Cerebral Embolization during Transcervical Carotid Stenting with Flow Reversal: A Diffusion-Weighted Magnetic Resonance Study

A Case of Acute Ischemic Stroke due to Tandem Lesion Treated with Endovascular Thrombectomy by Internal Carotid Artery Direct Puncture

Objective

Endovascular thrombectomy is widely performed for acute ischemic stroke due to proximal intracranial artery occlusion. The femoral artery is often selected for puncture. However, common carotid artery puncture may be considered in more challenging cases. When the internal carotid artery is occluded or obstructed by atherosclerosis, puncturing the distal internal carotid artery becomes necessary. This is rare and was reported in only 2 cases. We report here a case of endovascular thrombectomy using direct puncture of the internal carotid artery.

Case Presentation

A 76-year-old male presented with sudden-onset right upper limb hemiparesis and mild dysarthria. Hospital admittance 1 hour later. Diffusion-weighted imaging (DWI) on head MRI revealed a hyperintense area in the left basal ganglia and corona radiata. MRA showed occlusion of the left internal carotid artery and the M2 segment of the left middle cerebral artery. Intravenous tissue plasminogen activator (tPA) was initiated, and endovascular thrombectomy was attempted. However, navigating the occluded left internal carotid artery was impossible. Symptomatic improvement was observed with tPA therapy causing recanalization of the M2 segment. Thus, further treatment was halted. Two days later, aphasia and complete right hemiparesis developed. MRA revealed no left anterior circulation flow. Under general anesthesia, an incision parallel to the left sternocleidomastoid muscle was made, and a direct puncture of the left internal carotid artery was performed to complete thrombectomy.

Conclusion

In difficult-to-access cases, especially when considering puncturing the cervical vessels, our report suggests that exposing the cervical vessels first can improve the hemostasis and puncture performance.

Changes in Cognitive Functions after Carotid Endarterectomy and Carotid Stenting: A Decade-Apart Comparison

BACKGROUND

This study investigates changes in cognitive function in patients with severe carotid stenosis who underwent carotid endarterectomy (CEA) and carotid stenting (CAS) over two decades.

METHODS

We compared cognitive function within 30 days after the procedure in 267 patients (first 100 each for CEA and CAS in two periods: 2008-2012 and 2018-2022) in a single institution. Assessments used Adenbrooke's Cognitive Examination-Revised (ACE-R), the Mini-Mental State Examination (MMSE), Speech Fluency Test (SFT), and Clock Drawing Test (CDT), conducted before and 30 ± 2 days after surgery.

RESULTS

Patients (mean age 67.2 years, 70%+ carotid stenosis) exhibited different cognitive changes over periods. In 2008-2012, significant declines in MMSE (CEA, p = 0.049) and CDT (CAS, p = 0.015) were observed among asymptomatic patients. On the contrary, in 2018-2022, improvements were observed in ACE-R and MMSE for symptomatic and asymptomatic patients undergoing CEA and CAS.

CONCLUSION

Over a decade, advances in interventional techniques and patient management have reduced risks of cognitive decline in patients with asymptomatic carotid stenosis and also have improved cognitive functions in both symptomatic and asymptomatic individuals.

European Stroke Organisation guideline on endarterectomy and stenting for carotid artery stenosis

Atherosclerotic stenosis of the internal carotid artery is an important cause of stroke. The aim of this guideline is to analyse the evidence pertaining to medical, surgical and endovascular treatment of patients with carotid stenosis. These guidelines were developed based on the ESO standard operating procedure and followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. The working group identified relevant questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence, and wrote recommendations. Based on moderate quality evidence, we recommend carotid endarterectomy (CEA) in patients with ≥60-99% asymptomatic carotid stenosis considered to be at increased risk of stroke on best medical treatment (BMT) alone. We also recommend CEA for patients with ≥70-99% symptomatic stenosis, and we suggest CEA for patients with 50-69% symptomatic stenosis. Based on high quality evidence, we recommend CEA should be performed early, ideally within two weeks of the last retinal or cerebral ischaemic event in patients with ≥50-99% symptomatic stenosis. Based on low quality evidence, carotid artery stenting (CAS) may be considered in patients < 70 years old with symptomatic ≥50-99% carotid stenosis. Several randomised trials supporting these recommendations were started decades ago, and BMT, CEA and CAS have evolved since. The results of another large trial comparing outcomes after CAS versus CEA in patients with asymptomatic stenosis are anticipated in the near future. Further trials are needed to reassess the benefits of carotid revascularisation in combination with modern BMT in subgroups of patients with carotid stenosis.

