for carotid stenosis. A total of 177 patients were symptomatic and 139 patients were asymptomatic. Angiography was performed routinely in the beginning of the study but later was performed only in selected patients. Preoperative duplex ultrasound of carotid artery was performed by a laboratory accredited by the Intersocietal Commission for the Accreditation of Vascular Laboratories. Data were reviewed to obtain morbidity and mortality rates, and duplex imaging results were compared with operative findings. Cost and risk analysis of carotid angiography reviewed. This study reviewed variables of age, sex, race, diabetes, smoking, hypertension, hypercholesterolemia, coronary artery disease, and renal failure. Five patients had a lesion in the proximal portion of the carotid artery by duplex imaging criteria. Duplex ultrasound results were grossly confirmed intraoperatively in all patients except in one patient who was found to have complete occlusion of carotid artery whose duplex was read as high-grade stenosis. The duration of stay ranged from two to 30 days. This duration was influenced by patients' comorbid conditions, postoperative complications or simultaneous coronary artery bypass graft. Four patients had a stroke within 30 days of surgery making the stroke rate of 1.26 per cent. There has been considerable debate on the use of duplex ultrasound as the only method of preoperative evaluation of carotid stenosis before carotid endarterectomy. Our study demonstrates that it is safe to perform carotid endarterectomy based on neurologic history and duplex ultrasound with good technical quality performed in an accredited vascular laboratory. This approach eliminates the cost and risk associated with angiography. Proximal carotid and intrathoracic lesions are rare and can be predicted by the duplex study. We think that carotid angiography is required only when duplex imaging is suboptimal or equivocal in the presence of atypical symptoms or uncommon vascular abnormalities.     

External carotid endarterectomy in the treatment of symptomatic patients with internal carotid artery occlusion

In patients with internal carotid artery (ICA) occlusion, the external carotid artery (ECA) can be both a source of collateral flow and a pathway for emboli. We identified 11 patients with ICA occlusion and ipsilateral ECA stenosis who underwent ECA endarterectomy to determine its role in treating extracranial cerebrovascular disease. Follow-up ranged from 1–65 months, with a mean of 27 months. Seven of eight patients with unilateral disease remained symptom free. The eighth patient had recurrent symptoms that were subsequently diagnosed as hemi-Parkinsonism. Two of three patients with bilateral occlusive disease had developed non-hemispheric symptoms at 12 and 24 months, respectively; the third remains asymptomatic after extracranial-intracranial bypass. None of the seven patients who presented with amaurosis fugax had recurrent visual symptoms. ECA endarterectomy is a safe and effective operation in treating symptomatic patients with ICA occlusion, especially those with transient monocular blindness or unilateral occlusive disease. It is less effective in those patients who have diffuse bilateral occlusive disease.     

The prevalence of carotid artery stenosis in patients undergoing aortic reconstruction.

BACKGROUND: Coronary artery disease occurs frequently in patients undergoing aortic reconstruction, and it has been presumed that internal carotid artery occlusive disease is also common. This has led to the practice of screening for and repairing significant carotid lesions in asymptomatic patients prior to aortic reconstruction. The purpose of this study was to determine the true prevalence of internal carotid artery disease in these patients. METHODS: The records of 240 patients who underwent duplex ultrasound screening for carotid artery disease prior to aortic reconstruction were reviewed. Surgery was performed for aortic aneurysm (AA) or aorto-iliac occlusive disease (AO). The prevalence of hyperlipidemia and coronary artery disease was similar between the two groups, but tobacco use, hypertension, and diabetes mellitus differed. RESULTS: Internal carotid artery stenosis > or = 50% occurred in 26.7% of the total group (64 of 240 cases). Stenosis > or = 50% was more common in the AO group (40 of 101 cases, 39.6%) than the AA group (24 of 139 cases, 17.3%, P = 0.0001). Severe disease (70% to 99%) was also more common in the AO group than the AA group (9.9% versus 3.6%, P = 0.0464). CONCLUSION: Internal carotid artery disease occurs commonly in patients undergoing aortic reconstruction, and screening is worthwhile. Significant disease is more common in patients with aorto-iliac occlusive disease than in those with aortic aneurysm, although atherosclerotic risk factors occur with varying frequency in the two groups. These findings suggest that additional factors may contribute to the higher prevalence of internal carotid artery stenosis in aorto-iliac occlusive disease.     

