Diagnosis of carotid artery stenosis: comparison of oculoplethysmography and Doppler supraorbital examination

Both Doppler supraorbital examination (OSM) and oculoplethysmography (OPG) were administered to 101 patients (202 arteries) to document the presence or absence of hemodynamically significant lesions of the internal carotid artery prior to angiography. There was no significant difference between the OSM and OPG with respect to diagnostic sensitivity or specificity, incidence of false-negative or false-positive results, and overall diagnostic accuracy. The diagnostic accuracy for the OSM and the OPG were 94.2% and 91.6%, respectively. In 171/202 (84.6%) arteries, the OSM and OPG were in diagnostic agreement, and the overall diagnostic accuracy of the combined tests was 97%. However, when the OSM and OPG did not agree (31/202 arteries, 15.4%), the diagnostic accuracy of neither the OSM nor the OPG was acceptable. Although the best diagnostic accuracy was obtained using two means of noninvasive cerebrovascular testing, in those instances where only one test may be available, the OPG would appear to be the test of choice. In those laboratories in which high diagnostic accuracy is obtained with the OSM, the addition of OPG testing will increase the overall diagnostic accuracy to a very high level. The presence of a midcervical bruit was found to have a very poor correlation with the incidence of hemodynamically significant stenoses of the internal carotid artery. Although both the OSM and OPG have minimal value in patients with symptomatic cerebrovascular disease, these tests play a very important role in screening patients for asymptomatic carotid stenosis or atypical cerebrovascular symptoms.     

Prospective study of carotid endarterectomy and contralateral carotid occlusion

A total of 700 patients who had carotid endarterectomy (CEA) in the UK and Ireland during a 6-month interval between March and August 1994 were studied prospectively. Some 108 patients (15.4 per cent) had a contralateral internal carotid artery occlusion. Previous reports have shown an associated stroke rate of about 10 per cent in these patients. This study assessed complications and outcome for patients undergoing CEA with contralateral internal carotid artery occlusion compared with those without. The indications for surgery were comparable between the two groups although the patients with occlusion had a slightly higher incidence of arrhythmia and stroke. Intraoperative shunts were used in a significantly higher proportion of those with occlusion (83.3 versus 64.7 per cent, P = 0.0001). The combined death and stroke rate for patients with occlusion was 5.6 per cent compared with 2.4 per cent for the remainder (P not significant). On the basis of the present data, CEA with a contralateral carotid artery occlusion carries only a slight increase in the rate of postoperative stroke and death. This increase was not statistically significant and is lower than that reported previously.     

Asymptomatic carotid artery stenosis and stroke in patients undergoing cardiopulmonary bypass

PURPOSE: This study was undertaken to assess the natural history of carotid artery stenosis in patients undergoing cardiopulmonary bypass (CPB) at a Veterans Administration Medical Center. METHODS: Between January 1989 and August 1993, all patients undergoing CPB were offered preoperative carotid artery ultrasound screening as part of an investigative protocol. Patients were monitored in-hospital for the occurrence of perioperative neurologic deficit. RESULTS: A total of 582 patients underwent carotid artery ultrasound screening. Greater than 50% stenosis or occlusion of one or both internal carotid arteries was present in 130 patients (22%), with 80% or greater stenosis or occlusion of one or both arteries present in 70 patients (12%). In-hospital stroke or death occurred in 12 (2.1%) and 36 (6.2%) patients, respectively. Of the 12 strokes, five were global and seven were hemispheric in distribution. Of the five patients who had global events, none had evidence of carotid artery stenosis. However, of the seven patients who had hemispheric events, five had significant 50% or greater stenosis or occlusion of the internal carotid artery ipsilateral to the hemispheric stroke. Therefore the presence of carotid artery stenosis or occlusion was significantly associated with hemispheric stroke (no stenosis 0.34% vs stenosis 3.8%; p = 0.0072). Furthermore, the risk of hemispheric stroke in patients with unilateral 80% to 99% stenosis, bilateral 50% to 99% stenosis, or unilateral occlusion with contralateral 50% or greater stenosis was 5.3% (4 of 75). No strokes occurred in patients with unilateral 50% to 79% stenosis (n = 52). CONCLUSIONS: It is concluded that carotid atherosclerosis is a risk factor for hemispheric stroke in patients undergoing CPB.     

