Stenting in the carotid artery: initial experience in 110 patients

Learning curve of transfemoral carotid artery stenting in the Vascular Quality Initiative registry

OBJECTIVE

With the recent expansion of the Centers for Medicare and Medicaid Services coverage, transfemoral carotid artery stenting (tfCAS) is expected to play a larger role in the management of carotid disease. Existing research on the tfCAS learning curve, primarily conducted over a decade ago, may not adequately describe the current effect of physician experience on outcomes. Because approximately 30% of perioperative strokes/deaths post-CAS occur after discharge, appropriate thresholds for in-hospital event rates have been suggested to be <4% for symptomatic and <2% for asymptomatic patients. This study evaluates the tfCAS learning curve using Vascular Quality Initiative (VQI) data.

METHODS

We identified VQI patients who underwent tfCAS between 2005 and 2023. Each physician's procedures were chronologically grouped into 12 categories, from procedure counts 1-25 to 351+. The primary outcome was in-hospital stroke/death rate; secondary outcomes were in-hospital stroke/death/myocardial infarction (MI), 30-day mortality, in-hospital stroke/transient ischemic attack (stroke/TIA), and access site complications. The relationship between outcomes and procedure counts was analyzed using the Cochran-Armitage test and a generalized linear model with restricted cubic splines. Our results were then validated using a generalized estimating equations model to account for the variability between physicians.

RESULTS

We analyzed 43,147 procedures by 2476 physicians. In symptomatic patients, there was a decrease in rates of in-hospital stroke/death (procedure counts 1-25 to 351+: 5.2%-1.7%), in-hospital stroke/death/MI (5.8%-1.7%), 30-day mortality (4.6%-2.8%), in-hospital stroke/TIA (5.0%-1.1%), and access site complications (4.1%-1.1%) as physician experience increased (all P values < .05). The in-hospital stroke/death rate remained above 4% until 235 procedures. Similarly, in asymptomatic patients, there was a decrease in rates of in-hospital stroke/death (2.1%-1.6%), in-hospital stroke/death/MI (2.6%-1.6%), 30-day mortality (1.7%-0.4%), and in-hospital stroke/TIA (2.8%-1.6%) with increasing physician experience (all P values <.05). The in-hospital stroke/death rate remained above 2% until 13 procedures.

CONCLUSIONS

In-hospital stroke/death and 30-day mortality rates after tfCAS decreased with increasing physician experience, showing a lengthy learning curve consistent with previous reports. Given that physicians' early cases may not be included in the VQI, the learning curve was likely underestimated. Nevertheless, a substantially high rate of in-hospital stroke/death was found in physicians' first 25 procedures. With the recent Centers for Medicare and Medicaid Services coverage expansion for tfCAS, a significant number of physicians would enter the early stage of the learning curve, potentially leading to increased postoperative complications.

The Evolution of Current Management for Carotid Artery Bifurcation Disease

Options for treatment of symptomatic carotid bifurcation disease include carotid endarterectomy (CEA) and carotid artery stenting (CAS). While over the years CEA has established itself as the gold standard for carotid artery revascularization, results from recent trials have shown CAS to be safe and effective in selected patients. This review details the evolution of carotid artery bifurcation disease by highlighting key clinical trials.

Long-term outcomes of carotid endarterectomy vs transfemoral carotid stenting in a Medicare-matched database

BACKGROUND

Carotid endarterectomy (CEA) is associated with lower risk of perioperative stroke compared with transfemoral carotid artery stenting (TFCAS) in the treatment of carotid artery stenosis. However, there is discrepancy in data regarding long-term outcomes. We aimed to compare long-term outcomes of CEA vs TFCAS using the Medicare-matched Vascular Quality Initiative Vascular Implant Surveillance and Interventional Outcomes Network database.

METHODS

We assessed patients undergoing first-time CEA or TFCAS in Vascular Quality Initiative Vascular-Vascular Implant Surveillance and Interventional Outcomes Network from January 2003 to December 2018. Patients with prior history of carotid revascularization, nontransfemoral stenting, stenting performed without distal embolic protection, multiple or nonatherosclerotic lesions, or concomitant procedures were excluded. The primary outcome of interest was all-cause mortality, any stroke, and a combined end point of death or stroke. We additionally performed propensity score matching and stratification based on symptomatic status.

RESULTS

A total of 80,146 carotid revascularizations were performed, of which 72,615 were CEA and 7531 were TFCAS. CEA was associated with significantly lower risk of death (57.8% vs 70.4%, adjusted hazard ratio [aHR], 0.46; 95% confidence interval [CI], 0.41-0.52; P < .001), stroke (21.3% vs 26.6%; aHR, 0.63; 95% CI, 0.57-0.69; P < .001) and combined end point of death and stroke (65.3% vs 76.5%; HR, 0.49; 95% CI, 0.44-0.55; P < .001) at 10 years. These findings were reflected in the propensity-matched cohort (combined end point: 34.6% vs 46.8%; HR, 0.53; 95% CI, 0.46-0.62) at 4 years, as well as stratified analyses of combined end point by symptomatic status (asymptomatic: 63.2% vs 74.9%; HR, 0.49; 95% CI, 0.43-0.58; P < .001; symptomatic: 69.9% vs 78.3%; HR, 0.51; 95% CI, 0.45-0.59; P < .001) at 10 years.

CONCLUSIONS

In this analysis of North American real-world data, CEA was associated with greater long-term survival and fewer strokes compared with TFCAS. These findings support the continued use of CEA as the first-line revascularization procedure.

Peak systolic velocity ratio for evaluation of internal carotid artery stenosis correlated with plaque morphology: substudy results of the ANTIQUE study

Background

Accurate assessment of carotid stenosis severity is important for proper patient management. The present study aimed to compare the evaluation of carotid stenosis severity using four duplex sonography (DUS) measurements, including peak systolic velocity (PSV), PSV ratio in stenosis and distal to stenosis (PSVICA/ICA ratio), end-diastolic velocity (EDV), and B-mode, with computed tomography angiography (CTA), and to evaluate the impact of plaque morphology on correlation between DUS and CTA.

Methods

Consecutive patients with carotid stenosis of ≥40% examined using DUS and CTA were included. Plaque morphology was also determined using magnetic resonance imaging. Spearman's correlation and Kendall's rank correlation were used to evaluate the results.

Results

A total of 143 cases of internal carotid artery stenosis of ≥40% based on DUS were analyzed. The PSVICA/ICA ratio showed the highest correlation [Spearman's correlation r = 0.576) with CTA, followed by PSV (r = 0.526), B-mode measurement (r = 0.482), and EDV (r = 0.441; p < 0.001 in all cases]. The worst correlation was found for PSV when the plaque was calcified (r = 0.238), whereas EDV showed a higher correlation (r = 0.523). Correlations of B-mode measurement were superior for plaques with smooth surface (r = 0.677), while the PSVICA/ICA ratio showed the highest correlation in stenoses with irregular (r = 0.373) or ulcerated (r = 0.382) surfaces, as well as lipid (r = 0.406), fibrous (r = 0.461), and mixed (r = 0.403; p < 0.01 in all cases) plaques. Nevertheless, differences between the mentioned correlations were not statistically significant (p > 0.05 in all cases).

Conclusion

PSV, PSVICA/ICA ratio, EDV, and B-mode measurements showed comparable correlations with CTA in evaluation of carotid artery stenosis based on their correlation with CTA results. Heavy calcifications and plaque surface irregularity or ulceration negatively influenced the measurement accuracy.

Transcarotid Artery Revascularization: Is It Better than Carotid Endarterectomy?

