Ipsilateral Carotid Territory Research Articles

Carotid Stump Syndrome: Rare Cause of Recurrent Stroke Post-Ipsilateral Carotid Occlusion - A Case Report.

Carotid stump is blind remnant of occluded proximal segment of the internal carotid artery (ICA) that can become the potential source of embolism. Carotid stump syndrome is a potentially treatable cause of recurrent ischemic events in the carotid territory in the setting of occlusion of the ipsilateral ICA. It is thought to be caused by turbulent blood flow in the patent stump of the occluded ICA causing microemboli migrating in the brain through external carotid-ophthalmic anastomotic channels and retrograde flow. Here, we report a patient with known ipsilateral chronic ICA occlusion, who was on best medical management, presented on two separate occasions with recurrent embolic infarctions in ipsilateral carotid territory. She was diagnosed with carotid stump syndrome and treated through endovascular route with clinical and angiographic follow-up.

Contrast enhanced ultrasound of carotid plaque in acute ischemic stroke (CUSCAS study).

Carotid atherosclerosis represents 8 to 15% of ischemic strokes in relation to the concept of "vulnerable" plaque. Contrast enhanced ultrasound (CEUS) can detect moving microbubbles within the plaque corresponding to neovessels that constitute "precursors" of vulnerable plaque and intraplaque hemorrhage. CEUS was not studied specifically in acute ischemic strokes. The aim of this study is to analyse the prevalence of CEUS carotid plaque ipsilateral at the ischemic stroke as well as the main characteristics of contrast-plaques. A single-centre prospective pilot study involving 33 consecutive patients with a stroke ≤10 days, diagnosed by an MRI with positive diffusion sequence and having a carotid plaque thickness ≥2.5mm with low or heterogeneous echogenicity, located in the ipsilateral carotid territory at the stroke. Plaque echogenicity was done by visual analysis and by measurement of the gray scale median (GSM). A transcranial Doppler monitoring was carried out in search of HITS. The contrast ultrasound was performed after 2.5 cc IV injection of SonoVue®. A video clip was recorded after injection which was used for interpretation by visual analysis in 3 grades, provided by two independent expert readers. The population consisted of 10 women and 23 men aged 73 on average. The topography of strokes in the carotid territory was located on the right in 11 (33%) cases and on the left in 22 (67%) cases. Seventeen patients had carotid stenosis between 0 and 49% according to the Nascet method and 16 patients had stenosis of 50 to 99%. The visual characterisation of the plaques had echolucent dominance (Type 1-2) in 18 cases and echogenic dominance (Type 3-4a) in 15 cases. Cardiovascular risk factors were common with no difference by sex. The inter-observer agreement of plaque enhancement was moderate in first reading (k=0.48) and excellent at consensus (k=0.91). Only one disagreement was found. Contrast agent enhancement of carotid plaque was observed in 11/32 patients, representing a prevalence of 34.4% - CI95% [17.9-50.9]. Variables associated with contrast plaque included the absence of antiplatelet drug (63.6% vs. 23.8%, P=0.05) and the presence of a regular edge on the plaque (91% vs. 48%, P=0.04). There was no difference in contrast enhancement for stenosis>or<50% in diameter and neither for the type of plaque. In a consecutive cohort of 33 patients, the prevalence of CEUS from an ipsilateral carotid plaque to a recent acute ischemic stroke was 34.4%. There was a statistically significant association between the contrast enhancement of the plaque and the absence of antiplatelet drug (P=0.05) and also the presence of a regular edge on the plaque (P=0.04). There was no correlation between plaque contrast and clinical and biological characteristics of patients or the presence of HITS.

Correlation of MRI-detected vulnerable carotid plaques with clinical presentation: a systematic review and meta-analysis.

