Silent Cerebral Ischemia Detected With Diffusion-Weighted Imaging in Patients Treated With Protected and Unprotected Carotid Artery Stenting

Clinical Significance of Diffusion-Weighted Brain MRI Lesions After TAVR: Results of a Patient-Level Pooled Analysis

BACKGROUND

Acute brain infarction detected by diffusion-weighted magnetic resonance imaging (DW-MRI) is common after transcatheter aortic valve replacement (TAVR), but its clinical relevance is uncertain.

OBJECTIVES

The authors investigated the relationship between DW-MRI total lesion number (TLN), individual lesion volume (ILV), and total lesion volume (TLV) and clinical stroke outcomes after TAVR.

METHODS

Patient-level data were pooled from 4 prospective TAVR embolic protection studies, with consistent predischarge DW-MRI acquisition and core laboratory analysis. C-statistic was used to determine the best DW-MRI measure associated with clinical stroke.

RESULTS

A total of 495 of 603 patients undergoing TAVR completed the predischarge DW-MRI. At 30 days, the rate of clinical ischemic stroke was 6.9%. Acute ischemic brain injury was seen in 85% of patients with 5.5 ± 7.3 discrete lesions per patient, mean ILV of 78.2 ± 257.1 mm3, and mean TLV of 555 ± 1,039 mm3. The C-statistic was 0.84 for TLV, 0.81 for number of lesions, and 0.82 for maximum ILV in predicting ischemic stroke. On the basis of the TLV cutpoint as defined by receiver operating characteristic (ROC), patients with a TLV >500 mm3 (vs TLV ≤500 mm3) had more ischemic stroke (18.2% vs 2.3%; P < 0.0001), more disabling strokes (8.8% vs 0.9%; P < 0.0001), and less complete stroke recovery (44% vs 62.5%; P = 0.001) at 30 days.

CONCLUSIONS

Our study confirms that the number, size, and total volume of acute brain infarction defined by DW-MRI are each associated with clinical ischemic strokes, disabling strokes, and worse stroke recovery in patients undergoing TAVR and may have value as surrogate outcomes in stroke prevention trials. (A Prospective, Randomized Evaluation of the TriGuard™ HDH Embolic Deflection Device During TAVI [DEFLECT III]; NCT02070731) (A Study to Evaluate the Neuro-embolic Consequences of TAVR [NeuroTAVR]; NCT02073864) (The REFLECT Trial: Cerebral Protection to Reduce Cerebral Embolic Lesions After Transcatheter Aortic Valve Implantation [REFLECT I]; NCT02536196) (The REFLECT Trial: Cerebral Protection to Reduce Cerebral Embolic Lesions After Transcatheter Aortic Valve Implantation [REFLECT II]; NCT02536196).

Percutaneous transluminal angioplasty and stenting of post-irradiated stenosis of subclavian artery: A matched case-control study

BACKGROUND

Although radiotherapy is common for head/neck and chest cancers (HNCC), it can result in post-irradiation stenosis of the subclavian artery (PISSA). The efficacy of percutaneous transluminal angioplasty and stenting (PTAS) to treat severe PISSA is not well-clarified.

AIMS

To compare the technical safety and outcomes of PTAS between patients with severe PISSA (RT group) and radiation-naïve counterparts (non-RT group).

METHODS

During 2000 and 2021, we retrospectively enrolled patients with severe symptomatic stenosis (>60%) of the subclavian artery who underwent PTAS. The rate of new recent vertebrobasilar ischaemic lesions (NRVBIL), diagnosed on diffusion-weight imaging (DWI) within 24 h of postprocedural brain MRI; symptom relief; and long-term stent patency were compared between the two groups.

RESULTS

Technical success was achieved in all 61 patients in the two groups. Compared with the non-RT group (44 cases, 44 lesions), the RT group (17 cases, 18 lesions) had longer stenoses (22.1 vs 11.1 mm, P = 0.003), more ulcerative plaques (38.9% vs 9.1%, P = 0.010), and more medial- or distal-segment stenoses (44.4% vs 9.1%, P<0.001). The technical safety and outcome between the non-RT group and the RT group were NRVBIL on DWI of periprocedural brain MRI 30.0% vs 23.1%, P = 0.727; symptom recurrence rate (mean follow-up 67.1 ± 50.0 months) 2.3% vs 11.8%, P = 0.185; and significant in-stent restenosis rate (>50%) 2.3% vs 11.1%, P = 0.200.

CONCLUSION

The technical safety and outcome of PTAS for PISSA were not inferior to those of radiation-naïve counterparts. PTAS for PISSA is an effective treatment for medically refractory ischaemic symptoms of HNCC patients with PISSA.

Percutaneous transluminal angioplasty and stenting of post-irradiation stenosis of the vertebral artery

BACKGROUND

The outcomes of percutaneous transluminal angioplasty and stenting (PTAS) in patients with medically refractory post-irradiation stenosis of the vertebral artery (PISVA) have not been clarified.

AIM

This retrospective study evaluated the safety and outcomes of PTAS in patients with severe PISVA compared with their radiation-naïve counterparts (non-RT group).

METHODS

Patients with medically refractory severe symptomatic vertebral artery stenosis and undergoing PTAS between 2000 and 2021 were classified as the PISVA group or the non-RT group. The periprocedural neurological complications, periprocedural brain magnetic resonance imaging, the extent of symptom relief, and long-term stent patency were compared.

RESULTS

As compared with the non-RT group (22 cases, 24 lesions), the PISVA group (10 cases, 10 lesions) was younger (62.0 ± 8.6 vs 72.4 ± 9.7 years, P = 0.006) and less frequently had hypertension (40.0% vs 86.4%, P = 0.013) and diabetes mellitus (10.0% vs 54.6%, P = 0.024). Periprocedural embolic infarction was not significantly different between the non-RT group and the PISVA group (37.5% vs 35.7%, P = 1.000). At a mean follow-up of 72.1 ± 58.7 (3-244) months, there was no significant between-group differences in the symptom recurrence rate (0.00% vs 4.55%, P = 1.000) and in-stent restenosis rate (10.0% vs 12.5%, P = 1.000).

CONCLUSION

PTAS of severe medically refractory PISVA is effective in the management of vertebrobasilar ischemic symptoms in head and neck cancer patients. Technical safety and outcome of the procedure were like those features in radiation-naïve patients.

The safety and efficacy of the Mo.Ma system device for carotid artery stenting: A single-center experience from Taiwan

Background

Proximal protection devices, such as the Mo.Ma system provides better neurological outcomes than the distal filter system in the carotid artery stenting (CAS) procedure. This study first evaluated the safety and efficacy of the Mo.Ma system during CAS in a single tertiary referral hospital from Taiwan. The outcomes of distal vs. proximal embolic protection devices were also studied.

