Predictors of stroke complicating carotid artery stenting

A Simplified One-Size-Fits-All Approach to Carotid Stenting

BACKGROUND

Carotid artery stenosis causes up to 20% of ischemic strokes. Stenting is used as an alternative to endarterectomy in symptomatic patients. Each commercially available stent offers numerous stent diameters/lengths. Most centers thus carefully match each individual stenosis to a specific stent length/diameter stent size. However, this process can be time-consuming and costly while the relative benefit of a custom stent sizing versus one-size-fits-all approach has not been well evaluated yet. We hypothesized that a 'one-size-fits-all' default approach to carotid stenting results in comparable results to a customized approach.

METHODS

We conducted a descriptive retrospective cohort study on 154 patients who presented to our academic carotid revascularization clinic with symptomatic carotid artery stenosis who underwent carotid artery stenting for peri- and postprocedural carotid artery stenting complications. The primary outcomes were periprocedural (within 24 hours of the procedure) or postprocedural (within 30 days of the procedure) TIA, stroke, or death. The secondary outcome was the estimated degree of stenosis on follow-up ultrasound performed within 6 months of the procedure.

RESULTS

The complication rate within the first 24 hours was 4.5% while that during the first 30 days postprocedure was 6.5%. Age over 80 and degree of stenosis on postprocedural cerebral angiogram were associated with an increased risk of complications. Severe restenosis was reported in 16.8% of patients within 6 months postprocedure.

CONCLUSION

Our study suggests that using a simplified, one-size-fits-all, approach to carotid stenting results in safe and effective outcomes, suggesting an alternative to simplify a complex medical procedure.

Evidence and Mechanisms for Embolic Stroke in Contralateral Hemispheres From Carotid Artery Sources

BACKGROUND

Disambiguation of embolus pathogenesis in embolic strokes is often a clinical challenge. One common source of embolic stroke is the carotid arteries, with emboli originating due to plaque buildup or perioperatively during revascularization procedures. Although it is commonly thought that thromboemboli from carotid sources travel to cerebral arteries ipsilaterally, there are existing reports of contralateral embolic events that complicate embolus source destination relationship for carotid sources. Here, we hypothesize that emboli from carotid sources can travel to contralateral hemispheres and that embolus interactions with collateral hemodynamics in the circle of Willis influence this process.

METHODS AND RESULTS

We use a patient-specific computational embolus-hemodynamics interaction model developed in prior works to conduct an in silico experiment spanning 4 patient vascular models, 6 circle of Willis anastomosis variants, and 3 different thromboembolus sizes released from left and right carotid artery sites. This led to a total of 144 different experiments, estimating trajectories and distribution of approximately 1.728 million embolus samples. Across all cases considered, emboli from left and right carotid sources showed nonzero contralateral transport (P value <-0.05). Contralateral movement revealed a size dependence, with smaller emboli traveling more contralaterally. Detailed analysis of embolus dynamics revealed that collateral flow routes in the circle of Willis played a role in routing emboli, and transhemispheric movement occurred through the anterior and posterior communicating arteries in the circle of Willis.

CONCLUSIONS

We generated quantitative data demonstrating the complex dynamics of finite size thromboembolus particles as they interact with pulsatile arterial hemodynamics and traverse the vascular network of the circle of Willis. This leads to a nonintuitive source-destination relationship for emboli originating from carotid artery sites, and emboli from carotid sources can potentially travel to cerebral arteries on contralateral hemispheres.

Evidence And Mechanisms For Embolic Stroke In Contralateral Hemispheres From Carotid Artery Sources

Disambiguation of embolus etiology in embolic strokes is often a clinical challenge. One common source of embolic stroke is the carotid arteries, with emboli originating due to plaque build up, or perioperatively during revascularization procedures. While it is commonly thought that thromboemboli from carotid sources travel to cerebral arteries ipsilaterally, there are existing reports of contralateral embolic events which complicate embolus source destination relationship for carotid sources. Here, we hypothesize that emboli from carotid sources can travel to contralateral hemispheres, and that embolus interactions with collateral hemodynamics in the Circle of Willis influences this process. We use a patient-specific computational embolus-hemodynamics interaction model developed in prior works to conduct an in silico experiment spanning 4 patient vascular models, 6 Circle of Willis anastomosis variants, and 3 different thromboembolus sizes released from left and right carotid artery sites. This led to a total of 144 different experiments, estimating trajectories and distribution of approximately 1.728 million embolus samples. Across all cases considered, emboli from left and right carotid sources showed non-zero contralateral transport (p value < 0.05). Contralateral movement revealed a size-dependence, with smaller emboli traveling more contralaterally. Detailed analysis of embolus dynamics revealed that collateral flow routes in Circle of Willis played a role in routing emboli, and transhemispheric movement occurred through the anterior and posterior communicating arteries in the Circle of Willis. We generated quantitative data demonstrating the complex dynamics of finite size thromboembolus particles as they interact with pulsatile arterial hemodynamics, and traverse the vascular network of the Circle of Willis. This leads to a non-intuitive source-destination relationship for emboli originating from carotid artery sites, and emboli from carotid sources can potentially travel to cerebral arteries on contralateral hemispheres.

Length and location of post-PIRCS predict percutaneous transluminal angioplasty and stenting-related restenosis in nasopharyngeal cancer

PURPOSE

Post-irradiated carotid stenosis (PIRCS) commonly occurs in patients with nasopharyngeal cancer (NPC) after receiving radiotherapy. A high in-stent restenosis (ISR) is observed in these patients after percutaneous transluminal angioplasty and stenting (PTAS) for PIRCS. Risk factors for ISR in these patients remain unclear.

METHODS

Data were retrospectively analyzed from 68 NPC patients with 70 lesions treated with PTAS for PIRCS. The median follow-up was 40 months (range: 4-120). Evaluations of demographic and clinical characteristics included stenotic severity, stenotic lesion length (SLL), stenotic lesion location, and ISR-related stroke during follow-up. The risk for ISR was evaluated using multiple Cox regression analysis.

RESULTS

The median age of the patients was 61 (35-80) years and 94.1% were male. The median stenosis was 80% (60-99%) and the median SLL was 2.6 cm (0.6-12.0 cm) before PTAS. Compared to those without ISR, patients with longer SLL were at significantly greater risk of developing significant ISR, defined as > 50% after PTAS (hazard ratio [HR] and 95% confidence interval [CI]: 2.06 [1.30-3.28]). PTAS for lesions from the internal carotid artery (ICA) to common carotid artery (CCA) was associated with a significantly greater risk of ISR than lesions located only in the ICA (HR: 9.58 [1.79-51.34]). The baseline cut-off value for SLL that best predicted significant ISR was 1.6 cm (area under the curve 0.700, sensitivity 83.3% and specificity 62.5%).

CONCLUSION

Stenotic lesions located from the ICA to CCA with longer SLL at baseline appear to predict ISR in NPC patients with PIRCS after PTAS. Intensive post-procedural follow-up is advised for this patient population.

Carotid Artery Stenting: Applications and Technical Considerations

PURPOSE OF THE REVIEW

To examine current understanding of diverse etiologies of extracranial carotid disease, including clinical and imaging manifestations as well as treatment approaches.

RECENT FINDINGS

Increasing availability of advanced cerebrovascular imaging modalities continues to elucidate atherosclerotic and nonatherosclerotic carotid steno-occlusive disease as a common culprit of cerebral ischemia. Individualized treatment strategies targeting each etiologic subset would optimize preventive measures and minimize recurrence of cerebral ischemia.

SUMMARY

Ischemic stroke is a prominent cause of mortality and long-term disability worldwide. The magnified effect of carotid disease warrants constant and close inspection.