Transcervical carotid artery revascularization: A systematic review and meta-analysis of outcomes

OBJECTIVE

Carotid artery stenosis is considered a determinant factor for cerebrovascular events, estimated to be the cause of 10% to 20% of all ischemic strokes. Transcervical carotid artery revascularization (TCAR) has been offered as an alternative to transfemoral carotid artery stenting and carotid endarterectomy to treat carotid artery stenosis.

METHODS

We performed a systematic review and meta-analysis of prospective and retrospective studies reporting the outcomes of patients who had undergone TCAR for carotid artery stenosis. The incidence of periprocedural adverse events was calculated.

RESULTS

A total of 45 studies with 14,588 patients met the predefined eligibility criteria and were included in the present meta-analysis. The technical success rate was 99% (95% confidence interval [CI], 98%-99%). The reasons for technical failure included an inability to cross the lesion and/or failure to deploy the stent. Access site complications occurred in 2% of all cases (95% CI, 1%-2%; 30 studies). Overall, the incidence of cranial nerve (CN) injuries was very rare, with only 33 of 8994 patients experiencing neurologic deficits attributed to CN involvement. Bleeding complications were reported by 20 studies and occurred in 2% (95% CI, 1%-3%) of all cases. The overall periprocedural all-cause mortality and stroke rate was 0.5% and 1.3%, respectively. In-stent restenosis was observed in 4 of 260 patients (1.5%; 7 studies), and early (30-day) reocclusion or acute thrombosis of the target lesion occurred in 12 of 1243 patients (∼1%; 11 studies).

CONCLUSIONS

The results from the present study have provided significant evidence that TCAR is a very promising and safe carotid revascularization approach with favorable technical success rates associated with low periprocedural stroke and CN injury rates.

Editor's Choice - Early and Late Outcomes after Transcarotid Revascularisation for Internal Carotid Artery Stenosis: A Systematic Review and Meta-Analysis

OBJECTIVE

Transcarotid/transcervical revascularisation (TCAR) is an alternative to carotid endarterectomy (CEA) and transfemoral carotid stenting (tfCAS). This review aimed to evaluate pooled data on patients undergoing TCAR.

DATA SOURCES

Medline, Embase, Scopus, and Cochrane Library databases were used.

REVIEW METHODS

This systematic review was conducted under Systematic Reviews and Meta-Analysis guidelines. Eligible studies (published online up to September 2020) reported 30 day mortality and stroke/transient ischaemic attack (TIA) rates in patients undergoing TCAR. Data were pooled in a random effects model and weight of effect for each study was also reported. Quality of studies was evaluated according to Newcastle - Ottawa scale.

RESULTS

Eighteen studies (three low, seven medium, and eight high quality) included 4 852 patients (4 867 TCAR procedures). The pooled 30 day mortality rate was 0.7% (n = 32) (95% confidence interval [CI] 0.5 - 1.0), 30 day stroke rate 1.4% (n = 62) (95% CI 1.0 - 1.7), and 30 day stroke/TIA rate 2.0% (n = 92) (95% CI 1.4 - 2.7). Pooled technical success was 97.6% (95% CI 95.9 - 98.8). The cranial nerve injury rate was 1.2% (95% CI 0.7 - 1.9) (n = 14; data from 10 studies) while the early myocardial infarction (MI) rate was 0.4% (95% CI 0.2 - 0.6) (n = 16; data from 17 studies). The haematoma/bleeding rate was 3.4% (95% CI 1.7 - 5.8) (n = 135; data from 10 studies), with one third of these cases needing drainage or intervention. Within a follow up of 3 - 40 months the restenosis rate was 4% (95% CI 0.1 - 13.1) (data from nine studies; n = 64/530 patients) and death/stroke rate 4.5% (95% CI 1.8 - 8.4) (data from five studies; n = 184/3 742 patients). Symptomatic patients had a higher risk of early stroke/TIA than asymptomatic patients (2.5% vs. 1.2%; odds ratio 1.99; 95% CI 1.01 - 3.92); p = .046; data from eight studies).