Methods

A total of 294 patients with carotid artery stenosis who underwent the CAS procedure were retrospectively included and divided into two groups: 152 patients in the distal filter system group and 142 patients in the Mo.Ma system. The outcomes of interest were compared between the two groups. The factors contributing to occlusion intolerance (OI) in the Mo.Ma system were evaluated.

Results

The procedure success rates were more than 98% in both groups. No major stroke occurred in this study. The minor stroke rates were 2.8% (4/142) and 4.6% (7/152) in the Mo.Ma system and filter system, respectively (p = 0.419). Patients with hypoalbuminemia significantly predicted the risk of stroke with an odds ratio of 0.08 [95% confidence interval (CI), 0.01–0.68, p = 0.020] per 1 g/day of serum albumin in the filter group. A total of 12 patients developed OI in the Mo.Ma system (12/142, 8%). Low occlusion pressure predicted the occurrence of OI in the Mo.Ma group with the hazard ratios of 0.88 (95% CI: 0.82–0.96) and 0.90 (95% CI: 0.84–0.98) per 1 mmHg of occlusion systolic pressure (OSP) and diastolic pressure (ODP), respectively. We further indicated that patients with an OSP of ≥60 mmHg or an ODP of ≥44 mmHg could tolerate the procedure of occlusion time up to 400 s, while patients with an OSP of <49 mmHg or an ODP of <34 mmHg should undergo the procedure of occlusion time less than 300 s to prevent the occurrence of OI.

Conclusion

We have demonstrated the safety and effectiveness of the Mo.Ma system during CAS in an Asia population. By reducing the occlusion time, our study indicated a lower risk of OI in the Mo.Ma system and proposed the optimal occlusion time according to occlusion pressure to prevent OI during the CAS procedure. Further large-scale and prospective studies are needed to verify our results.

Evolution, Predictors, and Neurocognitive Effects of Silent Cerebral Embolism During Transcatheter Aortic Valve Replacement

OBJECTIVES

The aim of this study was to assess the characteristics, predictors, evolution, and neurocognitive effects of silent cerebral ischemic lesions (SCILs).

BACKGROUND

Most patients undergoing transcatheter aortic valve replacement (TAVR) develop SCILs detectable on magnetic resonance imaging (MRI). The natural history and clinical relevance of SCILs are not well established.

METHODS

Cerebral MRI was performed within 7 days before TAVR to assess baseline status and age-related white matter change score. MRI was repeated post-operatively to assess the occurrence, location, number, and dimensions of SCILs. Patients developing SCILs underwent a third MRI examination at 3- to 5-month follow-up. A neurocognitive evaluation was performed before TAVR, at discharge, and at 3-month follow-up.

RESULTS

Of the 117 patients enrolled, 96 underwent post-procedural MRI; SCILs were observed in 76% of patients, distributed in all vascular territories, with a median number of 2 lesions, a median diameter of 4.5 mm, and a median total volume of 140 mm³. Independent predictors of SCIL occurrence were higher baseline age-related white matter change score and the use of self-expanding or mechanically expanded bioprostheses. Among 47 patients who underwent follow-up MRI, only 26.7% of post-procedural SCILs evolved into gliotic scar. SCIL occurrence was associated with a more pronounced transient neurocognitive decline early after TAVR and with lower recovery at follow-up.

CONCLUSIONS

SCILs occur in the vast majority of patients undergoing TAVR and are predicted by more diffuse white matter damage at baseline and by the use of non-balloon-expandable prostheses. Although most SCILs disappear within months, their occurrence has a limited but significant impact on neurocognitive function.

A Systematic Review and Meta-Analysis of Transcarotid Artery Revascularization with Dynamic Flow Reversal Versus Transfemoral Carotid Artery Stenting and Carotid Endarterectomy

BACKGROUND

Transfemoral carotid artery stenting (TFCAS) was introduced as a less invasive option for carotid revascularization in patients at high risk for complications from carotid endarterectomy (CEA). The increased perioperative stroke and death risk of TFCAS has however prevented TFCAS from widespread acceptance as an alternative to CEA in high-risk patients. Recent research suggests that transcarotid artery revascularization (TCAR) may be associated with a low stroke and death risk and potentially meet the needs of patients at high surgical risk. We aimed to estimate the 30-day risk of stroke or death of TCAR and compare it to TFCAS and CEA.

METHODS

We searched PubMed, Cochrane, Embase, and Scopus for studies of patients treated with TCAR. Meta-analysis was conducted when appropriate. A logistic-normal random-effects model with logit transformation was used to estimate the pooled event rates after TCAR. Pooled Mantel-Haenszel odds ratios (ORs) of events comparing TCAR to TFCAS and CEA were calculated using a fixed-effects model. Heterogeneity among studies was quantified with the chi-squared statistic of the likelihood ratio (LR) test that compares the random-effects and fixed-effects models.

RESULTS

Nine nonrandomized studies evaluating 4012 patients who underwent TCAR were included. The overall 30-day risks after TCAR were stroke/death, 1.89% (95% confidence interval [CI]: 1.50, 2.37); stroke, 1.34% (95% CI: 1.02,1.75); death, 0.76% (95% CI: 0.56, 1.08); myocardial infarction (MI), 0.60% (95% CI: 0.23, 1.59); stroke/death/MI, 2.20% (95% CI: 1.31, 3.69); cranial nerve injury (CNI), 0.31% (95% CI: 0.12, 0.83). The failure rate of TCAR was 1.27% (95% CI: 0.32, 4.92). Two nonrandomized studies suggested that TCAR was associated with lower risk of stroke and death as compared with TFCAS (1.33% vs. 2.55%, OR: 0.52, 95% CI: 0.36, 0.74 and 0.76% vs. 1.46%, OR: 0.52, 95% CI: 0.32, 0.84, respectively). Four nonrandomized studies suggested that TCAR was associated with a lower risk of CNI (0.54% and 1.84%, OR: 0.52, 95% CI: 0.36, 0.74) than CEA, but no statistically significant difference in the 30-day risk of stroke, stroke/death, or stroke/death/MI.

CONCLUSIONS

Among patients undergoing TCAR with dynamic flow reversal for carotid stenosis the 30-day risk of stroke or death was low. The perioperative stroke/death rate of TCAR was similar to that of CEA while CNI risk was lower. Larger prospective studies are needed to account for confounding factors and provide higher certainty.

The impact of post-dilatation on periprocedural outcomes during carotid artery stenting: A single-center experience

BACKGROUND AND AIMS

Carotid artery stenting (CAS) is an accepted treatment modality for carotid artery disease. However, CAS is associated with periprocedural embolic events, and the effect of balloon post-dilatation has not been sufficiently investigated in large studies. We assessed the effect of post-dilatation on periprocedural outcomes during CAS.

METHODS

The study included 128 patients who underwent CAS. The patients were divided into groups according to whether post-dilatation was (post-dilatation [+], group 1) or was not (post dilatation [-], group 2) performed after stent deployment. Major adverse events were defined as death, minor or major stroke, and transient ischemic attack at 30 days. Silent ischemia was assessed using diffusion-weighted magnetic resonance imaging.

