Long-term results of carotid stenting are competitive with surgery

Low-Density Lipoprotein Cholesterol Levels Are Associated With Subsequent Stented-Territory Ischemic Stroke After Carotid Artery Stenting: A Single Center Retrospective Study

Objective

The role of low-density lipoprotein cholesterol (LDL-C) after carotid artery stenting (CAS) is not well known with respect to stented-territory infarction (STI) and in-stent restenosis (ISR). We hypothesized that LDL-C levels after CAS might be independently associated with STI and ISR.

Methods

We conducted a retrospective study for patients with significant extracranial carotid stenosis who were subjected to CAS between September 2013 and May 2021. LDL-C levels were measured after 6 and 12 months following CAS. The association between STI and ISR, and LDL-C was explored using Cox proportional-hazard model.

Results

Of 244 patients enrolled, STI and ISR were observed in 11 (4.5%) and 10 (4.1%) patients, respectively. In multivariable analysis, higher white blood cell count (hazard ratio [HR], 1.408 per 10³/mm³; 95% confidence interval [CI], 1.085-1.828; p=0.010), higher LDL-C levels after 12 months (HR, 1.037 per 1 mg/dL; 95% CI, 1.011-1.063; p=0.005), and ISR (HR, 13.526; 95% CI, 3.405-53.725; p<0.001) were independent predictors of STI. Diabetes (HR, 4.746; 95% CI, 1.026-21.948; p=0.046), smaller stent diameter (HR, 0.725 per 1 mm; 95% CI, 0.537-0.980; p=0.036), and higher LDL-C levels after 12 months (HR, 1.031 per 1 mg/dL; 95% CI, 1.007-1.055; p=0.011) were independent predictors of ISR.

Conclusion

We showed that LDL-C levels after 12 months independently predict STI and ISR after CAS. It is necessary to investigate the optimal target LDL-C level for STI prevention through well designed research in the future.

Clinical Outcomes of Second- versus First-Generation Carotid Stents: A Systematic Review and Meta-Analysis

Background: Single-cohort studies suggest that second-generation stents (SGS; “mesh stents”) may improve carotid artery stenting (CAS) outcomes by limiting peri- and postprocedural cerebral embolism. SGS differ in the stent frame construction, mesh material, and design, as well as in mesh-to-frame position (inside/outside). Objectives: To compare clinical outcomes of SGS in relation to first-generation stents (FGSs; single-layer) in CAS. Methods: We performed a systematic review and meta-analysis of clinical studies with FGSs and SGS (PRISMA methodology, 3302 records). Endpoints were 30-day death, stroke, myocardial infarction (DSM), and 12-month ipsilateral stroke (IS) and restenosis (ISR). A random-effect model was applied. Results: Data of 68,422 patients from 112 eligible studies (68.2% men, 44.9% symptomatic) were meta-analyzed. Thirty-day DSM was 1.30% vs. 4.11% (p < 0.01, data for SGS vs. FGS). Among SGS, both Casper/Roadsaver and CGuard reduced 30-day DSM (by 2.78 and 3.03 absolute percent, p = 0.02 and p < 0.001), whereas the Gore stent was neutral. SGSs significantly improved outcomes compared with closed-cell FGS (30-day stroke 0.6% vs. 2.32%, p = 0.014; DSM 1.3% vs. 3.15%, p < 0.01). At 12 months, in relation to FGS, Casper/Roadsaver reduced IS (−3.25%, p < 0.05) but increased ISR (+3.19%, p = 0.04), CGuard showed a reduction in both IS and ISR (−3.13%, −3.63%; p = 0.01, p < 0.01), whereas the Gore stent was neutral. Conclusions: Pooled SGS use was associated with improved short- and long-term clinical results of CAS. Individual SGS types, however, differed significantly in their outcomes, indicating a lack of a “mesh stent” class effect. Findings from this meta-analysis may provide clinically relevant information in anticipation of large-scale randomized trials.

Predicting the Risk of Stroke in Chinese Internal Carotid Artery Stenosis Patients Underwent Carotid Artery Stenting: Validation and Improvement of Siena Carotid Artery Stenting Risk Score

BACKGROUND

Siena carotid artery stenting (CAS) risk score is developed based on Chinese internal carotid artery (ICA) stenosis patients recruited in Italy, whether it is equally applicable in Chinese remains unknown. We aimed to investigate Siena CAS risk score value for predicting stroke risk in ICA stenosis patients underwent CAS and explore additional factors for improving accuracy of scoring system.