Endarterectomy versus stenting for the prevention of periprocedural stroke or death in patients with symptomatic or asymptomatic carotid stenosis: a meta-analysis of 10 randomized trials

Background

The incidence of stroke or death in carotid endarterectomy (CEA) versus carotid artery stenting (CAS) cannot be estimated accurately. We aimed to compare periprocedural stroke or death in patients with symptomatic or asymptomatic carotid artery stenosis (CS) treated with CEA versus CAS.

Methods

Ten randomized trials (with ≥100 randomized patients per trial) compared the relative effectiveness of CAS and CEA for the prevention of stroke or death.

Results

In the symptomatic group during the periprocedural period, the results showed that the risk of death or any stroke [risk ratio (RR): 0.627; 95% CI: 0.497-0.792; P<0.001] and the risk of any stroke (RR: 0.654; 95% CI: 0.522-0.820; P<0.001) were significantly greater with CAS than with CEA. The difference in the risk of periprocedural stroke was mostly attributed to nondisabling stroke (RR: 0.407; 95% CI: 0.264-0.627; P<0.001), which was driven especially by ipsilateral ischemic stroke (RR: 0.649; 95% CI: 0.494-0.851; P=0.002) and bradycardia or hypotension (RR: 0.105; 95% CI: 0.051-0.217; P<0.001). However, we found that the CEA group had a higher rate of myocardial infarction than the CAS group (RR: 2.496; P=0.025). Meanwhile, ipsilateral stenosis >70% increased the incidence of periprocedural death or stroke for post-CEA patients (RR: 2.166, 95% CI: 1.112 to 4.220, P=0.023), but no risk factors were identified for post-CAS. Regarding the asymptomatic group, the results demonstrated that patients randomized to CEA had a significantly reduced risk of periprocedural stroke (RR: 0.518; 95% CI: 0.281-0.954; P=0.035), which seems to be driven by periprocedural minor stroke (RR: 0.482; 95% CI: 0.231-0.982; P=0.046).

Conclusions

Among patients with symptomatic CS, CEA was associated with reduced rates of periprocedural stroke and periprocedural nondisabling stroke. Among patients with asymptomatic CS, the rates of minor stroke and stroke in general were higher with stenting than with CEA. Based on the current data, CEA is more beneficial than CAS for 30-day stroke prevention.

Adjunctive treatment with low dose intra-arterial eptifibatide and intravenous aspirin during carotid stenting: A case series

PURPOSE

According to most guidelines, medical protocol for carotid stenting includes the administration of oral Aspirin and Clopidogrel at least four days before the procedure, with intraprocedural intravenous (IV) heparin. Some publications have also reported the safety of adding glycoprotein 2b/3a inhibitors to the protocol. In this retrospective study, we evaluate the safety of a new medication protocol that includes IV aspirin and intra-arterial Eptifibatide (glycoprotein 2b/3a inhibitor) during carotid stenting. All patients who underwent carotid stenting at Soroka University Medical Center between January 2015 and May 2020 were included (emergent cases were excluded). We divided patients into two groups-patients treated under the standard protocol, and patients treated under the new protocol. In the latter, patients received both the standard protocol regimen, as well as 150 mg IV aspirin immediately before stenting, and a slow intra-arterial injection of 2-3 mg Eptifibatide (glycoprotein 2b/3a antagonist) immediately after stenting. Forty-four patients were treated according to the standard protocol (group 1), and 41 patients were treated according to the new protocol (group 2). In group 1, six patients had complications, while in group 2, no complications of any kind were noted (p = 0.027). The safety and possible efficacy of this novel protocol was preliminarily demonstrated in the present study. Future studies are needed to prove the safety and efficacy of a specific drug regimen that will further reduce the complication rates of carotid stenting.

Evaluation of ischemic lesions after carotid artery stenting with diffusion-weighted imaging

BACKGROUND

Almost 90% of cerebral thromboembolism cases are caused by atherosclerosis. Craniocervical atherosclerosis is often observed at the carotid bifurcation and is responsible for 20%-30% of all stroke cases. The course of atherosclerotic carotid artery stenosis varies depending on the grade of stenosis and characteristics of the plaque. Carotid artery stenting (CAS) can be used as a less invasive method in patients with symptomatic and asymptomatic high-grade carotid artery stenosis. Diffusion-weighted imaging (DWI) is an effective method for detection of silent or symptomatic acute ischemic lesions that may arise due to CAS or carotid endarterectomy. The number and volume of new ischemic lesions are determined using DWI.

AIM

To evaluate the number and volume of ischemic lesions and their cerebral parenchymal and vascular distribution after CAS using DWI.

METHODS

Forty-seven male (73.4%) and seventeen female (26.6%) patients (total, n = 64) aged 42-84 years (mean 67.96 ± 8.03 years) diagnosed with carotid stenosis between October 2006 and July 2012 were included in this retrospective study. Twelve of the cases (18.8%) were asymptomatic, while fifty-two (81.2%) were symptomatic. The area where the stenosis was highest was measured, and the stenosis rate was determined using the North American Symptomatic Carotid Endarterectomy Trial method. DWI of the cases was evaluated by two radiologists experienced in neuroradiology (B.A. with more than 15 years of experience, E.G. with more than 10 years of experience). Routine DWI examinations were carried out by a 1.5 T MR device 1 h before and after the operation. Since the ischemic lesions that developed in the first hour and in the follow-up period of 5-24 h were assumed to be due to CAS, all lesions within the first 24 h were considered as new ischemias.

RESULTS

In the present study, 39 new ischemic lesions were detected in 20 cases. The average number of new lesions after all CAS operations was 0.62. They were mostly located in the occipital lobes, followed by the frontal and parietal lobes. These new ischemic lesions were most common in the middle cerebral artery territory, followed by the posterior cerebral artery territory and middle cerebral artery-posterior cerebral artery watershed areas. New lesions were found in 31.2% (20/64) of patients, including 17 (26.5%) in ipsilateral and three (4.6%) in contralateral hemispheres. New bilateral lesions were detected in one case (1.5%). The average volume of the new ischemic lesions detected by the two observers was 1.10 cm³. The numbers of newly appearing ischemic lesions in DWI after CAS were significantly higher in cases where stenting was applied on the left side of the carotid artery and in cases where longer plaques (> 1 cm) were responsible for the narrowing in symptomatic patients. The stenosis rate was low in the group with ulcerated plaques.

CONCLUSION

New ischemic lesions due to CAS appear mostly in the main arterial territory but they may also occur in watershed areas.

Neurologic complications in patients with carotid artery stenting

Objective

Carotid artery stenting is helpful in patients with carotid artery stenosis and is a common method of treatment. However, data on the neurological consequences that might arise from, especially Asian patients after CAS is not enough. The purpose of this study was to investigate the outcome and prognostic factors affecting CAS patients.

Methods

From January 2013 to June 2018 it was enrolled 97 patients who underwent CAS with severe carotid artery stenosis in a single institution. We retrospectively reviewed neurologic complications such as restenosis, ipsilateral or contralateral stroke, and hyperperfusion during the 6-month follow-up period.

Results

There were no complication occured during the procedure in all 97 patients. Neurologic complications occurred in 30 patients (30.9%) after the procedure, and ipsilateral stroke 6 (6.2%), contralateral stroke 9 (9.4%), restenosis 2 (2.1%) and hyperperfusion 13 respectively. One of them had died (1.0%), of which the rest were discharged after symptoms improve. On univariate analysis, DM and pre-op NIHSS score was associated with the risk of CAS complication, exclusively. On the binary logistic regression for risk factors, DM (OR 0.144, 95% CI [0.029-0.718]), history of radiotheraphy (OR 36.103, 95% CI [1.009-1291.789]) and preoperative NIHSS (OR 1.266, 95% CI [1.059-1.513]) showed independent risk factors associated with post procedural neurological complications, statistically.

