Effect of Pitavastatin on Preventing Ischemic Complications with Carotid Artery Stenting: A Multicenter Prospective Study—EPOCH-CAS Study

Purpose

Periprocedural ischemic stroke is one problem associated with carotid artery stenting (CAS). This study was designed to assess whether preoperative statin therapy reduces the risk of periprocedural ischemic complications with CAS.

Methods

In this prospective study at 11 centers, patients with carotid artery stenosis (symptomatic ≥50 %, asymptomatic ≥80 %) and a high risk of carotid endarterectomy but without previous statin treatments were divided into two groups by low-density lipoprotein cholesterol (LDL-C) levels. With LDL-C ≥120 mg/dl, the pitavastatin-treated (PS) group received pitavastatin at 4 mg/day. With LDL-C <120 mg/dl, the non-PS group received no statin therapy. After 4 weeks, both groups underwent CAS. Frequencies of new ipsilateral ischemic lesions on diffusion-weighted imaging within 72 h after CAS and cerebrovascular events (transient ischemic attack, stroke, or death) within 30 days were assessed.

Results

Among the 80 patients enrolled, 61 patients (PS group, n = 31; non-PS group, n = 30) fulfilled the inclusion criteria. New ipsilateral ischemic lesions were identified in 8 of 31 patients (25.8 %) in the PS group and 16 of 30 patients (53.3 %) in the non-PS group (P = 0.028). Cerebrovascular events occurred in 0 patients in the PS group and in 3 of 30 patients (10.0 %) in the non-PS group (P = 0.071). Multivariate analyses demonstrated the pitavastatin treatment (β = 0.74, 95 % confidence interval 0.070–1.48, P = 0.042) to be an independent factor for decreasing post-CAS ischemic lesions.

Conclusion

Pretreatment with pitavastatin significantly reduced the frequency of periprocedural ischemic complications with CAS.     

Initial experience of using the filter protection device during carotid artery stenting in Japan

PURPOSE: No filter protection devices for carotid artery stenting (CAS) have been formally approved for use in Japan; however, as of April 2008, the Angioguard XP (AGXP) was approved. This article describes our initial results using the AGXP during CAS for the treatment of carotid artery stenosis. MATERIAL AND METHODS: A group of 15 patients (14 men) with a mean age of 72.3 years (range 53-81 years) were treated by CAS using the AGXP. Among them, 10 were symptomatic with >50% stenosis of the common or internal carotid artery (ICA), and 5 were asymptomatic with >70% stenosis. The rates of technical success, periprocedural stroke, ICA flow impairment, filter movement, and development of new ischemic lesions on diffusion-weighted imaging (DWI) were assessed. RESULTS: CAS using the AGXP was successful in all cases. There was one minor stroke, and flow impairment occurred in six patients. Filter movement averaged 1.9 vertebral bodies. DWI showed new ipsilateral ischemic lesions in eight of the patients. CONCLUSION: Initial clinical experience using the AGXP for CAS has been generally sufficient. However, attention must be paid to three problems when using the AGXP: the filter may move after placement; the filter may disturb blood flow in the ICA; and debris may pass around the filter.     

Late evaluation of silent cerebral ischemia detected by diffusion-weighted MR imaging after filter-protected carotid artery stenting

BACKGROUND AND PURPOSE: Postoperative diffusion-weighted MR imaging (DWI) often discloses new lesions after carotid artery stent placement (CAS), most of them asymptomatic. Our aim was to investigate the fate of these silent ischemic lesions.MATERIALS AND METHODS: We prospectively studied 110 patients undergoing protected transfemoral CAS, 98 of whom underwent DWI before and after the intervention. Patients in whom DWI disclosed silent postoperative lesions also had delayed MR imaging. Preoperative, postoperative, and delayed scans were compared.RESULTS: Of the 92 patients without postoperative symptoms, DWI disclosed 33 new silent ischemic lesions in 14 patients (15.2%), 13 of whom (30 lesions) underwent delayed MR imaging after a mean follow-up of 6.2 months. In 8 of these 13 patients (61%), MR imaging disclosed 12 persistent lesions (12/30, 40%). The reversibility rate depended significantly on the location (cortical versus subcortical) and size (0–5 versus 5–10 mm) of the lesions (P < .05 by χ² test).CONCLUSIONS: Because many silent ischemic lesions seen on postoperative DWI after CAS reverse within months, the extent of permanent CAS-related cerebral damage may be overestimated.

