Carotid Siphon Stenosis Research Articles

Bilateral stenosis of carotid siphon in Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is a rare premature aging disease, caused by a de novo mutation of lamin-A gene, LMNA G608G. Accumulation of abnormal lamin-A (progerin) compromises nuclear membrane integrity and results in the accelerated senescence. Affected patients show a typical feature of birdlike face, alopecia, sclerotic skin, loss of subcutaneous fat, and short stature with advancing years. Neonatal scleroderma is the first presentation, although early diagnosis is challenging. The leading cause of death is cardio-/cerebro-vascular accidents associated with atherosclerosis. However, not all findings may recapitulate the aging process. We herein report a 9-year-old Japanese male with HGPS who developed cerebral infarction. The genetic study of peripheral blood-derived DNA determined a heterozygous c.1824C>T mutation, p.G608G. Telomere length of lymphocytes was normal. Bilateral stenosis of carotid siphons was prominent, while systemic arteriosclerosis was unremarkable assessed by the ankle-brachial index, carotid ultrasound imaging and funduscopic study. HGPS patients have marked loss and functional defects in vascular smooth muscle cells, leading to the vulnerability to circulatory stress. Symmetrical stenosis of siphons might occur as a distinctive cerebral vasculopathy of HGPS, rather than simple vascular senescence. Peripheral blood study on LMNA G608G and telomere length could screen progerias in infancy for early therapeutic intervention.

The Argument to Support Broader Application of Extracranial Carotid Artery Stent Technology

As new technology becomes available, the stent technique for the extracranial carotid artery continues to evolve into a safer, more effective therapy for stroke prevention. With the availability of embolic protection, improved stent designs, and added endovascular physician experience, outcomes for carotid artery stenting (CAS) now consistently parallel those for carotid endarterectomy (CEA). Although carotid endarterectomy was established as the gold standard for carotid revascularization, the available scientific evidence must continue to be interpreted in the context of further advancements in nearly all related areas of medicine. One multicenter randomized trial and several nonrandomized registries have successfully established the CAS indications for patients with high surgical risk and have provided evidence to support the use of CAS techniques in patients with low surgical risk. Clinicians must continue to improve their understanding of patient-specific factors and conduct research that will refine indications while optimizing current medical therapy and that will integrate CAS and carotid endarterectomy as complementary treatments. Response by LoGerfo p 1610 The outcomes for CAS have been improving over the past 10 years and now appear nearly equivalent to those for CEA. In fact, many historical similarities are seen in the development of these 2 techniques. Although CEA was established as the gold standard for extracranial carotid revascularization, the available scientific evidence must continue to be interpreted in the context of further advancements in nearly all related areas of medicine. The current research comparing CAS and CEA has not shown a clinically robust and statistically significant difference between the 2 treatments. When differences do exist, clinicians must continue to refine patient-specific indications and to conduct further research to understand these complex risk-benefit analyses in the context of advanced medical treatments and complementary revascularization techniques. The following review details the argument to support implementation of CAS technology for athero-occlusive carotid …

Prevalence of Carotid Siphon Stenosis in Patients Referred for Cerebrovascular Evaluation

Introduction The carotid siphon is second only to the carotid bifurcation in the prevalence of hemodynamically significant atherosclerotic plaque formation, yet few noninvasive vascular laboratories report interrogation of this region during routine noninvasive vascular evaluations. The purpose of this investigation was to determine the prevalence of carotid siphon stenosis in patients referred for noninvasive cerebrovascular evaluation. Materials and Methods During a 2-month period, 178 patients (94 male, 84 female, mean age, 71.8 years) were referred to the vascular laboratory for cerebrovascular evaluation, which included interrogation of the extracranial carotid, vertebral, and subclavian arteries as well as the intracranial ophthalmic artery and carotid siphon. All intracranial examinations were performed using a phased array imaging transducer (2–4 MHz). Results Ten patients (6%, 10/178) were found to have hemodynamically significant carotid siphon stenosis. There was a statistically significant association between the presence of carotid siphon stenosis and cervical bruit ( p ≤ 0.05), follow-up of known extracranial carotid artery atherosclerosis ( p ≤ 0.001), and a combination of hypertension, hyperlipidemia, and coronary artery disease ( p ≤ 0.01). Conclusion Investigation of the carotid siphon is worthwhile when performed in conjunction with extracranial carotid duplex examinations. Siphon lesions detected during the cerebrovascular examination, especially in those with cervical bruits, known extracranial atherosclerotic disease, and combinations of risk factors, may affect medical or interventional therapy and can lead to a reduction in neurovascular events.