Conclusion

Carotid artery stenting is a relatively safe and reliable long-term outcome for patients with carotid artery stenosis. However, careful observation should be taken after procedure immediately for any possible complications.

Presenting time-based risks of stroke and death for Patients facing carotid stenosis treatment options: Patients prefer pie charts over icon arrays

OBJECTIVE

To user-test graphical display formats (icon arrays, pie, bar, and line charts) to identify preferred formats and metrics ('probability of death or stroke' or 'proportion of time lived without death or stroke') in order to display time-dependent risks of stroke or death for three carotid stenosis treatments: endarterectomy (surgery), stenting, and medical therapy.

METHODS

Iterative cycles of semi-structured interviews with patients recruited from a Vascular Clinic.

RESULTS

A total of 27 patients (mean age = 68; range: 50-85) were interviewed over four cycles. Patients strongly preferred the pie chart over icon arrays, and over bar or line graphs. The preference was based on patient recognition of the time-based increase in risk for stroke or death for treatment options. Patients preferred data presented as probabilities instead of the proportion of time lived. We did not assess patients' understanding.

CONCLUSION

Patients preferred the pie chart formats and reported better realization that risks increase with time for each option and that tradeoffs exist when surgery has a higher short-term risk than medical therapy.

PRACTICE IMPLICATIONS

There remains debate on how best to convey time-dependent risk information to patients, especially where low literacy and numeracy might exist.

A systematic review and meta-analysis of results of simultaneous bilateral carotid artery stenting

BACKGROUND

Although staged procedures to treat bilateral carotid artery stenosis are mainstream, a growing number of articles on simultaneous bilateral carotid artery stenting (SBCAS) have been published. Thus, this meta-analysis was performed to evaluate the efficacy and safety of SBCAS.

METHODS

The PubMed and Embase databases were searched to identify all studies reporting SBCAS from January 1, 2000, to October 1, 2017. Patients' characteristics, comorbidities, technical success, deaths, and complications were collected and analyzed. Forest plots were drawn with either a random-effects model or fixed-effects model according to their heterogeneities. Publication biases were tested by funnel plots and linear regression test.

RESULTS

Overall, 333 patients with bilateral carotid stenosis in 10 retrospective studies were enrolled in this meta-analysis. The mean age was 67.4 years; 75% of the patients were male, and 85.6% of them were symptomatic. The mean severity of stenosis was 82.1%. The overall technical success rate reached 99.38% (95% confidence interval [CI], 96.58%-100.00%). The pooled incidences of periprocedural complications were as follows: hemodynamic depression, 46.12% (95% CI, 33.16%-59.35%); hyperperfusion syndrome, 3.33% (95% CI, 1.66%-5.55%); stroke, 3.20% (95% CI, 1.59%-5.36%); myocardial infarction (MI), 0.60% (95% CI, 0.00%-1.43%); and death, 1.20% (95% CI, 0.03%-2.38%). The occurrence of a periprocedural primary end point, defined as a combination of any stroke, MI, and death, affected 4.28% (95% CI, 2.37%-6.71%) of patients. For long-term patency, there were too few follow-up results available to evaluate.

CONCLUSIONS

Except for hyperperfusion syndrome, all other periprocedural complications including hemodynamic depression, stroke, and MI were comparable with the literature reporting unilateral carotid artery stenting. However, the analysis was based on retrospective studies. Further studies, including prospective and randomized controlled studies, are needed to confirm these results.

Predictors of Perioperative Stroke/Death after Carotid Artery Stenting: A Review Article

Carotid artery stenting (CAS) has been recommended as an alternative treatment to carotid endarterectomy for patients with significant carotid stenosis. Only a few studies have analyzed clinical/anatomical and technical variables that affect perioperative outcomes of CAS. Following a comprehensive Medline search, it was reported that clinical factors, including age of >80 years, chronic renal failure, diabetes mellitus, symptomatic indications, and procedures performed within 2 weeks of transient ischemic attack symptoms, are associated with high perioperative stroke and death rates. They also highlighted that angiographic variables, e.g., ulcerated and calcified plaques, left carotid intervention, >90% stenosis, >10-mm target lesion length, ostial involvement, type III aortic arch, and >60°-angulated internal carotid and common carotid arteries, are predictors of increased stroke rates. Technical factors associated with increased perioperative risk of stroke include percutaneous transluminal angioplasty (PTA) without embolic protection devices, PTA before stent placement, and the use of multiple stents. This review describes the most widely quoted data in defining various predictors of perioperative stroke and death after CAS. (This is a review article based on the invited lecture of the 45th Annual Meeting of Japanese Society for Vascular Surgery.)

Predicting ischemic stroke after carotid artery stenting based on proximal calcification and the jellyfish sign

OBJECTIVE Carotid artery stenting (CAS) has been considered to prevent ischemic strokes caused by stenosis of the cervical carotid artery. The most common complication of CAS is new cerebral infarction. The authors have previously reported that the jellyfish sign-the rise and fall of the mobile component of the carotid plaque surface detected by carotid ultrasonography-suggests thinning and rupture of the fibrous cap over the unstable plaque content, such as the lipid-rich necrotic core or internal plaque hemorrhage. The authors' aim in the present study was to evaluate the risk of a new ischemic lesion after CAS by using many risk factors including calcification (size and location) and the jellyfish sign. METHODS Eighty-six lesions (77 patients) were treated with CAS. The presence of ischemic stroke was determined using diffusion-weighted imaging (DWI). Risk factors included calcification of the plaque (classified into 5 groups for size and 3 groups for location) and the jellyfish sign, among others. Multiple linear regression analysis (stepwise analysis and partial least squares [PLS] analysis) was conducted, followed by a machine learning analysis using an artificial neural network (ANN) based on the log-linearized gaussian mixture network (LLGMN). The additive effects of the jellyfish sign and calcification on ischemic stroke after CAS were examined using the Kruskal-Wallis test, followed by the Steel-Dwass test. RESULTS The stepwise analysis selected the jellyfish sign, proximal calcification (proximal Ca), low-density lipoprotein (LDL) cholesterol, and patient age for the prediction model to predict new DWI lesions. The PLS analysis revealed the same top 3 variables (jellyfish sign, proximal Ca, and LDL cholesterol) according to the variable importance in projection scores. The ANN was then used, showing that these 3 variables remained. The accuracy of the ANN improved; areas under the receiver operating characteristic curves of the stepwise analysis, the PLS analysis, and the ANN were 0.719, 0.727, and 0.768, respectively. The combination of the jellyfish sign and proximal Ca indicates a significantly increased risk for ischemic stroke after CAS. CONCLUSIONS The jellyfish sign, proximal Ca, and LDL cholesterol were considered to be important predictors for new DWI lesions after CAS. These 3 factors can be easily determined during a standard clinical visit. Thus, these 3 variables-especially the jellyfish sign and proximal Ca-may be useful for reducing the ischemic stroke risk in patients with stenosis of the cervical carotid artery.

Carotid plaque with expansive arterial remodeling is a risk factor for ischemic complication following carotid artery stenting

BACKGROUND

Carotid artery stenting (CAS) is associated with a higher risk of periprocedural stroke than carotid endarterectomy. For better patient selection, more accurate risk factors should be identified. The aim of this study was to determine whether expansive arterial remodeling can predict ischemic complications in patients undergoing CAS.

METHODS

This retrospective study included 82 patients with carotid stenosis treated by CAS. The plaque component was evaluated using MR plaque imaging before the procedure. Following the procedure, lesion assessment was performed using MRI diffusion-weighted imaging (DWI), and patients were classified as DWI positive or negative for comparison between groups.