METHODS

Totally 401 patients with ICA stenosis who underwent CAS were enrolled. The clinical data (including patient characteristics, lesion features, and procedure-related features) were collected and the Siena CAS score was calculated. Stroke incidence with 30 days was documented.

RESULTS

The incidence of stroke was 4.5%, and the Siena CAS score in stroke patients was higher compared with nonstroke patients, further receiver operating characteristic (ROC) curve illustrated that Siena CAS score was acceptable at predicting stroke risk with area under curve (AUC) of .743 (95%CI: .638-.848). Multivariate logistic regression model revealed that Siena CAS score and current fasting-blood glucose (FBG) greater than 7.1 mmol/l independently predicted higher stroke risk; followed ROC curve disclosed that Siena CAS score combined with current FBG greater than 7.1 mmol/l was of good value in predicting stroke risk (AUC: .770 (95%CI: .677-.863)), which was numerically increased compared with Siena CAS score alone.

CONCLUSIONS

Siena CAS risk scoring system exhibits to be a useful tool to predict stroke risk, and the combination of Siena CAS score and current increased FBG might be a more accurate stratification for stroke risk in Chinese ICA stenosis patients after CAS.

Risk Factors for Recurrent Carotid-Artery Stenosis Following Stenting Treatment

BACKGROUND Carotid artery stenting (CAS) has been regarded as a reliable treatment approach for carotid artery stenosis. However, recurrent carotid artery stenosis after CAS affects long-term outcomes. In this study, we aimed to investigate the potential risk factors for carotid restenosis. MATERIAL AND METHODS We retrospectively analyzed the clinical data of patients diagnosed with carotid artery stenosis who underwent CAS implantation at our department from September 2012 to July 2015. Each included study patient was followed up with serial duplex ultrasound scanning. Kaplan-Meier estimates were used to evaluate freedom from restenosis and potential risk factors were analyzed. RESULTS There were 33 patients enrolled in our study. The mean age was 65.5±11.5 years. The technique was successfully achieved in all patients. No death or major stroke occurred after stenting. There were 2 events of minor stroke and one myocardial infarction within 30 days after stent implantation. All the patients were followed up for 3 years. Cumulative rates of freedom from recurrent stenosis at 1, 2, and 3 years were 87.4%, 74.6%, and 68.3% respectively. Cox multivariate regression analysis revealed that male sex, smoking and hyperlipidemia were independent risk factors associated with restenosis. CONCLUSIONS In this study, we identified that CAS was a reliable approach for carotid artery stenosis. Male sex, smoking, and hyperlipidemia were independent risk factors associated with restenosis. Thus, hyperlipidemia should be monitored and routine follow-up with ultrasonography are recommended especially for male patients with current or history of smoking.

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.

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.)

Restenosis after carotid artery stenting

As a common etiology for ischemic stroke, atherosclerotic carotid stenosis has been targeted by vascular surgery since 1950s. Compared with carotid endarterectomy, carotid angioplasty and stenting (CAS) is almost similarly efficacious and less invasive. These advantages make CAS an alternative in treating carotid stenosis. However, accumulative evidences suggested that the long-term benefit-risk ratio of CAS may be decreased or even neutralized by the complications related to in-stent restenosis (ISR). Therefore, investigating the mechanisms and identifying the influential factors of ISR are of vital importance for improving the long-term outcomes of CAS. As responses to intrinsic and extrinsic injuries, intimal hyperplasia and vascular smooth muscle cell proliferation have been regarded as the principle mechanisms for ISR development. Due to the lack of consensus-based definition and consistent follow-up protocol, the reported incidences of ISR after CAS varied widely among studies. These variations made the inter-study comparisons of ISR largely illogical. To eliminate restenosis after CAS, both surgery and endovascular procedures have been attempted with promising results. For preventing ISR, drug-eluting stents and antiplatelets have been proposed as potential solutions.

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.

Analysis of Florida and New York state hospital discharges suggests that carotid stenting in symptomatic women is associated with significant increase in mortality and perioperative morbidity compared with carotid endarterectomy

BACKGROUND

Although large randomized studies have established the efficacy and safety of carotid endarterectomy (CEA) and, recently, carotid artery stenting (CAS), the under-representation of women in these trials leaves the comparison of risks to benefits of performing these procedures on women an open question. To address this issue, we reviewed the hospital outcomes and delineated patient characteristics predicting outcome in women undergoing carotid interventions using New York and Florida statewide hospital discharge databases.