CONCLUSION

TCAR is associated with promising early and late outcomes, with symptomatic patients having a higher risk of early cerebrovascular events. More prospective comparative studies are needed in order to verify TCAR as an established alternative treatment technique.

Critical Appraisal on the Quality of Reporting on Safety and Efficacy of Transcarotid Artery Stenting With Flow Reversal

Transcarotid revascularization is an alternative to transfemoral carotid artery stenting, designed to avoid aortic arch manipulation and concomitant periprocedural stroke. This article aims to perform a detailed analysis on the quality of the currently available evidence on safety and efficacy of transcarotid artery revascularization. Although current evidence is promising, independent randomized controlled studies comparing transcarotid artery revascularization with carotid endarterectomy in recently symptomatic patients are lacking and will be necessary to establish the true value of transcarotid artery revascularization in carotid artery revascularization.

A systematic review and meta-analysis of carotid artery stenting using the transcervical approach

INTRODUCTION

Carotid artery stenting (CAS) via a transcarotid revascularization (TCAR) approach has emerged as an alternative when carotid endarterectomy or conventional CAS is contraindicated. The present study was conducted to assess the feasibility and safety of TCAR in patients with carotid artery stenosis.

EVIDENCE ACQUISITION

A systematic review of the literature was performed, according to PRISMA guidelines (Preferred Reporting Items for Systematic reviews and Meta-Analyses), using PubMed, EMBASE and CENTRAL databases. The primary outcomes included technical success, perioperative neurological event, myocardial ischemic events, death and their composite. Operational duration, flow reversal time and any local procedure related complication (carotid dissection and cranial nerve injury) were also recorded.

EVIDENCE SYNTHESIS

Twenty-three studies were included, reporting on 3130 patients, undergoing TCAR. Thirty-five per cent of them were symptomatic. Technical success was 98% (95% CI: 0.97-0.99; P=0.11, I²=32%). Early (30-day) new neurological event rate was estimated at 2% (95% CI: 0.01-0.02; P=1.0, I²=0%, respectively) while early death rate was 1% (95% CI: 0.00-0.01; P=1.0, I²=0%). Myocardial ischemic (MI) event rate was 1% (95% CI, 0.00-0.01, P=0.97, I²=6.6%). The composite outcome of neurological event/MI/death at 30-day follow-up was 2% (95% CI: 0.01-0.02, P=0.79, I²=14%). Carotid dissection rate during the intervention was 2% (95% CI: 0.01-0.03, P=0.58, I²=2.9%) while the post-operatively detected cranial nerve injury rate was 1% (95% CI, 0.00-0.01, P=1.0, I²=0%). Regarding the technical aspects of the procedures, operational and flow reversal time were at 73.8 min and 13.7 min, respectively (95% CI: 68.2-79.3, P=0.18, I²=37.6% and 95% CI: 11.3-16.1, P=0.48, I²=0%, respectively).

CONCLUSIONS

TCAR is feasible with high technical success rate. The procedure presents low incidence of local complications, neurological events, myocardial complications and mortality during the early postoperative period and should be considered an acceptable alternative for patients treated for carotid artery stenosis.

An updated systematic review and meta-analysis of results of transcervical carotid artery stenting with flow reversal

OBJECTIVE

Transcervical carotid artery stenting (CAS) has emerged as an alternative to transfemoral CAS. An earlier systematic review from our group (n = 12 studies; 739 transcervical CAS procedures [489/739 with flow reversal]) demonstrated that transcervical CAS is a safe procedure associated with a low incidence of stroke and complications. Since then, new studies have been published adding nearly 1600 patients to the literature. We aimed to update our early systematic review and also to perform a meta-analysis to investigate outcomes specifically after transcervical CAS with flow reversal.