Transcarotid artery revascularization (TCAR) is a novel carotid stenting method that avoids the manipulation of the aortic arch and uses a flow-reversal neuroprotection system that effectively reduces the risk of embolic events during carotid intervention. Studies have shown a lower risk of stroke or death compared with the transfemoral carotid stenting approach, and an equivalent risk of stroke or death compared with traditional carotid endarterectomy. TCAR has added benefits of lower risk of myocardial infarction, cranial nerve injuries, and shorter operative times compared with endarterectomy. TCAR has become widely adopted by vascular surgeons in the United States for the treatment of patients with high-risk medical comorbidities and those with challenging surgical anatomy.

Carotid Lesion Length Independently Predicts Stroke and Death After TransCarotid Artery Revascularization and TransFemoral Carotid Artery Stenting

OBJECTIVES

Prior data from the CREST trial suggested that the higher perioperative stroke or death event rate among patients treated with transfemoral carotid artery stenting (TFCAS) appears to be strongly related to the lesion length. Nonetheless, data regarding the impact of lesion length on outcomes of transcarotid artery revascularization (TCAR) with flow reversal is lacking. Herein, we aimed to compare the outcomes of TCAR versus TFCAS stratified by the length of the carotid lesion.

METHODS

Our cohort was derived from the Vascular Quality Initiative (VQI) database for carotid artery stenting between 2016 and 2021. Restricted cubic spline analysis was used to describe the relationship between the primary outcome (in-hospital stroke/death) and the exposure variable (lesion length) in the overall cohort. This relationship was not linear, and knots were identified where significant changes in the slope of the curve occurred. We therefore divided patients based on knot with the most significant inflection into two groups: lesion length<25mm (short) and lesion length ≥25mm. Clinically relevant and statistically significant variables on univariable analysis were added to the final logistic regression model clustered by center identifier to study the association between lesion length and in-hospital outcomes stratified by stent approach.

RESULTS

The study cohort included 17,931 TCAR (52.6% with long lesions), and 12,036 TFCAS (53.2% with long lesions). Patients with long lesions had higher rates of being symptomatic among both TCAR (27.2% vs 24.3%, P<0.001) and TFCAS (43.5% VS 38.5%, p<0.001) and were more likely to undergo general anesthesia in TCAR (84.7% vs 81.9%, P<0.001) and TFCAS (21.6% vs 15.8%, P<0.001). After adjusting for potential confounders, long carotid lesions were associated with higher odds of stroke, stroke/TIA and stroke/death compared to short lesions among patients undergoing TCAR or TFCAS. However, when comparing TCAR vs TFCAS outcomes in patients with long lesions, TCAR was found to be associated with 30% reduction in stroke/TIA (aOR: 0.7, 95%CI:0.6-0.9, P=0.015), stroke (aOR: 0.7, 95%CI:0.5-0.9, P=0.009), and extended length of stay (ELOS) (aOR: 0.7, 95%CI:0.6-0.8, P<0.001). There was also a 40% reduction in the odds of in-hospital stroke/death (aOR: 0.6, 95%CI:0.5-0.8, P<0.001), and 70% reduction in mortality (aOR: 0.3, 95%CI:0.2-0.4, P<0.001) in TCAR compared to TFCAS.

CONCLUSIONS

In this large contemporary retrospective national study, carotid lesion length appears to negatively impact in-hospital outcomes for TCAR and TFCAS. In the presence of lesions longer than 25 mm, TCAR appears to be safer than TFCAS with regard to the risk of in-hospital stroke, stroke/TIA, death, stroke/death and ELOS. These favorable outcomes seem to confirm the relative advantage of flow reversal compared to distal embolic protection (DEP) devices in terms of neuroprotection.

Quantitative comparison between carotid plaque hardness and histopathological findings: an observational study

Background

Plaque hardness in carotid artery stenosis correlates with cerebral infarction. This study aimed to quantitatively compare plaque hardness with histopathological findings and identify the pathological factors involved in plaque hardness.

Methods

This study included 84 patients (89 lesions) undergoing carotid endarterectomy (CEA) at our institution. Plaque hardness was quantitatively measured immediately after excision using a hardness meter. Collagen and calcification were evaluated as the pathological factors. Collagen was stained with Elastica van Gieson stain, converted to a gray-scale image, and displayed in a 256-step histogram. The median gray-scale median (GSM) was used as the collagen content. The degree of calcification was defined by the hematoxylin–eosin stain as follows: "0:" no calcification, "1:" scattered microcalcification, or "2:" calcification greater than 1 mm or more than 2% of the total calcification. Carotid echocardiographic findings, specifically echoluminance or the brightness of the narrowest lesion of the plaque, classified as hypo-, iso-, or hyper-echoic by comparison with the intima-media complex surrounding the plaque, and clinical data were reviewed.

Results

Plaque hardness was significantly negatively correlated with GSM [Spearman's correlation coefficient: -0.7137 (p < 0.0001)]: the harder the plaque, the higher the collagen content. There were significant differences between plaque hardness and degree of calcification between "0" and "2" (p = 0.0206). For plaque hardness and echoluminance (hypo-iso-hyper), significant differences were found between hypo-iso (p = 0.0220), hypo-hyper (p = 0.0006), and iso-hyper (p = 0.0015): the harder the plaque, the higher the luminance. In single regression analysis, GSM, sex, and diabetes mellitus were significant variables, and in multiple regression analysis, only GSM was extracted as a significant variable.

Conclusions

Plaque hardness was associated with a higher amount of collagen, which is the main component of the fibrous cap. Greater plaque hardness was associated with increased plaque stability. The degree of calcification may also be associated with plaque hardness.

[Hybrid interventions for tandem occlusions in acute phase of ischemic stroke]

OBJECTIVE

To evaluate the effectiveness of hybrid interventions, i.e. endovascular mechanical thrombectomy from intracranial arteries combined with open thrombectomy or carotid endarterectomy from extracranial internal carotid artery.

MATERIAL AND METHODS

We analyzed 16 patients who underwent mechanical thrombectomy/thrombaspiration combined with open surgery between January 2014 and March 2021. All patients had occlusion of extracranial and intracranial segments internal carotid artery or initial segments of the middle cerebral artery. Baseline data, diagnostic algorithm, timing and results of treatment were analyzed. Study endpoints were technical success of revascularization, clinically significant hemorrhagic transformation, NIHSS and modified Rankin score of neurological impairment, as well as outcome of disease within 90 days.

RESULTS

We restored patency of ICA and intracranial arteries in 13 out of 16 patients. In 9 patients, we obtained a positive effect with significant regression of neurological symptoms (mRS <2). In 3 patients, severe neurological deficit persisted throughout the entire follow-up period. Four patients died. Thus, effectiveness of technique was 56.2% (t=3), mortality rate was 25% (t=2.3). There was a relationship between the timing of interventions and outcomes of disease. Indeed, all dead and most of disabled patients underwent surgery later than 6 hours from the onset of disease.

CONCLUSION

Hybrid interventions for tandem occlusions of carotid arteries can significantly increase efficiency and accelerate recanalization of great extracranial vessels in patients with tandem lesions in acute phase of ischemic stroke. Moreover, hybrid interventions significantly reduce the cost of reperfusion procedure. In case of severe atherosclerotic stenosis, simultaneous open endarterectomy from common and internal carotid arteries has a significant advantage over stenting due to no need for antithrombotic therapy.

The impact of carotid lesion calcification on outcomes of carotid artery stenting

OBJECTIVE

The impact of carotid artery lesion calcification on adverse events following carotid artery stenting is not well-studied. Few reports associated heavily calcified lesions with high risk of perioperative stroke following transfemoral carotid artery stenting (TFCAS). With the advent of transcarotid artery revascularization (TCAR), we aimed to compare the outcomes of these two procedures stratified by the degree of lesion calcification.