METHODS

We analyzed in-hospital mortality, postoperative stroke, cardiac postoperative complications, and combined postoperative stoke and mortality in 20,613 CEA or CAS hospitalizations for the years 2007 to 2009. Univariate and multiple logistic regression analyses of variables were performed.

RESULTS

CEA was performed in 16,576 asymptomatic and 1744 symptomatic women and CAS in 1943 asymptomatic and 350 symptomatic women. Compared with CAS, CEA rates, in asymptomatic vs symptomatic, were significantly lower for in-hospital mortality (0.3% vs 0.8% and 0.4% vs 3.4%), stroke (1.5% vs 2.6% and 3.5% vs 9.4%), and combined stroke/mortality (1.7% vs 3.1% and 3.8% vs 10.9%). In cohorts matched by propensity scores, the same trend favoring CEA remained significant in symptomatic women. There was no difference in cardiac complication rates among asymptomatic women, but among symptomatic woman cardiac complications were more frequent after CAS (10.6% vs 6.5%; P = .0077). Among symptomatic women, the presence of renal disease, coronary artery disease, or age ≥80 years increased the risk of CAS over CEA threefold for the composite end point of stroke or death. For asymptomatic women only in those with coronary artery disease or diabetes, there was a statistical difference in the composite mortality/stroke rates favoring CEA (1.9% vs 3.3% and 1.7% vs 3.4%, respectively). After adjusting for relevant clinical and demographic risk factors and hospital annual volume, for CAS vs CEA, the risk of the composite end point of stroke or mortality was 1.7-fold higher in symptomatic and 3.4-fold higher in asymptomatic patients. Medicaid insurance, symptomatic patient, history of cancer, and presence of heart failure on admission were among other strong predictors of composite stroke/mortality outcome.

CONCLUSIONS

Databases reflecting real-world practice performance and management of carotid disease in women suggest that CEA compared with CAS has overall better perioperative outcomes in women. Importantly, CAS is associated with significantly higher morbidity in certain clinical settings and this should be taken into account when choosing a revascularization procedure.

Paradoxical embolism, stroke and sclerotherapy

Sclerotherapy has been associated with 13 published cases of stroke since 1994. Four earlier reports implicated liquid sclerosants while nine recent cases have followed foam sclerotherapy. This adverse event represents a very rare complication of a very popular procedure. Ten of the 13 reported patients recovered completely with no long-term sequelae. A right-to-left shunt and in particular a patent foramen ovale (PFO) was the most consistent risk factor. Paradoxical gas emboli were observed in the brain-supplying or the intra-cranial arteries of five patients with an immediate onset of stroke after foam sclerotherapy. Paradoxical clot embolism was suspected in three patients with a delayed onset of stroke and concurrent venous thrombosis. In the remaining five cases, which included two cases with an immediate onset after liquid sclerotherapy, no specific cause was identified. Patients with a past history of cryptogenic stroke or a long life history of recurrent classic migraine attacks (with aura) have a higher risk of neurological adverse events and may benefit from preoperative screening and percutaneous closure of PFO.

Article Commentary: Late Outcomes of Carotid Artery Stenting: A Critical Review

The role of carotid artery stenting (CAS) as an alternative to carotid endarterectomy for the treatment of extracranial carotid occlusive disease for stroke prevention continues to evolve. Although technical and device refinements aimed at making CAS safer continue to this day, safety as measured by 30-day and 1-year outcomes has been the primary recipient of regulatory and practice attention. Relatively less emphasis has been placed on the incidence of recurrent stenosis after CAS and the efficacy of CAS in late stroke prevention. Data on late outcomes of CAS, including factors of potential influence, have been emerging and are addressed in this review.

In vivo serial MR imaging of magnetically labeled endothelial progenitor cells homing to the endothelium injured artery in mice

BACKGROUND

Emerging evidence of histopathological analyses suggests that endothelial progenitor cells (EPCs) play an important role in vascular diseases. Neointimal hyperplasia can be reduced by intravenous transfusion of EPCs after vascular injury in mice. Therefore, it would be advantageous to develop an in vivo technique that can explore the temporal and spatial migration of EPCs homing to the damaged endothelium noninvasively.