Incidence and morphology of carotid shudders in aortic valve disease

The incidence and morphology of shudders in carotid arterial pulse tracings were examined in 73 patients with aortic valve disease documented by cardiac catheterization. Two forms of carotid shudder were recorded: coarse and fine. Shudders were present in 67 per cent of patients with aortic stenosis, 48 per cent of patients with aortic insufficiency, and 57 per cent of patients with mixed aortic stenosis and insufficiency. No significant difference existed among these three groups of patients with respect to the over-all incidence of carotid shudders or with respect to the incidence of coarse or fine shudders. In patients with aortic insufficiency, stroke volume index (Fick) and phonocardiographic systolic ejection murmur amplitude were significantly greater (p less than 0.01, p less than 0.001, respectively) in those with coarse carotid shudders compared with those manifesting fine or absent shudders. Loud, flow-related, systolic ejection murmurs of aortic insufficiency are capable of producing radial vibrations in the aortic wall which are recorded as carotid shudders. The finding of a carotid shudder in a patient with aortic valve disease does not enable the physician to distinguish between stenosis, insufficiency, or mixed stenosis and insufficiency.     

Asymptomatic occlusive lesions of carotid and intracranial arteries in Japanese patients with ischemic heart disease: evaluation by brain magnetic resonance angiography

BACKGROUND AND PURPOSE: The purpose of this study was to elucidate the prevalence and degree of asymptomatic occlusive lesions in the carotid and intracranial arteries in Japanese patients with ischemic heart disease (IHD). METHODS: We performed carotid and intracranial MR angiography (MRA) on 67 patients (49 men, 18 women; age range, 40 to 78 years; mean age, 60.1 years) who had received selective coronary angiography for the clinical diagnosis of IHD. On the basis of these images, degree of stenosis in the regions of the bilateral carotid artery bifurcation and five regions of the intracranial arteries, ie, bilateral intracranial portions of the internal carotid arteries and the middle cerebral arteries and the basilar artery were estimated. RESULTS: Stenosis of more than 25% narrowing of the diameter of the target arteries was found in 15 patients (22.4%) in the extracranial carotid arteries and in 11 patients (16.4%) in the intracranial arteries. Most of the stenotic lesions were mild. The incidence of extracranial carotid stenosis and the severity of coronary atherosclerosis showed a significant correlation. The mean age of the patients with intracranial arterial lesions was statistically higher than those without intracranial lesions. CONCLUSIONS: Our data suggest that asymptomatic occlusive lesions in the carotid and intracranial arteries are fairly common in Japanese patients with IHD, although the degree of stenosis is relatively mild. Coexistence of carotid atherosclerosis should be suspected in IHD patients with severe coronary atherosclerosis, and the possibility of atherosclerosis in the intracranial arteries should be considered in aged IHD patients.     

Combined carotid endarterectomy and coronary artery bypass grafting in asymptomatic carotid artery stenosis

The role of combined carotid endarterectomy (CEA) and coronary artery bypass grafting (CABG) in patients with severe asymptomatic carotid artery disease and concurrent symptomatic coronary artery disease is controversial. The objective of this report is to investigate the safety of combined CEA/CABG. The medical records of 30 patients who underwent combined CEA/CABG for coexistent asymptomatic carotid and symptomatic coronary artery occlusive disease were reviewed. All patients were scheduled for either elective or urgent myocardial revascularization due to their symptomatic coronary artery disease. Color-flow duplex scanning identified internal carotid artery stenosis of 80 to 99 per cent in 28 patients (93%) and 50 to 79 per cent in 2 patients (7%). Seventeen patients (57%) were male. The mean age was 64 +/- 10 years (range, 42-84 years). Contralateral internal carotid artery occlusion was present in four patients. Severe left main coronary artery disease was present in 12 patients (40%) and 7 patients (23%) had an ejection fraction of less than 50 per cent. There were no perioperative deaths or strokes. One patient suffered a myocardial infarction on postoperative day 1. This study demonstrates the safety of combined CEA/CABG for coexistent coronary and asymptomatic carotid disease. Using this surgical approach for critical coexistent disease may minimize the incidence of perioperative cerebrovascular complications in patients undergoing CABG.     