RESULTS

No significant between-group differences were found in baseline characteristics, comorbid diseases, or lesion characteristics. The degree of stenosis and procedure duration was greater in group 1 than in group 2. The rate of major adverse events at 30 days was similar between the two groups (5.1% vs. 4.3%, p = 0.844). The silent ischemia rate and number of high-intensity signals were higher in group 1 than in group 2 (45.8% vs. 26.1%, p = 0.020 and 1.01 [1.2] vs. 0.42 [0.79], p = 0.002). Multivariate analysis revealed that post-dilatation was associated with a 2.4-fold increase in silent ischemia (95% confidence interval: 1.15-5.20, p = 0.020).

CONCLUSIONS

Although post-dilatation was not associated with an increase in major adverse events, it significantly increased the incidence of periprocedural silent ischemia. Therefore, post-dilation should be performed only in cases with severe residual stenosis after CAS.

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.

Risk Factors of Contralateral Microembolic Infarctions Related to Carotid Artery Stenting

This study sought to analyze the incidence of contralateral microembolic infarctions (MIs) on diffusion-weighted imaging (DWI) following protected carotid artery stenting (CAS) and compared the difference of risk factors between ipsilateral and contralateral lesions. From April 2010 to March 2017, 147 CASs in 140 patients were performed. All the patients underwent DWI within 1 week before and 24 hrs after the procedures. CAS was successfully completed in 145 (98.6%) of the 147 procedures. Forty-nine (33.8%) patients with new MIs revealed on postprocedural DWI were enrolled. They were divided into ipsilateral and contralateral groups based on the side of the CAS and MIs. The ipsilateral group indicates patients with MIs exclusively on the side of CAS. The contralateral group includes patients with MIs on the opposite side of the CAS or both sides. Patients with MIs at vertebrobasilar territory were excluded. Patient characteristics, morphology of the carotid artery and aortic arch, and procedural data were retrospectively assessed and compared between the two groups. Twenty-two (15.2%) and 14 (9.7%) patients were assigned to the ipsilateral and contralateral groups, respectively. Advanced age, left-sided stenosis, severe aortic arch calcification (AAC) on chest X-ray and contralateral carotid occlusion significantly increased the occurrence of contralateral MIs. On multivariable logistic regression analysis, severe AAC was statistically more frequent in the contralateral group. In the present study, the incidences of contralateral MIs after CAS is relatively not low. Advanced aortic atherosclerosis is statistically predictive for contralateral MIs. AAC on chest X-ray is a useful finding for estimating aortic atherosclerosis in candidates for CAS.

Protected versus Unprotected Carotid Artery Stenting : Meta-Analysis of the Current Literature

Objective

To compare peri-operative any symptomatic stroke after carotid angioplasty and stenting (CAS), based on the application or absence of a cerebral protection device.

Methods

A systematic literature review using PubMed, Embase, and the Cochrane Central was done across an online data base from January 1995 to October 2016. Procedures which were performed due to carotid dissection or aneurysm, procedures using covered stents or conducted in an emergency, were excluded. The primary endpoint was perioperative any symptomatic stroke within 30 days after the procedure. A fixed effect model was used in cases of heterogeneity less than 50%.

Results

In the 25 articles included in this study, the number of stroke events was 326 (2.0%) in protected CAS and 142 (3.4%) in unprotected CAS. The use of cerebral protection device significantly decreased stroke after CAS (odds ratio [OR] 0.633, 95% confidence interval [CI] 0.479–0.837, p=0.001). In the publication bias analysis, Egger’s regression test disclosed that the intercept was -0.317 (95% CI -1.015–0.382, p=0.358). Regarding symptomatic patients (four studies, 539 CAS procedures), the number of stroke was six (1.7%) in protected CAS and 11 (5.7%) in unprotected CAS. The protective effect against stroke events by cerebral protection device did not have a statistical significance (OR 0.455, 95% CI 0.151–1.366, p=0.160).

Conclusion

The use of protection device significantly decreased stroke after CAS. However, its efficacy was not demonstrated in symptomatic patients. Routine use of protection device during CAS should be critically assessed before mandatory use.

Low carotid stump pressure as a predictor for ischemic symptoms and as a marker for compromised cerebral reserve in octogenarians undergoing carotid endarterectomy

BACKGROUND

Carotid artery occlusive disease can cause stroke by embolization, thrombosis, and hypoperfusion. The majority of strokes secondary to cervical carotid atherosclerosis are believed to be of embolic etiology. However, cerebral hypoperfusion could be an important factor in perioperative stroke. We retrospectively reviewed the stump pressure (SP) of carotid endarterectomy (CEA) of patients at Pennsylvania Hospital to identify whether physiologic perfusion differences account for differences in perioperative stroke rates, particularly in octogenarians.

METHODS

We conducted a retrospective review of our prospectively maintained database for CEA performed between 1992 and 2015. SP was measured and recorded for 1190 patients. A low SP was defined as systolic pressure <50 mm Hg. Shunts were used only for patients under general anesthesia with SP <50 mm Hg, for awake patients with neurologic changes with carotid clamping, and in some patients with recent stroke.

RESULTS

Symptomatic patients were more likely to have SP <50 mm Hg compared with asymptomatic patients (35.6% vs 26.2%; P = .0015). Patients having SP <50 mm Hg had a higher postoperative stroke rate compared with patients with SP >50 mm Hg (2.9% vs 0.9%; P = .0174). Octogenarians were more likely to have a lower SP compared with patients younger than 80 years (35.7% vs 27.7%; P = .0328). Symptomatic patients with low SP were at highest risk for perioperative stroke (6.4% vs 1.2%; P = .001) compared with patients without these factors.

CONCLUSIONS

SP is a marker for decreased cerebrovascular reserve and along with symptomatic status identifies those at highest risk for periprocedural stroke with CEA. Whereas patients older than 80 years may benefit from carotid intervention, they are likely to be at somewhat elevated stroke risk because of higher prevalence of low SP, and shunting does not eliminate this risk.

The Role of White Matter Damage in the Risk of Periprocedural Diffusion-Weighted Lesions after Carotid Artery Stenting

Background

White matter hyperintensities (WMH) are a common finding in aged individuals affected by carotid artery disease and are a risk factor for first-ever and recurrent stroke. We investigated if white matter damage increases the risk of brain microembolism during carotid artery stenting (CAS), as evaluated by the appearance of new areas of restricted diffusion on diffusion-weighted images (DWI).

Methods

We evaluated 47 patients with severe internal carotid artery (ICA) stenosis undergoing CAS, comparing preprocedural clinical, ultrasound and radiological characteristics. WMH volume was computed on FLAIR images before CAS. After CAS, the DWI scan was looked over for areas of restricted diffusion (DWI lesions). A first univariate analysis was adopted to compare groups according to the occurrence of DWI lesions. Then, the variable DWI lesion was modelled by means of a logistic regression model.