RESULTS

Fifteen patients were classified as DWI positive and 67 patients as DWI negative. The mean expansive remodeling rate was 1.76 ± 0.21 in the DWI-positive group and 1.35 ± 0.18 in the DWI-negative group (P < 0.001). Receiver-operating characteristic analysis revealed that the threshold for the expansive remodeling rate separating the two groups was 1.52 (area under the curve = 0.933). The positive predictive value of postoperative new DWI lesions in the high-intensity plaque associated with a high expansive remodeling rate was 64.3%, and the negative predictive value of the isointensity plaque associated with a low expansive remodeling rate was 97.8%. These values were higher than those of the plaque component alone (32.1% and 81.7%, respectively).

CONCLUSIONS

This study revealed that expansive arterial remodeling is a strong risk predictor of ischemic complication in CAS. Expansive remodeling rate measurements are very simple and provide useful information for determining treatment strategies for patients with carotid stenosis.

Anatomical and technical predictors of perioperative clinical outcomes after carotid artery stenting

BACKGROUND

A few other studies have reported the effects of anatomical and technical factors on clinical outcomes of carotid artery stenting (CAS). This study analyzed the effect of these factors on perioperative stroke/myocardial infarction/death after CAS.

METHODS

This was a retrospective analysis of prospectively collected data of 409 of 456 patients who underwent CAS during the study period. A logistic regression analysis was used to determine the effects of anatomical and technical factors on perioperative stroke, death, and myocardial infarction (major adverse events [MAEs]).

RESULTS

The MAE rate for the entire series was 4.7% (19 of 409), and the stroke rate was 2.2% (9 of 409). The stroke rate for asymptomatic patients was 0.46% (1 of 218; P = .01). The MAE rates for patients with transient ischemic attack (TIA) were 7% (11 of 158) vs 3.2% (8 of 251) for other indications (P = .077). The stroke rates for heavily calcified lesions were 6.3% (3 of 48) vs 1.2% (4 of 332) for mildly calcified/noncalcified lesions (P = .046). Differences in stroke and MAE rates regarding other anatomical features were not significant. The stroke rate for patients with percutaneous transluminal angioplasty (PTA) before embolic protection device (EPD) insertion was 9.1% (2 of 22) vs 1.8% (7 of 387) for patients without (P = .07) and 2.6% (9 of 341) for patients with poststenting PTA vs 0% (0 of 68) for patients without. The MAE rate for patients with poststenting PTA was 5.6% (19 of 341) vs 0% (0 of 68) for patients without (P = .0536). The MAE rate for patients with the ACCUNET (Abbott, Abbott Park, Ill) EPD was 1.9% (3 of 158) vs 6.7% (16 of 240) for others (P = .029). The differences between stroke and MAE rates for other technical features were not significant. A regression analysis showed that the odds ratio for stroke was 0.1 (P = .031) for asymptomatic indications, 13.7 (P = .014) for TIA indications, 6.1 (P = .0303) for PTA performed before EPD insertion, 1.7 for PTA performed before stenting, and 5.4 (P = .0315) for heavily calcified lesions. The MAE odds ratio was 0.46 (P = .0858) for asymptomatic indications, 2.1 for PTAs performed before EPD insertion, 2.2 for poststent PTAs, and 2.2 (P = .1888) for heavily calcified lesions. A multivariate analysis showed that patients with TIA had an odds ratio of stroke of 11.05 (P = .029). Patients with PTAs performed before EPD insertion had an OR of 6.15 (P = .062). Patients with heavily calcified lesions had an odds ratio of stroke of 4.25 (P = .0871). The MAE odds ratio for ACCUNET vs others was 0.27 (P = .0389).

CONCLUSIONS

Calcific lesions and PTA before EPD insertion or after stenting were associated with higher stroke or MAE rates, or both. The ACCUNET EPD was associated with lower MAE rates. There was no correlation between other anatomical/technical variables and CAS outcome.

Incidence and risk factors of embolized particles in carotid artery stenting and association with clinical outcome

BACKGROUND

One of the mechanisms for periprocedural neurologic events in carotid artery stenting (CAS) is catheter manipulation within the aorta and supraaortic arteries causing plaque embolization. Therefore, the present analysis sought to determine risk factors for embolic particle dimensions and their relationship with adverse clinical events after CAS.

METHODS

Between 1999 and 2015 embolic protection devices (EPD) of a total of 944 CAS procedures were evaluated regarding the occurrence and size of captured particles.

RESULTS

Particles were found in 819 of 944 (87%) EPDs. Larger particles were detected in procedures using open cell stents (150±282μm vs. 107±177μm; p=0.005) and longer stents (≥40mm) (165±315μm vs. 122±215μm; p=0.026). With increasing learning curve, particle size was continually reduced (168±282μm in the first third of the cohort vs. 127±309μm in the second third vs. 108±114μm in the last third; p=0.009). Longer stents and use of Acculink stent were found to be independent predictors for particle diameter. In patients who died or sustained a stroke during long-term follow-up (median 5.5years [IQR 2.6-7.9]) significantly larger particles were captured during CAS compared to those patients with an uneventful follow-up (160±330μm vs. 121±195μm; p=0.047).

CONCLUSIONS

In the vast majority of CAS procedures particles could be retrieved from the EPDs used. Procedural characteristics such as stent type and stent length were associated with larger particles.

Secondary Prevention of Ischemic Cerebrovascular Disease. What Is the Evidence?

Patients who had a transient ischemic attack or stroke are at increased risk of experiencing recurrent cerebrovascular events. For this reason, secondary prevention of ischemic cerebrovascular disease is essential. Several modifiable, lifestyle-associated risk factors have been implicated, such as physical activity, smoking, and alcohol consumption. Established and emerging vascular risk factors are associated with an increased risk of stroke. Pharmacologic treatment, including the use of antiplatelet, antihypertensive, and lipid-lowering agents, has also been shown to reduce the risk of secondary cerebrovascular events. Surgical intervention, either open or endovascular, may be the preferred therapeutic option in well-defined subsets of patients. It is important to establish specific measures for the early detection and prevention of recurrent cerebrovascular disease. Therefore, further research and greater awareness in this field are needed.

Angioplasty and Stenting of the Extracranial Carotid Arteries

Purpose:

To study the feasibility and safety of stent-supported angioplasty in the treatment of atherosclerotic stenoses of the extracranial carotid arteries.

Methods:

Carotid angioplasty was attempted in 174 arteries (163 patients: 126 males; mean age: 71 ± 10 years, range 47 to 93). Mean lesion length was 15.1 ± 4.1 mm, and mean percent stenosis was 83.8% ± 7.3% (reference diameter 5.8 ± 0.7 mm). The majority (106, 65%) were asymptomatic (51% of all patients had severe coronary disease, 32% had peripheral vascular diseases). Patients underwent independent neurological examination, computed tomography, duplex ultrasonography, and angiography preprocedurally, 24 hours after the procedure, and at 6-month follow-up intervals. Most (142, 82%) carotid arteries were treated without cerebral protection, but a protective triple coaxial catheter was used in 32 (18%) patients. Stents (primarily Palmaz and Wallstent) were deployed routinely in all cases; 18% were implanted without predilation.

Results:

Immediate technical success was 173 of 174 (99.4%) (1 access failure referred electively to surgery). Eight (4.6%) neurological complications occurred in the periprocedural period: 3 transient ischemic attacks, 2 minor strokes, and 3 major strokes (1 amaurosis and 2 hemiplegias). Two major complications developed despite cerebral protection. There were no deaths or myocardial infarctions and only 3 cervical access site hematomas. Over a mean 12.7 ± 9.2 month follow-up (range 1 to 36), no ipsilateral neurological complications have been seen. There were 4 (2.3%) restenoses (3 redilated, 1 treated medically) and 1 mild Palmaz stent compression, all found within the first 6 months. Primary and secondary patencies at 3 years are 96% and 99%, respectively.