The relative contributions of carotid duplex scanning,magnetic resonance angiography,and cerebral arteriography to clinical decisionmaking: A prospective study in patients with carotid occlusive disease

Purpose: Recent reports suggest that 80% to 90% of patients can safely undergo carotid endarterectomy on the basis of duplex scanning alone without cerebral angiography. Other investigators have recommended that a complementary imaging study such as magnetic resonance angiography (MRA) also be obtained.Methods: We prospectively evaluated 103 consecutive patients with carotid occlusive disease. Eighty percent of patients were symptomatic. All 103 patients underwent duplex scanning and arteriography. Additional noninvasive tests included computed tomography, magnetic resonance imaging, and MRA in 50%, 56%, and 48% of patients, respectively. At a multispecialty conference all studies except angiograms were reviewed, and a treatment decision was made by a panel of attending vascular surgeons, neurosurgeons, and neurologists. The cerebral angiograms then were reviewed and changes made to final treatment plans were noted.Results: After review of noninvasive studies, 30 of 103 of patients (29%) were believed to require arteriography because of diagnostic uncertainty of carotid occlusion in three patients, suggestion of nonatherosclerotic disease in four, suggestion of proximal disease in two, suboptimal noninvasive studies in one, and uncertainty of therapy despite good-quality noninvasive studies in 20 patients primarily with borderline stenoses and unclear symptoms. In 10 of these 30 patients (33%) management decisions were changed on the basis of angiogram results. Of the remaining 73 patients (71%) in whom the panel felt comfortable proceeding with operative or medical therapy without angiography, only one patient (1.4%) would have had management altered by results of angiography. MRA results concurred with duplex findings in 92% of studies, but did not alter management in any patient.Conclusions: In patients with good-quality duplex images, focal atherosclerotic bifurcation disease, and clear clinical presentation, treatment decisions can be made without arteriography. In 30% of patients angiography is useful in clarifying decisionmaking. MRA is unlikely to influence management decisions and is thus rarely indicated. (J Vasc Surg 1996;23:950-6.)     

Doppler ultrasound and supraorbital photoplethysmography for noninvasive screening of carotid occlusive disease

Doppler ultrasound and supraorbital photoplethysmography (PPG) were performed on 156 vessels of 76 consecutive patients undergoing contrast arteriography for suspected cerebrovascular disease. Each screening technic was approximately 95 per cent accurate in identifying or excluding significant (≥50 per cent) stenosis or occlusion of the extracranial internal carotid artery. Supraorbital PPG was slightly more sensitive but less specific than Doppler ultrasound. When the results of the two technics were in agreement, the diagnostic sensitivity was 100 per cent and the specificity 97 per cent in 139 vessels studied. Although noninvasive diagnostic technics are of limited value in symptomatic patients with cerebrovascular disease, a combination of Doppler ultrasound and supraorbital PPG is a simple, rapid, and accurate technic to screen asymptomatic or high risk patients for significant carotid occlusive disease.     

The utility of preoperative routine carotid artery duplex scanning in patients undergoing aortic valve replacement

Patients with aortic valve disease (AVD) typically have a cardiac murmur that radiates to the neck and may be indistinguishable from a cervical bruit secondary to carotid artery occlusive disease. The purpose of this report was to determine the prevalence of significant asymptomatic carotid artery occlusive disease in patients undergoing aortic valve replacement (AVR). All patients scheduled for AVR were prospectively studied. Preoperative carotid artery color-flow duplex was performed in all patients. A total of 204 patients were included in the study and significant carotid disease (>50% stenosis of the internal carotid artery) was found in 17 (8%). In patients with isolated aortic valve disease, 4/129 (3%) had significant stenosis. Of the patients with concurrent aortic valve and coronary artery disease, 13/75 (17%) had significant stenosis. The incidence of significant carotid stenosis in patients with aortic valve disease was over five fold higher in patients with concurrent coronary artery disease (3% vs. 17%, p <0.001). The yield of routine carotid duplex scanning for patients undergoing isolated AVR is low. However, in the subset of patients with concurrent coronary disease, the yield is higher. This finding supports the use of routine carotid duplex scanning in patients with coexistent aortic valve and coronary artery disease.     