Results

Seventeen patients developed at least 1 DWI lesion after CAS. Compared with non-DWI, DWI patients were more commonly treated in the left ICA (p = 0.007) and had a more severe WMH damage (p = 0.027). Indeed, the risk of a DWI lesion was higher in left versus right stenosis (OR = 9.0, 95% CI 1.9-42.7, p = 0.005) and increased for each log-unit of WMH lesion load (OR = 7.05, 95% CI 1.07-46.49, p = 0.042). A WMH lesion load of at least 5.25 cm³ had a 50% probability of occurrence of a new DWI lesion.

Conclusions

Treated side and preexisting white matter damage are risk conditions for brain microembolism during CAS. This should be taken into account to optimize severe carotid artery disease management.

Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): a randomised controlled trial with cost-effectiveness analysis

BACKGROUND

Carotid artery stenting (CAS) is an alternative to carotid endarterectomy (CEA) for the treatment of carotid stenosis, but safety and long-term efficacy were uncertain.

OBJECTIVE

To compare the risks, benefits and cost-effectiveness of CAS versus CEA for symptomatic carotid stenosis.

DESIGN

International, multicentre, randomised controlled, open, prospective clinical trial.

SETTING

Hospitals at 50 centres worldwide.

PARTICIPANTS

Patients older than 40 years of age with symptomatic atheromatous carotid artery stenosis.

INTERVENTIONS

Patients were randomly allocated stenting or endarterectomy using a computerised service and followed for up to 10 years.

MAIN OUTCOME MEASURES

The primary outcome measure was the long-term rate of fatal or disabling stroke, analysed by intention to treat (ITT). Disability was assessed using the modified Rankin Scale (mRS). A cost-utility analysis estimating mean costs and quality-adjusted life-years (QALYs) was calculated over a 5-year time horizon.

RESULTS

A total of 1713 patients were randomised but three withdrew consent immediately, leaving 1710 for ITT analysis (853 were assigned to stenting and 857 were assigned to endarterectomy). The incidence of stroke, death or procedural myocardial infarction (MI) within 120 days of treatment was 8.5% in the CAS group versus 5.2% in the CEA group (72 vs. 44 events) [hazard ratio (HR) 1.69, 95% confidence interval (CI) 1.16 to 2.45; p = 0.006]. In the analysis restricted to patients who completed stenting, age independently predicted the risk of stroke, death or MI within 30 days of CAS (relative risk increase 1.17% per 5 years of age, 95% CI 1.01% to 1.37%). Use of an open-cell stent conferred higher risk than a closed-cell stent (relative risk 1.92, 95% CI 1.11 to 3.33), but use of a cerebral protection device did not modify the risk. CAS was associated with a higher risk of stroke in patients with an age-related white-matter changes score of 7 or more (HR 2.98, 95% CI 1.29 to 6.93; p = 0.011). After completion of follow-up with a median of 4.2 years, the number of patients with fatal or disabling stroke in the CAS and CEA groups (52 vs. 49), and the cumulative 5-year risk did not differ significantly (6.4% vs. 6.5%) (HR 1.06, 95% CI 0.72 to 1.57; p = 0.776). Stroke of any severity was more frequent in the CAS group (15.2% vs. 9.4% in the CEA group) (HR 1.712, 95% CI 1.280 to 2.300; p < 0.001). There was no significant difference in long-term rates of severe carotid restenosis or occlusion (10.8% in the CAS group vs. 8.6% in the CEA group) (HR 1.25, 95% CI 0.89 to 1.75; p = 0.20). There was no difference in the distribution of mRS scores at 1-year, 5-year or final follow-up. There were no differences in costs or QALYs between the treatments.

LIMITATIONS

Patients and investigators were not blinded to treatment allocation. Interventionists' experience of stenting was less than that of surgeons with endarterectomy. Data on costs of managing strokes were not collected.

CONCLUSIONS

The functional outcome after stenting is similar to endarterectomy, but stenting is associated with a small increase in the risk of non-disabling stroke. The choice between stenting and endarterectomy should take into account the procedural risks related to individual patient characteristics. Future studies should include measurement of cognitive function, assessment of carotid plaque morphology and identification of clinical characteristics that determine benefit from revascularisation.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN25337470.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 20. See the NIHR Journal Library website for further project information. Further funding was provided by the Medical Research Council, Stroke Association, Sanofi-Synthélabo and the European Union.

Cognitive Function After Carotid Artery Revascularization

Clinical investigations designed to contrast the efficacy of carotid endarterectomy (CEA) versus best medical therapy and CEA versus carotid artery stenting (CAS) in patients with carotid artery stenosis have been based on the traditional endpoints of stroke, myocardial infarction, and death. Cognitive function is being increasingly recognized as an important outcome measure that affects patient well-being and functional status. However, it has not been evaluated systematically in the context of carotid revascularization. A decline in cognitive function could occur from microembolic ischemia during surgical dissection (CEA) or intravascular instrumentation (CAS). It could also occur from hypoperfusion during clamping (CEA) or balloon dilation (CAS). Conversely, restoring perfusion could improve cognitive dysfunction that might have occurred from a state of chronic hypoperfusion. It is still unclear whether these complex interactions ultimately result in a net improvement or a deterioration of cognitive function. Furthermore, it is not known whether the 2 methods of carotid revascularization have a differential effect on cognitive outcomes. It is becoming increasingly clear, though, that there is a positive relationship between improvement in cognition and improvement in functional outcome of patients. Vascular surgeons will be well served to remain informed and even actively engaged in the development of this field if they wish to continue providing the high-quality, well-informed care they have traditionally offered to patients with carotid stenosis.

A Prospective, Multicenter Study of a Novel Mesh-Covered Carotid Stent: The CGuard CARENET Trial (Carotid Embolic Protection Using MicroNet)

OBJECTIVES

This study sought to evaluate the feasibility of the CGuard Carotid Embolic Protective Stent system-a novel thin strut nitinol stent combined with a polyethylene terephthalate mesh covering designed to prevent embolic events from the target lesion in the treatment of carotid artery lesions in consecutive patients suitable for carotid artery stenting.

BACKGROUND

The risk of cerebral embolization persists throughout the carotid artery stenting procedure and remains during the stent healing period.

METHODS

A total of 30 consecutive patients (age 71.6 ± 7.6 years, 63% male) meeting the conventional carotid artery stenting inclusion criteria were enrolled in 4 centers in Germany and Poland.