Conclusions:

Angioplasty with routine stenting seems feasible and safe for treating certain types of carotid stenoses even in high-surgical risk patients; however, randomized trials are necessary before this treatment can be offered as an alternative to endarterectomy.

Carotid Stenting with Cerebral Protection: First Clinical Experience Using the PercuSurge GuardWire System

Purpose:

To study the feasibility and safety of carotid angioplasty and stenting using a new cerebral protection device that temporarily occludes the distal internal carotid artery (ICA).

Methods:

Forty-eight high-risk patients (39 men, mean age 69.1 ± 8 years, range 54 to 86) with 53 ICA stenoses underwent percutaneous angioplasty and stenting via the femoral approach under cerebral protection afforded by a 0.014-inch GuardWire balloon occlusion device. Mean stenosis was 82.1% ± 9.65% (range 70 to 96) and mean lesion length was 16.0 ± 7.5 mm (range 6 to 50). Thirty-three (62%) lesions were calcified, and 38 (72%) were ulcerated. Thirty-two (60%) of the lesions were asymptomatic. With the occlusion balloon inflated in the distal ICA, the lesion was dilated and stented. The area was cleaned by aspiration and flushed via an aspiration catheter advanced over the wire. Blood samples were collected from the external carotid artery (ECA) and analyzed to measure the size and number of particles collected. Computed tomography and neurological examinations were performed the day after the procedure.

Results:

Immediate technical success was achieved in all patients with the implantation of 38 Palmaz stents, 8 Expander stents, and 11 Wallstents. Carotid occlusion was well tolerated in all patients but 1 who had multiple, severe carotid lesions and poor collateralization. Mean cerebral flow occlusion time was 346 ± 153 seconds during predilation and 303 ± 143 seconds during stent placement. Total mean flow occlusion time was 542 ± 243 seconds. One immediate neurological complication (transient amaurosis) occurred in a patient who had an anastomosis between the external carotid (EC) and ICA territories. Debris was removed in all patients with a mean 0.8-mm diameter catheter.

Conclusion:

Cerebral protection with the GuardWire device is easy, safe, and effective in protecting the brain from cerebral embolism. Larger studies are warranted.

Neurological Monitoring during Carotid Artery Stenting: The Duck Squeezing Test

Purpose:

To examine the usefulness of a novel method for neurological monitoring during carotid artery stenting (CAS).

Methods:

The records of patients who underwent elective CAS between June 1996 and October 1998 were reviewed to identify those who had neurological changes during the procedure. We examined whether the neurological change had been detected by a change in the ability of the patient to respond to predetermined commands involving a small rubber duck placed in the contralateral hand.

Results:

Two hundred seventy patients (320 vessels) underwent monitoring using the Duck Squeezing Test; 10 suffered neurological events during the procedure. Four of these were transient and temporally related to balloon inflation. Another 6 were tentatively ascribed to distal embolism. All instances were accompanied by a change in the patient's ability to perform the Duck Squeezing Test, which allowed the identification of the abnormal clinical situation. In addition, there were 4 false-positive tests secondary to the patient accidentally dropping the rubber duck.

Conclusions:

The Duck Squeezing Test is a sensitive and specific method for monitoring patients during elective CAS. Its practical applicability is based on sound neurophysiological concepts, which underscore the clinical importance of the test.

Hypotension and Bradycardia after Elective Carotid Stenting: Frequency and Risk Factors

Purpose:

To investigate the frequency of and risk factors for hypotension and bradycardia in response to elective carotid stenting and their association with neurological complications.

Methods:

A retrospective analysis was conducted of 471 patients (321 men; median age 72 years, interquartile range 64–77) who underwent elective carotid artery stenting without cerebral protection for high-grade (>70%) symptomatic (n = 147) or asymptomatic (n=324) internal carotid artery stenosis at a single center. Frequency and potential risk factors for severe hypotension (systolic blood pressure <80 mmHg) or bradycardia (heart rate <50 bpm) were studied.

Results:

Thirty-four (7%) patients had severe hypotension (n=23), bradycardia (n=2), or both (n=9) despite routine premedication with atropine and adequate fluid balance. Intravenous catecholamines (dopamine) were necessary in 8 patients with prolonged hypotension; none of the patients with bradycardia needed pacemaker support. Neurological complications (transient ischemic attack, minor stroke, major stroke, death) occurring in 33 (7%) patients were not significantly associated with hemodynamic instability (4/34 [12%] versus 29/437 [7%], p = 0.26). Age >77 years (fourth quartile; OR 6.40, 95% CI 1.80 to 22.78, p=0.004) and coronary artery disease (OR 2.81, 95% CI 1.29 to 6.14, p=0.010) were associated with an increased adjusted risk for hypotension or bradycardia.

Conclusions:

Hemodynamic instability due to hypotension and bradycardia in response to carotid artery stenting occurs in a relatively low proportion of patients. Elderly patients and those with coronary artery disease are at highest risk. Although the rate of neurological complications was not significantly increased in patients with hemodynamic instability, the higher frequencies of neurological complications in these patients admonish us to be careful.

Influence of Age upon Complications of Carotid Artery Stenting

Purpose:

To examine the impact of age upon the development of neurological and major systemic complications during or after carotid artery stenting.

Methods:

We reviewed the complications that occurred in patients undergoing elective carotid stent implantation between September 1994 and August 1996. The study population was then divided into 3 groups according to age: ≥ 80 (group A), 75 to 79 (group B), and ≤ 74 (group C) years. The rates of death, major and minor stroke, and myocardial infarction were compared among the groups, as well as with the rates reported by the major carotid endarterectomy (CEA) trials.

Results:

During the study period, 182 patients (216 vessels) were treated with carotid stenting. There were 19 (10.4%) complications: 1 (0.5%) death, 2 (1.1%) major strokes, 15 (8.2%) minor strokes, and 1 (0.5%) myocardial infarction. Neurological complications were clearly related to increased age with rates of 25.0% in group A versus 8.6% in group C (p = 0.042). The overall per patient rate of death or major stroke was 1.6% (1.4% per vessel).

Conclusions:

Increasing age has a negative impact on the rate of complications in carotid stent patients. However, the majority of those complications are minor. The relative roles of medical therapy, stenting, and CEA in patients > 80 years of age must await the results of randomized trials.

Carotid Plaque Characterization Using Digital Image Processing and its Potential in Future Studies of Carotid Endarterectomy and Angioplasty

Purpose:

To corroborate the validity of a computerized methodology for evaluating carotid lesions at risk for stroke based on plaque echogenicity.

Methods:

The records of 96 carotid endarterectomy patients (59 men; median age 69.5 years, range 52 to 83) with stenoses > 50% were studied retrospectively. Forty-one patients (43%) had been symptomatic preoperatively. All patients had undergone computed tomography (CT) to detect infarction in the carotid territory and a duplex scan to measure carotid stenosis. Plaque echogenicity was analyzed by computer, expressing the echodensity in terms of the gray scale median (GSM). The incidence of CT-documented cerebral infarction was analyzed in relation to symptomatology, percent stenosis, and echodensity.

Results:

Symptoms correlated well with CT evidence of brain infarction: 32% of symptomatic patients had a positive CT scan versus 16% for asymptomatic plaques (p = 0.076). The mean GSM value was 56 ± 14 for plaques associated with negative CT scans and 38 ± 13 for plaques from patients with positive scans (p < 0.0001). However, there was no difference in the GSM value between plaques with > or < 70% stenosis. Furthermore, the incidence of CT infarction was 40% in the cerebral territory of carotid plaques with a GSM value < 50 and only 9% in those with a GSM > 50 (p < 0.001).