Distribution of carotid arterial lesions in Chinese patients with transient monocular blindness

Background and Purpose— Asian patients with cerebrovascular diseases have more intracranial atherosclerosis and less extracranial carotid artery stenosis compared with white patients. We systemically evaluated the distribution of carotid arterial lesions in Chinese patients with transient monocular blindness (TMB), which was rarely reported. Methods— We prospectively evaluated 105 consecutive patients with TMB. All of the patients received ocular and physical examinations, blood tests for coagulation function and autoimmune diseases, and ultrasonography of cervical and intracranial arteries. All of the carotid lesions were confirmed by magnetic resonance angiography or cerebral angiography. Results— Of the 36 (34.3%) patients with significant carotid stenosis (≥50%), 16 (15.2%) had extracranial carotid stenosis; 17 (16.2%) had carotid siphon stenosis; and 3 (2.9%) had both. The duration, onset, and patterns of visual loss were not different between patients with and without carotid arterial lesion. Conclu...

Maladie de Horton d’évolution fatale avec atteinte sévère bilatérale des artères vertébrales

With steroid therapy, it is commonly considered that prognosis is good in giant cell arteritis. However serious or even fatal complications may occur. Here we report the case of a patient who developed fatal giant cell arteritis with severe stenosis of both vertebral arteries and right carotid siphon. Several similar cases have been reported in the literature. Initially diagnosis may be difficult because neurological manifestations are intermittent and classical signs of giant cell arteritis may be lacking. In such condition the reason of poor outcome is unknown and therapy remains empiric.

Distribution of Carotid Arterial Lesions in Chinese Patients With Transient Monocular Blindness

Asian patients with cerebrovascular diseases have more intracranial atherosclerosis and less extracranial carotid artery stenosis compared with white patients. We systemically evaluated the distribution of carotid arterial lesions in Chinese patients with transient monocular blindness (TMB), which was rarely reported. We prospectively evaluated 105 consecutive patients with TMB. All of the patients received ocular and physical examinations, blood tests for coagulation function and autoimmune diseases, and ultrasonography of cervical and intracranial arteries. All of the carotid lesions were confirmed by magnetic resonance angiography or cerebral angiography. Of the 36 (34.3%) patients with significant carotid stenosis (> or =50%), 16 (15.2%) had extracranial carotid stenosis; 17 (16.2%) had carotid siphon stenosis; and 3 (2.9%) had both. The duration, onset, and patterns of visual loss were not different between patients with and without carotid arterial lesion. This study signified the importance of carotid siphon stenosis as a probable underlying etiology for TMB in Chinese patients.

Multicenter review of preoperative risk factors for carotid endarterectomy in patients with ipsilateral symptoms.