Carotid artery stent placement (CAS) is today considered in many centers a valid alternative to carotid surgery for treating carotid artery stenosis because it achieves stroke and death rates matching those after surgery.^1,2Despite widespread use of cerebral protection systems in patients undergoing endovascular carotid interventions,^3,4 diffusion-weighted MR imaging (DWI) of the brain, currently the most effective tool for diagnosing acute cerebral ischemia,^5,6 detects a high incidence of asymptomatic ischemic lesions after CAS, ranging from 21% to 54% for unprotected procedures^7,8 and from 21% to 40% for protected procedures.^9–13 Few studies have described the late outcome of early postoperative DWI lesions.^14–16 Whether these silent ischemic lesions cause permanent brain damage with cognitive impairment or merely transient ischemia without sequelae remains unclear.In this prospective study, to investigate the extent of permanent cerebral ischemic damage in patients undergoing protected CAS, we used postoperative DWI and delayed MR imaging to assess the outcome (patient and lesion reversibility rates) of asymptomatic ischemic lesions after CAS and studied factors potentially influencing reversibility.     

Karotisstents – eine Standortbestimmung

Clinical/methodical issue

Therapy of carotid stenosis should be based on an accurate assessment of the stenosis and a differentiation between symptomatic and asymptomatic patients.

Standard radiological methods

According to current guidelines carotid artery stenting (CAS) can be considered as an established therapeutic alternative to carotid endarterectomy (CEA).

Methodical innovations

For the therapy of carotid stenosis CAS has become established as a minimally invasive alternative to CEA because the complication rate has been reduced due to growing experience, technical innovations and external quality assessment.

Performance

The CAS procedure should be performed in centers with documented complication rates of <?3?% for asymptomatic and <?6?% for symptomatic stenoses.

Achievements

Overall there are no significant differences between CAS and CEA in the treatment of carotid stenosis concerning the secondary prophylactic effect.

Practical recommendations

Ideally an interdisciplinary approach should be chosen for the therapy regime. Revascularization of asymptomatic stenoses should be considered critically as these patients might profit from optimized conservative medicinal therapy.     

Long-term outcome in patients with carotid artery stenting and contralateral carotid occlusion: a single neurovascular center prospective analysis

Introduction

The aim of this study was to analyze the clinical features and early and late outcome of patients treated with carotid artery stenting for carotid stenosis with occlusion of the contralateral vessel (CAS-CCO), and compare them to patients without occlusion (CAS-NO).

Methods

From 1999 through 2010, 426 patients with 479 procedures were prospectively recorded, 61 patients (14.3%) CAS-CCO, and 365 patients CAS-NO. Immediate CAS complications, complications within the first 30?days and long-term complications were documented through annual clinical and ultrasonological follow-up visits. Stenosis rate was recorded.

Results

Patients with mean age of 68.4?years, 80% men had: (1) periprocedural stroke in three cases (0.7%), (2) cumulative 30-day stroke, ischemic cardiopathy, and death in 4.2%, without differences between groups (CAS-CCO 3.3%, CAS-NO 4.4%). Mean follow-up period was 55?±?32.78?months, median 56?months. (3) Stroke during the follow-up in 8%, without differences between CAS-CCO and CAS-NO groups (3.7% and 8.8%). (4) Myocardial infarction in 11.2% and (5) global mortality in 24.3%, without statistical differences between groups. Of the 254 cases enrolled in the restenosis analysis, 44 patients (17.3%) had restenosis of any grade during a mean follow-up period of 52?months, without statistical differences between CAS-CCO and CAS-NO groups. Only 7.5% presented restenosis?≥?50%. Its occurrence was statistically associated with previous neck radiation.

Conclusions

Periprocedural risks and long-term outcomes of patients treated with CAS and presenting a contralateral carotid occlusion does not differ from regular patients treated with CAS. Based on the low stenosis rate of our study, our results do not give credit to extra surveillance measures in patients with contralateral carotid occlusion.     

New ischemic brain lesions on diffusion-weighted MRI after carotid artery stenting with filter protection: frequency and relationship with plaque morphology

BACKGROUND AND PURPOSE:CAS carries an inherent risk of distal cerebral embolization, precipitating new brain ischemic lesions and neurologic symptoms. Our purpose was to evaluate the frequency of new ischemic lesions found on DWI after protected CAS placement and to determine its association with plaque morphology.MATERIALS AND METHODS:Fifty patients (mean age 65.13 ± 7.08 years) with moderate and severe internal carotid artery stenosis underwent CAS with distal filter protection. Fibrolipid and fibrocalcified plaque morphology was determined by sonography according to the relative contribution of echogenic and echolucent material, and by multisection CT using plaque attenuation. There were 46.81% of patients with fibrolipid and 53.19% with fibrocalcified plaques. DWI was performed before and 24 hours after CAS.RESULTS:Seven (14.89%) patients showed new lesions. Four (8.51%) had 6 new lesions inside the treated vascular territory. Three had a single lesion and 1 patient had 3 lesions (mean: 1.5 ± 1). Most lesions (66.66%) were subcortical, with a mean diameter of 9 mm (range 5–15 mm). All lesions occurred in the area supplied by the middle cerebral artery and were clinically silent. A significant relationship was found between plaque morphology and the appearance of new lesions. Patients with fibrolipid plaques had a significantly higher number of new lesions compared with patients with fibrocalcified plaques (P = .041). The absolute risk of new lesions in the fibrolipid group was 18.18%.CONCLUSIONS:New ischemic lesions were observed in the treated vascular territory in 8.51% of patients. The appearance of new ischemic lesions was significantly related to the plaque morphology. Fibrolipid plaques were associated with higher numbers of new lesions.