Profile of anti-stratum corneum autoantibodies in patients with aural cholesteatoma

A study was performed to evaluate immediate changes in carotid artery blood flow after carotid endarterectomy using a Doppler ultrasonographic flowmeter. Forty-seven consecutive patients aged 49-78 (median 64) years with symptomatic internal carotid artery (ICA) stenosis underwent carotid endarterectomy. Volume flow, resistance and pulsatility index were measured in the common carotid artery (CCA) and ICA both before and after operation. ICA flow increased by 54 per cent (P < 0.01) and resistance decreased by 58 per cent (P = 0.01). CCA flow rose by 17 per cent (P = 0.1) and resistance fell by 21 per cent (P = 0.02). The pulsatility index did not change significantly. The Doppler ultrasonographic flowmeter offers a simple, non-invasive and convenient means of improving understanding of the immediate haemodynamic effects of carotid endarterectomy. It is useful in everyday practice to confirm the adequacy of endarterectomy, particularly in the absence of other methods of quality control. Duplex ultrasonography might still be necessary after surgery if the flowmeter does not demonstrate an increase in flow compared with the preoperative value.     

MR imaging of the liver with Resovist: safety, efficacy, and pharmacodynamic properties

PURPOSE: To determine whether ultrasound (US) is a sensitive follow-up method after placement of a carotid artery stent for the detection of significant stenosis, occlusion, and other complications at early and intermediate follow-up. MATERIALS AND METHODS: Doppler US examinations were performed after stent placement in 170 carotid arteries in 119 patients with angiographic correlation. Prospective diagnostic US criteria for stenosis were peak-systolic velocity greater than 1.25 m/sec, internal carotid artery (ICA) to common carotid artery (CCA) peak-systolic velocity ratio of greater than or equal to 3:1, and intrastent doubling of peak-systolic velocity. Retrospective criteria for stenosis were also applied: peak-systolic velocity greater than 1.7 m/sec, ICA end-diastolic velocity greater than 0.4 m/sec, ICA/CCA peak-systolic velocity ratio greater than 2.0, and ICA/CCA end-diastolic velocity ratio greater than 2.4. RESULTS: Eighty-seven immediate and 83 intermediate (average, 7.3 months) follow-up US examinations were performed. Two stent occlusions were detected. One or more prospective US criteria were abnormal in 26 arteries with a stent. One or more retrospective criteria were positive in 47 arteries. Angiography showed corresponding findings, with only one significant stenosis (63%) in the ICA stents. Moderate collapse of a CCA stent was depicted at US. CONCLUSION: Only one significant recurrent stenosis was detected, and no significant stenoses were missed at US. US successfully depicted carotid artery stent occlusion and a moderate stent collapse. Sensitivity in the detection of intrastent stenosis is promising. Further study to refine US criteria in a study with longer term follow-up is needed owing to the lack of significant recurrent stenosis in the intermediate follow-up group.     

Fibromuscular dysplasia of the internal carotid artery associated with alpha1-antitrypsin deficiency

OBJECTIVE: A deficiency of alpha1-antitrypsin has been implicated in the development of various disorders affecting medium-sized arteries, including intracranial aneurysms, cervicocephalic arterial dissections, and fibromuscular dysplasia (FMD). We performed alpha1-antitrypsin phenotyping in three consecutive patients who underwent bypass surgery for FMD of the extracranial internal carotid artery to test the hypothesis that alpha1-antitrypsin deficiency is a genetic risk factor for the development of FMD. METHODS: The study population consisted of three women (aged 37, 49, and 53 years, respectively) who had bilateral internal carotid artery stenosis caused by FMD. The indications for surgery included ocular or cerebral ischemic symptoms in two patients and progressive stenosis in one patient. The diagnosis of FMD was confirmed by histological examination of the resected segment of artery. The alpha1-antitrypsin phenotype was determined by isoelectric focusing in polyacrylamide gels. RESULTS: Two of the three patients had a heterozygous alpha1-antitrypsin deficiency (PiMZ phenotype). Pathological examination of the resected arterial segment showed typical medial FMD with focal intimal fibroplasia in both patients with the PiMZ phenotype. CONCLUSION: These findings suggest that a heterozygous alpha1-antitrypsin deficiency may be a genetic risk factor for the development of FMD of the internal carotid artery.     