METHODS

Our cohort was derived from the Vascular Quality Initiative database for carotid artery stenting. Patients with missing information on the degree of carotid artery calcification were excluded. Patients were stratified into two groups: >50% (heavy) calcification and ≤50% (no/mild) calcification. The Student t test and the χ² test were used to compare patients' baseline characteristics and crude outcomes, as appropriate. Clinically relevant and statistically significantly variables on univariable analysis were added to a logistic regression model clustered by center identifier.

RESULTS

A total of 11,342 patients were included. Patients with >50% calcification were older, had more comorbidities, and more contralateral occlusion. There were more patients with prior ipsilateral carotid endarterectomy in the ≤50% calcification group. In patients who underwent TCAR, there were no significant differences between those who had >50% vs ≤50% carotid calcification in the odds of in-hospital adverse outcomes. However, in patients with heavy calcification who underwent TFCAS, there was a 50% to 60% increase in the odds of stroke (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.04-2.5; P = .03), stroke/transient ischemic attack (TIA) (OR, 1.6; 95% CI, 1.1-2.3; P = .013), and stroke/death (OR, 1.5; 95% CI, 1.02-2.08; P = .039). Compared with TFCAS in patients with heavy calcification, TCAR was associated with a 40% to 90% reduction in the odds of contralateral stroke (OR, 0.13; 95% CI, 0.04-0.4; P = .001), contralateral stroke/TIA (OR, 0.3; 95% CI, 0.1-0.87; P = .024), any stroke/TIA (OR, 0.6; 95% CI, 0.38-0.91; P = .02), death (OR, 0.3; 95% CI, 0.13-0.72; P = .006), stroke/death (OR, 0.5; 95% CI, 0.32-0.8; P = .004), and stroke/death/myocardial infarction (OR, 0.58; 95% CI, 0.39-0.87; P = .008). There were no significant differences in the odds of stroke and myocardial infarction.

CONCLUSIONS

In this retrospective analysis of patients undergoing TFCAS vs TCAR in the Vascular Quality Initiative database, TCAR demonstrated favorable outcomes compared with TFCAS among patients with calcification greater than 50% of the carotid circumference. Advance burden of carotid artery calcification was associated with worse outcomes in patients undergoing TFCAS but not TCAR. These results are consistent with previously demonstrated superiority of flow reversal compared with distal embolic protection devices. Further research is needed to assess long-term outcomes and confirm the durability of TCAR in heavily calcified lesions.

Transcarotid Arterial Revascularization Adoption Should not Be Hindered by a Concern for a Long Learning Curve

BACKGROUND

Transcarotid arterial revascularization (TCAR) offers a novel technique for carotid artery stenting (CAS) that provides flow reversal in the carotid artery and avoids aortic arch manipulation, thus, potentially lowering ipsilateral and contralateral periprocedural stroke rates. As a new technology, adoption may be limited by concern for learning a new technique. This study seeks to examine the number of cases needed for a surgeon to reach technical proficiency.

METHODS

Retrospective analysis was performed using a prospectively collected database of all TCAR procedures performed in a tertiary health care system between 2016 and 2020. Patient demographics and anatomic characteristics were collected. Intraoperative variables and perioperative outcomes were examined. These variables were collated into groups for the first 4 procedures, procedures 5-8, and after 8. Independent Samples t test, 1-way ANOVA, and logarithmic regression were used to statistically analyze the data.

RESULTS

One-hundred and eighty-seven TCARs were performed by 14 surgeons. One hundred and twenty-two (65%) were male, 59 (32%) were older than 75 years, and 83 (44%) were symptomatic. The most common indications were high-lesions in 87 patients (47%) and recurrent stenosis after CEA in 37 patients (20%). Significant differences were found between the first and second groups of 4 cases when comparing mean operative time (71 vs. 58 min; P = 0.001) and flow reversal time (10.8 vs. 7.9 min; P= 0.004). similar significant differences were found between the first and third groups of 4 cases but not between the second and third groups. There was a reduction in contrast usage and fluoroscopy time after the first 4 cases, however, this did not reach statistical significance. There was no ipsilateral perioperative strokes. One patient had a contralateral stroke on postoperative day 2 due to intracranial atherosclerosis, and there was one perioperative mortality that occurred on postoperative day 3 after discharge.

CONCLUSIONS

Procedural and flow reversal times significantly shorten after 4 TCAR procedures are performed. Other metrics, such as fluoroscopy time and contrast usage, are also decreased. Complications, in general, are minimal. Proficiency in TCAR, as measured by these metrics, is met after performing only 4 procedures.

The predictive value of CHADS2 score for subclinical cerebral ischemia after carotid artery stenting (from the PREVENT-CAS trial)

BACKGROUND

Carotid artery stenting (CAS) is being increasingly used as an alternative revascularization procedure to carotid endarterectomy; however, subclinical ischemic cerebral lesions after CAS remain as a matter of concern. Hence, we aimed to assess the clinical utility of the CHADS₂ score in predicting subclinical ischemic events after CAS.

METHODS

We prospectively evaluated 107 patients (mean age: 70.4 ± 6.6 years, male:77) who underwent CAS for carotid artery revascularization. The patients having symptomatic transient ischemic attack or stroke after CAS were excluded. The presence of new hyperintense lesion on diffusion-weighted imaging (DWI) without any neurological findings was considered as silent ischemia. Patients were classified into two groups as DWI-positive and DWI-negative patients.

RESULTS

Among study population, 28 patients (26.2%) had subclinical embolism. The DWI-positive group had a significantly higher CHADS2 scores, older age, more frequent history of stroke, higher proportion of type III aortic arch, and longer fluoroscopy time than the DWI-negative group. Increased CHADS₂ score was identified as one of the independent predictors of silent embolism (OR = 5.584; 95%CI: 1.516-20.566; p = .010), and CHADS₂ score higher than 2.5 predicted subclinical cerebral ischemia with a sensitivity of 72% and a specificity of 71% (AUC: 0.793; 95% CI: 0.696 - 0.890; p < .001).

CONCLUSIONS

CHADS₂ score was able to predict the risk of periprocedural subclinical ischemic events in CAS and might be of clinical value in the management of patients with carotid artery stenosis.

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.

Learning curve and proficiency of transcarotid artery revascularization compared to transfemoral carotid artery stenting

Both transfemoral carotid artery stenting (TF-CAS) and transcarotid artery revascularization (TCAR) are competing endovascular alternatives to carotid endarterectomy for the treatment of atherosclerotic carotid artery stenosis. TF-CAS is an endovascular procedure associated with a long learning curve and higher periprocedural stroke and death rates during an operator's early experience. Estimates suggest that more than 50 cases are required to achieve outcomes similar to carotid endarterectomy. TCAR is a novel hybrid procedure combining direct common carotid artery access and cerebral blood flow reversal with carotid stent placement. In distinction from TF-CAS, TCAR has a rather short learning curve. A multi-institutional analysis showed that operators achieved technical proficiency after approximately 10 to 15 cases. This was reinforced by a large Society for Vascular Surgery, Vascular Quality Initiative Transcarotid Artery Revascularization Surveillance Project analysis that demonstrated that expertise peaked after approximately 20 cases. Both studies found that TCAR was not associated with an increased rate of stroke or death during operator's early experience. These data suggest that TCAR is readily learned and patients are not at increased risk during a surgeon's early experience.

Risk factors and impact of postoperative hypotension after carotid artery stenting in the Vascular Quality Initiative

OBJECTIVE

Hypotension is a frequent complication of carotid artery stenting (CAS). Although common, its occurrence is unpredictable, and association with adverse events has not been well defined. The aim of this study was to identify predictors of postoperative hypotension after CAS and the association with stroke/transient ischemic attack (TIA), major adverse cardiac events (MACEs), increased length of stay (LOS), and in-hospital mortality.