METHODS

An electronic search of PubMed/MEDLINE, Embase, and the Cochrane databases was carried out to identify studies reporting outcomes after transcervical CAS with flow reversal. Crude event rates for outcomes of interest were estimated by simple pooling of data. A proportion meta-analysis was also performed to estimate pooled outcome rates.

RESULTS

A total of 18 studies (n = 2110 transcervical CAS procedures with flow reversal) were identified. A high technical success (98.25%) and a low mortality rate (0.48%) were recorded. The crude rates of major stroke, minor stroke, transient ischemic attack, and myocardial infarction (MI) were 0.71%, 0.90%, 0.57%, and 0.57%, respectively; a cranial nerve injury occurred in 0.28% of the procedures. A neck hematoma was reported in 1.04% of the procedures, and a carotid artery dissection occurred in 0.76% of the interventions; in 1.09% of the cases, conversion to carotid endarterectomy was required. After a meta-analysis was undertaken, the pooled technical success rate was 98.69% (95% confidence interval [CI], 97.19-99.70). A pooled mortality rate of 0.04% (95% CI, 0.00-0.29) was recorded. The pooled rate of any type of neurologic complications was 1.88 (95% CI, 1.24-2.61), whereas the pooled rates of major stroke, minor stroke, and transient ischemic attack were 0.12% (95% CI, 0.00-0.46), 0.15% (95% CI, 0.00-0.50), and 0.01% (95% CI, 0.00-0.22), respectively. The pooled rate of bradycardia/hypotension was 10.21% (95% CI, 3.99-18.51), whereas the pooled rate of MI was 0.08% (95% CI, 0.00-0.39). A neck hematoma after transcervical CAS was recorded in 1.51% (95% CI, 0.22-3.54) of the procedures; in 0.74% (95% CI, 0.05-1.95) of the interventions, conversion to CEA was required. Finally, a carotid artery dissection during transcervical CAS occurred in 0.47% (95% CI, 0.00-1.38) of the procedures.

CONCLUSIONS

This updated systematic review and meta-analysis demonstrated that transcervical CAS with flow reversal is associated with high technical success, almost zero mortality, and low rates of major stroke, minor stroke, MI, and complications.

Silent brain infarcts on diffusion-weighted imaging after carotid revascularisation: A surrogate outcome measure for procedural stroke? A systematic review and meta-analysis

Aim

To investigate whether lesions on diffusion-weighted imaging (DWI+) after carotid artery stenting (CAS) or endarterectomy (CEA) might provide a surrogate outcome measure for procedural stroke.

Materials and Methods

Systematic MedLine® database search with selection of all studies published up to the end of 2016 in which DWI scans were obtained before and within seven days after CAS or CEA. The correlation between the underlying log odds of stroke and of DWI+ across all treatment groups (i.e. CAS or CEA groups) from included studies was estimated using a bivariate random effects logistic regression model. Relative risks of DWI+ and stroke in studies comparing CAS vs. CEA were estimated using fixed-effect Mantel-Haenszel models.

Results

We included data of 4871 CAS and 2099 CEA procedures (85 studies). Across all treatment groups (CAS and CEA), the log odds for DWI+ was significantly associated with the log odds for clinically manifest stroke (correlation coefficient 0.61 (95% CI 0.27 to 0.87), p = 0.0012). Across all carotid artery stenting groups, the correlation coefficient was 0.19 (p = 0.074). There were too few CEA groups to reliably estimate a correlation coefficient in this subset alone. In 19 studies comparing CAS vs. CEA, the relative risks (95% confidence intervals) of DWI+ and stroke were 3.83 (3.17-4.63, p < 0.00001) and 2.38 (1.44-3.94, p = 0.0007), respectively.

Discussion

This systematic meta-analysis demonstrates a correlation between the occurrence of silent brain infarcts on diffusion-weighted imaging and the risk of clinically manifest stroke in carotid revascularisation procedures.

Conclusion

Our findings strengthen the evidence base for the use of DWI as a surrogate outcome measure for procedural stroke in carotid revascularisation procedures. Further randomised studies comparing treatment effects on DWI lesions and clinical stroke are needed to fully establish surrogacy.