To determine the association between magnetic resonance imaging (MRI)-detected vulnerable Carotid Plaques and clinical presentation related to ipsilateral carotid artery territory. We searched three databases including Ovid MEDLINE, Ovid EMBASE, and Scopus from 2000 to 2018 for studies that evaluated vulnerable carotid plaques by MRI defined as intraplaque hemorrhage (IPH), lipid-rich necrotic core (LRNC), or thinning/rupture of the fibrous cap (TRFC). Data on study characteristics, clinical presentation, and MRI findings were extracted. Publication bias, methodologic quality, and study heterogeneity were assessed. Random-effects meta-analysis model was used to estimate incidence rate ratio (IRR) and 95% confidence intervals (CI) of MRI-detected vulnerable carotid plaque between symptomatic and asymptomatic arteries. Of 2855 studies, 33 studies containing 6210 participants with 8401 assessed arteries were included. Overall, the risk of bias was moderate in 13, and low in 20 studies. The prevalence of MRI-positive IPH, TRFC, and LRNC were higher in symptomatic groups compared with the asymptomatic groups. In 11 studies that compared vulnerable carotid plaques between symptomatic and asymptomatic groups, symptomatic presentation was correlated with increased risk of IPH (IRR=1.57; 95% CI: 1.24-1.99), TRFC (IRR=2.26; 95% CI: 1.83 to 3.76), and LRNC (IRR=1.95; 95% CI: 1.28 to 2.97), respectively. The presence of MRI-positive vulnerable carotid plaques including IPH, LRNC, and TRFC is positively associated with symptomatic clinical presentation. Therefore, carotid plaque MRI might be a useful risk stratification tool in determining the risk of ischemic stroke.

Carotid Endarterectomy for Medical Therapy-Resistant Symptomatic Low-Grade Stenosis

Plaque characteristics play pivotal roles in ischemic events, but stenosis severity does not accurately reflect carotid plaque volume due to expansive remodeling in some patients with low-grade stenosis (LGS). This study aimed to assess the safety, efficacy, and durability of carotid endarterectomy (CEA) for symptomatic LGS. Study participants comprised 61 consecutive patients who underwent CEA for symptomatic carotid stenosis. Patients were divided into an LGS group (<50%, n= 17) and a non-LGS group (≥50%, n= 44). Patient characteristics and short-term (within 30 days of CEA) and long-term outcomes were compared between groups for selective usage of internal shunt and known complications of CEA. Magnetic resonance imaging-detected intraplaque hemorrhage was more significant in LGS than in non-LGS (P= 0.04). For short-term outcomes, no symptomatic infarcts, hyperperfusion syndrome, or acute myocardial infarction was confirmed in either group. Internal shunts were used in 4 LGS (23.5%) and 6 non-LGS (13.6%). Asymptomatic diffusion-weighted imaging-positive lesions were confirmed in 2 LGS patients (11.8%) and 5 non-LGS patients (11.4%), neck hematoma in 1 LGS patient, and transient cranial nerve palsy in 1 LGS patient and 2 non-LGS patients, with no significant differences apparent between groups. For long-term outcomes, 5 non-LGS patients showed restenosis (P= 0.17). Hemorrhagic stroke was not observed in either group. No significant differences were seen for infarct in the ipsilateral carotid territory, any ischemic stroke, AMI, or mortality. CEA represents a safe and feasible therapeutic option for a subset of patients with symptomatic LGS.

Abstract 65: Magnetic Resonance Plaque Imaging Before Carotid Artery Stenting (MR-CAS) Study: Initial Results

Background: Carotid artery stenting (CAS) has recently emerged as a potential alternative to carotid endarterectomy. A major disadvantage of CAS is the high incidence of periprocrdural cerebral embolization. Previous studies suggested carotid plaque composition as lesion-specific risk factors for cerebral embolization during CAS, yet prospective studies are lacking. Magnetic resonance imaging (MRI) is a validated, noninvasive technique that affords quantitative analysis of carotid plaque tissue composition. MR-CAS is a prospective multicenter observational study to test the hypothesis that carotid plaque characteristics evaluated by pre-surgical MRI predict ischemic complications after CAS. Materials and Methods: We enrolled 128 arteries which underwent CAS. Multicontrast MRI was performed prior to CAS. Quantitative analysis of carotid plaque composition was done blinded to clinical information, including measures of intraplaque hemorrhage (IPH), lipid-rich necrotic core (LRNC), and calcification. Pre- and post-CAS diffusion weighted (DW) MRI were performed to detect new cerebral infarction after CAS. New ischemic symptoms within 30 days after CAS were also recorded. Associations between quantitative measures of plaque composition and new ischemic lesions on DW-MRI and new ischemic symptoms were evaluated. Results: Fifty arteries (39%) had new DW-MRI positive lesions in the ipsilateral carotid territory after CAS. Five patients (3.9%) developed new ischemic symptoms within 30 days after CAS. There were no significant differences in IPH volume or LRNC volume between the groups with and without ipsilateral DW-MRI positive lesions (IPH: 42 mm 3 [95%CI: 0-1140] vs. 20 mm 3 [0-804] p=0.55, LRNC: 240 mm 3 [0-1606] vs. 312 mm 3 [0-1374] p=0.76). However, IPH and LRNC volume were significantly larger in the patients with new ischemic symptoms after CAS than those without (IPH: 323 mm 3 [95%CI: 18-478] vs. 22 mm 3 [0-1140] p=0.009, LRNC: 501 mm 3 [392-1185] vs. 261 mm 3 [0-1606] p=0.013). Conclusions: Quantitative measures of carotid plaque composition predicted new ischemic symptoms after CAS but not new DW-MRI.