RESULTS

The primary combined endpoint was the procedure success of the CGuard system and the number and volume of new lesions on the ipsilateral side assessed by diffusion-weighted magnetic resonance imaging at 48 h post-procedure and at 30 days. The secondary endpoint was 30-day major adverse cardiac or cerebrovascular events (death, stroke, or myocardial infarction). Protection devices were used in all procedures. Procedure success was 100%, with 0% procedural complications. The 30-day major adverse cardiac or cerebrovascular events rate was 0%. New ipsilateral ischemic lesions at 48 h occurred in 37.0% of patients and the average lesion volume was 0.039 ± 0.08 cm(3). The 30-day diffusion-weighted magnetic resonance imaging showed complete resolution of all but 1 periprocedural lesion and only 1 new minor (0.116 cm(3)) lesion in relation to the 48-h scan.

CONCLUSIONS

The use of the CGuard system in patients undergoing carotid artery stenting is feasible. In addition, the benefit of using CGuard may extend throughout the stent healing period.

Transcervical Carotid Stenting With Dynamic Flow Reversal Demonstrates Embolization Rates Comparable to Carotid Endarterectomy

PURPOSE

To evaluate a series of patients treated electively with carotid endarterectomy (CEA), transfemoral carotid artery stenting with distal filter protection (CASdp), and transcervical carotid stenting with dynamic flow reversal (CASfr) monitored continuously with transcranial Doppler (TCD) during the procedure to detect intraoperative embolization rates.

METHODS

Thirty-four patients (mean age 67.6 years; 24 men) with significant carotid stenosis underwent successful TCD monitoring during the revascularization procedure (10 CEA, 8 CASdp, and 16 CASfr). Ipsilateral microembolic signals were segregated into 3 phases: preprotection (until internal carotid artery cross-shunted or clamped if no shunt was used, filter deployed, or flow reversal established), protection (until clamp/shunt was removed, filter retrieved, or antegrade flow reestablished), and postprotection (after clamp/shunt or filter removal or restoration of normal flow).

RESULTS

CASdp showed higher embolization rates than CEA or CASfr in the preprotection phase (p<0.001). In the protection phase, CASdp was again associated with more embolization compared with CEA and CASfr (p<0.001). In the postprotection phase, no differences between the revascularization therapies were observed. CASfr and CEA did not show significant differences in intraoperative embolization during any of the phases.

CONCLUSION

TCD recordings demonstrated a significant reduction in embolization to the brain during transcervical carotid artery stent placement with the use of dynamic flow reversal compared to transfemoral CAS using distal filters. No significant differences in microembolization could be detected between CEA and CASfr. The observed lower embolization rates and lack of adverse events suggest that transcervical CAS with dynamic flow reversal is a promising technique and may be the preferred method when performing CAS.

Carotid Anatomy Does Not Predict the Risk of New Ischaemic Brain Lesions on Diffusion-Weighted Imaging after Carotid Artery Stenting in the ICSS-MRI Substudy

INTRODUCTION

The International Carotid Stenting Study (ICSS, ISRCTN25337470) randomized patients with recently symptomatic carotid artery stenosis > 50% to carotid artery stenting (CAS) or endarterectomy. CAS increased the risk of new brain lesions visible on diffusion-weighted magnetic resonance imaging (DWI-MRI) more than endarterectomy in the ICSS-MRI Substudy. The predictors of new post-stenting DWI lesions were assessed in these patients.

METHODS

ICSS-MRI Substudy patients allocated to CAS were studied. Baseline or pre-stenting catheter angiograms were rated to determine carotid anatomy. Baseline patient demographics and the influence of plaque length, plaque morphology, internal carotid angulation, and external or common carotid atheroma were examined in negative binomial regression models.

RESULTS

A total of 115 patients (70% male, average age 70.4) were included; 50.4% had at least one new DWI-MRI-positive lesion following CAS. Independent risk factors increasing the number of new lesions were a left-sided stenosis (incidence risk ratio [IRR] 1.59, 95% CI 1.04-2.44, p = .03), age (IRR 2.10 per 10-year increase in age, 95% CI 1.61-2.74, p < .01), male sex (IRR 2.83, 95% CI 1.72-4.67, p < .01), hypertension (IRR 2.04, 95% CI 1.25-3.33, p < .01) and absence of cardiac failure (IRR 6.58, 95% CI 1.23-35.07, p = .03). None of the carotid anatomical features significantly influenced the number of post-procedure lesions.

CONCLUSION

Carotid anatomy seen on pre-stenting catheter angiography did not predict of the number of ischaemic brain lesions following CAS.

Dilation of the Internal Carotid Artery at the Entrance to the Carotid Canal following Carotid Artery Stenting Predicts Postprocedural Hyperperfusion

OBJECTIVE

Ischemic stroke and hyperperfusion (HP) are the most frequent and important complications in carotid artery stenosis surgery. Carotid artery stenting (CAS) has replaced carotid endarterectomy in high medical risk patients. Prior to CAS, initial angiographic findings disclose a small caliber internal carotid artery (IC) due to stenosis, but after the stenosis is relieved, the diameter of the IC becomes enlarged. We investigated whether a change in the IC diameter was related to ischemic complication and HP using cerebral blood flow single photon emission computed tomography (SPECT).

METHODS

From February 2008 to December 2009 we consecutively performed 39 CAS on 35 patients. We retrospectively analyzed the relationship between changes at the level before the entry to the petrous bone canal of the IC and stenosis of the etiological artery, improvement in stenosis, HP and postintervention diffusion-weighted image high-intensity lesions. Statistical analyses comprised Wilcoxon/Kruskal-Wallis analysis, analysis of variance and a multivariate logistic analysis.

RESULTS

A total of 9 cases showed HP in SPECT. Severity of IC stenosis and change in the IC at the level before the entry to the petrous bone canal were related with statistical significance to HP. Other factors did not correlate with HP.

CONCLUSION

Procedure-related dilation of the IC at the level before the entry to the petrous bone canal occurred due to release of the etiological stenosis. This finding can also support the prediction of HP.

Carotid artery stenting - current status of the procedure

Surgical carotid endarterectomy (CEA) was long considered the standard approach for the treatment of atherosclerotic carotid artery disease. This was based on results of several randomized trials demonstrating its effectiveness over the best medical therapy. In the past two decades, patients identified high-risk for surgery were offered carotid artery stenting (CAS) as a less invasive option. Despite its initial limitations, CAS has evolved into an elaborate method currently considered to be equivalent and in selected patients even preferable to CEA. However, outcomes of both procedures are highly operator dependent and a simple stratifying method to prioritize CAS, CEA or medical therapy only has not yet been proposed. In addition, recently published randomized trials highlighted the importance of proper patient selection and rigorous training contributing to low absolute rates of (procedural) adverse events. This review discusses the history and evidence for carotid revascularization and briefly presents technical aspects and innovations in CAS.

Combination of flow reversal and distal filter for cerebral protection during carotid artery stenting

BACKGROUND

Carotid artery stenting (CAS) with distal filter protection allows continuous cerebral perfusion, although it is associated with a greater risk of cerebral ischemic complications than other protection systems. To reduce cerebral ischemic complications, CAS was performed under combined cerebral protection using both flow reversal (FR) and a distal filter.