Recent advances in carotid angioplasty and stenting

Atherosclerotic carotid stenosis accounts for about 15% of ischemic strokes. Carotid endarterectomy reduces the risk of stroke in patients with severe carotid stenosis. Carotid artery stenting has emerged as a potentially less invasive alternative to carotid endarterectomy. However, randomized clinical trials in patients with symptomatic stenosis have shown that carotid artery stenting is associated with a higher risk of peri-procedural stroke compared with carotid endarterectomy. Carotid artery stenting is associated with a lower risk of peri-procedural myocardial infarction and local complications (cranial nerve palsies, access site hematoma) and appears to be as durable as carotid endarterectomy in terms of long-term protection against ipsilateral stroke and risk of restenosis. The main risk factors for peri-procedural stroke in patients treated with carotid artery stenting are age >70 years and high burden of white-matter lesions on brain imaging. Patients with asymptomatic carotid stenosis receiving modern medical treatment have a low risk (<1%/year) of ipsilateral stroke and it is uncertain whether the benefit of revascularization still justifies the procedural risk of stroke or death. In particular, the small excess of procedural risk of stroke associated with carotid artery stenting (compared with carotid endarterectomy) may offset the small benefit (if any) of carotid endarterectomy versus medical therapy in unselected patients. Randomized clinical trials are ongoing to solve this issue.

Feasibility of combined surgical and endovascular carotid access for interventional treatment of ischemic stroke

BACKGROUND

Rapid recanalization of occluded vessels is crucial for good clinical outcome in acute ischemic stroke. Endovascular treatment is usually performed via a transfemoral approach, but catheterization of the carotid arteries can be problematic in cases of difficult anatomy or vascular pathologies in some cases.

OBJECTIVE

To describe our experience with a technique involving surgical access to the carotid artery and consecutive transcarotid endovascular thrombectomy in patients with acute stroke.

METHODS

In a retrospective review of a prospectively maintained registry we identified 6 patients who underwent acute endovascular thrombectomy via a surgical access to the carotid artery.

RESULTS

Admission National Institute of Health Stroke Scale (NIHSS) ranged from 7 to 23. Intracranial recanalization (thrombolysis in cerebral infarction, TICI≥2b) was achieved in all patients (100%). Recanalization was achieved within 19±5 min after establishing carotid access. One patient developed a small neck hematoma, which was surgically removed without complications. No complications related to endovascular therapy were seen. At 3 months' follow-up, five patients had survived. Three patients (50%) had regained excellent neurological function (modified Rankin Scale, mRS 0-1).

CONCLUSIONS

Surgical carotid access for endovascular stroke treatment is feasible, with considerable advantages, in patients with expected problematic access or for whom transfemoral endovascular carotid access has failed.

Stenting or endarterectomy for patients with symptomatic carotid stenosis

Carotid artery stenting is a less invasive alternative to endarterectomy to treat symptomatic carotid stenosis. Clinical trials showed a higher periprocedural risk of nondisabling stroke with stenting, and a higher periprocedural risk of myocardial infarction, cranial nerve palsy, and access site hematoma with endarterectomy. The excess in procedure-related strokes with stenting is mainly seen in patients aged 70 and over. After the procedural period, stenting and endarterectomy are equally effective in preventing stroke and recurrent carotid stenosis in the medium to long term. The choice of stenting versus endarterectomy should take into account risks of both procedures in individual patients.

Flow reversal versus filter protection: a pilot carotid artery stenting randomized trial

BACKGROUND

Carotid artery stenting (CAS) has become an alternative treatment for patients presenting symptomatic carotid artery stenosis. The improvement in clinical outcomes with CAS has been associated with the development of embolic protection devices. The trial aim is to compare flow reversal versus filter protection during CAS through femoral access.