Transcarotid Approach for Retrograde Stenting of Proximal Innominate and Common Carotid Artery Stenosis

To evaluate the hybrid treatment of severe stenosis or occlusion of the proximal innominate artery (IA) and common carotid artery (CCA) via surgical cutdown of the CCA and distal clamping for cerebral protection against thromboembolic events during retrograde stenting. Consecutive patients undergoing retrograde stenting of proximal IA and CCA stenosis or occlusion via surgical cutdown of the CCA and with distal clamping for prevention of embolization, with or without concomitant endarterectomy of the carotid bifurcation, between April 1999 and August 2015 were reviewed. Perioperative and long-term outcomes were assessed. Thirty-five patients underwent a total of 36 successful interventions. One patient underwent staged bilateral stenting. Additional concomitant carotid endarterectomy was performed in 13 patients (36%). No new neurological symptoms neither perioperatively nor in-hospital were recorded. Thirty-day follow-up revealed 1 new ipsilateral and 1 new contralateral stroke (6%) with completely patent stents, no reinterventions, and 2 unrelated deaths (6%). Median follow-up was 56months (range: 1-197). After 5 and 10years, the Kaplan-Meier estimated overall survival rate was 85% and 52%. Primary assisted patency rate was 94% during follow-up. Overall freedom from reintervention was 91%. Three reinterventions were performed during the first postoperative year. Three new neurological events occurred during follow-up, 1ipsilateral (3%) and 2 contralateral (6%). The ipsilateral event occurred during the first year and both contralateral events during the second year postoperatively. The retrograde hybrid approach to proximal IA and CCA disease is a safe procedure with surgical outflow control preventing perioperative stroke in ipsilateral carotid territory. Most relevant in-stent stenoses/occlusions and new neurological events occurred within the first 2 years, suggesting these patients should undergo regular monitoring early postoperatively. High patency rates without further neurological events can be expected thereafter.

Abstract TP128: Prognosis and Stratification of High-risk Patients with Mild (&lt;50%), but Unstable Stenosis of Internal Carotid Artery - Multi-center Observational Study in Japan

Background and Purpose: Previous clinical trials have shown that clinical benefits of carotid endarterectomy (CEA) are unclear in symptomatic mild (&lt;50%) stenosis of the internal carotid artery. However, it is not rare that the patients with mild carotid stenosis repeat TIA or ischemic stroke in spite of the best medical treatments. Although only the degree of stenosis have been accepted as “gold standard” in deciding treatment strategy, recent development of non-invasive MR imaging enables us to identify unstable plaque. Therefore, we have designed “ M ild, but U nstable S tenosis of I nternal C arotid artery (MUSIC) Study” in Japan. The objectives of this nation-wide, multicenter prospective study are to clarify the prognosis of patients with symptomatic mild carotid stenosis and identify the predictors for the patients at higher risk for recurrent TIA and ischemic stroke in spite of the best medical treatments. Impact of CEA is also evaluated in those refractory to the best medical treatments. Methods and Results: MUSIC Study is conducted in Japan, using a multi-center prospective observational design (UMIN000023635). The MUSIC Study Group is composed of 28 hospitals. This study will register totally 250 patients who are 20 years or older, experience TIA, ischemic stroke, or retinal ischemia in the ipsilateral carotid territory, have mild (&lt;50%) stenosis in the ipsilateral cervical carotid artery, and are independent in daily life (modified Rankin scale=0-2). Using MRI, plaque components are precisely evaluated in all patients. After informed consent is obtained, their clinical and radiological data are registered. They are followed up for two years and MRI/MRA examinations are repeated at 6, 12, and 24 months after the enrollment. Primary endpoint includes the incidence of ischemic stroke in the ipsilateral carotid territory. Secondary endpoints include the incidence of all-ischemic stroke, ipsilateral or all TIA, ipsilateral or all retina ischemia, all stroke, all death, de novo silent cerebral infarct, and progression of carotid stenosis. Conclusion: In this conference, we emphasize the importance to identify the patients at higher risk for recurrent ischemic events due to symptomatic mild carotid stenosis in spite of the best medical treatments.