METHODS

Fifty-six stenoses of 52 patients were treated with CAS using the combined protection of FR and a distal filter, with intermittent occlusion of both the common carotid artery (CCA) and the external carotid artery. The blood flow was reversed into the guiding catheter to the central venous system via an external filter, which collected the debris. Clinical outcomes, the rates of capturing visible debris, and new ischemic signals on diffusion-weighted magnetic resonance imaging (DWI-MRI) were evaluated.

RESULTS

The overall technical success rate was 92.9% (52/56). Successful stent deployment was achieved in 100% (56/56) of the cases. No procedural-related emboli causing a neurologic deficit were observed. In 38.5% (20/52) of the cases, visible debris were captured by only the external filter, and in 17.3% (9/52), visible debris were captured by both external and distal filters. In no case was visible debris noted in only the distal filter. New ischemic signals on DWI-MRI were detected in 9.6% (5/52). The 30-day myocardial infarction, stroke, and death rates were 0%.

CONCLUSIONS

The additional use of a distal filter captures emboli in 17.3% of cases, and because the occlusion is only intermittent, the procedure is potentially applicable even in those who cannot tolerate prolonged balloon occlusion of the CCA.

A tailored approach to overcoming challenges of a bovine aortic arch during left internal carotid artery stenting

PURPOSE

To investigate the efficacy and safety of a tailored approach to fit access and engagement techniques to the individual arch anatomy in patients with bovine-type aortic arch (BTAA) to overcome the perceived increased risk of technical failure and cerebral embolization during left internal carotid artery (LICA) stenting.

METHODS

Thirty-five high surgical risk patients (23 men; mean age 68.6 years, range 62-90) with BTAA and LICA stenosis underwent carotid artery stenting (CAS). Left common carotid artery (LCCA) engagement was achieved by means of different techniques according to the configuration of the BTAA, arch type (I, II, or III), and angle between the innominate artery and the LCCA. The clinical, anatomical, and procedural data were retrieved from a prospectively maintained database and analyzed retrospectively to identify technical modifications required during the procedure compared with planning.

RESULTS

The technical success rate was 100%. Transfemoral access was used in 21 (60%) cases. In this group, the soft engagement technique with hockey stick (HS) guiding catheter and buddy wire in the external carotid artery (ECA) was used in 13 (62%) cases, a simple telescopic technique with 6-F armed introducer or 7-F 40° guiding catheter in 5 (24%) cases, and a sequential technique with a MOMA proximal protection system in the remaining 3 (14%) cases. Among the 14 (40%) right brachial access cases, the telescopic technique with 6-F armed introducer was used in 13 cases. The remaining case was the only one in which the planned technique was changed (from the telescopic to sequential technique with ECA wire exchange). There were no intraprocedural or 30-day neurological events.

CONCLUSION

An appropriate tailored interventional strategy, planned by means of preprocedural recognition of bovine arch anatomy, is associated with satisfactory safety and good success.

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.

What is the real risk of dislodging thrombi during endovascular revascularization of a proximal internal carotid artery occlusion?

BACKGROUND

There is a theoretical concern that a thrombus may be dislodged distally when crossing the occluded segment during recanalization of a complete occlusion.

OBJECTIVE

To assess the immediate postprocedural brain diffusion-weighted image (DWI) findings following endovascular recanalization using an embolic protection device for proximal internal carotid artery (ICA) occlusion.

MATERIALS AND METHODS

We retrospectively identified 12 patients who underwent stent implantation for sudden symptomatic occlusion of the proximal ICA. In 8 patients, no additional intracranial occlusions were identified. In 4 patients, an additional intracerebral thrombus was detected in the middle cerebral artery. Distal protection devices were used in all cases. We evaluated the presence and amount of retrieved embolic fragments in the distal protection devices. The incidence and location of postprocedural emboli were determined using DWI.

RESULTS

Recanalization of the proximal ICA was achieved in all patients. After complete occlusion of the proximal ICA was demonstrated, primary passage of the embolic protection device through the occluded ICA was gently navigated in 7 patients. However, this was not possible in 5 patients. Three patients developed new lesions on postprocedural DWI. Of the 12 patients in which distal protection devices were used, debris was detected in 7 patients.

CONCLUSION

In endovascular revascularization of proximal ICA occlusion, postprocedural emboli occur less frequently than reported in a systematic review of the DWI literature. The real risk of dislodging thrombi appears to be from plaque fragment mobilization by angioplasty, rather than from crossing an occluded segment.

Cognitive changes after surgery vs stenting for carotid artery stenosis

OBJECTIVES

Cognitive function has not been evaluated systematically in the context of carotid endarterectomy (CEA) versus carotid artery stenting (CAS). Cognitive decline can occur from microembolization or hypoperfusion during CEA or CAS. Carotid revascularization may, however, also improve cognitive dysfunction resulting from chronic hypoperfusion. We compared cognitive outcomes in consecutive asymptomatic patients undergoing CAS or CEA.

METHODS

This is a prospective nonrandomized single-center study of patients with asymptomatic carotid stenosis ≥ 70% undergoing CAS or CEA using standard techniques. Neurologic symptoms were evaluated by history, physical examination, and the National Institutes of Health Stroke Scale. A 50-minute cognitive battery was performed 1 to 3 days before and 4 to 6 months after CEA/CAS. The tests (Trail Making Tests A/B, Processing Speed Index (PSI) of the Wechsler Adult Intelligence Scale - Third Edition (WAIS-III), Boston Naming Test, Working Memory Index (WMI) of the Wechsler Memory Scale - Third Edition (WMS-III), Controlled Oral Word Association, and Hopkins Verbal Learning Test) for six cognitive domains (motor speed/coordination and executive function, psychomotor speed, language (naming), working memory/concentration, verbal fluency, and learning/memory) were conducted by a neuropsychologist. The primary analysis of impact of treatment modality was a normalized cognitive change score.

RESULTS

Forty-six patients underwent prepost testing (CEA = 25, CAS = 21). Women comprised 36% of the cohort, mean preprocedural stenosis was 84%, and 54% were right-sided lesions. All patients were successfully revascularized without periprocedural complications. The scores for each test improved after CEA except WMI, which decreased in 20 of 25 patients. Improvement occurred in all tests after CAS except PSI, which decreased in 18 of 21 patients. In addition to comparing the changes in individual test scores, overall cognitive change was measured by calculating the change in composite cognitive score (CCS) postprocedure versus baseline. To compute the CCS, the raw scores from each test were transformed into z scores and then averaged to calculate each patient's composite score. The composite score at baseline was then compared with that from the postprocedure testing. The CCS improved after both CEA and CAS, and the changes were not significantly different between the groups (.51 vs .47; P = NS).