METHODS AND RESULTS

Patients were randomly enrolled in CAS using flow reversal or filter protection. The primary end points were the incidence, number, and size of new ischemic brain lesions after CAS. The secondary end points included major adverse cardiac and cerebrovascular events, transient ischemic attack, and definitive ischemic brain lesions on fluid-attenuated inversion recovery magnetic resonance image at a 3-month follow-up. Ischemic brain lesions were assessed by a 3T magnetic resonance image. Neurological outcomes were evaluated by means of the National Institutes of Health Stroke Scale and the modified Rankin Scale (mRS). Forty consecutive patients were randomly assigned. Compared with flow reversal (n=21), filter protection (n=19) resulted in a significant reduction in the incidence (15.8% versus 47.6%, P=0.03), number (0.73 versus 2.6, P=0.05), and size (0.81 versus 2.23 mm, P=0.05) of new ischemic brain lesions. Two patients, 1 from each group, presented transient ischemic attack at 3-month follow-up. There were no major adverse cardiac and cerebrovascular events in the hospital or at 3-month follow-up.

CONCLUSIONS

In this small sample size trial, filter protection was more effective than flow reversal in reducing ischemic brain lesions during CAS through femoral approach.

CLINICAL TRIAL REGISTRATION URL

http://portal2.saude.gov.br/sisnep/. Unique identifier: 0538.0.004.000-10.

Results of carotid artery stenting with transcervical access

OBJECTIVE

Carotid artery stenting (CAS) is usually performed with femoral access; however, this access may be impeded by anatomic limitations. Moreover, many embolic events happen during aortic arch catheterization. To overcome these problems, transcervical access to the carotid artery can be used as an alternative approach for CAS.

METHODS

An electronic search of the literature using PubMed was performed. All studies reporting the results of CAS using the transcervical approach were retrieved and analyzed.

RESULTS

The analysis included 12 studies reporting the results of 739 CAS procedures performed in 722 patients (mean age, 75.5 years). Of 533 lesions reported, 235 (44%) were symptomatic, with no data regarding symptomatic status available for 206 lesions. Two techniques were used: direct CAS with transcervical access (filter protected or unprotected) in 250 patients and CAS with transcervical access under reversed flow (with arteriovenous shunt in most cases) in 489 patients. Local anesthesia was used in 464 of 739 procedures (63%), and the remaining were performed under general anesthesia or cervical block. Technical success was 96.3% for 579 procedures with available data (558 successful procedures and 21 failures: inability to cross the lesion, 10; dissection, 5; failure of predilatation, 1; stent thrombosis, 1; patient agitation, 1; and no data, 3). The incidence of conversion to open repair was 3.0% (20 of 579 procedures: 18 carotid endarterectomies and two common carotid-internal carotid bypass grafts). Stroke occurred in eight patients (two fatal) and a fatal myocardial infarction in one patient. The incidence of stroke, myocardial infarction, and death was 1.1%, 0.14%, and 0.41%, respectively. The incidence of stroke was 1.2% (3 of 250) in direct CAS with transcervical access and 1.02% (5 of 489) in CAS under reversed flow (P > .05). Transient ischemic attack occurred in 20 patients (2.7%). Local complications were encountered in 17 of 579 CAS (2.9%), comprising 15 hematomas and two patients with transient laryngeal palsy.

CONCLUSIONS

CAS with the transcervical approach is a safe procedure with low incidence of stroke and complications. It can be used as an alternative to femoral access in patients with unfavorable aortoiliac or aortic arch anatomy.

The clinical results of transcervical carotid artery stenting and frequency chosen as the approach route of carotid artery stenting in 1,067 consecutive cases

BACKGROUND

Carotid artery stenting (CAS) is generally performed via a transfemoral approach. A transbrachial approach is usually chosen as an alternative when CAS via a transfemoral approach is difficult. At our institutions, a transcervical approach is chosen when the previous two approach routes are not available. We reviewed CAS cases treated via the transcervical route in our 1,067 CAS series to investigate the safety, feasibility, and frequency of this procedure as an approach route of CAS.

METHODS

We performed 1,067 CAS procedures in 1,067 consecutive cases between December 2002 and June 2011. Initially, a transfemoral route was chosen, and secondarily a transbrachial route, the last choice was a transcervical route. A transbrachial approach was chosen in 96 (9.0%) cases and a transcervical approach in ten (0.9%). We reviewed the characteristics and outcomes of CAS performed via a transcervical approach.