SPACE-2: A Missed Opportunity to Compare Carotid Endarterectomy, Carotid Stenting, and Best Medical Treatment in Patients with Asymptomatic Carotid Stenoses

Because of recent advances in best medical treatment (BMT), it is currently unclear whether any additional surgical or endovascular interventions confer additional benefit, in terms of preventing late ipsilateral carotid territory ischemic stroke in asymptomatic patients with significant carotid stenoses. The aim was to compare the stroke-preventive effects of BMT alone, with that of BMT in combination with carotid endarterectomy (CEA) or carotid artery stenting (CAS) in patients with high grade asymptomatic extracranial carotid artery stenosis. SPACE-2 was planned as a three-armed, randomized controlled trial (BMT alone vs CEA plus BMT vs CAS plus BMT, ISRCTN 78592017). However, because of slow patient recruitment, the three-arm study design was amended (July 2013) to become two parallel randomized studies (BMT alone vs CEA plus BMT, and BMT alone vs CAS plus BMT). The change in study design did not lead to any significant increase in patient recruitment, and trial recruitment ceased after recruiting 513 patients over a 5 year period (CEA vs BMT (n = 203); CAS vs BMT (n = 197), and BMT alone (n = 113)). The 30 day rate of death/stroke was 1.97% for patients undergoing CEA, and 2.54% for patients undergoing CAS. No strokes or deaths occurred in the first 30 days after randomization in patients randomized to BMT. There were several potential reasons for the low recruitment rates into SPACE-2, including the ability for referring doctors to refer their patients directly for CEA or CAS outwith the trial, an inability to convince patients (who had come “mentally prepared” that an intervention was necessary) to accept BMT, and other economic constraints. Because of slow recruitment rates, SPACE-2 had to be stopped after randomizing only 513 patients. The German Research Foundation will provide continued funding to enable follow up of all recruited patients, and it is also planned to include these data in any future meta-analysis prepared by the Carotid Stenosis Trialists Collaboration.

SPACE-2: A Missed Opportunity to Compare Carotid Endarterectomy, Carotid Stenting, and Best Medical Treatment in Patients with Asymptomatic Carotid Stenoses

Because of recent advances in best medical treatment (BMT), it is currently unclear whether any additional surgical or endovascular interventions confer additional benefit, in terms of preventing late ipsilateral carotid territory ischemic stroke in asymptomatic patients with significant carotid stenoses. The aim was to compare the stroke-preventive effects of BMT alone, with that of BMT in combination with carotid endarterectomy (CEA) or carotid artery stenting (CAS) in patients with high grade asymptomatic extracranial carotid artery stenosis. SPACE-2 was planned as a three-armed, randomized controlled trial (BMT alone vs. CEA plus BMT vs. CAS plus BMT, ISRCTN 78592017). However, because of slow patient recruitment, the three-arm study design was amended (July 2013) to become two parallel randomized studies (BMT alone vs. CEA plus BMT, and BMT alone vs. CAS plus BMT). The change in study design did not lead to any significant increase in patient recruitment, and trial recruitment ceased after recruiting 513 patients over a 5 year period (CEA vs. BMT (n=203); CAS vs. BMT (n=197), and BMT alone (n=113)). The 30 day rate of death/stroke was 1.97% for patients undergoing CEA, and 2.54% for patients undergoing CAS. No strokes or deaths occurred in the first 30 days after randomization in patients randomized to BMT. There were several potential reasons for the low recruitment rates into SPACE-2, including the ability for referring doctors to refer their patients directly for CEA or CAS outwith the trial, an inability to convince patients (who had come "mentally prepared" that an intervention was necessary) to accept BMT, and other economic constraints. Because of slow recruitment rates, SPACE-2 had to be stopped after randomizing only 513 patients. The German Research Foundation will provide continued funding to enable follow up of all recruited patients, and it is also planned to include these data in any future meta-analysis prepared by the Carotid Stenosis Trialists Collaboration.