METHODOLOGY/PRINCIPAL FINDINGS

The left carotid common artery (LCCA) was injured by removal of endothelium with a flexible wire in Kunming mice. EPCs were collected by in vitro culture of spleen-derived mouse mononuclear cells (MNCs). EPCs labeling was carried out in vitro using Fe₂O₃-poly-L-lysine (Fe₂O₃-PLL). In vivo serial MR imaging was performed to follow-up the injured artery at different time points after intravenous transfusion of EPCs. Vessel wall areas of injured artery were computed on T₂WI. Larger MR signal voids of vessel wall on T₂WI was revealed in all 6 mice of the labeled EPC transfusion group 15 days after LCCA injury, and it was found only in 1 mouse in the unlabeled EPC transfusion group (p = 0.015). Quantitative analyses of vessel wall areas on T₂WI showed that the vessel wall areas of labeled EPC transfusion group were less than those of unlabeled EPC transfusion group and control group fifteen days after artery injury (p<0.05). Histopathological analyses confirmed accumulation and distribution of transfused EPCs at the injury site of LCCA.

CONCLUSIONS/SIGNIFICANCE

These data indicate that MR imaging might be used as an in vivo method for the tracking of EPCs homing to the endothelium injured artery.

Carotid artery surgery: back to the future

In this study we performed 548 carotid revascularizations between 2006 and 2008 at the Department of Vascular Surgery of the A.Z. Sint-Blasius, Dendermonde, Belgium - a high-volume experienced center for carotid artery stenting (CAS). In 2006, our 30-day complication rates were 3.21 and 1.51% for symptomatic and asymptomatic patients, respectively. At that time, CAS represented approximately 86% of all cases we performed. However, the publication of the results of EVA-3S and SPACE studies drove us to reconsider our treatment allocation algorithm. In 2007 and 2008, CAS procedures only accounted for 43% of all carotid procedures, which was a result of strict patient selection with comorbidities and high-risk lesions assessment, especially in symptomatic patients. Our current 30-day stroke/death rates are 1.24% for symptomatic patients and 0.53% for asymptomatic ones, which reflects that correct patient selection is the key to maintain CAS as a valuable alternative to carotid endarterectomy.

In vivo serial MR imaging evaluates neointimal hyperplasia inhibited by intravenously transfused endothelial progenitor cells in carotid artery injured mice

PURPOSE

to study the feasibility of in vivo MR imaging in evaluation of endothelial progenitor cells (EPCs) on the progress of neointimal hyperplasia after carotid artery injury in mice.

METHODS

fifteen Kunming mice were injured in left carotid artery by removal of endothelium with a flexible wire 7 days after splenectomy. EPCs were collected by in vitro culture of spleen-derived mouse mononuclear cells (MNCs) in endothelial basal medium. After artery injury, the mice received EPCs (n= 6), phosphate buffered solution (PBS) (n= 6), and DiI-Ac-LDL labeled EPCs (n= 3) intravenously. In vivo serial MR imaging were performed at different time points after artery injury, and vessel-wall thickness and vessel-wall area at injury site were measured on MR imaging.

RESULTS

transfused Dil-Ac-LDL-labeled EPCs were found at the injury site by histopathological analyses. Vessel wall of injured artery was observed and quantitatively analyzed with MR imaging. Vessel-wall thickness was .487 ± .122 mm in the non-EPCs transfusion group and .294 ± .051 mm in the EPCs transfusion group 15 days after artery injury (P= .005). While vessel-wall area was .860 ± .182 mm(2) in the non-EPCs transfusion group and .468 ± .141 mm(2) in the EPCs transfusion group 15 days after artery injury (P= .002). Therefore, the neointimal hyperplasia of injured artery in the EPCs transfusion group was lesser than that in the non-EPCs transfusion group.

CONCLUSION

neointimal hyperplasia can be reduced by intravenous transfusion of EPCs and analyzed on in vivo MR imaging after vascular injury.

Long-Term Results of Carotid Artery Stents to Manage Symptomatic Carotid Artery Stenosis and Factors That Affect Outcome

Background— Limited data are available about the long-term outcomes of the use of carotid artery stents in symptomatic patients and the impact of patient variables on the durability of endovascular carotid procedures. Outcome data previously reported from registry series mix symptomatic and asymptomatic patients. We present analysis of long-term follow-up, with independent neurological assessment, for patients with symptomatic high-grade carotid lesions undergoing stenting to identify patients at risk of recurrence.