CONCLUSIONS

Carotid revascularization results in an overall improvement in cognitive function. There are no differences in the composite scores of five major cognitive domains between CEA and CAS. When individual tests are compared, CEA results in a reduction in memory, while CAS patients show reduced psychomotor speed. Larger studies will help confirm these findings.

Are distal protection devices 'protective' during carotid angioplasty and stenting?

BACKGROUND AND PURPOSE

To evaluate the periprocedural outcome after carotid artery stenting with embolic brain protection (EBP+) versus without embolic brain protection (EBP-).

METHODS

We retrospectively reviewed data from a prospective nonrandomized database of 357 patients who underwent carotid artery stenting in the neuroradiology division of our institution from 1999 to 2009. One hundred five patients underwent angioplasty and stenting without distal protection, whereas 252 were treated with distal protection. Patients were analyzed according to their EBP status (+ or -) for the primary end points of perioperative stroke, death, or myocardial infarction.

RESULTS

Unprotected stenting was mostly performed in the early years of this study and this is reflected in significant baseline differences between the two groups. In our earlier experience, carotid artery stenting was used in patients with more significant comorbidities. Diabetes mellitus (P=0.04), previous coronary artery disease (P=0.02) and myocardial infarction (P=0.04), and symptomatic lesion (P=0.01) were significantly more common in the EBP- cohort. Despite these baseline differences, there were no significant differences in the primary end points (2% in the EBP+ group and 4.8% in the EBP-, P=0.15). The incidence of ipsilateral stroke in the EBP- and in the EBP+ group was 3.8% versus 0.8%, respectively (P=0.6). There were 2 perioperative deaths (1 in each group) and 4 myocardial infarctions (3 in the EBP+ arm and 1 in the EBP- arm, all non-Q infarcts; P=nonsignificant).

CONCLUSIONS

In accordance with recent literature, this series cast doubts as to the real effectiveness of distal embolic protection devices in reducing periprocedural complications.

Significance of blood aspiration in carotid artery stenting with Angioguard XP

BACKGROUND AND PURPOSE

In some patients, angiographic flow impairment is observed during carotid artery stenting (CAS) using Angioguard XP (AGXP), resulting in neurological symptoms. CAS was thus modified to improve clinical outcome.

METHODS

Ninety-seven patients were treated with CAS using AGXP from January 2008 to October 2009. In period I (January-December 2008; n = 53), blood aspirations were performed only in no-flow cases. In period II (January-October 2009; n = 44), blood aspirations were performed in no-flow and slow-flow cases. Clinical outcome, detection of microembolic lesions on diffusion-weighted imaging (DWI) and flow impairment during CAS were examined between these two periods before and after modifying the CAS procedure.

RESULTS

Periprocedural transient ischemic attacks occurred in 10 patients (18.9%) and one patient (2.27%) in periods I and II, respectively (P = .018). Minor and major strokes were observed in two patients in each period (P = .849). New ipsilateral DWI lesions were detected in 25 patients (47.2%) and 11 patients (25.0%) in periods I and II, respectively (P = .024). Among 18 slow-flow cases, new DWI lesions were detected in one patient (9.09%) and five patients (71.4%) with (n = 11) and without (n = 7) blood aspirations, respectively (P = .013). Neurological symptoms were observed only in three of seven patients (42.9%) without aspirations, compared to one of 11 patients (9.1%) with aspirations (P = .043).

CONCLUSION

Postoperative symptomatic stroke and new DWI lesions are significantly associated with blood flow impairment during CAS using AGXP. When flow impairment occurs, blood aspiration should be performed.

Radiofrequency Catheter Ablation of Atrial Fibrillation: A Cause of Silent Thromboembolism?

Background—

Radiofrequency left atrial catheter ablation has become a routine procedure for treatment of atrial fibrillation. The aim of this study was to assess with preprocedural and postprocedural cerebral magnetic resonance imaging the thromboembolic risk, either silent or clinically manifest, in the context of atrial fibrillation ablation. The secondary end point was the identification of clinical or procedural parameters that correlate with cerebral embolism.

Methods and Results—

A total of 232 consecutive patients with paroxysmal or persistent atrial fibrillation who were candidates for radiofrequency left atrial catheter ablation were included in the study. Pulmonary vein isolation or pulmonary vein isolation plus linear lesions plus atrial defragmentation with the use of irrigated-tip ablation catheters was performed. All of the patients underwent preprocedural and postablation cerebral magnetic resonance imaging. A periprocedural symptomatic cerebrovascular accident occurred in 1 patient (0.4). Postprocedural cerebral magnetic resonance imaging was positive for new embolic lesions in 33 patients (14). No clinical parameters such as age, hypertension, diabetes mellitus, previous history of stroke, type of atrial fibrillation, and preablation antithrombotic treatment showed significant correlation with ischemic cerebral embolism. Procedural parameters such as activated clotting time value and, in particular, electric or pharmacological cardioversion to sinus rhythm correlated with an increased incidence of cerebral embolism. Cardioversion was also associated with an increased risk of 2.75 (95 confidence interval, 1.29 to 5.89; P =0.009).

Conclusions—

Radiofrequency left atrial catheter ablation carries a low risk of symptomatic cerebral ischemia but is associated with a substantial risk of silent cerebral ischemia detected on magnetic resonance imaging. Independent risk factors for cerebral thromboembolism are the level of activated clotting time and, in particular, the electric or pharmacological cardioversion to sinus rhythm during the procedure.

Classification for carotid artery stenting complications: manifestation, management, and prevention

Carotid artery stenting is a rapidly evolving method for treating carotid artery disease. Various intraprocedural and postprocedural complications have been reported in the literature. However, the absence of a unified classification scheme for these complications makes it difficult, if not impossible, to study their precise incidence, predictors, and management. The aim of this article is to propose the first joint classification of periprocedural complications, to analyze their incidence and etiology, and suggest possible ways to manage and prevent them. This classification is intended to be used as a common platform for prompt recognition, evaluation, treatment, and universal study of the complications during carotid stenting procedures. For this purpose, the opinions of the major experts on carotid interventions worldwide were merged with all the available information reported in the English-language literature to present as accurately as possible the management and prevention of carotid stenting complications according to this proposed classification.

Treatment of carotid artery disease: endarterectomy or angioplasty?

The management of carotid stenosis has enjoyed renewed interest in the neurological community in recent years due to the advent of endovascular approaches. In concert, progress in medical treatment of these patients has rekindled the debate regarding the best management of carotid stenosis overall, both for symptomatic and asymptomatic disease. For symptomatic carotid stenosis, the major decision required is choosing the type of intervention best suited for individual patients: carotid endarterectomy versus carotid artery stenting. For patients with asymptomatic carotid stenosis, intensive medical management has evolved significantly over the past decade to decrease the risk of ischemic stroke to match surgical intervention under most circumstances. This review will examine the supporting evidence for each intervention, and discuss the recent advances in medical and endovascular therapy that provide the data for a new era in clinical decision making.