Computed tomographic angiography for the evaluation of carotid artery stenosis

BACKGROUND AND PURPOSE: No previous study has compared the reliability of carotid artery measurement provided by axial images, shaded surface display (SSD), and maximum intensity projection (MIP). METHODS: Helical CT and conventional angiography were performed prospectively in 20 patients with atherosclerotic stenosis of the internal carotid artery. Stenosis measurement was performed in a blinded fashion on angiography and CT by two independent examiners. Calcifications were segmented when they were located far enough from the vascular lumen. SSD and MIP were systematically performed for each carotid bifurcation. We measured stenosis using conventional angiography as standard and the different CT reconstructions (axial images, SSD, and MIP) by comparing the stenosis diameter at its narrowest point to the normal internal carotid artery. The degree of stenosis was classified into six groups: no stenosis, mild stenosis (< 30%), moderate stenosis (30% to 70%), severe stenosis (> 70%), near occlusion, and occlusion (100%). No measurement was made in cases of normal artery, near occlusion, and occlusion. RESULTS: Correlations between angiography and the three types of reconstruction were very good. Axial sections correctly classified the carotid arteries in 95% of cases. In 10 carotid arteries, stenosis was not assessable by SSD and MIP because of calcifications. In the remaining carotid arteries, MIP correctly classified the degree of stenosis in 96% of cases, whereas SSD misclassified 21% of cases. CONCLUSIONS: Our study showed that axial images provide a reliable evaluation of carotid artery stenosis. Calcifications are limiting factors in SSD or MIP. When atherosclerotic plaques are not calcified, MIP reconstructions provide a more reliable measurement of the vascular lumen than SSD.     

Progression of asymptomatic carotid stenosis: a natural history study in 1004 patients

PURPOSE: The purpose of this study was to delineate the natural history of the progression of asymptomatic carotid stenosis. METHODS: In a 10-year period, 1701 carotid arteries in 1004 patients who were asymptomatic were studied with serial duplex scans (mean follow-up period, 28 months; mean number of scans, 2.9/patient). At each visit, stenoses of the internal carotid artery (ICA) and the external carotid artery (ECA) were categorized as none (0 to 14%), mild (15% to 49%), moderate (50% to 79%), severe (80% to 99%), preocclusive, or occluded. Progression was defined as an increase in ICA stenosis to >/=50% for carotid arteries with a baseline of <50% or as an increase to a higher category of stenosis if the baseline stenosis was >/=50%. The Cox proportional hazards model was used for data analysis. RESULTS: The risk of progression of ICA stenosis increased steadily with time (annualized risk of progression, 9.3%). With multivariate modeling, the four most important variables that affected the progression (P <.02) were baseline ipsilateral ICA stenosis >/=50% (relative risk [RR], 3.34), baseline ipsilateral ECA stenosis >/=50% (RR, 1.51), baseline contralateral ICA stenosis >/=50% (RR, 1.41), and systolic pressure more than 160 mm Hg (RR, 1. 37). Ipsilateral neurologic ischemic events (stroke/transient ischemic attack) occurred in association with 14.0% of the carotid arteries that were studied. The progression of ICA stenosis correlated with these events (P <.001), but baseline ICA stenosis was not a significant predictor. CONCLUSION: In contrast to recently published studies, we found that the risk of progression of carotid stenosis is substantial and increases steadily with time. Baseline ICA stenosis was the most important predictor of the progression, but baseline ECA stenosis also was identified as an important independent predictor. Contralateral ICA stenosis and systolic hypertension were additional significant predictors. We found further that the progression of ICA stenosis correlated with ischemic neurologic events but not baseline stenosis. The data provide justification for the use of serial duplex scans to follow carotid stenosis and suggest that different follow-up intervals may be appropriate for different patient subgroups.     