Methods and Results— Prospectively collected data on 563 carotid stenting procedures in a single center were analyzed. Univariate and multivariate techniques were used to identify risk groups and beneficial technical adaptations. Ipsilateral stroke rates for all patients were 4.8%, 7.0%, and 9.5% at 30 days, 1 year, and 4 years, respectively. The rates improved to 2.7%, 4.1%, and 4.5% when patients were treated with optimal therapy. Retinal events had a lower risk of long-term recurrent ipsilateral stroke (hazard ratio=0.228, CI=0.082 to 0.632, P =0.004) than cerebral events. A recurrent or residual stenosis of >50% had a statistically significant effect on long-term stroke recurrence in multivariate analysis (hazard ratio=2.187, CI=1.173 to 4.078, P =0.014).

Conclusions— Patients with retinal presentations are a lower risk group to treat. Residual stenosis or restenosis >50% has a statistically significant trend to an increased risk of recurrence for ipsilateral stroke in the long term in this population. In our patients, a combination of procedural modifications and pharmacological changes seems to improve outcomes.

An old problem, a new solution

A 75-year-old woman with painful visual loss was diagnosed with ocular ischemic syndrome secondary to restenosis of the carotid artery following endarterectomy. She underwent carotid artery stenting, which has become an alternative to carotid endarectomy for primary carotid stenosis but is now also becoming more popular for recurrent carotid artery stenosis.

Long-term risk of carotid restenosis in patients randomly assigned to endovascular treatment or endarterectomy in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS): long-term follow-up of a randomised trial

Background

In the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS), early recurrent carotid stenosis was more common in patients assigned to endovascular treatment than it was in patients assigned to endarterectomy (CEA), raising concerns about the long-term effectiveness of endovascular treatment. We aimed to investigate the long-term risks of restenosis in patients included in CAVATAS.

Methods

413 patients who were randomly assigned in CAVATAS and completed treatment for carotid stenosis (200 patients had endovascular treatment and 213 patients had endarterectomy) had prospective clinical follow-up at a median of 5 years and carotid duplex ultrasound at a median of 4 years. We investigated the cumulative long-term incidence of carotid restenosis after endovascular treatment and endarterectomy, the effect of the use of stents on restenosis after endovascular treatment, risk factors for the development of restenosis, and the effect of carotid restenosis on the risk of recurrent cerebrovascular events. Analysis was by intention to treat. This study is registered, number ISRCTN01425573.

Findings

Severe carotid restenosis (≥70%) or occlusion occurred significantly more often in patients in the endovascular arm than in patients in the endarterectomy arm (adjusted hazard ratio [HR] 3·17, 95% CI 1·89–5·32; p<0·0001). The estimated 5-year incidence of restenosis was 30·7% in the endovascular arm and 10·5% in the endarterectomy arm. Patients in the endovascular arm who were treated with a stent (n=50) had a significantly lower risk of developing restenosis of 70% or greater compared with those treated with balloon angioplasty alone (n=145; HR 0·43, 0·19–0·97; p=0·04). Current smoking or a history of smoking was a predictor of restenosis of 70% or more (2·32, 1·19–4·54; p=0·01) and the early finding of moderate stenosis (50–69%) up to 60 days after treatment was associated with the risk of progression to restenosis of 70% or more (3·76, 1·88–7·52; p=0·0002). The composite endpoint of ipsilateral non-perioperative stroke or transient ischaemic attack occurred more often in patients in whom restenosis of 70% or more was diagnosed in the first year after treatment compared with patients without restenosis of 70% or more (5-year incidence 23% vs 11%; HR 2·18, 1·04–4·54; p=0·04), but the increase in ipsilateral stroke alone was not significant (10% vs 5%; 1·67, 0·54–5·11).

Interpretation

Restenosis is about three times more common after endovascular treatment than after endarterectomy and is associated with recurrent ipsilateral cerebrovascular symptoms; however, the risk of recurrent ipsilateral stroke is low. Further data are required from on-going trials of stenting versus endarterectomy to ascertain whether long-term ultrasound follow-up is necessary after carotid revascularisation.