CAS carries an inherent risk of distal cerebral embolization, precipitating new brain ischemic lesions and neurologic symptoms.^1–4 This has led to the development and widespread application of cerebral protection devices.^5,6 The most widely used devices are those based on distal filter placement that capture emboli dislodged from plaque; however, their application may result in additional complications.^7–12Several reviews have reported contradictory data concerning the rate of stroke and ischemia after protected versus unprotected stent placement.^3,13–15 The frequency of new ischemic lesions after CAS may be associated with numerous factors, such as clinical status, vascular anatomy, plaque morphology, and complexity. Therefore, the need to identify patients at risk for embolic events has become increasingly important. The morphologic characteristics of atherosclerotic carotid plaques may be useful in heralding embolic potential in the carotid arteries. Several authors have reported that plaques in the carotid arteries that are associated with large lipid pools or soft extracellular lipid are more prone to rupture and production of emboli.¹⁶ DWI is the most sensitive tool for the detection of neurologically silent or asymptomatic infarcts at a very early stage.^17–19The aim of this study was to determine the frequency of new ischemic DWI lesions in patients with moderate and severe ICA stenosis after protected CAS using a filter device, and to determine its potential association with plaque morphology.     

The usefulness of diffusion-weighted/fluid-attenuated inversion recovery imaging in the diagnostics and timing of lacunar and nonlacunar stroke

Introduction

The DWI/FLAIR mismatch is a potential radiological marker for the timing of stroke onset. The aim of the study was to assess if the DWI/FLAIR mismatch can help to identify patients with both lacunar and nonlacunar acute ischemic stroke within 4.5 h of onset.

Methods

A retrospective study was performed in which the authors analysed data from 86 ischemic lacunar and nonlacunar stroke patients with a known time of symptom onset, imaged within the first 24 h from stroke onset (36 patients <4.5 h, 14 patients 4.5–6 h, 15 patients 6–12 h, and 21 patients 12–24 h). Patients underwent the admission CT and MR scan. The presence of lesions was assessed in correlation with the duration of the stroke.

Results

The time from stroke onset to neuroimaging was significantly shorter in patients with an ischemic lesion visible only in the DWI (mean 2.78 h, n?=?24) as compared to patients with signs of ischemia also in other modalities (mean 8.6 h, n?=?62) (p?=?0.0001, Kruskal–Wallis ANOVA). The DWI/FLAIR mismatch was characterised by a global sensitivity of 58 %, specificity 94 %, PPV 87.5 %, and NPV 76 % in identifying patients in the 4.5 h thrombolysis time window. For lacunar strokes (n?=?20), these parameters were as follows: sensitivity 50 %, specificity 92.8 %, PPV 75 %, and NPV 81.2 %.

Conclusions

The presence of acute ischemic lesions only in DWI can help to identify both lacunar and nonlacunar stroke patients who are in the 4.5 h time window for intravenous thrombolysis with high specificity.     

Distal protection filter device efficacy with carotid artery stenting: comparison between a distal protection filter and a distal protection balloon

Purpose

This retrospective study aimed to compare the effectiveness of the embolization prevention mechanism of two types of embolic protection device (EPD)—a distal protection balloon (DPB) and a distal protection filter (DPF).

Methods

Subjects were 164 patients scheduled to undergo carotid artery stenting: a DPB was used in 82 cases (DPB group) from April 2007 until June 2010, and a DPF was used in 82 cases (DPF group) from July 2010 to July 2011. Rates of positive findings on postoperative diffusion-weighted imaging (DWI) and stroke incidence were compared.

Results

Positive postoperative DWI results were found in 34 cases in the DPB group (41.4 %), but in only 22 cases in the DPF group (26.8 %), and there was only a small significant difference within the DPF group. In the DPB group, there was one case of transient ischemic attack (TIA) (1.2 %) and four cases of brain infarction (2 minor strokes, 2 major strokes; 4.9 %), compared to the DFP group with one case of TIA (1.2 %) and no cases of minor or major strokes.

Conclusions

In this study, significantly lower rates of occurrence of DWI ischemic lesions and intraoperative embolization were associated with use of the DPF compared to the DPB.     

Calcium at the carotid siphon as an indicator of internal carotid artery stenosis

Objectives

Carotid siphon calcification is often visible on unenhanced head CT (UCT), but the relation to proximal carotid artery stenosis (CAS) is unclear. We investigated the association of carotid siphon calcification with the presence of CAS.