METHODS

This is a retrospective analysis of all CAS procedures, including transfemoral CAS (TF-CAS) and transcarotid artery revascularization (TCAR), performed in the Vascular Quality Initiative between 2003 and 2018. The primary study end point was postoperative hypotension, defined as hypotension treated with continuous infusion of a vasoactive agent for ≥15 minutes. Secondary end points included any postoperative neurologic events (stroke/TIA), MACEs (myocardial infarction, congestive heart failure, and dysrhythmias), prolonged LOS (>1 day), and in-hospital mortality. Patients' demographics predictive of hypotension were determined by multivariable logistic regression, and a risk score was developed for correlation with outcomes.

RESULTS

During the time period of study, 24,699 patients underwent CAS; 19,716 (80%) were TF-CAS, 3879 (16%) were TCAR, and 1104 (4%) were not defined. Fifty-six percent were for symptomatic disease, 75% were for a primary atherosclerotic lesion, and 72% were performed under local or regional anesthesia. Postoperative hypotension occurred in 15% of TF-CAS and 14% of TCAR patients (P = .50). Patients with hypotension (vs no hypotension) had higher rates of stroke/TIA (7.3% vs 2.6%; P < .001), MACEs (9.6% vs 2.1%; P < .001), prolonged LOS (65% vs 28%; P < .001), and in-hospital mortality (2.9% vs 0.7%; P < .001). By multivariable analysis, risk factors associated with hypotension included an atherosclerotic (vs restenotic) lesion (odds ratio, 2.2; 95% confidence interval, 2.0-2.4; P < .001), female sex (1.3 [1.2-1.4]; P < .001), positive stress test result (1.3 [1.2-1.4]; P < .001), age 70 to 79 years (1.1 [1.1-1.3]; P < .002), age >80 years (1.2 [1.1-1.4]; P < .001), history of myocardial infarction or angina (1.3 [1.2-1.4]; P < .001), and an urgent (vs elective) procedure (1.1 [1.0-1.2]; P < .01). A history of hypertension was protective (0.9 [0.8-0.9]; P < .02). A normalized risk score for hypotension was created from the multivariable model. Increasing risk scores correlated directly with rates of adverse events, including postoperative stroke/TIA, MACEs, increased LOS, and increased in-hospital mortality.

CONCLUSIONS

Hypotension after CAS is associated with adverse neurologic and cardiac events as well as with prolonged LOS and in-hospital mortality. A scoring tool may be valuable in stratifying patients at risk. Interventions aimed at preventing postoperative hypotension may improve outcomes with CAS.

Carotid artery stenting versus endarterectomy for treatment of carotid artery stenosis

BACKGROUND

Carotid artery stenting is an alternative to carotid endarterectomy for the treatment of atherosclerotic carotid artery stenosis. This review updates a previous version first published in 1997 and subsequently updated in 2004, 2007, and 2012.

OBJECTIVES

To assess the benefits and risks of stenting compared with endarterectomy in people with symptomatic or asymptomatic carotid stenosis.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched August 2018) and the following databases: CENTRAL, MEDLINE, Embase, and Science Citation Index to August 2018. We also searched ongoing trials registers (August 2018) and reference lists, and contacted researchers in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing stenting with endarterectomy for symptomatic or asymptomatic atherosclerotic carotid stenosis. In addition, we included RCTs comparing carotid artery stenting with medical therapy alone.

DATA COLLECTION AND ANALYSIS

One review author selected trials for inclusion, assessed trial quality and risk of bias, and extracted data. A second review author independently validated trial selection and a third review author independently validated data extraction. We calculated treatment effects as odds ratios (OR) and 95% confidence intervals (CI), with endarterectomy as the reference group. We quantified heterogeneity using the I² statistic and used GRADE to assess the overall certainty of evidence.

MAIN RESULTS

We included 22 trials involving 9753 participants. In participants with symptomatic carotid stenosis, compared with endarterectomy stenting was associated with a higher risk of periprocedural death or stroke (the primary safety outcome; OR 1.70, 95% CI 1.31 to 2.19; P < 0.0001, I² = 5%; 10 trials, 5396 participants; high-certainty evidence); and periprocedural death, stroke, or myocardial infarction (OR 1.43, 95% CI 1.14 to 1.80; P = 0.002, I² = 0%; 6 trials, 4861 participants; high-certainty evidence). The OR for the primary safety outcome was 1.11 (95% CI 0.74 to 1.64) in participants under 70 years old and 2.23 (95% CI 1.61 to 3.08) in participants 70 years old or more (interaction P = 0.007). There was a non-significant increase in periprocedural death or major or disabling stroke with stenting (OR 1.36, 95% CI 0.97 to 1.91; P = 0.08, I² = 0%; 7 trials, 4983 participants; high-certainty evidence). Compared with endarterectomy, stenting was associated with lower risks of myocardial infarction (OR 0.47, 95% CI 0.24 to 0.94; P = 0.03, I² = 0%), cranial nerve palsy (OR 0.09, 95% CI 0.06 to 0.16; P < 0.00001, I² = 0%), and access site haematoma (OR 0.32, 95% CI 0.15 to 0.68; P = 0.003, I² = 27%). The combination of periprocedural death or stroke or ipsilateral stroke during follow-up (the primary combined safety and efficacy outcome) favoured endarterectomy (OR 1.51, 95% CI 1.24 to 1.85; P < 0.0001, I² = 0%; 8 trials, 5080 participants; high-certainty evidence). The rate of ipsilateral stroke after the periprocedural period did not differ between treatments (OR 1.05, 95% CI 0.75 to 1.47; P = 0.77, I² = 0%). In participants with asymptomatic carotid stenosis, there was a non-significant increase in periprocedural death or stroke with stenting compared with endarterectomy (OR 1.72, 95% CI 1.00 to 2.97; P = 0.05, I² = 0%; 7 trials, 3378 participants; moderate-certainty evidence). The risk of periprocedural death or stroke or ipsilateral stroke during follow-up did not differ significantly between treatments (OR 1.27, 95% CI 0.87 to 1.84; P = 0.22, I² = 0%; 6 trials, 3315 participants; moderate-certainty evidence). Moderate or higher carotid artery restenosis (50% or greater) or occlusion during follow-up was more common after stenting (OR 2.00, 95% CI 1.12 to 3.60; P = 0.02, I² = 44%), but the difference in risk of severe restenosis was not significant (70% or greater; OR 1.26, 95% CI 0.79 to 2.00; P = 0.33, I² = 58%; low-certainty evidence).

AUTHORS' CONCLUSIONS

Stenting for symptomatic carotid stenosis is associated with a higher risk of periprocedural stroke or death than endarterectomy. This extra risk is mostly attributed to an increase in minor, non-disabling strokes occurring in people older than 70 years. Beyond the periprocedural period, carotid stenting is as effective in preventing recurrent stroke as endarterectomy. However, combining procedural safety and long-term efficacy in preventing recurrent stroke still favours endarterectomy. In people with asymptomatic carotid stenosis, there may be a small increase in the risk of periprocedural stroke or death with stenting compared with endarterectomy. However, CIs of treatment effects were wide and further data from randomised trials in people with asymptomatic stenosis are needed.