Funding

British Heart Foundation; UK National Health Service Management Executive; UK Stroke Association.

Carotid artery stenting: a single-centre experience with up to 8 years' follow-up

Carotid artery stenting (CAS) may be an alternative to surgical endoarterectomy not only in high-risk patients. We report results in the endovascular treatment of carotid artery disease with up to 8 years' follow-up. In this retrospective study, we analysed data from 853 consecutive patients (946 arteries) treated for carotid artery stenosis between April 1999 and March 2007; 491 (52%) arteries were symptomatic and 455(48%) were asymptomatic. Preprocedural evaluation of the patients was performed with echo Doppler, magnetic resonance angiography (MRA) or computed tomographic angiography (CTA) and a neurological examination. A cerebral protection device was used in 879 (92.9%) procedures. Anti-platelet therapy was administered before and after the procedure. All patients were included in a follow-up of up to 8 years. Technical success was achieved in 943 (99.6%) lesions. At 30 days, there was a 0.21% (n = 2) death rate, a 0.42% major stroke rate, a 1.69% minor stroke/transient ischaemic attack (TIA) rate and a combined 2.32% TIA/stroke and death rate. During follow-up, echo Doppler evidenced restenosis in 39 (4.85%) cases; of these, only five, presenting restenosis >80%, were treated with an endovascular reintervention. At the long-term follow-up, two strokes (0.23%) were reported, which both occurred within the first 2 years. In our experience, carotid artery stenting seems to be a safe and effective treatment, providing satisfactory long-term clinical results.

Carotid artery stenting: findings based on 8 years' experience

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Postprocedural high-density lipoprotein cholesterol predicts carotid stent patency at 1 year

The durability of carotid artery stenting (CAS) is affected by the occurrence of myointimal proliferation and in-stent restenosis (ISR). We aimed to identify clinical, angiographic, and laboratory predictors of ISR, paying special attention to postprocedural metabolic factors. A total of 102 consecutive patients with successful CAS for > or =70% atherosclerotic internal carotid artery stenosis were followed up with neurological assessment and duplex sonography 1 day, 1 month, and 1 year after CAS. Lipid profile and hemoglobin A(1c) were tested at the 1-month follow-up visit. Ten (10%) patients had ISR > or =50% after 1 year. Compared with patients without ISR (n = 92), patients with ISR were more often current smokers (33% vs. 70%, P = 0.034) and had significantly lower 1-month high-density lipoprotein (HDL) cholesterol: median (range) 47 (24-95) mg/dl vs. 39.5 (25-50) mg/dl, P = 0.031. Multivariate logistic regression analyses identified 1-month HDL cholesterol >45 mg/dl as the only independent predictor of carotid stent patency at 1 year (P = 0.033, OR = 0.09, 95% CI 0.01-0.83). Postprocedural HDL cholesterol levels predict carotid stent patency at 1 year. With the possibility of elevation of HDL cholesterol by lifestyle changes and medication, this finding may have implications for the future management of patients undergoing CAS.

Endarterectomy or carotid artery stenting: the quest continues

BACKGROUND

Carotid endarterectomy (CEA) is still considered the "gold-standard" of the treatment of patients with significant carotid stenosis and has proven its value during past decades. However, endovascular techniques have recently been evolving. Carotid artery stenting (CAS) is challenging CEA for the best treatment in patients with carotid stenosis. This review presents the development of CAS according to early reports, results of recent randomized trials, and future perspectives regarding CAS.

METHODS

A literature search using the PubMed and Cochrane databases identified articles focusing on the key issues of CEA and CAS.

RESULTS

Early nonrandomized reports of CAS showed variable results, and the Stenting and Angioplasty With Protection in Patients at High Risk for Endarterectomy trial led to United States Food and Drug Administration approval of CAS for the treatment of patients with symptomatic carotid stenosis. In contrast, recent trials, such as the Stent-Protected Angioplasty Versus Carotid Endarterectomy trial and the Endarterectomy Versus Stenting in Patients with Symptomatic Severe Carotid Stenosis trial, (re)fuelled the debate between CAS and CEA. In the Stent-Protected Angioplasty Versus Carotid Endarterectomy trial, the complication rate of ipsilateral stroke or death at 30 days was 6.8% for CAS versus 6.3% for CEA and showed that CAS failed the noninferiority test. Analysis of the Endarterectomy Versus Stenting in Patients With Symptomatic Severe Carotid Stenosis trial showed a significant higher risk for death or any stroke at 30 days for endovascular treatment (9.6%) compared with CEA (3.9%). Other aspects-such as evolving best medical treatment, timely intervention, interventionalists' experience, and analysis of plaque composition-may have important influences on the future treatment of patients with carotid artery stenosis.