Randomized clinical trials have shown that carotid endarterectomy decreases the risk of subsequent stroke in patients with high-grade carotid stenosis and ipsilateral transient ischemic attack or minor stroke. The benefit of surgery is highly dependent on surgical risk. We previously found that patients with ipsilateral hemispheric symptoms were at greater risk of carotid endarterectomy complications compared with those who were asymptomatic or had nonipsilateral symptoms. The goals of the present study were (1) to identify preoperative clinical factors that may increase the risk of complications after carotid endarterectomy in patients with ipsilateral hemispheric symptoms and (2) to develop a risk index based on this patient-level data. Records from 1160 carotid endarterectomies performed at 12 academic medical centers composed the primary data set. Hospital charts for the admission during which carotid endarterectomy was performed were systematically reviewed by abstractors using a defined protocol. The present analysis was carried out on data from the subset of patients who had carotid endarterectomy for ipsilateral hemispheric symptoms. Candidate variables were identified based on univariate Fisher's exact tests or chi 2 tests. A risk index was then developed using those variables with a greater than 90% probability of being associated with adverse outcomes. Of the 697 patients with ipsilateral symptoms, 8.5% had either stroke, myocardial infarction, or died during the postoperative period of hospitalization. Those over the age of 75 had a greater risk of myocardial infarction (6.6% versus 2.3%, P = .024) but not of stroke or death (P > .10). The overall frequencies of adverse outcomes were also higher in the 5 patients with complete ipsilateral carotid occlusions (40% versus 8.2%, P < .01), the 28 patients with ipsilateral intraluminal thrombus (17.9% versus 8.1%, P = .07), and the 65 patients with ipsilateral carotid siphon stenosis (13.9% versus 7.9%, P = .10). There were no differences in adverse outcomes among those with different degrees of ipsilateral stenosis (30% to 49%, 50% to 69%, and 70% to 99%). Adverse outcome rates were similar regardless of the type of symptom (transient ischemic attack, recent ipsilateral minor stroke, remote ipsilateral minor stroke). There were no significant differences in adverse outcome rates based on sex, race, history of angina, recent myocardial infarction, congestive heart failure, chronic obstructive pulmonary disease, hypertension, degree of stenosis of the contralateral carotid artery, or presence of ulceration in the ipsilateral artery (Fisher's exact tests, P > .10). A count of variables with greater than 90% probability of being associated with adverse outcomes (age > or = 75 years or angiographic evidence of ipsilateral carotid occlusion, stenosis in the region of the carotid siphon, or intraluminal thrombus) was used to form a simple risk index. "High-risk" patients (one or more risk factors) had more than two times the risk of complications compared with "low-risk" patients who had no risk factors (odds ratio, 2.18; 95% confidence interval, 1.25 to 3.81). Certain preoperative clinical variables may place patients with ipsilateral symptoms at greater risk of perioperative complications after carotid endarterectomy. Prospective validation of a simple risk index would provide an additional method for assessing preoperative risk in endarterectomy candidates.

The influence of carotid siphon stenosis on short- and long-term outcome after carotid endarterectomy

Purpose: This study was designed to determine whether the presence of ipsilateral carotid siphon stenosis influenced the risk of early and late stroke and death after carotid endarterectomy (CEA).Methods: The outcomes of patients with moderate (20% to 49%), severe (> 50%), and no siphon stenosis were compared over a 16-year period from April 1976 to February 1992. Complete angiographic data were available in 393 carotid arteries.Results: Siphon stenosis was found ipsilateral to the CEA in 84 (21.4%) of the arteries. Most lesions were in the 20% to 49% diameter-reducing range (77.4%), with the remainder in the greater than 50% range (22.6%). There were no occlusions. The perioperative mortality rate was nearly identical for the groups with and without siphon stenosis, 0.0% versus 0.6%, respectively (p = 0.99). Perioperative stroke morbidity rates (no stenosis, 2.3%; moderate stenosis, 3.1%; > 50% stenosis, 5.3%) were acceptable and were not statistically different (p > 0.38). Late ipsilateral stroke-free rates were similar in the groups with and without siphon stenosis. The 5- and 7-year stroke-free incidences were 88.5% and 83.4% versus 94.9% and 94.9%, respectively (p > 0.20) for the two groups. Long-term ipsilateral stroke-free rates were not significantly different in the subgroups with moderate (20% to 49%) and hemodynamically significant (> 50%) siphon stenosis. The 3- and 5-year ipsilateral stroke-free rates were 96.7% and 87.9% versus 94.6% and 94.6%, respectively (p = 0.69). Late death was more common in the group with siphon stenosis than it was in the group without siphon stenosis, 23.8% versus 12.5% (p = 0.02). Heart disease was responsible for most late deaths, 47% in both groups. Late stroke-related deaths were infrequent: 1.3% in patients with and 0.0% in patients without siphon stenosis.Conclusions: Although carotid siphon stenosis seemed to be associated with a higher risk of late death, it did not alter the short- and long-term stroke morbidity rates after carotid endarterectomy significantly. We conclude that the presence of carotid siphon stenosis should not influence the decision to perform carotid endarterectomy in patients with the appropriate indications.