RESULTS

CAS was successfully performed on all ten transcervical-approach patients. Eight procedures were performed under local anesthesia and two under general anesthesia. Perioperative morbidity and mortality were both 0%. The modified Rankin scale (mRS) showed no deterioration at 3 months except for one case whose mRS became five because of an embolic stroke after aortic valve replacement.

CONCLUSIONS

CAS via a transcervical approach was safe and feasible, and its frequency chosen as an approach route was 0.9%. This procedure can be an alternative to transfemoral or transbrachial approaches when CAS via either of these approaches is too difficult.

Microembolization during carotid artery stenting in patients with high-risk, lipid-rich plaque. A randomized trial of proximal versus distal cerebral protection

OBJECTIVES

The goal of this study was to compare the rate of cerebral microembolization during carotid artery stenting (CAS) with proximal versus distal cerebral protection in patients with high-risk, lipid-rich plaque.

BACKGROUND

Cerebral protection with filters partially reduces the cerebral embolization rate during CAS. Proximal protection has been introduced to further decrease embolization risk.

METHODS

Fifty-three consecutive patients with carotid artery stenosis and lipid-rich plaque were randomized to undergo CAS with proximal protection (MO.MA system, n = 26) or distal protection with a filter (FilterWire EZ, n = 27). Microembolic signals (MES) were assessed by using transcranial Doppler during: 1) lesion wiring; 2) pre-dilation; 3) stent crossing; 4) stent deployment; 5) stent dilation; and 6) device retrieval/deflation. Diffusion-weighted magnetic resonance imaging was conducted before CAS, after 48 h, and after 30 days.

RESULTS

Patients in the MO.MA group had higher percentage diameter stenosis (89 ± 6% vs. 86 ± 5%, p = 0.027) and rate of ulcerated plaque (35% vs. 7.4%; p = 0.019). Compared with use of the FilterWire EZ, MO.MA significantly reduced mean MES counts (p < 0.0001) during lesion crossing (mean 18 [interquartile range (IQR): 11 to 30] vs. 2 [IQR: 0 to 4]), stent crossing (23 [IQR: 11 to 34] vs. 0 [IQR: 0 to 1]), stent deployment (30 [IQR: 9 to 35] vs. 0 [IQR: 0 to 1]), stent dilation (16 [IQR: 8 to 30] vs. 0 [IQR: 0 to 1]), and total MES (93 [IQR: 59 to 136] vs. 16 [IQR: 7 to 36]). The number of patients with MES was higher with the FilterWire EZ versus MO.MA in phases 3 to 5 (100% vs. 27%; p < 0.0001). By multivariate analysis, the type of brain protection was the only independent predictor of total MES number. No significant difference was found in the number of patients with new post-CAS embolic lesion in the MO.MA group (2 of 14, 14%) as compared with the FilterWire EZ group (9 of 21, 42.8%).

CONCLUSIONS

In patients with high-risk, lipid-rich plaque undergoing CAS, MO.MA led to significantly lower microembolization as assessed by using MES counts.

Assessment of reverse flow as a means of cerebral protection during carotid artery stent placement with diffusion-weighted and transcranial Doppler imaging

PURPOSE

To assess the effectiveness of flow reversal as an alternative means of cerebral protection by using transcranial Doppler recordings and diffusion-weighted imaging (DWI) as surrogate markers of brain injury.

MATERIALS AND METHODS

Eighteen patients with symptomatic carotid artery disease were recruited. Magnetic resonance imaging was performed before the intervention and at 3 and 24 hours and 30 days after the intervention to detect new ischemic lesions with DWI. Transcranial Doppler recordings were made during the procedure to assess for microembolic signals (MESs). Data were compared against data from a historical control cohort of patients who underwent CAS placement with or without filter protection (n = 15 each) under the same protocol in a different study.

RESULTS

There were fewer periprocedural new lesions on DWI in the reverse-flow cohort compared with the historical control cohort with filter protection (P = .084). Reverse flow revealed significantly fewer MESs during the whole procedure compared with the filter-protected group (P = .01) but not the unprotected group (P = .55). There was a marked decrease in MES counts for reverse flow protection during the embologenic stages of the procedure (P = .004).