The influence of carotid artery catheterization technique on the incidence of thromboembolism during carotid artery stenting

BACKGROUND AND PURPOSE

Thromboembolic events related to CAS continue to be the main limitation to the widespread use of this technique as a first-line treatment for carotid occlusive disease. Our aim was to evaluate thromboembolism during CAS using DWI for catheterization techniques of the carotid artery.

MATERIALS AND METHODS

Thirty-two consecutive patients with symptomatic carotid stenosis underwent CAS involving 1 of 2 carotid artery catheterization techniques: One used a 7F or 8F catheter (group 1, n = 16) and the other used a coaxial system in which a 7F or 8F catheter was used in conjunction with a 4F or 5F catheter (group 2, n = 16). DWI was performed before and after CAS. Clinical variables, the number and location of NES on DWI after CAS, were compared between the 2 groups.

RESULTS

NES on DWI occurred in 53% of all patients. The incidence of NES was significantly higher in patients 65 years of age and older versus those younger than 65 years of age (P = .013). All NESs were asymptomatic, and their rate of occurrence did not differ significantly between groups 1 and 2. The incidence of NES in the other territories that were outside that of the treated carotid artery (P = .004) and the incidence of multiple NESs (P = .04) were significantly higher in group 1.

CONCLUSIONS

NES in the other territories mainly arises from the atherosclerotic aortic arch and arch vessels during the manipulation of endoluminal devices. The carotid artery catheterization technique using the coaxial system with a 7F or 8F catheter in conjunction with a 4F or 5F catheter reduced the incidence of NES in the other territories.

Evaluation of small ischemic lesions after carotid artery stenting: the usefulness of thin-slice diffusion-weighted MR imaging

INTRODUCTION

There has been concern regarding the usefulness of diffusion-weighted imaging (DWI) to evaluate the ischemic lesions associated with carotid artery stent placement (CAS). Some small lesions may be detected not by standard DWI but by thin-slice DWI alone, since most of the cerebral lesions are very small in size and clinically silent. The purpose of this study is to compare the detectability of the small ischemic lesions after CAS by standard and thin-slice DWI.

METHODS

Both standard DWI with slice thickness of 6 mm and thin-slice DWI with slice thickness of 2 mm were obtained at the same MR examination within 2 to 7 days after 20 procedures of CAS in 17 patients. Number and measured diameter size of the detected lesions on both DWI were compared.

RESULTS

All CAS procedures in 17 patients were successfully completed. The focal ischemic lesions were detected in 14 of 20 on thin-slice DWI and seven examinations on standard DWI. The total numbers of hyperintense lesions were 31 on thin-slice DWI and ten on standard DWI (p < 0.001). The sizes of these ten lesions on thin-slice DWI were larger than those of standard DWI, and the mean size of the thin-slice DWI and that of standard DWI were significantly different (p < 0.005).

CONCLUSION

Thin-slice DWI was able to detect small cortical lesions better than standard DWI. Thin-slice DWI may be useful to evaluate small silent ischemic lesions after CAS.

Inraoperative and Histological Visualization of Disrupted Vulnerable Plaques following Diagnostic Angiography of Moderate Carotid Stenosis

Background. Digital subtraction angiography (DSA) remains an important tool for diagnosis of carotid stenosis but is associated with risk for periprocedural complications. This is the first report of direct intraoperative and histolopathologic visualization of DSA-related carotid plaque disruption. Case. A 64-year-old man diagnosed to have a 60% right carotid stenosis received diagnostic DSA for therapeutic decision-making. He developed transient left hand numbness and weakness immediately after the procedure. Intraoperative imaging during carotid endarterectomy revealed a fragile plaque with sharp surface laceration and intraplaque hemorrhage at the bifurcation. Microscopy of the specimen demonstrated a large atheromatous plaque with fibrous hypertrophy and intraplaque hemorrhage filled with recent hemorrhagic debris. Conclusion. The visualized carotid lesion was more serious than expected, warning the danger of embolization or occlusion associated with the catheter maneuvers. Thus the highest level of practitioner training and technical expertise that ensures precise assessment of plaque characteristics should be encouraged.

Cerebral ischemic lesions detected with diffusion-weighted magnetic resonance imaging after carotid artery stenting: Comparison of several anti-embolic protection devices

Distal embolism is an important periprocedural technical complication with carotid angioplasty and carotid artery stenting (CAS). We evaluated the safety and efficacy of protection devices used during CAS by detecting new cerebral ischemic lesions using diffusion-weighted magnetic resonance imaging in 95 patients who underwent 98 CAS procedures: 34 using single PercuSurge GuardWire, 31 using double balloon protection, 15 using proximal flow reverse protection devices, 14 using Naviballoon, and 4 using filter anti-embolic devices. Diffusion-weighted imaging was performed preoperatively and postoperatively to evaluate the presence of any new embolic cerebral lesions. Postoperative diffusion-weighted imaging revealed 117 new ischemic lesions. Three patients had new ischemic stroke, two minor and one major, all ipsilateral to the treated carotid artery. The remaining patients had clinically silent ischemia. The incidence of new embolic lesions was lower using the proximal flow reverse protection device than with the double balloon protection (33% vs. 48.4%), but the volume of ipsilateral new ischemic lesions per patient was 136.6 mm(3) vs. 86.9 mm(3), respectively. Neuroprotection with Naviballoon yielded ipsilateral lesions of large volume (86.6 mm(3)) and higher number (5.7 lesions per patient) than using the filter anti-embolic device (34.8 mm(3) and 1 lesion per patient). New cerebral ischemic lesions after neuroprotected CAS are usually silent. The lower incidence of distal ischemia using proximal flow reverse and double balloon protection devices is limited by the larger volume and higher number of ischemic lesions.

Spontaneous cervical artery dissection: an update on clinical and diagnostic aspects

Spontaneous cervical arterial dissection (SCAD) is a non-traumatic tear or disruption in the wall of the internal carotid arteries or the vertebral arteries. It accounts for about 25% of strokes in patients aged under 45 years. Awareness of its clinical features and advances in imaging over the last two decades have contributed to earlier identification of this condition. SCAD has become the commonest form of vascular lesion identified in the cervical carotid and vertebral arteries, second only to atherosclerosis. This review is an update on the epidemiology, vulnerable arterial segments, risk factors, clinical features, diagnosis, current treatment and prognosis of SCAD.

The optimal treatment of carotid atherosclerosis: a 2008 update and literature review

Carotid and cerebrovascular disease have major public health implications given the associated morbidity and mortality. However, the best treatment for this disease is uncertain. Carotid endarterectomy has proven useful in primary and secondary prevention of strokes for patients with significant internal carotid artery stenoses. Many patients are considered at high risk for such surgical procedures and therefore have relatively few treatment options. Carotid stenting is currently being investigated as an alternative therapeutic intervention for these patients. This article reviews the literature pertaining to carotid intervention and its current status in 2008.