Surgical results of two cases of simultaneous surgery of carotid and coronary occlusive disease]

Two cases of symptomatic extracranial carotid artery stenosis associated with ischemic heart disease are reported. The first case was 72-year-old male, who was admitted because of transient ischemic attack due to the stenosis of left internal carotid artery. He had a history of myocardial infarction and coronary angiography revealed three vessel disease. The second case was 74-year-old female with diabetes mellitus. She was admitted because of cerebral infarction. The carotid angiography revealed critical stenosis of bilateral internal carotid arteries. Her coronary angiography revealed three vessel disease. Her chest symptom became unstable after her admission. In both cases, simultaneous carotid endarterectomy and coronary bypass grafting were performed with successful outcome. In the patients with symptomatic extracranial carotid occlusive disease associated with severe ischemic heart diseases, we advocate simultaneous operation both for carotid and coronary artery occlusive disease.     

Combined carotid and coronary disease--a conservative strategy

The optimal approach to patients undergoing coronary bypass surgery for coronary artery disease with coexisting carotid disease is controversial. To determine the best approach to these patients, we screened carotid arteries in patients undergoing coronary artery bypass preoperatively with noninvasive ultrasonic duplex scanning. No correlation was noted between stroke and asymptomatic carotid disease in patients undergoing coronary revascularization. Prospective application of this finding in 2251 patients has yielded a very low incidence of perioperative stroke. We concluded that asymptomatic carotid arterial disease is not a significant risk to patients undergoing cardiopulmonary bypass and should be managed conservatively.     

Symptomatic acute occlusion of the internal carotid artery: reappraisal of urgent vascular reconstruction based on current stroke imaging

OBJECTIVE: We hypothesized that a subgroup of patients with frank stroke due to sudden occlusion of the internal carotid artery could safely undergo surgery to restore carotid patency and to rescue brain tissue not yet irreversibly damaged if current stroke diagnostic methods were applied. METHODS: From November 1997 to March 2007, 1810 patients underwent carotid endarterectomy of the internal carotid artery for occlusive disease at our department. Within the same period, 5369 patients were examined at our stroke unit, and 502 from this cohort underwent internal carotid artery reconstruction. A subgroup of 35 patients (28 men, 7 women; mean age, 61 +/- 10 years) underwent urgent surgical revascularization due to an acute internal carotid artery occlusion < or =72 hours (mean 25 +/- 17 hours) after the onset of stroke symptoms and < or =36 hours (mean 16 +/- 10 hours) after admission to our stroke unit. Our diagnostic workup consisted of extracranial intracranial duplex sonography, cerebral computed tomography, digital subtraction angiography, magnetic resonance imaging, and angiography, including diffusion- and perfusion-weighted imaging, to discriminate between viable and irreversibly damaged brain tissue. The study excluded patients who presented an impaired level of consciousness, occlusion of the intracranial internal carotid artery, occlusion of the ipsilateral middle cerebral artery, or infarction more than one-third of the territory perfused by the middle cerebral artery. Imaging showed signs of recent ischemic infarction in all 35 cases. On admission, eight patients (23%) scored 0 to 2 points and 27 (77%) scored 3 to 5 points in Rankin scale. RESULTS: Confirmed by postoperative Doppler and duplex sonography at discharge, internal carotid artery patency could be achieved in 30 of 35 cases (86%). Intracranial hemorrhage occurred in two patients (6%) and reinfarction in another two (6%). Two patients died during their hospital stay (30-day mortality, 6%). Compared with the preoperative neurologic status, rates of clinical improvement (> or =1 point in Rankin scale), stability, and deterioration were 57%, 31%, and 6%, respectively. CONCLUSIONS: Restoration of blood flow in an acutely occluded internal carotid artery can only be achieved in the acute stage. Our pilot study demonstrated that a thorough diagnostic workup allows selection of patients who may benefit from urgent revascularization of acute internal carotid artery occlusion in the stage of an acute stroke. A prospective randomized multicenter trial comparing surgery with conservative medical treatment is needed.     