Internal borderzone infarction following acute middle cerebral artery occlusion

In 36 patients suffering acute middle cerebral artery (MCA) occlusion, we studied the angiographic findings within 6 hours of the ictus and the chronic CT results at 3 months. Seven patients suffering distal pial MCA branch occlusion developed a pattern of internal borderzone infarction on follow-up CT. Carotid artery or carotid siphon stenosis or occlusion was absent in all seven. Proximal MCA branch occlusions, prior to the origin of the lenticulostriate arteries, were associated with extensive cortical and deep infarction in the entire MCA territory in 14 patients. There was proximal carotid artery or siphon stenosis or occlusion in 12 of these 14 patients. The remaining 15 patients showed a mixture of proximal and distal MCA occlusions and patchy ischemic damage in the MCA territory. There were no cases of superficial cortical watershed infarction. These data show that internal borderzone infarctions may result from intracranial MCA branch occlusions alone and need not be associated with hemodynamic alterations due to large vessel extracranial disease.

The prognosis of carotid siphon stenosis.

We retrospectively reviewed the clinical course and angiograms of 15 patients with carotid siphon stenosis of 50% or greater. Fourteen had less than 50% stenosis at the origin of the ipsilateral internal carotid artery, and one had a greater degree of stenosis but underwent endarterectomy after an initial angiogram. Angiograms were examined for evidence of hemodynamic abnormalities in addition to residual lumen diameter. Seven patients initially had TIAs, 5 had strokes, and 3 were asymptomatic. In an average followup of 51 months (range 4-123 months) subsequent cerebral ischemic events occurred in 6 (40%), but only 1 had a stroke with a persisting neurological deficit that could be directly attributed to the siphon stenosis. Stenoses were hemodynamically significant by angiography in 5 of 7 TIA patients, and only 1 of 5 stroke patients. The incidence of subsequent ischemic events in this study was similar to 2 previous studies of siphon stenosis, however in this study most of the events ipsilateral to the siphon stenosis were TIAs or minor strokes. The association of hemodynamic angiographic abnormalities and initial TIAs but not strokes suggests that the mechanism producing ischemic symptoms may differ in patients with TIA and stroke who have carotid siphon stenosis.

Long-Term Mortality and Stroke Morbidity After Superficial Temporal Artery-Middle Cerebral Artery Bypass Operation

Among 239 patients with transient ischemic attacks, mild stroke, or transient monocular visual symptoms who had superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass, no deaths occurred during the operation or within 30 days thereafter. After the first month, mortality on an actuarial basis was 3% per year. Survival at 5 years was 84% in comparison with an expected survival of 89% for persons of comparable age and sex in a general population. Among the 25 deaths that occurred during follow-up, 2 were due to stroke and 16 to cardiac causes. Of 28 strokes that occurred, 5 occurred during operation or that same day, and 3 others occurred within 30 days postoperatively. Thereafter, strokes occurred at the rate of 2.5% per year on an actuarial basis; a third of the strokes occurred contralateral to the surgical site. No difference was found in survival or in survival free of stroke among patients who had proven carotid artery occlusion (N = 157), carotid siphon stenosis (N = 53), or MCA stenosis or occlusion (N = 29). In regard to the probability of stroke, this group of patients compares favorably with population studies of patients with transient ischemic attacks of undetermined cause. When this surgical group was compared with 130 nonsurgical patients who had had ischemic symptoms related to proven internal carotid artery occlusion between 1965 and 1975, however, we could not conclude that the risk of occurrence of stroke was less in patients who had STA-MCA bypass than in the nonsurgical patients.(ABSTRACT TRUNCATED AT 250 WORDS)