Pseudo-tandem stenosis of the internal carotid artery

Two cases of pseudo-tandem stenosis of the internal carotid artery are presented. Proximal stenosis was produced by a large, focal atherosclerotic plaque. The severe intracranial "stenosis" was thought to be an angiographic artifact. Repeat cerebral angiography after carotid endarterectomy revealed normal intracranial arteries. The recognition of this entity is important because a decision to operate is based largely upon angiographic findings.     

Surgical decisions on the basis of magnetic resonance angiography of the carotid arteries

The recent demonstration of the efficacy of carotid endarterectomy in certain patients emphasizes the advantages of having a noninvasive, accurate means of evaluating the carotid arteries. Advances in magnetic resonance (MR) angiography now allow accurate depiction of the carotid arteries that may be adequate for surgical planning in many cases. This report examines the accuracy of MR angiography compared with that of conventional angiography in symptomatic patients undergoing carotid endarterectomy and compares them with surgical findings. Twenty-one carotid arteries in 20 patients were treated surgically for severe stenosis or occlusion. Preoperatively, all patients had both MR and conventional angiograms, which were interpreted on a five-grade scale by two independent neuroradiologists who were unaware of the patient's clinical history. The two studies were highly correlated, particularly in the case of severe stenosis and occlusion. There were no false-negative MR studies that missed surgically significant lesions. In two cases, MR angiography overestimated the stenosis by one grade. On MR angiography, surgically significant stenosis appears as focal areas of signal intensity loss at the level of stenosis with reappearance of the signal distally. If the distal signal intensity does not reappear, the artery is likely to be occluded. In symptomatic patients, MR angiograms that demonstrate a flow-void gap with distal reappearance at a site consistent with the symptoms may be adequate as the sole preoperative study. Three patients who underwent carotid endarterectomy on this basis are presented. The factors that contribute to artifactual and overestimated stenosis are reviewed.     

Ischaemic stroke from cerebral embolism in cephalic fibromuscular dysplasia

Fibromuscular dysplasia (FMD) of the internal carotid arteries and its relationship with focal cerebral ischaemia is unproven. This vasculopathy is often detected incidentally during a cerebral angiogram for non-ischaemic cerebral events. FMD affects the proximal one-third of the internal carotid artery in almost all cases and is bilateral in 60% to 85%, with middle-aged women affected in 85% of the cases. Ischaemic stroke has been postulated to result from severe stenosis or thrombotic occlusion at the FMD site. Cerebral embolism from FMD has rarely been reported. We report 3 young patients with acute ischaemic stroke who had FMD on cerebral angiography. They presented with a focal hemispheric stroke where the probable pathophysiology is embolism to the distal internal carotid artery from thrombus formed at the proximal FMD site. The patients were all males, with unilateral proximal internal carotid artery FMD lesions and occlusion of the internal carotid artery distally on the same side. All were extensively investigated and no other causes for stroke were found.     

Mycotic aneurysm of the innominate artery with supravalvular aortic stenosis

A case of mycotic innominate artery aneurysm in association with supravalvular aortic stenosis has been presented with successful resection as the first such case documented. Blood flow was restored with low cervical autogenous internal jugular vein, as an end-to-side vein graft from the left common carotid and end-to-end to the right subclavian and right common carotid arteries. The future repair of the supravalvular aortic stenosis could then be more easily accomplished.     

Role of carotid sonography as a first examination in the evaluation of patients with transient ischemic attacks and strokes: benefit in relation to age

PURPOSE: We studied the influence of age on the utility of carotid sonography in patients with transient ischemic attacks and strokes. METHODS: The results of Doppler ultrasound examinations of the carotid arteries in 613 consecutive patients with transient ischemic attacks (n = 450) or strokes (n = 163) were analyzed for different age groups. For each patient, the grade of stenosis was scored for the ipsilateral internal carotid artery. The results of the ultrasound examinations were correlated with angiographic findings and findings at endarterectomy. The extent of atherosclerosis for each age group was expressed as the ratio between the number of grade II-IV stenoses (> or = 50%) in the carotid arteries and the number of patients in that group ("atherosclerosis ratio"). RESULTS: Under the age of 40 years, high-grade atherosclerotic stenoses were not found. However, 3 relatively young patients had dissections of the internal carotid arteries. The atherosclerosis ratio exceeded 0.5 for age groups 65-69 years through 80+ years. Among the patients with high-grade stenoses, ischemic heart disease prevented endarterectomy in 63% of patients in age group 80+ years, 44% in age group 75-79 years, and 26% in age group 70-74 years. CONCLUSIONS: Carotid sonography did not detect any significant atherosclerotic changes in young patients but was useful for diagnosing other etiologies of ischemic cerebral disease, eg, carotid dissection. At the other end of the spectrum, the impact of carotid sonography on patient management appears to be limited in patients over the age of 70 years. Carotid sonography seems to be most useful for patients 40-69 years old.     