Restenosis After Carotid Endarterectomy Performed With Routine Intraoperative Duplex Ultrasonography and Arterial Patch Closure: A Contemporary Series

The restenosis rates of 5% to 15% have been reported after carotid endarterectomy (CEA). We undertook this investigation to determine whether the routine practice of carotid artery patch closure and intraoperative completion duplex ultrasonography would result in lower rates of carotid restenosis after CEA. All consecutive carotid endarterectomies performed between 2000 and 2004 at a single institution were reviewed retrospectively. Patients underwent CEA using a longitudinal arteriotomy, followed by routine patching and intraoperative completion duplex ultrasonography. Only patients with at least one postoperative duplex scan performed at a minimum of 180 days after CEA were included. During the 5-year study period, 407 consecutive carotid endarterectomies were performed, with a combined 30-day stroke and mortality rate of 2.5%; 217 patients (53%) had one or more duplex ultrasound examinations performed at least 180 days after CEA. The mean follow-up duration was 692 days. Of the patients who underwent intraoperative intervention based on the results of the completion duplex study, none experienced restenosis, stroke, or death. CEA that is performed with routine patching and intraoperative duplex completion ultrasonography is a safe, durable operation with restenosis rates below those commonly reported.

Comorbidities and Health-Related Quality of Life Following Revascularization for Asymptomatic Critical Internal Carotid Artery Stenosis Treated with Carotid Endarterectomy or Angioplasty with Stenting

Background

This study aimed to evaluate the relationship between existing comorbidities and the effectiveness of revascularization of asymptomatic critical internal carotid artery (ICA) stenosis treated with carotid endarterectomy (CEA) or carotid artery stenting (CAS) and short-term and long-term outcome in terms of health-related quality of life (HRQoL).

Material/Methods

Patients with asymptomatic critical ICA stenosis (n=62) included a group treated with CEA (n=31) and a group treated with CAS (n=31). A Health Assessment Questionnaire designed for this study was used to assess ten comorbidities, and the Short Form 36 Health Survey Questionnaire (SF-36) was used to evaluate HRQoL following CEA and CAS.

Results

Three comorbidities significantly influenced the effectiveness of revascularization in all patients studied who underwent CEA and CAS, which included symptomatic atherosclerosis in other vascular areas (p=0.048), coronary artery disease (CAD) (p=0.004), and previous myocardial infarction (MI) (p=0.004). In the CEA group, CAD and previous MI were significant comorbidities (p=0.002), when compared with the CAS group (p=0.635). In the CAS group, chronic obstructive pulmonary disease (COPD) was a significant comorbidity in terms of outcome (p=0.025).

Conclusions

The comorbidities of atherosclerotic vascular disease, CAD, and previous MI had a significant influence of the effectiveness of the revascularization and postoperative HRQoL in all patients studied with asymptomatic critical ICA stenosis who were treated with CEA and CAS. When the two groups were compared, CAD and previous MI were significant comorbidities in the CEA group, and COPD was a significant comorbidity in the CAS group.

Intravascular ultrasound assisted carotid artery stenting: randomized controlled trial. Preliminary results on 60 patients

AIMS

The primary aim is the evaluation of the usefulness of intravascular ultrasound (IVUS) in the identification of otherwise unnoticed complications during carotid stenting. The secondary aim is the evaluation of the impact of IVUS assistance in the procedural outcomes and long-term patency rates of carotid artery stenting.

MATERIALS AND METHODS

Sixty patients who underwent carotid artery stenting (CAS) during a 14-month period were evaluated prospectively. Thirty patients (50%) underwent IVUS assisted CAS, 30 patients (50%) underwent CAS using angiography as the unique diagnostic tool. All patients were enrolled through a primary duplex ultrasound evaluation; as a secondary evaluation, 54 patients (90%) underwent a preprocedural magnetic resonance angiography, whereas six patients (10%) underwent computed tomography-angiography. Patients with preocclusive stenoses (>85%) were excluded. Mean follow-up was 23 W 5.3 months.

RESULTS

No periprocedural or late complications were observed. No statistical significance was observed in long-term stent patency between the two groups. Mean procedural time length of IVUS-assisted procedures was 10.3 W 5 min longer than non-IVUS-assisted procedures. Virtual histology (VH) IVUS evaluation of plaque morphology led to a different stent choice in three patients. In two cases, the IVUS assessment revealed a suboptimal stent deployment, solved by angioplasty; in one patient VH-IVUS detected plaque protrusion through stent cells, immediately treated by manual aspiration.

CONCLUSIONS

Though not recommended as a routine intraprocedural evaluation, IVUS may be useful for a real-time CAS control when treating challenging plaques, such as 'soft' or lipidic ones or those prone to rupture, or whenever an intraprocedural morphologic evaluation is required for the appropriate stent choice, or when higher embolic risk is evaluated.

Technical improvements in carotid revascularization based on the mechanism of procedural stroke

The benefit of carotid revascularization in patients with severe carotid artery stenosis is hampered by the risk of stroke due to the intervention itself. The risk of periprocedural strokes is higher for carotid artery stenting (CAS) as compared to carotid endarterectomy (CEA). Over the past years, the pathophysiological mechanism responsible for periprocedural stroke seems to unfold step by step. Initially, all procedural strokes were thought to be the result of technical errors during surgical repair: cerebral ischemia due to clamping time of the carotid artery, cerebral embolization of atherosclerotic debris due to manipulation of the atheroma or thrombosis of the artery. Following improvements in surgical techniques, technical skills, new intraoperative monitoring technologies such as angioscopy, and the results of the first large clinical randomized controlled trials (RCT) it was believed that most periprocedural strokes were of thromboembolic nature, while a large part of these caused by technical error. Nowadays, analyses of underlying pathophysiological mechanisms of procedural stroke make a clinically relevant distinction between intra-procedural and postprocedural strokes. Intra-procedural stroke is defined as hypoperfusion due to clamping (CEA) or dilatation (CAS) and embolization from the carotid plaque (both CEA and CAS). Postprocedural stroke can be caused by thrombo-embolisation but seems to have a primarily hemodynamic origin. Besides thrombotic occlusion of the carotid artery, cerebral hyperperfusion syndrome (CHS) due to extensively increased cerebral revascularization is the most reported pathophysiological mechanism of postprocedural stroke. Multiple technical improvements have attempted to lower the risk of periprocedural stroke. The introduction of antiplatelet therapy (APT) has significantly reduced the risk of thromboembolic events in patients with carotid stenosis. Over the years, recommendations regarding APT changed. While for a long time APT was discontinued prior to surgery because of a fear of increased bleeding risk, nowadays continuation of APT during carotid intervention (aspirin monotherapy or even dual APT including clopidogrel) is found to be safe and effective. In CAS patients, dual APT up to three months' postprocedural is considered best. Stent design and cerebral protection devices (CPD) for CAS procedure are continuously under development. Trials have suggested a benefit of closed-cell stent design over open-cell stent design in order to reduce procedural stroke, while the benefit of CPD during stenting is still a matter of debate. Although CPD reduce the risk of procedural stroke, a higher number of new ischemic brain lesions detected on diffusion weighted imaging was found in patients treated with CPD. In patients undergoing CEA under general anesthesia, adequate use of cerebral monitoring (EEG and transcranial Doppler [TCD]) has reduced the number of intraoperative stroke by detecting embolization and thereby guiding the surgeon to adjust his technique or to selectively shunt the carotid artery. In addition, TCD is able to adequately identify and exclude patients at risk for CHS. For CAS, the additional value of periprocedural cerebral monitoring to prevent strokes needs urgent attention. In conclusion, this review provides an overview of the pathophysiological mechanism of stroke following carotid revascularization (both CAS and CEA) and of the technical improvements that have contributed to reducing this stroke risk.