Methods

This IRB-waived retrospective study included 160 consecutive patients suspected of stroke (age 64?±?14 years, 63 female) who underwent head UCT and CTA of the head and neck. CAS was rated on CTA as not present or present with non-significant (<50 %), moderate (50–69 %) or significant (≥70 %) stenosis. Presence, shape (on UCT) and volume (on CTA) of carotid siphon calcifications were related to CAS.

Results

Carotid siphon calcification was absent in 41 % of patients and bilateral in 94 % of those with calcifications. Presence, shape and volume of calcification resulted in odds ratios for having significant CAS of 10.1, 3.9 and 8.4, with 95 % CIs of 1.3–79.6, 1.1–14.1 and 2.6–26.8, respectively. Corresponding NPVs were 0.98, 0.98 and 0.96, while PPVs were 0.14, 0.07 and 0.29, respectively.

Conclusion

Absence of calcification in the carotid artery siphon on UCT has high negative predictive value for carotid artery stenosis in patients with suspected stroke. However, siphon calcification is not a reliable indicator of significant carotid artery stenosis.

Key Points

? Many stroke patients do not have calcification in the carotid artery siphon. ? Carotid stenosis ≥50?% is unlikely in stroke patients without siphon calcification. ? Carotid siphon calcium is a poor indicator of significant carotid artery stenosis.     

Treatment of intracranial atherosclerotic arterial stenoses with a balloon-expandable cobalt chromium stent (Coroflex Blue): procedural safety, efficacy, and midterm patency

Introduction

We evaluated the coronary balloon-expandable cobalt chromium stent Coroflex Blue for the treatment of intracranial atherosclerotic arterial stenoses (IAAS).

Methods

Between March 2007 and October 2007, a total of 25 patients (20 male, age median 67 years) with 30 IAAS underwent endovascular treatment using Coroflex Blue stents (B. Braun, Germany). Location and degree of target stenoses before and after treatment and at follow-up and adverse clinical sequelae of treatment were registered. Angiographic follow-up was scheduled for 6, 12, 26, and 52 weeks after the treatment.

Results

The 30 treated lesions were located as follows: nine in intracranial–extradural internal carotid artery (ICA), three in intradural ICA, five in middle cerebral artery, eight in intradural vertebral artery, and five in basilar artery. The technical success rate was 100%. The degree of stenoses prior to and after treatment was 61?±?2% and 26?±?3% (mean ± SE), respectively. A residual stenosis of <50% was achieved in 29 (97%) procedures. Treatment was uneventful in 28 out of 30 procedures (93%); one patient suffered a transient and one patient a permanent neurological deficit. Angiographic follow-up was available in all of the patients (100%) after 15.2 months (median) and showed significant (i.e., more than 50%) degree of recurrent stenosis in 11 (37%) of the lesions. Retreatment was performed in 11 (37%) lesions.

Conclusion

The Coroflex Blue stent is easily inserted and safely deployed into intracranial arteries. The incidence of recurrent stenoses remains a concern. Stringent angiographic and clinical follow-up and retreatment are therefore mandatory.     

Fragmentation of calcified plaque after carotid artery stenting in heavily calcified circumferential stenosis

Introduction

We assessed the morphological change of calcified plaque after carotid artery stenting (CAS) in vessels with heavily calcified circumferential lesions and discuss the possible mechanisms of stent expansion in these lesions.

Methods

We performed 18 CAS procedures in 16 patients with severe carotid artery stenosis accompanied by plaque calcification involving more than 75% of the vessel circumference. All patients underwent multidetector-row computed tomography (MDCT) to evaluate lesion calcification before and within 3 months after intervention. The angiographic outcome immediately after CAS and follow-up angiographs obtained 6 months post-CAS were examined.

Results

The preoperative mean arc of the calcifications was 320.1?±?24.5° (range 278–360°). In all lesions, CAS procedures were successfully carried out; excellent dilation with residual stenosis ≤30% was achieved in all lesions. Post-CAS MDCT demonstrated multiple fragmentations of the calcifications in 17 of 18 lesions (94.4%), but only cracks in the calcified plaque without fragmentation in one (5.6%). Angiographic study performed approximately 6 months post-CAS detected severe restenosis in one lesion (5.6%) without fragmentation of calcified plaque.

Conclusions

Excellent stent expansion may be achieved and maintained in heavily calcified circumferential carotid lesions by disruption and fragmentation of the calcified plaques.     

Can Doppler Flow Parameters of Carotid Stenosis Predict the Occurrence of New Ischemic Brain Lesions Detected by Diffusion-Weighted MR Imaging after Filter-Protected Internal Carotid Artery Stenting?