Diffusion-weighted MR imaging with a single-shot echoplanar sequence: detection and characterization of focal hepatic lesions

BACKGROUND: The aim of this study was to establish the feasibility, safety, and diagnostic accuracy of the dipyridamole echocardiography test in patients with severe aortic valve stenosis for noninvasive detection of coexisting coronary artery disease. METHODS: The high-dose dipyridamole echocardiography test was performed in 52 patients with severe aortic stenosis; all patients also underwent coronary angiography, independent of test results, before cardiac operation. RESULTS: The dipyridamole echocardiography test was completed without major complications. One patient had transient atrial fibrillation that was reversed by aminophylline. Thirty-one patients (60%) had a negative test result; all had normal coronary arteries. Ten of the 21 patients (48%) with a positive test result had coexisting coronary artery disease. The positive predictive value of the dipyridamole echocardiography test for detection of coronary disease in patients with severe aortic stenosis was 48%. The negative predictive value was 100%. The sensitivity was 100% and the specificity was 74%. CONCLUSIONS: Dipyridamole echocardiography is a safe and feasible tool in patients with severe aortic stenosis eligible for a cardiac operation. A negative test result reliably rules out a significant stenosis, whereas a positive one is much less accurate in predicting coronary artery disease.     

Fibromuscular dysplasia and multiple dissecting aneurysms of intracranial arteries. A further cause of Moyamoya syndrome

A 16-year-old boy, who had sudden left-sided hemiplegia, died two weeks following onset of symptoms. A right carotid angiogram showed stenosis at the termination of the internal carotid artery. The middle cerebral artery had a beaded appearance and some of its branches were occluded. A basal "moyamoya" syndrome and transdural anastomoses were present. At autopsy, multiple intracranial dissecting aneurysms were found. Arteries of the body displayed fibromuscular dysplasia (FMD). The relevance of dysplastic changes of intracranial arteries and the relationship to moyamoya syndrome are discussed.     

Shortening and reimplantation for tortuous internal carotid arteries

PURPOSE: The purpose of this study was to assess the outcome after the shortening and reimplantation of tortuous internal carotid arteries to prevent kinking after endarterectomy. METHODS: Through a review of prospective records, we studied patients who underwent carotid endarterectomy (CEA) (n = 233) between 1993 and 1996 who had symptomatic stenosis of the internal carotid artery (ICA) of more than 70%. An elongated proximal ICA was excised, and the ICA was reimplanted into the bifurcation in 30 (13%) patients, with additional patch angioplasty in 5 patients. Of the remaining 203 patients, 50 (21%) had Dacron patch angioplasty, and the rest had conventional CEA with simple closure. RESULTS: In the reimplanted group, one patient had a minor stroke with complete recovery on discharge. Three patients (10%) had neck hematomas requiring reexploration, but in none of these was the bleeding from the artery. At mean follow-up of 15 months, 93% of the arteries were widely patent. Significant stenosis secondary to neointimal hyperplasia was detected in only two patients, for a restenosis rate of 6.7%, which is in line with other published reports. In the control group, 8 (3.9%) patients had perioperative transient ischemic attacks, 5 (2.5%) had strokes, and 13 (6.4%) had hematomas requiring evacuation. At follow-up, 14 (6.9%) of the arteries had restenosed. CONCLUSION: In carotid surgery, reconstructive techniques must be tailored to operative findings. Excision of a tortuous elongated proximal ICA with reimplantation is not associated with additional mortality or morbidity rates over those of conventional CEA alone and has the advantage of removing disease at the bifurcation. This procedure was carried out in 13% of our patients and should be a procedure with which the vascular surgeon is familiar.