Conclusions:

Computerized analysis of plaque echogenicity appears to provide clinically useful data that correlates with the incidence of cerebral infarction and symptoms. This method of analyzing plaque echolucency could be used as a screening tool for carotid stent studies to identify high-risk lesions better suited to conventional surgical treatment.

Safety Outcomes Using a Proximal Protection Device in Carotid Stenting of Long Carotid Stenoses

BACKGROUND

Embolic protection devices can prevent atherosclerotic emboli during carotid stenting. Newer proximal protection devices reverse flow in the internal carotid artery (ICA), leading to reduction in perioperative microemboli. The risk of stroke is high for carotid stenting of ICA lesions with a length >10 mm and/or angiographic string sign.

OBJECTIVE

We aimed to evaluate the safety outcomes of proximal embolic protection device usage in this high-risk group.

METHODS

This is a retrospective analysis of patients who underwent carotid stenting procedures with proximal embolic protection devices at a tertiary care center. High-risk features for adverse events with carotid stenting were identified. Peri- and postprocedural outcomes were recorded. We further compared outcomes in patients with a carotid stenosis length >10 mm to those with shorter stenosis.

RESULTS

From January 2011 to December 2014, we included 27 patients; 96.3% were symptomatic and 3.7% were asymptomatic. There was a stent placement technical success rate of 100%. No major stroke or coronary events were recorded. One minor stroke event developed in one patient. A carotid lesion length >10 mm and/or angiographic string sign was noted in 21/27 patients, with an average lesion length of 14.4 mm. One patient (4.8%) in this group developed a minor stroke event. Neither a coronary nor a major stroke event was recorded in this group. There was no significant difference in the complication rate between the long lesion and the control group.

CONCLUSION

In our patient cohort, it was found that a proximal embolic protection device is safe for patients with carotid stenosis, including those with a carotid lesion length >10 mm and/or angiographic string sign.

Association between age and risk of stroke or death from carotid endarterectomy and carotid stenting: a meta-analysis of pooled patient data from four randomised trials

BACKGROUND

Age was reported to be an effect-modifier in four randomised controlled trials comparing carotid artery stenting (CAS) and carotid endarterectomy (CEA), with better CEA outcomes than CAS outcomes noted in the more elderly patients. We aimed to describe the association of age with treatment differences in symptomatic patients and provide age-specific estimates of the risk of stroke and death within narrow (5 year) age groups.

METHODS

In this meta-analysis, we analysed individual patient-level data from four randomised controlled trials within the Carotid Stenosis Trialists' Collaboration (CSTC) involving patients with symptomatic carotid stenosis. We included only trials that randomly assigned patients to CAS or CEA and only patients with symptomatic stenosis. We assessed rates of stroke or death in 5-year age groups in the periprocedural period (between randomisation and 120 days) and ipsilateral stroke during long-term follow-up for patients assigned to CAS or CEA. We also assessed differences between CAS and CEA. All analyses were done on an intention-to-treat basis.

FINDINGS

Collectively, 4754 patients were randomly assigned to either CEA or CAS treatment in the four studies. 433 events occurred over a median follow-up of 2·7 years. For patients assigned to CAS, the periprocedural hazard ratio (HR) for stroke and death in patients aged 65-69 years compared with patients younger than 60 years was 2·16 (95% CI 1·13-4·13), with HRs of roughly 4·0 for patients aged 70 years or older. We noted no evidence of an increased periprocedural risk by age group in the CEA group (p=0·34). These changes underpinned a CAS-versus CEA periprocedural HR of 1·61 (95% CI 0·90-2·88) for patients aged 65-69 years and an HR of 2·09 (1·32-3·32) for patients aged 70-74 years. Age was not associated with the postprocedural stroke risk either within treatment group (p≥0·09 for CAS and 0·83 for CEA), or between treatment groups (p=0·84).

INTERPRETATION

In these RCTs, CEA was clearly superior to CAS in patients aged 70-74 years and older. The difference in older patients was almost wholly attributable to increasing periprocedural stroke risk in patients treated with CAS. Age had little effect on CEA periprocedural risk or on postprocedural risk after either procedure.

FUNDING

None.

Simultaneous Bilateral vs Unilateral Carotid Artery Stenting: 30-Day and 1-Year Results

PURPOSE

To evaluate clinical outcomes of simultaneous bilateral carotid artery stenting (sbCAS) compared with unilateral CAS (uCAS).

METHODS

The database in our institution was queried to identify all patients treated with CAS from January 2005 to December 2012. In this time frame, 120 (18.8%) patients (mean age 64.9 ± 7.7 years; 96 men) underwent sbCAS and 517 (81.2%) patients (mean age 65.7 ± 7.7 years; 421 men) received uCAS. The primary endpoint was the composite of stroke, myocardial infarction, or death within 30 days or any ipsilateral stroke within 1 year.

RESULTS

There was no significant difference in the rates of the primary endpoint between the sbCAS and uCAS groups (6.7% vs 4.6%, p=0.358). The rates of the primary endpoint among symptomatic patients was 8.0% in the sbCAS group and 5.0% in the uCAS group (p=0.299) and 3.1% and 4.0%, respectively (p=0.821) among asymptomatic patients. During the 30-day periprocedural period, the rates of the primary endpoint did not differ significantly between the sbCAS and uCAS groups among all patients (5.8% vs 4.4%, p=0.479), symptomatic patients (6.8% vs 5.0%, p=0.594), or asymptomatic patients (3.1% vs 3.5%, p>0.999). After this period, the incidences of any ipsilateral stroke were similarly low (0.8% and 0.2%, respectively; p=0.342).

CONCLUSION

The study showed that simultaneous bilateral CAS had no more adverse events than unilateral CAS during the periprocedural period or within 1 year. This 1-stage strategy may become a valuable alternative in the treatment of patients with severe bilateral carotid stenosis.

Endovascular Advances for Extracranial Carotid Stenosis

Carotid artery stenting has become a viable alternative to carotid endarterectomy in the management of carotid stenosis. Over the past 20 years, many trials have attempted to compare both treatment modalities and establish the indications for each one, depending on clinical and anatomic features presented by patients. Concurrently, carotid stenting techniques and devices have evolved and made endovascular management of carotid stenosis safe and effective. Among the most important innovations are devices for distal and proximal embolic protection and new stent designs. This paper reviews these advances in the endovascular management of carotid artery stenosis within the context of the historical background.

Patient, Anatomic, and Procedural Characteristics That Increase the Risk of Carotid Interventions

Subjective characteristics for increased risk of carotid artery stenting (CAS) have included thrombus-containing lesions, heavily calcified lesions, very tortuous vessels, and near occlusions. More objective high-risk features include contraindications to dual antiplatelet therapy, a history of bleeding complications, and lack of femoral artery vascular access. Variables that increase the risk of CAS complications are attributed to patient characteristics, anatomic features, or procedural factors. Operator and hospital volume affect the risk of complications occurring with CAS. As the complexity and difficulty of CAS patients increases, the need for more highly skilled operators and teams becomes even more necessary to minimize complications.

Carotid artery stenting: patient, lesion, and procedural characteristics that increase procedural complications

From the earliest experiences with carotid artery stenting (CAS) presumptive high risk features have included thrombus-containing lesions, heavily calcified lesions, very tortuous vessels, and near occlusions. In addition patients have been routinely excluded from CAS trials if they have contra-indications to dual antiplatelet therapy (aspirin and thienopyridines), a history of bleeding complications and severe peripheral arterial disease (PAD) making femoral artery vascular access difficult. Variables that increase the risk of CAS complications can be attributed to patient characteristics, anatomic or lesion features, and procedural factors. Clinical features such as older age (≥80 years), decreased cerebral reserve (dementia, multiple prior strokes, or intracranial microangiopathy) and angiographic characteristics such as excessive tortuosity (more than two 90° bends within 5 cm of the target lesion) and heavy calcification (concentric calcification ≥ 3 mm in width) have been associated with increased CAS complications. Other high risk CAS features include those that prolong catheter or guide wire manipulation in the aortic arch, make crossing a carotid stenosis more difficult, decrease the likelihood of successful deployment or retrieval of an embolic protection device (EPD), or make stent delivery or placement more difficult. Procedure volume for the operator and the catheterization laboratory team are critical elements in reducing the risk of the procedure. In this article, we help CAS operators better understand procedure risk to allow more intelligent case selection, further improving the outcomes of this emerging procedure.