BACKGROUND AND PURPOSE:Carotid angioplasty and stent placement are increasingly being used for the treatment of symptomatic and asymptomatic carotid artery disease. Carotid angioplasty and stent placement carry an inherent risk of distal cerebral embolization, precipitating new brain ischemic lesions and neurologic symptoms. Our purpose was to evaluate the frequency of new ischemic lesions found on diffusion-weighted imaging after protected carotid angioplasty and stent placement and to determine the association of new lesions with ICA Doppler flow parameters.MATERIALS AND METHODS:Fifty-two patients (mean age, 68 ± 11 years) with 50%–69% (n = 20, group 1) and ≥70% (n = 32, group 2) internal carotid artery stenosis underwent carotid angioplasty and stent placement with distal filter protection. DWI was performed before and 48 hours after carotid angioplasty and stent placement.RESULTS:Thirty-three (63.4%) patients showed new lesions. The average number of new postprocedural lesions was 3.4 per patient. Most of the postprocedural lesions were <5 mm (range, 3–23 mm), cortical and corticosubcortical, and clinically silent. Group 2 had a significantly higher number of new lesions compared with group 1 (P < .001). A significant relationship was found between ICA Doppler flow parameters and the appearance of new lesions.CONCLUSIONS:The appearance of new ischemic lesions was significantly related to the Doppler flow parameters, particularly peak systolic velocity.

Stroke is the most common life-threatening neurologic disorder and the most important single cause of disability.^1,2 Carotid artery stenosis, a major risk factor for stroke, and distal embolization, arising from degenerative breakdown or thrombotic occlusion of complex plaques, are important mechanisms of stroke in patients with atherosclerotic internal carotid artery stenosis.^3–6 Duplex sonography is currently the principal and, undoubtedly, the most accurate noninvasive and inexpensive diagnostic technique available for the evaluation of internal carotid artery stenosis. It provides information about the presence and severity of carotid stenosis, the velocity and characteristics of blood flow, and plaque morphology.^7–10Carotid angioplasty and stent placement for severe internal carotid artery stenosis have been introduced as a safe alternative to medical and/or surgical treatment in patients at high risk for surgical procedures.^11,12 However, there is still a major concern regarding its safety because of the risk of distal cerebral embolization during the procedure. Recent technical refinements, therefore, have led to the widespread use of carotid artery stenting (CAS) with cerebral-protection devices, markedly reducing thromboembolic complication rates.¹³ Diffusion-weighted MR imaging is a very sensitive and specific technique for diagnosing cerebral ischemia.^14,15 It has been used to detect structural damage of the brain due to cerebral embolism after cerebral angiography, neurointerventional procedures, and carotid endarterectomy.^16,17The purpose of our study was to assess, with DWI, the number, size, and location of new brain lesions after protected CAS and to evaluate the association of these new lesion deficits and Doppler flow parameters of ICA.     

Associations between Cerebral Embolism and Carotid Intraplaque Hemorrhage during Protected Carotid Artery Stenting

BACKGROUND AND PURPOSE:Carotid artery stent placement in patients with intraplaque hemorrhage remains controversial because of the incidence of cerebral embolism after the procedure. The purpose of this study is to determine if intraplaque hemorrhage is a significant risk factor for cerebral embolism during carotid artery stent placement.MATERIALS AND METHODS:This prospective study assessed 94 consecutive patients with severe carotid stenosis. These patients underwent preprocedural carotid MR imaging and postprocedural DWI after carotid artery stent placement. Intraplaque hemorrhage was defined as the presence of high signal intensity within the carotid plaque that was >200% of the signal from the adjacent muscle on MPRAGE. We then analyzed the incidence of postprocedural ipsilateral ischemic events on DWI and primary outcomes within 30 days of carotid artery stent placement.RESULTS:Forty-three patients (45.7%) had intraplaque hemorrhage on an MPRAGE image. There was no significant difference in the incidence of postprocedural ipsilateral ischemic events and primary outcomes between the intraplaque hemorrhage and non–intraplaque hemorrhage group. However, postprocedural ipsilateral ischemic events were more frequently observed in the symptomatic group (17/41 [41.5%]) than in the asymptomatic group (8/53 [15.1%]; P = .005).CONCLUSIONS:Intraplaque hemorrhage was not a significant risk factor for cerebral embolism during carotid artery stent placement in patients with severe carotid stenosis. Symptomatic patients should receive more careful treatment during carotid artery stent placement because of the higher risk of postprocedural ipsilateral ischemic events.