Targeting von Willebrand Factor in Ischaemic Stroke: Focus on Clinical Evidence

Despite great efforts in stroke research, disability and recurrence rates in ischaemic stroke remain unacceptably high. To address this issue, one potential target for novel therapeutics is the glycoprotein von Willebrand factor (vWF), which increases in thrombogenicity especially under high shear rates as it bridges between vascular sub-endothelial collagen and platelets. The rationale for vWF as a potential target in stroke comes from four bodies of evidence. (1) Animal models which recapitulate the pathogenesis of stroke and validate the concept of targeting vWF for stroke prevention and the use of the vWF cleavage enzyme ADAMTS13 in acute stroke treatment. (2) Extensive epidemiologic data establishing the prognostic role of vWF in the clinical setting showing that high vWF levels are associated with an increased risk of first stroke, stroke recurrence or stroke-associated mortality. As such, vWF levels may be a suitable marker for further risk stratification to potentially fine-tune current risk prediction models which are mainly based on clinical and imaging data. (3) Genetic studies showing an association between vWF levels and stroke risk on genomic levels. Finally, (4) studies of patients with primary disorders of excess or deficiency of function in the vWF axis (e.g. thrombotic thrombocytopenic purpura and von Willebrand disease, respectively) which demonstrate the crucial role of vWF in atherothrombosis. Therapeutic inhibition of VWF by novel agents appears particularly promising for secondary prevention of stroke recurrence in specific sub-groups of patients such as those suffering from large artery atherosclerosis, as designated according to the TOAST classification.

Comparison between Quantitative Stiffness Measurements and Ultrasonographic Findings of Fresh Carotid Plaques

Using a stiffness meter, we quantitatively measured the stiffness of fresh plaques that had been excised by carotid endarterectomy. The objective of this study was to clarify the correlation between plaque stiffness and pre-operative carotid ultrasonographic findings, and predict the stiffness of plaques before surgery by comparison with the stiffness of common items. The study population comprised 44 patients (44 lesions) who had undergone carotid endarterectomy at our institution between December 2009 and October 2014. The stiffness of excised fresh plaques was measured using a stiffness meter and compared with the pre-operative echographic findings for the plaques and the stiffness of selected foods and common items. The mean stiffness value for all plaques was 4.52 ± 3.30 MPa (mean ± standard deviation). The plaques exhibiting calcification were significantly harder (p = 0.001). On classification of lesions on the basis of echographic findings, plaque hardness was in the order low-echoic (15 lesions) < iso-echoic (20 lesions) < high-echoic (9 lesions) (p = 0.02). The stiffness of the low-echoic group was equivalent to that of tofu or sliced cheese, whereas the plaques in the iso- and high-echoic groups exhibited stiffness similar to that of ham and a plastic eraser, respectively. A significant correlation was observed between the quantitative stiffness values of carotid plaques and their brightness on carotid ultrasonography. Using these data, operators might be able to predict plaque stiffness from pre-operative echographic findings. In addition, it might be useful for operators to compare such quantitative stiffness measurements with stiffness data for foods and common items to gain an understanding of the state of the target plaque before treatment.

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.

Reoperation for Recurrent Carotid Stenosis: A Ten-Year Experience

Owing to the supposed risks of reoperation, carotid stenting has been proposed as a treatment for carotid restenosis. The purpose of this study is to determine the safety and efficacy of carotid reoperation. From March 1988 to March 1997, 40 patients, 18 men and 22 women (mean age: 65 years) underwent a total of 43 redo carotid procedures by our group. Two patients had both sides repaired and one required a second reoperation. Symptomatic recurrent carotid stenosis (>70%) was the indication in 25 reoperations and asymptomatic high-grade stenosis (>80%) was the indication in 18. The initial operation in 35 reoperations was carotid endarterectomy (CEA) with primary closure and in eight it was CEA with a prosthetic patch. The interval to recurrence was less in the 24 reoperations in patients who had myointimal hyperplasia (21 months) compared with 17 reoperations in patients with recurrent atherosclerosis (90 months). The other two reoperations were for an intimal flap 2 months after the original CEA, and for operative dilation of fibromuscular dysplastic bands missed on magnetic resonance angiography (MRA), distal to the site of a previous CEA.

The technique of reoperation included redo CEA in two, CEA with vein patch in eight, CEA with prosthetic patch in 22, vein interposition graft in five, and prosthetic interposition graft in five. In addition, operative dilation with an arterial dilator was used in one reoperation.

No perioperative strokes or deaths occurred other than one patient who died from cardiac complications following combined CEA and coronary artery bypass grafting. Operative morbidity consisted of pneumonia in one patient, reversible cranial nerve injury in four, and hematoma requiring evacuation in two. During follow-up (mean: 34 months), carotid occlusion resulted in a mild stroke in one patient, there were 10 late deaths not related to carotid disease, one patient required a reoperation, and three patients were lost to follow-up.

The authors conclude that reoperation for recurrent carotid stenosis, using standard vascular techniques, is both safe and effective; it should continue to be the mainstay of treatment when intervention is required.

Factors Affecting Recurrent Carotid Stenosis

Recurrent carotid stenosis is an ongoing process that may develop at or near the site of an operational or interventional procedure to treat an atheromatous stenosis. Although such a restenosis is most often initially without symptoms, as the disease progresses it may become symptomatic, and thus endanger the patient's life. Such patients are therefore candidates for revisional surgery. Extensive research investigation and numerous studies have incriminated several risk factors as predisposing conditions for recurrent carotid stenosis. The definite role of each predisposing factor, however, is still widely debated. Clarifying the extent of involvement of each factor in the pathogenesis of carotid restenosis is indeed demanding, as it would contribute enormously to the identification of the group of high-risk patients, and, therefore, determine the therapeutic approach in these patients.

Stenting Treatment for Intra- and Extra-Cranial Atherosclerotic Diseases

The purpose of this study was to investigate the effect, safety and short-term outcome of stenting treatment for extra- and intra-cranial atherosclerotic diseases. Forty-one patients underwent stenting treatment using coronary and biliary stents.

Eleven patients had tubular or diffuse high-grade stenoses not amenable to standard balloon angioplasty involving intra-cranial arteries, while in thirty, extra-cranial arteries were involved. Stents were successfully implanted in 36 out of 41 lesions (88%) with 2% (1/41) of overall procedural morbidity rate. Procedural and clinical success rate of intra-cranial stent placement was 64% (7/11) and no complications occurred during or after intra-cranial stent placement: the morbidity rate was 0%. Hyperperfusion injury occurred in two patients after successful implantation of stents in subtotal occlusion of the internal carotid artery, and consequently the overall clinical success rate was 80% (33/41).

Restenosis occurred in four (12%) out of 33 patients who underwent six month follow-up arteriography. No ischemic attacks or stent-deformation occurred during follow-up after stenting treatment. For lesions not amenable to standard balloon angioplasty, endovascular stent placement seems to be a safe and effective treatment of modality.

Loss of labelling efficiency caused by carotid stent in pseudocontinuous arterial spin labelling perfusion study

AIM

To elucidate the cause of cerebral hypoperfusion on the stent placement side after carotid artery stent placement (CAS) measured by pseudocontinuous arterial spin labelling (PCASL) perfusion imaging.

MATERIALS AND METHODS

Consecutive patients with symptomatic internal carotid artery stenosis receiving CAS were included in the study. Cerebral blood flow (CBF) was measured by PCASL perfusion imaging at 3 T magnetic resonance imaging (MRI) the day before and 3 days after the procedure. Changes in cerebral haemodynamics after CAS were assessed.

RESULTS

Twenty-two patients were included; 17 patients had increased or stationary CBF after CAS and five patients had significantly reduced CBF on the stenting side after CAS whereas CBF increased on the contralateral side. High stent position was noticed in the five patients. After labelling plane adjustment to avoid labelling on the stent, no more cerebral hypoperfusion was noticed.

CONCLUSION

When using PCASL perfusion imaging to monitor post-stenting CBF, the stent may cause an artefact that leads to a low CBF in the territory of the stented vessel. Routinely adding a fast T2 star gradient-echo echo-planar-imaging covering the upper neck region before PCASL perfusion imaging to identify the stent position and avoid the stent-related artefact is recommended.

Is Extended Duration of Dual Antiplatelet Therapy After Carotid Stenting Beneficial?