Clinical analysis of carotid angioplasty stenting for high-grade extracranial carotid artery stenosis combined with severe tortuosity

To observe the feasibility and safety of carotid angioplasty stenting (CAS) for high-grade extracranial carotid artery stenosis combined with severe tortuosity. Twenty patients diagnosed with high-grade extracranial carotid artery stenosis combined with severe tortuosity by cerebral angiography, who were in hospital in neurology department of China-Janpan friendship from June 2011 to June 2014. Twelve of these patients were symptomatic. All cases weren't suit for or disagreed with carotid endarterectomy (CEA) to accept CAS. We retrospectively discussed the rates of technical success, the perioperative complications and clinical improvement. During the follow-up for 4 to 40 months we observed the events of cured carotid artery territory stroke and death, and record the plaque hyperplasia in stent, in-stent restenosis, stent deformation or fracture by color doppler ultrasonography or craniocervical CT angiography. (1) The results of operation: the rate of technical success was 19/20 and the rate of the distal protection device placement was 18/20. One stent and 2 distal protection device were difficult to pass the tortuous access vessels. The kinking was the most common in circuity classification of internal carotid artery. The stenosis was significantly improved after stenting, and the mean degree of stenosis was reduced from (82% ± 9%) before stenting to (7% ± 6%) after stenting. Although 5 patients were with perioperative complications, all symptoms disappeared within 1 weeks, and there was no stent related death and disability. There were 4 cases with vascular spasm, one of them was combined with carotid sinus reaction, and anther with transient ischemic attack (TIA) during operation. There was one with ipsilateral carotid territory minor stroke. (2) The results of prognosis and follow up: The clinical symptoms from 12 symptomatic patients were improved significantly on discharge, and the average NIHSS scores on admission were reduced from (4 ± 4) to (2 ± 2) on discharge. One patient experienced ipsilateral carotid territory minor stroke and another patient experienced ipsilateral carotid territory TIA during the follow-up for an average of 19 months, and there were 5 cases with mild plaque hyperplasia in stent and no in-stent restenosis, stent deformation or fracture. The severe tortuosity of extracranial carotid artery may affect the using of intervention materials and increase the complexity of CAS, but for the patients who disagree with CEA or were with the contraindications to CEA, CAS may be still a relatively safe, effective and alternative treatment.

Innominate Steal Syndrome: A Two Patient Case Report and Review

Like subclavian artery disease, innominate artery disease can result in reversal of flow in the ipsilateral vertebral artery. Unlike subclavian artery disease, innominate artery disease can also affect cerebral perfusion in the ipsilateral carotid territory, is less well characterized in the literature, and is more challenging to revascularize. Herein, we present two cases of ‘innominate steal’ and a summary of relevant literature focusing on innominate artery disease.

Management Strategies for Asymptomatic Carotid Stenosis

Adults with asymptomatic carotid artery stenosis are at increased risk for ipsilateral carotid territory ischemic stroke. To examine comparative evidence on management strategies for asymptomatic carotid stenosis and the incidence of ipsilateral stroke with medical therapy alone. MEDLINE, Cochrane Central Register of Controlled Trials, U.S. Food and Drug Administration documents, and review of references through 31 December 2012. Randomized, controlled trials (RCTs) and prospective or retrospective nonrandomized, comparative studies of medical therapy alone, carotid endarterectomy (CEA) plus medical therapy, or carotid artery stenting (CAS) plus medical therapy for adults with asymptomatic carotid stenosis, as well as single-group prospective cohort studies of medical therapy, were reviewed. Two investigators extracted information on study and population characteristics, results, and risk of bias. Forty-seven studies in 56 publications were eligible. The RCTs comparing CAS and CEA were clinically heterogeneous; 1 RCT reported more but not statistically significant ipsilateral stroke events (including any periprocedural stroke) in CAS compared with CEA, whereas another RCT, in a population at high surgical risk for CEA, did not. Three RCTs showed that CEA reduced the risk for ipsilateral stroke (including any periprocedural stroke) compared with medical therapy alone, but these results may no longer be applicable to contemporary clinical practice. No RCT compared CAS versus medical therapy alone. The summary incidence of ipsilateral stroke across 26 cohorts receiving medical therapy alone was 1.68% per year. Studies defined asymptomatic status heterogeneously. Participants in RCTs did not receive best-available medical therapy. Future RCTs of asymptomatic carotid artery stenosis should explore whether revascularization interventions provide benefit to patients treated by best-available medical therapy. Agency for Healthcare Research and Quality.