The natural history of isolated carotid siphon stenosis

Between August 1978 and July 1983, 93 patients (71 with unilateral and 22 with bilateral isolated carotid siphon stenosis) were identified from a review of 885 consecutive cerebral arteriograms. This yielded 115 cerebral hemispheres at risk. At the time of arteriography, 93 hemispheres were asymptomatic regarding the hemisphere with siphon stenosis (group I), whereas 22 hemispheres in 22 patients had had neurologic events referable to the hemisphere with siphon stenosis (group II). During follow-up (range 1 to 62 months, mean 22.5 months), 64.5% of initially asymptomatic hemispheres remained asymptomatic, 6.5% experienced transient ischemic attacks (TIAs), and 4.3% developed strokes. During the same follow-up period, 63.6% of initially symptomatic hemispheres became asymptomatic, 9.1% had recurrence of TIAs, and 9.1% developed strokes. Sixteen of 71 group I patients (22.5%) and 5 of 22 group II patients (22.7%) died during follow-up. The overall incidence of nonfatal stroke and TIAs was 6.5% and 8.6%, respectively. Myocardial infarction (MI) and stroke accounted for deaths in 6.5% and 4.3% of patients, respectively. There was no significant difference in the incidence of TIA, stroke, or death between group I and group II. The percentage of siphon stenosis in all patients experiencing stroke or TIA (35.4 ± 14.4%) was not significantly different from that in patients who remained asymptomatic (32.3 ± 10.6%). Patients with carotid siphon stenosis are at an increased risk of death, stroke, and TIAs compared with the population at large. However, the risk of stroke is less than the risk of stroke in patients with TIAs assumed to be caused by carotid bifurcation disease. The risk of fatal MI is similar to the annual incidence of MI in patients with other manifestations of atherosclerosis.

The natural history of isolated carotid siphon stenosis.

Between August 1978 and July 1983, 93 patients (71 with unilateral and 22 with bilateral isolated carotid siphon stenosis) were identified from a review of 885 consecutive cerebral arteriograms. This yielded 115 cerebral hemispheres at risk. At the time of arteriography, 93 hemispheres were asymptomatic regarding the hemisphere with siphon stenosis (group I), whereas 22 hemispheres in 22 patients had had neurologic events referable to the hemisphere with siphon stenosis (group II). During follow-up (range 1 to 62 months, mean 22.5 months), 64.5% of initially asymptomatic hemispheres remained asymptomatic, 6.5% experienced transient ischemic attacks (TIAs), and 4.3% developed strokes. During the same follow-up period, 63.6% of initially symptomatic hemispheres became asymptomatic, 9.1% had recurrence of TIAs, and 9.1% developed strokes. Sixteen of 71 group I patients (22.5%) and 5 of 22 group II patients (22.7%) died during follow-up. The overall incidence of nonfatal stroke and TIAs was 6.5% and 8.6%, respectively. Myocardial infarction (MI) and stroke accounted for deaths in 6.5% and 4.3% of patients, respectively. There was no significant difference in the incidence of TIA, stroke, or death between group I and group II. The percentage of siphon stenosis in all patients experiencing stroke or TIA (35.4 +/- 14.4%) was not significantly different from that in patients who remained asymptomatic (32.3 +/- 10.6%). Patients with carotid siphon stenosis are at an increased risk of death, stroke, and TIAs compared with the population at large. However, the risk of stroke is less than the risk of stroke in patients with TIAs assumed to be caused by carotid bifurcation disease.(ABSTRACT TRUNCATED AT 250 WORDS)

The significance of ocular bruits in ischaemic cerebro-vascular disease

The significance of ocular bruits has been studied in a series of 18 patients presenting with symptoms of atherothrombotic ischaemic cerebro-vascular disease and studied angiographically.Twenty-five ocular bruits were heard. They were nearly always associated with carotid bruits in the neck but were not simply the transmission of these bruits up the carotid; they were seldom related to a carotid siphon stenosis at least as a single cause. Most of them were 'augmentation bruits', pointing in over half the cases to a tight stenosis or an occlusion of the origin of the contralateral internal carotid artery and in 75% to widespread atheroma of both the carotid and vertebrobasilar systems.The presence of an ocular bruit in such patients should thus be considered as a warning of a complex and sometimes critical haemodynamic situation and should therefore lead to the greatest caution in contemplating both angiography and surgery.