The optimal antithrombotic regimen after carotid artery stenting (CAS) remains uncertain. We aimed to elucidate if long-term duration of aspirin plus clopidogrel after CAS would provide clinically relevant benefit. Patients receiving CAS were identified from the National Health Insurance Research Database, Taiwan. The discharge date following CAS was defined as index date. The study participants were divided into groups according to the prescribed duration of antiplatelet after the index date. They included the insufficient (< 30 days), moderate (30-41 days), and considerable (≥ 42 days) groups. The risk of ischemic stroke, composite vascular outcome, and death were interested outcomes. To eliminate event-related prescription change, all outcomes that occurred within 42 days were excluded. Follow-up started 42 days after the index date and was censored when an event occurred or at 6 months. A total of 4903 patients received CAS from 2004 to 2011. The total participants recruited for analysis (n = 2829) included the insufficient (n = 688), moderate (n = 372), and considerable groups (n = 1769). The event rates of ischemic stroke (3.92, 2.69, and 2.77%, P = 0.30), composite vascular stroke (5.52, 4.03, and 4.41%, P = 0.42), and death (3.05, 2.42, and 2.32%, P = 0.58) were similar for each group. Cox regression did not demonstrate significant associations between antiplatelet duration and the outcomes of interest. Long-term use of aspirin plus clopidorel after CAS did not decrease the risk of ischemic stroke, composite vascular events, or death during 6 months of follow-up. More research on the appropriate duration of post-CAS dual antiplatelet is essential.

Headache, cerebral aneurysms, and the use of triptans and ergot derivatives

BACKGROUND

Uncertainty exists regarding the correlation between unruptured cerebral aneurysms and their role in headache etiology. It is also unclear whether surgical endovascular treatment may improve or worsen the headache, and if there are predictable factors for headache outcome such as pre-existing headache features, aneurysm characteristics, or other medical history. There is debate regarding safe treatment of migraine in patients with aneurysms, both before and after endovascular treatments. Particularly, there is hesitancy to use the triptans and ergot derivatives such as dihydroergotamine because of their vasoconstrictive effects and concern for adverse events related to the aneurysm such as aneurysmal instability and rupture.

OBJECTIVE

To review the literature regarding the anatomy, pathophysiology, and association between headache, untreated vs surgically treated aneurysms, and the use of triptans and ergot derivatives for migraine treatment in this setting.

CONCLUSION

Associations between some headaches and aneurysms may exist. Some chronic headaches may respond to surgical aneurysm repair while others may worsen. These associations are undefined by current literature because of variable results, study methods, and limited data. Prospective studies are needed which incorporate pre- and post-procedure headache character and diagnosis, aneurysm characteristics, type of aneurysm repair, associated risk factors for worsening post-procedure headache, and ultimately combining all of these data to better predict headache outcome following surgical aneurysm treatment. Lastly, the caution and avoidance of triptan and ergot derivative use for migraine in the setting of aneurysm is not supported by the current evidence, and much of this concern may be excessive and unwarranted, although more evidence confirming safety is needed.

Carotid Endarterectomy Versus Stenting: A Meta-Analysis of Randomized Trials

Background:

A meta-analysis of randomized controlled trials (RCTs) was conducted to update the available evidence on the safety and efficacy of carotid endarterectomy (CEA) versus carotid artery stenting (CAS) in the treatment of carotid artery stenosis.

Methods:

A comprehensive search was performed of MEDLINE, EMBASE, CENTRAL, bibliographies of included articles and past systematic reviews, and abstract lists of recent scientific conferences. For each reported outcome, a Mantel-Haenszel random-effects model was used to calculate odds ratios (ORs) and 95% confidence intervals (CI). The I2 statistic was used as a measure of heterogeneity.

Results:

Twelve RCTs enrolling 6,973 patients were included in the meta-analysis. Carotid artery stenting was associated with a significantly greater odds of periprocedural stroke (OR 1.72, 95% CI 1.20 to 2.47) and a significantly lower odds of periprocedural myocardial infarction (OR 0.47, 95% CI 0.29 to 0.78) and cranial neuropathy (OR 0.08, 95% CI, 0.04 to 0.16). The odds of periprocedural death (OR 1.11, 95% CI 0.56 to 2.18), target vessel restenosis (OR 1.95, 95% CI 0.63 to 6.06), and access-related hematoma were similar following either intervention (OR 0.60, 95% CI 0.30 to 1.21).

Conclusions:

In comparison with CEA, CAS is associated with a greater odds of stroke and a lower odds of myocardial infarction. While the results our meta-analysis support the continued use of CEA as the standard of care in the treatment of carotid artery stenosis, CAS is a viable alternative in patients at elevated risk of cardiac complications.

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.

Has carotid artery stenting found its place? A 10-year regional centre perspective

INTRODUCTION

The post-Carotid Revascularization Endarterectomy versus Stenting Trial era has seen a dramatic decline in the practice of carotid artery stenting (CAS). A retrospective review of prospectively collected CAS outcomes over a 10-year period by a single operator was undertaken to determine if this change in practice is justified and to identify the place of carotid stenting in current practice.

METHODS

One hundred fifty-nine carotid stent procedures were undertaken on 137 patients from 2002 to 2012. Cases were selected for CAS only if they fulfilled the inclusion criteria for the SAPPHIRE trial. Post-procedural outcomes were compared against those of a contemporaneous cohort of patients undergoing carotid endarterectomy (CEA) by the same operator and against published meta-analyses. The measure of CAS durability was need for re-intervention, based on the presence of ultrasound-detected re-stenosis >70%.

RESULTS

No significant difference was identified in 30-days' complication rates between patients undergoing CAS and those having CEA. Compared to published meta-analyses of CAS, our practice was accompanied by a significantly lower rate of peri-procedural stroke (1.26% versus 6%, P = 0.014) while carrying equivalent 30-days' death and myocardial infarction. Four stented arteries had re-intervention, due to asymptomatic in-stent stenosis of >70%. Further intervention was declined in a fifth case. This represents a re-stenosis rate of 3.1% over a mean follow-up of 40.2 ± 27.6 months.

DISCUSSION

CAS can provide a safe and durable treatment option for selected patients with carotid artery disease, in the hands of appropriately trained proceduralists who meet accepted standards of practice.

Complications and Solutions with Carotid Stenting

Complications of carotid stenting can be classified as neurologic, cardiovascular, death, carotid, access site, device malfunctions, and general and late complications. The risk of most complications is related to readily identifiable patient and anatomic factors. Management and outcome of complications require immediate recognition and a team-based approach to patient care.

Carotid Artery Stenting: Operator and Institutional Learning Curves

Despite rapid growth in the frequency that carotid artery stenting (CAS) is performed, there remain concerns regarding the steep learning curve associated with this procedure. This article reviews the evidence base supporting operator and institutional CAS learning curves and discusses their implications for the establishment and maintenance of competencies. Attempts are made to delineate minimum volume thresholds to attain these goals and means to enhance procedural safety without compromising patient access.

An anchoring technique by looping with the tip of a super-stiff wire: may be a solution in patients with anomaly of the aortic arch and tortuous carotid artery disease?

Vascular anatomy is one of the most important factors for the successful carotid artery interventions, either angioplasty or stenting. We report a new technique for advancing a guiding catheter into the common carotid artery when there is an unfavourable aortic arch anatomy and tortuosity of the carotid artery.