Relationship Between Plasma Homocysteine and the Morphological and Immunohistochemical Study of Carotid Plaques in Patients With Carotid Stenosis Over 70%

Several clinical and epidemiological studies describe hyperhomocysteinemia as an independent cardiovascular risk factor. Implication of cellular immunity in atherosclerosis also seems clear. This study aimed to analyze the association among plasma hyperhomocysteinemia, neurological clinical events, and the morphology and immunocytology of carotid plaques in patients with carotid stenosis >70% receiving surgical treatment. Sixty-two patients with carotid stenosis >70% receiving surgical treatment were studied; 58% had a history of stroke in the ipsilateral carotid territory. Plasma homocysteine concentrations were determined by considering pathological values >12.4 μmol/L. Histopathological (stable and unstable plaques) and immunohistochemical (macrophages, T lymphocytes, and active T lymphocytes counts) studies were performed. Hyperhomocysteinemia prevalence was calculated in this population, as were the possible relationships between homocysteine plasma concentrations, and the carotid plaque type and the cell types in it. The relationship between this risk factor and the presence of a neurological event relating to carotid stenosis was also investigated. Hyperhomocysteinemia prevalence was 43.5%, with a mean value of 11.8 μmol/L (median; range = 2-41.8 μmol/L). No significant differences were found between homocysteine levels and the plaque's morphological characteristics, or between the cell types analyzed. Elevated concentrations of homocysteine were not significantly higher in patients with a history of stroke. The present study confirms high hyperhomocysteinemia prevalence in patients with extracranial cerebrovascular disease, although no relationship between plaque complication phenomena and this cardiovascular risk factor was observed.

Endovascular management of symptomatic carotid stenosis combined with kinking

To study the necessity, feasibility, security of carotid angioplasty and stenting (CAS) for symptomatic carotid stenosis combined with kinking. Twelve patients with symptomatic carotid stenosis and kinking demonstrated by digital subtraction angiography (DSA) received CAS from December 2003 to December 2009. There were 9 male and 3 female patients, age ranged from 59 to 77 years (mean 69.3 years). All the patients' clinical, imaging, intervention and follow up data were collected and analyzed. All CAS procedures were successfully performed with 14 self-expandable stents placed. The mean degree of stenosis was reduced from 85.6% before stenting to 11.2% after stenting, the angle of kinking, according to Metz' category, were improved from less than 90° to more than 120° in each case. No perioperative procedure related stroke and transient ischemic attack (TIA) occurred. The clinical symptoms and signs of cerebral ischemia were improved or disappeared for all patients. During follow-up of these 12 patients for 6 to 72 months, one patient experienced ipsilateral carotid territory TIA and another patient experienced contralateral carotid territory TIA. DSA follow up of 5 patients demonstrated 1 case with in-stent restenosis and arterial kinking remote to the stent of internal carotid artery. CAS were performed again and CT angiography follow up demonstrated no kinking and restenosis 2 years after the intervention. Duplex scan of the other 7 patients demonstrated neither kinking nor restenosis. CAS seems to be feasible and safe for the patients with symptomatic kinking and stenosis, and maybe helpful to lower the risk of cerebral ischemia, but further study is needed.

The International Carotid Stenting Study and the North American Carotid Revascularization Endarterectomy Versus Stenting Trial

Recently, 2 multicenter studies pitting carotid endarterectomy (CEA, the defending champion) against carotid artery stenting (CAS, the challenger) have been reported.1,2 These 2 studies have reported somewhat differing results, raising the question of whether 1 trial has the “right message” or is the “truth” somewhat more nuanced? The International Carotid Stenting Study (ICSS) was the first of the randomized CAS versus CEA trials that completed recruitment and was not stopped prematurely.1 The study enrolled patients with ipsilateral carotid territory symptoms within the previous 12 months and with at least 50% internal carotid artery stenosis. A total of 1713 patients were recruited from 50 academic centers. Surgeons were required to have performed at least 50 CEA operations and interventionalists were required to have done at least 50 stenting procedures with at least 10 in the internal carotid artery. The North American Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) originally included only symptomatic patients with at least 50% stenosis on angiography or 70% by ultrasound.2 In 2005, asymptomatic patients with at least 60% stenosis by angiography or 70% by ultrasound also became eligible. A total of 2502 patients were enrolled (including 1181 asymptomatic subjects) from 108 centers. Both surgeons and interventionalists were required to be certified as meeting performance benchmarks. Less experienced interventionalists were required to participate in a lead-in phase before joining the main study. In ICSS, the risk of stroke, death, and …