CONCLUSIONS

Use of the reverse flow device was associated with fewer overall lesions on DWI and proportionately fewer positive scans compared with the use of filter-type devices (P = .08, not significant). Transcranial Doppler recordings demonstrated a significant reduction in embolization to the brain during carotid artery stent placement with the use of reverse-flow cerebral protection.

Advances in the management of carotid artery disease: focus on recent evidence and guidelines

Recent landmark randomized trials and society guidelines have significantly revised the management of carotid artery disease. Duplex ultrasonography is the recommended initial diagnostic test for the assessment of extracranial carotid artery stenosis. Carotid artery imaging is reasonable in select patients scheduled for coronary artery bypass graft (CABG) surgery. Carotid revascularization can be achieved safely and effectively with carotid endarterectomy or carotid artery stenting. Because each procedure has a different risk/benefit profile, the optimal approach is to match the particular patient to the intervention that maximizes outcome benefit. Carotid revascularization is recommended in patients scheduled for CABG surgery when the carotid artery stenosis is symptomatic and/or bilateral. Further trials are required to guide the management of asymptomatic unilateral carotid artery stenosis in patients undergoing CABG surgery. Aggressive medical therapy remains the gold standard for intracranial carotid artery disease because landmark trials have shown no outcome improvement with vascular bypass or percutaneous angioplasty and stenting. A large recent trial showed that local anesthesia, as compared with general anesthesia, for carotid endarterectomy has no major clinical outcome advantage. Although carotid artery stenting is associated with a reduced risk of myocardial ischemia, it still has important risks of stroke and hemodynamic instability that significantly affect clinical outcome. The timing and choice of carotid revascularization technique ultimately depends on multiple clinical factors.

A diffusion-weighted magnetic resonance imaging-based study of transcervical carotid stenting with flow reversal versus transfemoral filter protection

BACKGROUND

Transfemoral carotid artery stenting (CAS) has been associated with a high incidence of embolic phenomena and silent brain infarction. The goal of this study was to compare the incidence of new ischemic cerebral lesions on diffusion-perfusion magnetic resonance imaging (MRI) sequences after transcervical CAS performed with carotid flow reversal vs stenting via transfemoral approach with distal filter protection.

METHODS

During a 26-month period, 64 consecutive patients diagnosed with significant carotid stenosis by ultrasound imaging were assigned to transcervical CAS with carotid flow reversal or a transfemoral approach with a distal filter. The Rankin stroke scale was administered by an independent neurologist, and diffusion-weighted MRI (DW-MRI) studies were performed ≤24 hours before and ≤24 to 48 hours after the procedure. DW-MRI studies were compared by two neuroradiologists not involved in the study and blinded for time, clinical status, and treatment option. Hyperintense DW-MRI signals found after the procedure were interpreted as postoperative ischemic infarcts. All patients were assessed at 1, 6, and 12 months after the intervention.

RESULTS

The distribution of demographic and pathologic variables was similar in both groups. All procedures were technically successful, with a mean carotid flow reversal time of 22 minutes. Twenty-one (70%) and 23 patients (69.69%) were symptomatic in the transcervical and transfemoral groups, respectively (P=.869). After intervention, new postprocedural DW-MRI ischemic infarcts were found in four transcervical (12.9%) and in 11 transfemoral (33.3%) patients (P=.03), without new neurologic symptoms. No major adverse events occurred at 30 days after the intervention. All patients remained neurologically intact, without an increase in stroke scale scoring. All stents remained patent, and all patients remained stroke-free during follow-up. In multivariate analysis, age (relative risk [RR], 1.022; P<.001), symptomatic status (RR, 4.109; P<.001), and open-cell vs closed-cell stent design (RR, 2.01; P<.001) were associated with a higher risk of embolization in the transfemoral group but not in the transcervical group.

CONCLUSIONS

These data suggest that transcervical carotid stenting with carotid flow reversal carries a significantly lower incidence of new ischemic brain infarcts than that resulting from transfemoral CAS with a distal filter. The transcervical approach with carotid flow reversal may improve the safety of CAS and has the potential to improve results in especially vulnerable patients such as the elderly and symptomatic.