Extracranial carotid artery stenosis is considered a causative factor in 20%–30% of all strokes.^1–3 Large randomized clinical trials showed that carotid endarterectomy is superior to carotid artery stent placement (CAS) for the management of carotid artery stenosis.^4–6 Other randomized clinical trials showed that CAS and carotid endarterectomy offer similar efficacy.⁷ Although indications for CAS remain controversial, CAS has emerged as a less-invasive treatment that requires shorter hospital times than carotid endarterectomy.Some studies found a relationship between the baseline presence of carotid intraplaque hemorrhage (IPH) and the development of ischemic stroke in previously asymptomatic and symptomatic patients.^8–10 IPH is associated with plaque progression and, consequently, induces luminal narrowing. Thus, IPH may serve as a measure of risk for the development of future ischemic stroke. The risk of cerebral embolism after CAS in patients with IPH is controversial. Yoshimura et al¹¹ reported that a high-intensity signal on TOF MRA indicates that carotid plaques are at high risk for cerebral embolism during stent placement. However, Yoon et al¹² reported that protected CAS seems to be safe in patients with severe carotid stenosis and IPH. This study did not perform DWI to evaluate ipsilateral ischemic lesions. In addition, these studies used TOF imaging to detect IPH. Alternative techniques proposed for more accurate detection of IPH include heavily T1-weighted techniques, such as the MPRAGE sequence. Ota et al¹³ reported that the MPRAGE sequence demonstrated higher diagnostic capability in detecting IPH when compared with conventional T1-weighted sequences or TOF sequences.We prospectively designed the study with the following inclusion criteria: 1) preoperative multicontrast carotid plaque MR; 2) protected CAS; 3) postprocedural imaging, including DWI and noncontrast CT within 24 hours; and 4) clinical outcomes after 30 days. The aim of this study was to determine whether IPH is a significant risk factor for cerebral embolism during CAS.     

Carotid Artery Stent Placement and Carotid Endarterectomy: A Challenge for Urgent Treatment after Stroke—Early and 12-Month Outcomes in a Comprehensive Stroke Center

Purpose

To compare feasibility, 12-month outcome, and periprocedural and postprocedural risks between carotid artery stent (CAS) placement and carotid endarterectomy (CEA) performed within 1 week after transient ischemic attack (TIA) or mild to severe stroke onset in a single comprehensive stroke center.

Carotid artery stenting: findings based on 8 years’ experience

Purpose

Carotid artery stenting (CAS) may be an alternative to surgical endarterectomy not only in high-risk patients. Few data are available regarding the long-term clinical efficacy of CAS with the use of cerebral protection devices and the incidence of restenosis. Our experience demonstrates that if certain requirements are fulfilled, CAS can be considered a safe and effective treatment with high short-and long-term success rates.

Materials and methods

In the past 8 years, we treated 1,003 patients (1,096 arteries) affected by internal carotid artery stenosis, 93 with bilateral stenosis. Of these, 567 (51.74%) were symptomatic and 529 (48.26%) asymptomatic lesions. The preprocedural evaluation was performed with Doppler ultrasound (US), magnetic resonance (MR) angiography/computed tomography (CT) angiography and a neurological evaluation. Antiplatelet therapy was administered before and after the procedure.

Results

Technical success was achieved in 1,092 cases (99.6%), and a cerebral protection device was successfully used in 1,019 procedures (92.9%). The 30-day transient ischaemic attack (TIA)/stroke/death rate was 2.16%: death (0.18%) major stroke (0.45%) and minor stroke/TIA (1.53%). During a follow-up up to 8 years, restenoses occurred in 39 cases (3.57%), of which 28 were post-CAS (2.57%) and 11 post-CAS performed for restenosis after carotid endarterectomy (1%). Only five symptomatic restenoses >80% were treated with a repeated endovascular procedure.

Conclusions

A retrospective analysis of our experience suggests that CAS is a safe and effective procedure with better results than endarterectomy. In up to 8 years of follow-up, CAS seems to be effective in preventing stroke, with a low restenosis rate.     

Effects of age and symptom status on silent ischemic lesions after carotid stenting with and without the use of distal filter devices

BACKGROUND AND PURPOSE: The routine use of distal filter devices during carotid angioplasty and stent placement (CAS) is controversial. The aim of this study was to analyze their effects on the incidence of new diffusion-weighted imaging (DWI) lesions as surrogate markers for stroke in important subgroups.materials and METHODS: DWI was performed immediately before and after CAS in 68 patients with and 175 without protection, and patients were further subdivided according to their age or symptom status.RESULTS: The proportion of patients with new ipsilateral DWI lesion(s) was significantly lower after protected versus unprotected CAS (52% versus 68%), as well as in symptomatic patients (56% versus 74%) or those at or younger than 75 years of age (46% versus 67%; all P < .05). Similarly, the total number of lesions was significantly lower after protected versus unprotected CAS (median, 1; interquartile range [IQR], 0–2; versus median, 1; IQR 0–4.75) and in symptomatic patients (median, 1; IQR, 0–3; versus median, 2; IQR, 0–6) or those at or younger than 75 years of age (median, 0; IQR, 0–2; versus median, 1; IQR, 0–4; all P < .05). In contrast, for asymptomatic patients (48% versus 52%; P = .8; median, 0; IQR, 0–2; versus median, 1; IQR, 0–2.5; P = .6) or those older than 75 years of age (73% versus 69%; P = .7; median, 1; IQR, 0–4; versus median, 1.5; IQR, 0–5.75; P = .6), the proportion of patients with new lesion(s) and the total number of these lesions were not significantly different between protected and unprotected CAS.CONCLUSIONS: The use of distal filter devices generally reduces the incidence of new DWI lesions; however, this beneficial effect might not necessarily pertain to older and asymptomatic patients.