Multidisciplinary approach to carotid stenting

Stroke neurologists, vascular surgeons, interventional neuroradiologists and interventional cardiologists have embraced carotid angioplasty and stenting (CAS) because of potential advantages over carotid endarterectomy (CEA). At Austin Health, a multidisciplinary neuro-interventional group was formed to standardise indications and facilitate training. The aims of this study were to describe our organisational model and to determine whether 30-day complications and early outcomes were similar to those of major trials. A clinical protocol was developed to ensure optimal management. CAS was performed on patients with high medical risk for CEA, with technically difficult anatomy for CEA, or who were randomised to CAS in a trial. From October 2003 to May 2008, 47 patients (34 male, mean age 71.5) underwent CAS of 50 carotid arteries. Forty-three cases had ipsilateral carotid territory symptoms within the previous 12 months. The main indications for CAS were high risk for CEA (n= 17) and randomised to CAS (n= 21). Interventionists were proctored in 27 cases. The procedural success rate was 94% with two cases abandoned because of anatomical problems and one because of on-table angina. Hypotension requiring vasopressor therapy occurred in 12 cases (24%). The duration of follow up was one to 44 months (mean 6.8 months). The 30-day rate of peri-procedural stroke or death was 6% and the one-year rate of peri-procedural stroke or death or subsequent ipsilateral stroke was 10.6%. Restenosis occurred in 13% (all asymptomatic). A multidisciplinary approach is a useful strategy for initiating and sustaining a CAS programme.

Routine or selective carotid artery shunting for carotid endarterectomy (and different methods of monitoring in selective shunting).

Large, randomized controlled trials have shown that carotid endarterectomy is beneficial for selected patients with significant, recently symptomatic carotid stenosis.1,2 However, surgery itself carries a significant risk of stroke and death. Most perioperative strokes are ipsilateral carotid territory cerebral infarcts and some may result from the temporary interruption of blood flow that occurs while the carotid artery is clamped. The duration of interrupted blood flow can be minimized by bridging the clamped section of the artery with a shunt. Although some surgeons advocate routine shunting, others prefer to use shunts selectively or avoid them altogether.3,4 Potential disadvantages of shunting include complications such as air and plaque embolism and carotid artery dissection, and an increased risk of local complications such as nerve injury, hematoma, infection, and long-term restenosis.5 However, reliable data on these risks are limited.6 We performed a systematic review of randomized controlled trials to determine the effect of a policy of routine or selective shunting on the risk of perioperative stroke, death, and other operative complications. We also tried to identify if any one method of selecting which patients undergoing endarterectomy, under general anesthetic, require a …

Carotid dissection with permanent and transient occlusion or severe stenosis: Long-term outcome.

To compare the rate of ischemic events and intracranial hemorrhage in the long-term follow-up of patients with persistent and transient severe stenosis or occlusion of the internal carotid artery (ICA) due to spontaneous dissection (ICAD). One hundred and sixty-one consecutive patients with unilateral ICAD causing severe stenosis or occlusion were examined clinically and by ultrasound 1 year after symptom onset. Forty-six cases with persistent and 46 age- and latency-matched cases with transient (recanalization complete or less than 50% stenosis) severe stenosis or occlusion of the ICA were enrolled. Nine patients with surgical, endovascular, or fibrinolytic therapy for ICAD or associated stroke were excluded. Antithrombotic therapy was given at the discretion of the treating physician. Clinical follow-ups were done annually. Antithrombotic therapy and follow-up were similar in patients with permanent (6.2 +/- 3.4 years) and transient (7.2 +/- 4.3 years) severe stenosis or occlusion of the ICA. Cases with permanent carotid stenosis or occlusion showed annual rates of 0.7% for ipsilateral carotid territory stroke and of 1.4% for any stroke. Cases with transient carotid stenosis or occlusion showed annual rates of 0.3% for ipsilateral carotid territory stroke and of 0.6% for any stroke. This study suggests that ICAD has a benign long-term prognosis with low rates of ipsilateral carotid territory and any stroke and that the stroke rate in ICAD is not related to the persistence of severe carotid stenosis or occlusion. These results question the rationale of surgical or catheter-based revascularization in patients with ICAD.

Long-term durability of carotid endarterectomy for symptomatic stenosis and risk factors for late postoperative stroke.