Length of carotid stenosis predicts peri-procedural stroke or death and restenosis in patients randomized to endovascular treatment or endarterectomy

Background

The anatomy of carotid stenosis may influence the outcome of endovascular treatment or carotid endarterectomy. Whether anatomy favors one treatment over the other in terms of safety or efficacy has not been investigated in randomized trials.

Methods

In 414 patients with mostly symptomatic carotid stenosis randomized to endovascular treatment (angioplasty or stenting; n = 213) or carotid endarterectomy (n = 211) in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS), the degree and length of stenosis and plaque surface irregularity were assessed on baseline intraarterial angiography. Outcome measures were stroke or death occurring between randomization and 30 days after treatment, and ipsilateral stroke and restenosis ≥50% during follow-up.

Results

Carotid stenosis longer than 0.65 times the common carotid artery diameter was associated with increased risk of peri-procedural stroke or death after both endovascular treatment [odds ratio 2.79 (1.17–6.65), P = 0.02] and carotid endarterectomy [2.43 (1.03–5.73), P = 0.04], and with increased long-term risk of restenosis in endovascular treatment [hazard ratio 1.68 (1.12–2.53), P = 0.01]. The excess in restenosis after endovascular treatment compared with carotid endarterectomy was significantly greater in patients with long stenosis than with short stenosis at baseline (interaction P = 0.003). Results remained significant after multivariate adjustment. No associations were found for degree of stenosis and plaque surface.

Conclusions

Increasing stenosis length is an independent risk factor for peri-procedural stroke or death in endovascular treatment and carotid endarterectomy, without favoring one treatment over the other. However, the excess restenosis rate after endovascular treatment compared with carotid endarterectomy increases with longer stenosis at baseline. Stenosis length merits further investigation in carotid revascularisation trials.

MRI lesions after invasive therapy of carotid artery stenosis: a risk-modeling analysis

BACKGROUND

Diffusion-weighted imaging (DWI) abnormalities can frequently be detected after carotid endarterectomy (CEA) and carotid angioplasty with stent placement (CAS) of the carotid arteries. We looked for possible predictors for the development of DWI lesions during the intervention.

METHODS

We investigated 41 patients who underwent CAS without protection devices and 93 patients who underwent CEA. DWI studies were performed 1 day before and after the intervention.

RESULTS

Ischemic complications consisted of two strokes (2.2%) in the CEA group and one stroke (2.4%) in the CAS group. DWI lesions were detected in 28.0% of all patients after intervention. Using a multivariate regression analysis, diabetes mellitus (DM), hyperlipidemia, symptomatic stenosis, age and CAS were found to be significant predictors for the occurrence of DWI lesions.

CONCLUSIONS

DWI is an objective and highly sensitive method for monitoring interventions of the carotid arteries. Our results point to an increased risk of patients with diabetes and hyperlipidemia to develop DWI lesions during invasive therapy of the ICA.

Direct Relationship between Angiographic Characteristics of Carotid Atherosclerotic Plaque and Filling Defect in the Cerebral Protection Filters : Based on the Conventional Angiography

Objective

Neurologic complications during carotid artery stenting (CAS) are usually associated with distal embolic event. These embolic incident during CAS are highly associated with the carotid plaque instability. The current study was undertaken to identify the angiographic characteristics of carotid plaque vulnerability, which was represented as filling defect in the cerebral protection filters during CAS.

Methods

A total of 107 patients underwent CAS with use of a distal protection filter. Angiographic carotid plaque surface morphology was classified as smooth, irregular, and ulcerated. To determine predictable factors of filling defect in the protection filters, 11 variables were retrospectively analyzed which might influence filling defect in the protection filters during CAS.

Results

Filling defects during CAS were presented in the 33 cerebral protection filters. In multivariate analysis, angiographic ulceration [odds ratio (OR), 6.60; 95% confidence interval (CI) : 2.24, 19.4; p=0.001], higher stenosis degree (OR, 1.06; 95% CI : 1.00, 1.12; p=0.039), and coexistent thrombus (OR, 7.58; 95% CI : 1.69, 34.05; p=0.08) were highly associated with filling defect in the cerebral protection devices during CAS. Among several variables, angiographic surface ulceration was the only significant factor associated with flow stagnation during CAS (OR, 4.11; 95% CI : 1.33, 12.72; p=0.014).

Conclusion

Plaque surface morphology on carotid angiography can be a highly sensitive marker of plaque instability during CAS. The independent risk factors for filling defect in the filter devices during CAS were plaque ulceration, stenosis degree, and coexistent thrombus.

Age and outcomes after carotid stenting and endarterectomy: the carotid revascularization endarterectomy versus stenting trial

BACKGROUND AND PURPOSE

High stroke event rates among carotid artery stenting (CAS)-treated patients in the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) lead-in registry generated an a priori hypothesis that age may modify the relative efficacy of CAS versus carotid endarterectomy (CEA). In the primary CREST report, we previously noted significant effect modification by age. Here we extend this investigation by examining the relative efficacy of the components of the primary end point, the treatment-specific impact of age, and contributors to the increasing risk in CAS-treated patients at older ages.

METHODS

Among 2502 CREST patients with high-grade carotid stenosis, proportional hazards models were used to examine the impact of age on the CAS-to-CEA relative efficacy, and the impact of age on risk within CAS-treated and CEA-treated patients.

RESULTS

Age acted as a treatment effect modifier for the primary end point (P interaction=0.02), with the efficacy of CAS and CEA approximately equal at age 70 years. For CAS, risk for the primary end point increased with age (P<0.0001) by 1.77-times (95% confidence interval, 1.38-2.28) per 10-year increment; however, there was no evidence of increased risk for CEA-treated patients (P=0.27). Stroke events were the primary contributor to the overall effect modification (P interaction=0.033), with equal risk at ≈64 years. The treatment-by-age interaction for CAS and CEA was not altered by symptomatic status (P=0.96) or by sex (P=0.45).

CONCLUSIONS

Outcomes after CAS versus CEA were related to patient age, attributable to increasing risk for stroke after CAS at older ages. Patient age should be an important consideration when choosing between the 2 procedures for treating carotid stenosis.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00004732.

Comparison of carotid artery stenting in patients with single versus bilateral carotid artery disease and factors affecting midterm outcome

BACKGROUND

Carotid artery stenting (CAS) is the method of choice for carotid artery revascularization of patients at high risk for carotid endarterectomy. In this study, we compared the midterm results of CAS in patients with unilateral versus bilateral carotid artery disease.

METHODS AND RESULTS

This is a retrospective analysis of 1-year outcome of 273 consecutive patients in whom 342 CAS procedures were performed. The incidence of periprocedural transient ischemic attacks (TIAs) differed significantly (8% vs. 1%; p = 0.01) among patients with and without bilateral internal carotid disease, and a tendency to a lower occurrence of early adverse events (death, stroke, periprocedural TIA, periprocedural myocardial infarction) was subsequently shown (11% vs. 5%; p = 0.12). At 1-year follow-up, there was a high incidence of adverse events (death, stroke, periprocedural TIA, periprocedural myocardial infarction, restenosis) in patients with bilateral carotid artery disease (40% vs. 14%; p < 0.01), which was mainly driven by a higher incidence of death, periprocedural TIA, and restenosis (p ≤ 0.02 for all). According to multivariate analysis, the independent predictors of midterm adverse events were left ventricular dysfunction, male gender, bilateral carotid artery disease, renal insufficiency, cerebral symptoms within the last 6 months before the intervention, and low-density lipoprotein cholesterol level.