Carotid endarterectomy (CEA) is currently the accepted standard of treatment for patients with symptomatic and some selected patients with a severe asymptomatic internal carotid artery stenosis.^1,2 In the past few years, however, carotid angioplasty and stent placement (CAS) has emerged as an alternative endovascular treatment strategy for these disorders. Although initial single-center case series and registries have reported acceptable periprocedural complication rates after CAS even in surgical high-risk patients,^3–6 recent randomized trials directly comparing CAS with CEA have produced conflicting results.^7–9 Compared with surgery, CAS potentially has the major disadvantage of producing more emboli to the brain,¹⁰ which has led to the development and widespread application of cerebral protection devices aimed at preventing the passage of embolic material into the cerebral vasculature. Although the concept of cerebral protection is generally appealing and has been corroborated by a meta-analysis of single-center studies and large registries,^6,11 the use of either balloon occlusion techniques or filter systems increases the duration, the technical complexity, as well as the costs of the intervention and is, thus, no panacea for CAS. Indeed, the periprocedural complication rates were comparable between those patients treated with and without cerebral protection in the recently published stent-protected angioplasty versus carotid endarterectomy in symptomatic patients (SPACE) trial.⁷ Moreover, the 30-day incidence of death and stroke was unacceptably high in the Endarterectomy Versus Angioplasty in Patients with Severe Symptomatic Carotid Stenosis Trial despite the use of cerebral protection devices during CAS.⁸ Although these results partially reflect a lack of experience of the interventional physicians in these trials,¹² it is also conceivable that only certain subgroups of patients actually profit from the use of these devices. In fact, it could be speculated that the potential impact of protection devices on outcome is pronounced in those patients who have been shown to have a high risk of embolic complications during unprotected CAS, such as older patients, and is negligible or even harmful in low-risk patients.^6,13 Because of the relatively small number of clinical events after CAS, it has become a major challenge to identify correlates of clinically silent events to define the role of cerebral protection devices on outcome overall, as well as in important subgroups. The use of diffusion-weighted imaging (DWI) to detect clinically silent emboli during CAS as surrogate markers for stroke could pave the way out of this dilemma.^14–16 In support of this notion, we demonstrated recently an overall positive effect of cerebral protection devices on the number of new DWI lesions after CAS, which were closely related to the clinical outcome.¹⁵ Using this prospective and updated CAS series, the aim of this study was to analyze the effects of cerebral protection devices on the incidence of new DWI lesions in 2 important subgroups, namely, younger and older patients, as well as those with a symptomatic or asymptomatic carotid stenosis.     

Complication rate in unprotected carotid artery stenting with closed-cell stents

Introduction

The discussion on the use of protection devices (PDs) in carotid artery stenting (CAS) is gaining an increasing role in lowering the periprocedural complication rates. While many reviews and reports with retrospective data analysis do promote the use of PDs the most recent multi-centre trials are showing advantages for unprotected CAS combined with closed-cell stent designs.

Methods

We retrospectively analysed 358 unprotected CAS procedures performed from January 2003 to June 2009 in our clinic. Male/female ratio was 2.68/1. The average age was 69.3 years. Seventy-three percent (261/358) showed initial neurological symptoms. All patients were treated on a standardised interventional protocol. A closed and small-sized cell designed stent was implanted in most cases (85.2%). One hundred seventy-one (47.8%) were controlled by Doppler ultrasonography usually at first in a 3-month and later in 6-month intervals.

Results

The peri-interventional and 30-day mortality/stroke rate was 4.19% (15/358). These events included three deaths, five hyperperfusion syndromes (comprising one death by a secondary fatal intracranial haemorrhage), one subarachnoid haemorrhage and seven ischaemic strokes. Only 20% (3/15) of all complications occurred directly peri-interventional. The overall peri-interventional complication rate was 0.8% (3/358). Most complications occurred in initial symptomatic patients (5.36%). The in-stent restenosis rate for more than 70% was 7% (12/171) detected at an average of 9.8 month.

Conclusion

Our clinical outcome demonstrates that unprotected CAS with small cell designed stents results in a very low procedural complication rate, which makes the use of a protection device dispensable.     