Carotid endarterectomy (CEA) reduces the risk of stroke ipsilateral to recently symptomatic severe carotid stenosis. Other techniques such as percutaneous transluminal angioplasty with stenting are currently being compared with CEA. Thus far, case series and several small, randomized, controlled trials of CEA versus percutaneous transluminal angioplasty (with and without stenting) have focused primarily on the 30-day procedural risks of stroke and death. However, long-term durability is also important. To determine the long-term risk of stroke after CEA and to identify risk factors, we studied patients in the European Carotid Study Trial (ECST), the largest published cohort with long-term follow-up by physicians after CEA. Risks of ipsilateral carotid territory ischemic stroke were calculated by Kaplan-Meier analysis starting on the 30th day after CEA in 1728 patients who underwent trial surgery. Risk factors were determined by Cox regression. For comparison, we also determined the "background" risk of stroke on medical treatment in the ECST in the territory of 558 previously asymptomatic contralateral carotid arteries with <30% angiographic stenosis (ECST method) at randomization. The risks of disabling ipsilateral ischemic stroke and any ipsilateral ischemic stroke were constant after CEA, reaching 4.4% [95% confidence interval (CI), 3.0 to 5.8] and 9.7% (95% CI, 7.6 to 11.7), respectively, by 10 years. The equivalent ischemic stroke risks distal to contralateral <30% asymptomatic carotid stenoses were 1.9% (95% CI, 0.8 to 3.2) and 4.5% (95% CI, 1.5 to 7.4). Presentation with cerebral symptoms, diabetes, elevated systolic blood pressure, smoking, male sex, increasing age, and a lesser severity of preoperative stenosis were associated with an increased risk of late stroke after CEA, but plaque morphology and patch grafting were not. Although the risk of late ipsilateral ischemic stroke after CEA for symptomatic stenosis is approximately double the background risk in the territory of <30% asymptomatic stenosis, it is still only approximately 1% per year and remains low for at least 10 years after CEA. This is the standard against which alternative treatments should be judged. Several risk factors may be useful in identifying patients at particularly high risk of late postoperative stroke.

Low risk of ischemic stroke in patients with reduced internal carotid artery lumen diameter distal to severe symptomatic carotid stenosis: cerebral protection due to low poststenotic flow? On behalf of the European Carotid Surgery Trialists' Collaborative Group.

Patients with recently symptomatic severe carotid stenosis have a high risk of ischemic stroke on medical treatment. The main mechanism of stroke appears to be plaque surface thrombus formation and distal embolism. It is unclear to what extent reduction in blood flow across the stenosis, and the consequent reduction in cerebral perfusion pressure, is also important. Angiographic indices of reduced cerebral perfusion may identify patients at a particularly high risk of stroke who require urgent endarterectomy. The most direct angiographic correlate of poststenotic perfusion pressure is the degree of narrowing of the distal internal carotid artery (ICA) lumen. We sought to develop criteria for the definition of poststenotic narrowing of the ICA and to determine the effect of this and other angiographic characteristics likely to be associated with reduced cerebral perfusion on the risk of ipsilateral ischemic stroke in patients with recently symptomatic carotid stenosis. We studied the carotid angiograms of 3007 patients in the European Carotid Surgery Trial. Poststenotic narrowing of the ICA was defined with use of the ratio of the lumen diameter of the ICA to that of the common carotid artery (CCA). The normal range of the ICA/CCA ratio was defined in 2966 symptomatic or contralateral carotid arteries with 0% to 49% stenosis. Arteries with 70% to 99% symptomatic stenosis and an ICA/CCA ratio below this range were categorized as narrowed. We related the presence of narrowing and other angiographic characteristics to the risk of ipsilateral ischemic stroke on medical treatment. An assessment of the ICA/CCA ratio had good interobserver reproducibility. Poststenotic narrowing of the ICA was defined as an ICA/CCA ratio of <0.42. The 5-year risk of ipsilateral carotid territory ischemic stroke on medical treatment was 8% in patients with 70% to 99% stenosis and narrowing of the ICA versus 25% in patients without narrowing (log rank test, P=0.02). This difference remained after correction for other clinical and angiographic variables (hazard ratio 0.40, 95% CI 0.17 to 0.94, P=0. 03). The other angiographic characteristics did not predict stroke. Poststenotic narrowing of the ICA was associated with a low risk of stroke on medical treatment. This suggests that low flow alone is not usually sufficient to cause ischemic stroke distal to symptomatic carotid stenosis. Poststenotic narrowing may be protective because blood flow distal to the stenosis is insufficient to carry emboli to the brain.