Direct percutaneous carotid artery stenting with distal protection: technical case report

We describe the technique of percutaneous carotid artery stent placement with distal protection in a patient in whom marked innominate artery ectasia prevented transfemoral access to the right common carotid artery. After induction of general anesthesia, ultrasound was used to guide direct puncture of the common carotid artery followed by the introduction of a 5 French sheath. A GuardWire distal protection balloon (Medtronic, Santa Rosa, CA) was placed distal to the lesion and deployed at nominal diameter. A balloon-expandable stent was deployed without difficulty. Following stent placement, angiography demonstrated improved flow in the entire right carotid artery territory. There were no complications related to cervical soft tissue damage or clinical embolism. The patient tolerated the procedure well and was discharged in 24 hours. Direct carotid access is acceptable in select patients in whom a transfemoral, brachial, or transradial approach is technically difficult. The use of distal cerebral protection devices may reduce cerebral embolism associated with these procedures.

Carotid endarterectomy without shunt: the role of cerebral metabolic protection

BACKGROUND

The optimal method to protect the brain from hemodynamic ischemia during carotid endarterectomy (CEA) remains controversial. This study reports our experience with induced arterial hypertension and selective etomidate cerebral protection in a cohort of patients who underwent CEA without shunting and continuous electroencephalography (EEG) monitoring.

METHODS

We reviewed retrospectively 102 consecutive CEAs performed in 102 patients with routine EEG monitoring and general anesthesia between March 1998 and October 2002. There were 65 (66%) symptomatic and 37 (34%) asymptomatic individuals. A protocol of induced arterial hypertension against EEG ischemic changes during carotid artery cross clamping was followed. Only patients with EEG changes refractory to induced hypertension went into etomidate-induced burst suppression.

RESULTS

EEG changes were classified as mild, moderate and severe. Twenty patients (19.6%) developed asymmetric EEG changes, of which the great majority were mild and moderate (75%, p< 0.05). Seven patients with moderate (n=3) and severe (n=4) EEG changes needed etomidate cerebral protection. There were no mortalities and only one stroke (0.98%) is reported in the series. The morbidity rate was 6.8% and included transient cranial nerve palsies (n=5) and wound hematoma (n=1).

CONCLUSIONS

Carotid endarterectomy can be safely performed with EEG monitoring and selective induced arterial hypertension and etomidate cerebral protection. Our results suggest that this method may be a good alternative for shunting and its inherent risks.

Risk factors for developing large emboli following carotid artery stenting

Objective

The introduction and development of the embolic protecting device (EPD) has resulted in a decreased rate of stroke after carotid artery stenting (CAS). The authors performed a retrospective study to investigate the risk factors for developing large emboli after CAS which can lead to ischemic events.

Methods

A total of 35 consecutive patients who underwent CAS between January 2009 and March 2012 were included in this study. Patients were divided into two groups including those with small emboli (group A; grade 1, 2) and those with large emboli (group B; grade 3, 4). The size and number of emboli were assigned one of four grades (1=no clots, 2=1 or 2 small clots, 3=more than 3 small clots, 4=large clots) by microscopic observation of the EPD after CAS. We compared demographic characteristics, medical history, and angiographic findings of each group.

Results

Thirty-five patients underwent CAS, and technical success was achieved in all cases. Twenty-three patients were included in group A and 12 patients in group B. Our results demonstrated that advanced age [odds ratio (OR) 1.24; 95% confidence interval (CI) 1.01-1.52; p=0.044] and smoking (OR 42.06; CI 2.828-625.65, p=0.006) were independent risk factors for developing large emboli after CAS.

Conclusion

In patients with carotid artery stenosis treated with CAS, advanced age and smoking increased the number and size of emboli. Although use of an EPD is controversial, it may be useful in CAS in patients with risk factors for large emboli in order to reduce the risk of ischemic events.

Percutaneous transluminal balloon angioplasty and stenting for carotid artery stenosis

BACKGROUND

Endovascular treatment by transluminal balloon angioplasty or stent insertion may be a useful alternative to carotid endarterectomy for the treatment of atherosclerotic carotid artery stenosis. This review updates a previous version first published in 1997 and subsequently updated in 2004 and 2007.

OBJECTIVES

To assess the benefits and risks of endovascular treatment compared with carotid endarterectomy or medical therapy in patients with symptomatic or asymptomatic carotid stenosis.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched January 2012) and the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 4), MEDLINE (1950 to January 2011), EMBASE (1980 to January 2011) and Science Citation Index (1945 to January 2011). We also searched ongoing trials registers (January 2011) and reference lists and contacted researchers in the field.

SELECTION CRITERIA

Randomised trials comparing endovascular treatment (including balloon angioplasty or stenting) with endarterectomy or medical therapy for symptomatic or asymptomatic atherosclerotic carotid stenosis.

DATA COLLECTION AND ANALYSIS

One review author selected trials for inclusion, assessed trial quality and extracted data. A second review author independently validated trial selection and a third review author independently validated data extraction. We calculated treatment effects as odds ratios (OR) and 95% confidence intervals (CI), with endovascular treatment as the reference group. We quantified heterogeneity using the I(2) statistic.

MAIN RESULTS

We included 16 trials involving 7572 patients. In patients with symptomatic carotid stenosis at standard surgical risk, endovascular treatment was associated with a higher risk of the following outcome measures occurring between randomisation and 30 days after treatment than endarterectomy: death or any stroke (the primary safety outcome) (OR 1.72, 95% CI 1.29 to 2.31, P = 0.0003; I(2) = 27%), death or any stroke or myocardial infarction (OR 1.44, 95% CI 1.15 to 1.80, P = 0.002; I(2) = 7%), and any stroke (OR 1.81, 95% CI 1.40 to 2.34, P < 0.00001;I(2) = 12%). The OR for the primary safety outcome was 1.16 (95% CI 0.80 to 1.67) in patients < 70 years old and 2.20 (95% CI 1.47 to 3.29) in patients ≥ 70 years old (interaction P = 0.02).The rate of death or major or disabling stroke did not differ significantly between treatments (OR 1.28, 95% CI 0.93 to 1.77, P = 0.13; I(2) = 0%). Endovascular treatment was associated with lower risks of myocardial infarction (OR 0.44, 95% CI 0.23 to 0.87, P = 0.02; I(2) = 0%), cranial nerve palsy (OR 0.08, 95% CI 0.05 to 0.14, P < 0.00001; I(2) = 0%) and access site haematomas (OR 0.37, 95% CI 0.18 to 0.77, P = 0.008; I(2) = 27%).The combination of death or any stroke up to 30 days after treatment or ipsilateral stroke during follow-up (the primary combined safety and efficacy outcome) favoured endarterectomy (OR 1.39, 95% CI 1.10 to 1.75, P = 0.005; I(2) = 0%), but the rate of ipsilateral stroke after the peri-procedural period did not differ between treatments (OR 0.93, 95% CI 0.60 to 1.45, P = 0.76; I(2) = 0%).Restenosis during follow-up was more common in patients receiving endovascular treatment than in patients assigned surgery (OR 2.41, 95% CI 1.28 to 4.53, P = 0.007; I(2) = 55%). In patients with asymptomatic carotid stenosis, treatment effects on the primary safety (OR 1.71, 95% CI 0.78 to 3.76, P = 0.18; I(2) = 0%) and combined safety and efficacy outcomes (OR 1.75, 95% CI 0.92 to 3.33, P = 0.09; I(2) = 0%) were similar to symptomatic patients, but differences between treatments were not statistically significant. Among patients not suitable for surgery, the rate of death or any stroke between randomisation and end of follow-up did not differ significantly between endovascular treatment and medical care (OR 0.22, 95% CI 0.01 to 7.92, P = 0.41; I(2)= 79%).

AUTHORS' CONCLUSIONS

Endovascular treatment is associated with an increased risk of peri-procedural stroke or death compared with endarterectomy. However, this excess risk appears to be limited to older patients. The longer term efficacy of endovascular treatment and the risk of restenosis are unclear and require further follow-up of existing trials. Further trials are needed to determine the optimal treatment for asymptomatic carotid stenosis.