Mid-cervical flame-shaped pseudo-occlusion: diagnostic performance of mid-cervical flame-shaped extracranial internal carotid artery sign on computed tomographic angiography in hyperacute ischemic stroke

Purpose

Flame-shaped pseudo-occlusion of the extracranial internal carotid artery (ICA) is a flow-related phenomenon that creates computed tomographic angiography (CTA) and digital subtraction angiography (DSA) findings that mimic tandem intracranial-extracranial ICA occlusion or dissection. We aim to determine the diagnostic performance of mid-cervical flame-shaped extracranial ICA sign on CTA in hyperacute ischemic stroke patients.

Methods

We retrospectively included consecutive anterior circulation ischemic stroke patients presenting within 6 h of symptom onset who underwent 4D brain CTA and arterial-phase neck CTA using a 320-detector CT scanner during August 2012 to July 2015. Two blinded readers independently reviewed arterial-phase neck CTA and characterized the extracranial ICA configurations into mid-cervical flame-shaped, proximal blunt/beak-shaped, and tubular-shaped groups. 4D whole brain CTA was used as a reference standard for intracranial ICA occlusion detection. Diagnostic performance of the mid-cervical flame-shaped extracranial ICA sign and interobserver reliability were calculated.

Results

Of the 81 cases, 11 had isolated intracranial ICA occlusion, and 6 had true extracranial ICA occlusion. Mid-cervical flame-shaped extracranial ICA sign was found in 45.5% (5/11) of isolated intracranial ICA occlusions but none in the true extracranial ICA occlusion group. The sensitivity, specificity, PPV, NPV, and accuracy of the mid-cervical flame-shaped extracranial ICA sign for the detection of isolated intracranial ICA occlusion were 45.5, 100, 100, 92.1, and 92.6%, respectively. Interobserver reliability was 0.90.

Conclusion

The mid-cervical flame-shaped extracranial ICA sign may suggest the presence of isolated intracranial ICA occlusion and allow reliable exclusion of tandem extracranial-intracranial ICA occlusion in hyperacute ischemic stroke setting.

     

United Kingdom Carotid Artery Stent Registry: Short- and Long-Term Outcomes

Background

Carotid artery stenting (CAS) has evolved to treat carotid artery disease with the intention of prevent stroke. The British Society of Interventional Radiologists developed a voluntary registry to monitor the practice of this novel procedure. We present the data from the United Kingdom (UK) CAS registry for short and long-term outcomes for symptomatic and asymptomatic carotid disease.

Methods

The UK CAS registry collected data from 1998 to 2010 from 31 hospitals across the UK for 1,154 patients. All interventions were enrolled in the registry for both asymptomatic and symptomatic patients. Initial entry forms were completed for each patient entered with data including indications, demographic data, CAS data (including stents and protection device details) and 30-day outcomes. Complications were documented. Follow-up data were collected at yearly intervals.

Results

Nine hundred fifty-three (83 %) symptomatic and 201 (17 %) asymptomatic patients were enrolled into the registry. The 30-day all stroke and death rates for symptomatic patients were 5.5 and 2.2 % for those with asymptomatic disease. The 30-day mortality rate was 1.7 % for symptomatic and 0.6 % for asymptomatic patients. For symptomatic patients undergoing CAS, the 7-year all-cause mortality rate was 22.2 % and for asymptomatic patients 18.1 %. The 7-year all-cause mortality and disabling stroke rates were 25.3 and 19.4 %, respectively.

Conclusion

These data indicate that outside of the tight constraints of a randomised trial, CAS provides effective prophylaxis against stroke and death.     

Frequency of emerging positive diffusion-weighted imaging in early repeat examinations at least 24 h after transient ischemic attacks

Introduction

The relationships between diffusion lesions and risk scores for patients with a Transient ischemic attack (TIA) and the optimal timing for diffusion lesion screening have not been characterized. The purpose of our study was to evaluate the appearance of diffusion-weighted imaging (DWI) lesions during follow-up examinations of patients with TIA or minor stroke without initial DWI lesions.

Methods

We identified 31 patients who did not show diffusion lesions in initial DWI. A second magnetic resonance imaging (MRI) examination was performed 24 h after the initial MRI, and the patients were divided into two groups based on the results. Demographic and clinical data, including initial National Institutes of Health Stroke Scale scores, ABCD and ABCD² scores, and other MRI findings were evaluated. The data were analyzed using Spearman’s rank tests and unpaired t?tests.

Results

Ten patients (32.3 %) showed diffusion lesions on the second DWI examination. Both risk scores were higher in these patients compared with patients with negative results on follow-up DWI (P?<?0.05, unpaired t?test) and correlated with the length of the TIA (R _s?=?0.017, P?<?0.05; R _s?=?0.003, P?<?0.01; Spearman’s rank test).

Conclusion

Our results suggest that TIA patients with high-risk scores might be underestimated if the first MRI was performed within 24 h of symptom onset.