CONCLUSIONS

At midterm follow-up, patients with bilateral carotid artery disease treated by CAS have significantly more adverse events than those with unilateral disease.

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.

MRI plaque imaging reveals high-risk carotid plaques especially in diabetic patients irrespective of the degree of stenosis

Background

Plaque imaging based on magnetic resonance imaging (MRI) represents a new modality for risk assessment in atherosclerosis. It allows classification of carotid plaques in high-risk and low-risk lesion types (I-VIII). Type 2 diabetes mellitus (DM 2) represents a known risk factor for atherosclerosis, but its specific influence on plaque vulnerability is not fully understood. This study investigates whether MRI-plaque imaging can reveal differences in carotid plaque features of diabetic patients compared to nondiabetics.

Methods

191 patients with moderate to high-grade carotid artery stenosis were enrolled after written informed consent was obtained. Each patient underwent MRI-plaque imaging using a 1.5-T scanner with phased-array carotid coils. The carotid plaques were classified as lesion types I-VIII according to the MRI-modified AHA criteria. For 36 patients histology data was available.

Results

Eleven patients were excluded because of insufficient MR-image quality. DM 2 was diagnosed in 51 patients (28.3%). Concordance between histology and MRI-classification was 91.7% (33/36) and showed a Cohen's kappa value of 0.81 with a 95% CI of 0.98-1.15. MRI-defined high-risk lesion types were overrepresented in diabetic patients (n = 29; 56.8%). Multiple logistic regression analysis revealed association between DM 2 and MRI-defined high-risk lesion types (OR 2.59; 95% CI [1.15-5.81]), independent of the degree of stenosis.

Conclusion

DM 2 seems to represent a predictor for the development of vulnerable carotid plaques irrespective of the degree of stenosis and other risk factors. MRI-plaque imaging represents a new tool for risk stratification of diabetic patients.

See Commentary: http://www.biomedcentral.com/1741-7015/8/78/abstract

The Coronary Technique for Complex Carotid Artery Stenting in the Setting of Complex Aortic Arch Anatomy

Carotid artery stenting (CAS) remains a viable option for treating carotid artery lesions in high surgical risk patients. We retrospectively reviewed our experience in performing CAS in patients with complex aortic arch anatomy. The ‘‘coronary technique’’ uses an AL1 guiding catheter to engage the origin of the common carotid artery permitting delivery of protection device and stent. In total, 12 patients had complex arch anatomy which precluded access using the standard technique as determined on preoperative imaging. A total of 8 patients with such anatomy underwent femoral artery catheterization with placement of an Amplatz AL1 guide catheter into the common carotid artery. All were able to be successfully treated, with no dissection, neurovascular deficit, or other major complication. Based on this case series, we describe the coronary technique as a safe and viable method for CAS in the setting of complex anatomy which might otherwise preclude CAS.

Catheter-based neurosalvage for acute embolic complication during carotid intervention

OBJECTIVES

Iatrogenic emboli may be released during carotid intervention, causing permanent neurologic complications and catastrophic outcomes. This article reports the procedural details and clinical results of our series of neurosalvage techniques to manage thromboembolic events during carotid procedures.

METHODS

Between March 2003 and December 2007, 342 patients (283 men, 72.1 +/- 8.9 years old, 121 symptomatic) underwent percutaneous stent deployment in 407 cervical internal carotid arteries in our institution. Visible distal embolization with flow occlusion caused neurologic complications in 10 patients (2.5%), and a structured and stepwise neurosalvage approach was attempted.

RESULTS

Guidewire fragmentation and microcatheter injection of heparin and nitroglycerin were performed in all 10 patients as step 1. Intra-arterial thrombolysis was given in four patients and balloon angioplasty in five, as step 2. Intracranial stenting was done in one patient as the last step. Successful angiographic recanalization (Thrombolysis in Myocardial Infarction [TIMI] grade 2-3) occurred in 9 of 10 (90%). Residual neurologic sequel was observed in five, including three patients with hemorrhage complications (1 received emergent craniotomy). There was no neurologic mortality in this series.

CONCLUSIONS

Acute embolic complication during carotid artery stenting can be managed by catheter-based neurosalvage with effective angiographic recanalization and marginal clinical success.

Simultaneous bilateral carotid stenting in high-risk patients

BACKGROUND AND PURPOSE

The safety and efficacy of SBCAS have not been evaluated in detail. The purpose of our study was to evaluate the outcome after SBCAS in high-risk patients compared with unilateral stent placement.

MATERIALS AND METHODS

Between March 2002 and October 2008, a total of 205 consecutive high-risk patients underwent CAS at our institution. Of these patients, 30 (14.6%) underwent SBCAS (n = 24) and staged SBCAS (n = 6). Patients who underwent unilateral CAS (n = 175) during the same period served as controls. The stroke risk factors, procedural results, and outcome at 30 days and 6 months, as well as the restenosis rate at 6 months, were compared by using either the chi(2) test or the Kruskal-Wallis equality-of-populations rank test.

RESULTS

Our data revealed no significant differences in the stroke risk factors between the SBCAS and the control group. HPS occurred more commonly in SBCAS (ie, 16.7%, 4/24) compared with 2.9% (5/175) in the control group (P = .014). However, there was no statistical significance between 2 groups in the event rate of stroke (minor and/or major stroke), death, or restenosis at 6 months.

CONCLUSIONS

There was no significant difference in outcome at 6 months following stent placement between SBCAS and unilateral CAS in the high-risk patient group, even though HPS occurred more commonly after SBCAS.

Regional variation in carotid artery stenting and endarterectomy in the Medicare population

BACKGROUND

To describe geographic variation in population-based rates of carotid artery stenting (CAS) and carotid endarterectomy (CEA) performed in Medicare beneficiaries.

METHODS AND RESULTS

Medicare claims and enrollment data were used to calculate age, sex, and race-adjusted rates of CAS and CEA for Medicare beneficiaries in each of 306 hospital referral regions between 1998 and 2007. Procedures were identified using a combination of Current Procedural Terminology codes as well as diagnostic and procedural ICD-9 codes. Overall, the rate of carotid revascularization has fallen slightly over the last decade (3.8 procedures per 1000 in 1998, 3.1 procedures per 1000 in 2007; P<0.0001). Although the use of CEA decreased, from 3.6 to 2.5 procedures per 1000 beneficiaries in 2007 (P<0.0001), the use of CAS has increased >4-fold between 1998 and 2007, growing from 0.1 to 0.6 CAS procedures per 1000 beneficiaries (P<0.0001). Further, CAS rapidly disseminated across the country over the last decade. In 1998, 66% of hospital referral regions had a hospital that performed CAS; however, by 2007, nearly all (95%) hospital referral regions performed CAS (P<0.0001). Last, in regions with the highest utilization rates of CAS, it appeared that CAS was performed as a substitute for CEA. There was little evidence that CAS was being performed in addition to CEA, as no correlation existed between regional rates of CAS and CEA (r=0.06).

CONCLUSIONS

Even though CEA was used less frequently in 2007 than 1998, the use of CAS has grown significantly. Although regional variation in the use of CEA has remained fairly constant, regional variation has increased in the use of CAS. Given these changes in practice patterns, careful examination of the efficacy and cost-effectiveness of CAS is necessary.