Carotid artery disease: clinical features and management

The most common single cause of ischaemic carotid territory stroke is thromboembolism from stenoses in the extracranial internal carotid artery (ICA). In the majority, embolism is preceded by an acute change in plaque morphology predisposing the patient to overlying thrombus formation and embolization. The management of patients with carotid artery disease mandates risk factor modification, antiplatelet and statin therapy in everyone. There is grade A, level I evidence that recently symptomatic patients with 50–99% NASCET stenoses gain significant benefit from carotid endarterectomy (CEA), despite a small risk of perioperative stroke. Maximum benefit is conferred if the patient undergoes surgery as soon as possible after onset of symptoms. The management of patients with asymptomatic disease remains controversial. The 2018 European Society for Vascular Surgery (ESVS) carotid guidelines now advise that asymptomatic patients with a 60–99% stenosis who have one or more clinical/imaging features that might make them at higher risk for stroke on medical therapy should be considered for CEA, with the remainder being treated medically. The 2018 ESVS carotid guidelines also advise that carotid artery stenting may be an alternative to CEA in ‘average risk’ symptomatic and asymptomatic patients, although CEA is still the preferred option when treating patients within 14 days of symptom onset.     

Incidental asymptomatic cerebral aneurysms in patients with extracranial cerebrovascular disease: is this a case against carotid endarterectomy without arteriography?

As less arteriography is performed before carotid surgery, concern arises about missing occult cerebral aneurysms and possible adverse outcomes. A study was conducted by the divisions of vascular surgery and neurosurgery of Northwestern University Medical School to evaluate the frequency of incidental cerebral aneurysms and outcomes of patients with extracranial cerebrovascular disease and asymptomatic cerebral aneurysms. From October 1995, through March 1997, 200 patients underwent intracranial and extracranial cerebrovascular angiography for evaluation of extracranial disease. Demographic data, symptoms, data of vascular lesions, surgical treatment and outcomes of stroke and death were recorded prospectively. Two patients (1%) had asymptomatic cerebral aneurysms found on angiography. Six more patients were referred with a known asymptomatic cerebral aneurysm with extracranial disease during this same period. Of these eight patients, five underwent extracranial vascular reconstruction surgery and seven received treatment for their aneurysms. There were two stroke complications, both occurred after treatment of a basilar artery aneurysm. One of these patients died. No aneurysms ruptured following 203 extracranial revascularizations during this same period. On the basis of the low prevalence of diagnosing coincidental cerebral aneurysms during work-up of extracranial disease, as well as the lack of evidence that carotid surgery predisposes to aneurysm rupture in these patients in both our study and the literature review, it is concluded that coexisting extracranial disease and asymptomatic cerebral aneurysms do not pose a case against carotid surgery without routine arteriography. However, arteriography should be considered in selected groups of patients where the yield of intracranial aneurysms is high; these include patients with a familial history of cerebral aneurysms, autosomal dominant polycystic kidney disease, extracranial internal carotid artery medial fibrodysplasia, Takayasu's arteritis, alpha1-antitripsin deficiency and atypical clinical presentations, including headache.     

Current management of the patient with internal carotid artery occlusion

Despite the recent controversy concerning surgical therapy of patients with carotid artery disease, rational therapeutic plans can be developed based on available data. The patient who is symptomatic from occlusion of one or both internal carotid arteries is at particularly high risk for development of stroke and can ill-afford indecision. All symptomatic patients, therefore, with any of the extracranial occlusive disease patterns described are potential surgical candidates. Conversely, among the asymptomatic patients with these same patterns of occlusion, only those with internal carotid occlusion and contralateral stenosis should be considered for surgical therapy. Treatment must be individualised and directed at revascularising stenotic (not occluded) internal carotid arteries, or important collateral vessels such as the external carotid artery and in fewer cases the vertebral artery. The asymptomatic patient with unilateral internal carotid artery occlusion and no contralateral lesions should be monitored closely with Duplex scanning for development of a contralateral stenosis. When a stenosis of 80% or greater is encountered, strong consideration should be given to prophylactic endarterectomy in these patients due to their high risk for stroke. Endarterectomy for a 50-60% stenosis may also be reasonable in a single patent internal carotid artery. In the absence of a significant contralateral stenosis, no treatment is necessary. Individuals with internal carotid artery occlusion and symptoms referable to a contralateral carotid stenosis should also be managed with endarterectomy of the stenotic carotid artery.(ABSTRACT TRUNCATED AT 250 WORDS)