CONCLUSIONS

CAS performed with or without embolic-protection devices can be an effective treatment for patients with carotid artery stenosis. However, presently there is no evidence that CAS provides better results in the prevention of stroke compared with CEA.

Carotid Artery Stenting in a Single Center: Are Six Years of Experience Enough to Achieve the Standard of Care?

OBJECTIVES

This study aims to determine safety, short and mid-term outcomes of Carotid Artery Stenting (CAS) and Endarterectomy (CEA) during the last 6 years in a single vascular surgery center.

METHODS

We retrospectively reviewed 2624 consecutive carotid revascularizations performed between December 2000 and December 2006 in 2176 patients with severe carotid artery stenosis (symptomatic > or = 70%, asymptomatic > or = 80%), of which 1589 were CEA and 1035 CAS. Patients were followed up at 1, 3, 6 and 12 months after the procedure and then yearly.

RESULTS

The percutaneous procedure was successful in 99.2% of the cases. No intra-procedural death occurred. The overall death and stroke rates at 30 days, 1 year and 3 years were 1.54%, 2.86%, 7.43% in the CAS group and 2.07%, 3.55%, 6.95% in the CEA group, respectively (p value not significant in any case).

CONCLUSIONS

At our vascular surgery centre the results of CEA and CAS are similar. CAS has become our standard of care in preventing strokes and is an effective alternative to CEA for low-risk patients as well.

Covered stent-graft treatment of traumatic internal carotid artery pseudoaneurysms: a review

OBJECTIVE

To review the literature concerning the management with placement of covered stent-grafts of traumatic pseudoaneurysms of the extracranial internal carotid artery (ICA) resulting from penetrating craniocervical injuries or skull base fractures.

METHOD

We have reviewed, from the Medline database, all the published cases in the English literature since 1990 and we have added a new case.

RESULTS

We identified 20 patients with traumatic extracranial ICA pseudoaneurysms due to penetrating craniocervical injuries or skull base fractures who had been treated with covered stent-graft implantation. Many discrepancies have been ascertained regarding the anticoagulation therapy. In 3 patients the ICA was totally occluded in the follow-up period, giving an overall occlusion rate 15%. No serious complication was reported as a result of the endovascular procedure.

CONCLUSION

Preliminary results suggest that placement of stent-grafts is a safe and effective method of treating ICA traumatic pseudoaneurysms resulting from penetrating craniocervical injuries or skull base fractures. The immediate results are satisfactory when the procedure takes place with appropriate anticoagulation therapy. The periprocedural morbidity and mortality and the early patency are also acceptable. A surveillance program with appropriate interventions to manage restenosis may improve the long-term patency.

Carotid Angioplasty and Stenting is a Safe and Durable Procedure in a Community Hospital

Carotid angioplasty and stenting (CAS) has been touted as a reasonable alternative to carotid endarterectomy (CEA) for high-risk surgical candidates. Several published CAS series, primarily from academic centers, show immediate results approaching those of CEA. However, very little is known about long-term results with CAS, particularly in the community hospital setting. Therefore, we retrospectively reviewed our CAS experience. From February 1999 to July 2003, 44 consecutive patients underwent placement of 46 stents. The mean patient age was 73 years, and 57 per cent were men. Most patients were asymptomatic (74%). High-risk categories included prior CEA (71%), other anatomic risks (13%), and/or significant medical comorbidities (16%). Technical success was achieved in all 46 cases. At 30 days, there were no deaths and one stroke, giving a combined stroke/mortality of 2 per cent. Clinical follow-up was obtained on all 44 patients at a mean follow-up of 42 months. Duplex scans performed on 44 stents (96%), at a mean follow-up of 40 months, demonstrated four 60 per cent to 79 per cent recurrent stenoses. CAS in a community hospital can have a 30-day stroke/mortality equivalent to CEA. The procedure is durable, with no critical (80%–99%) carotid restenoses and no stroke or transient ischemic attacks referable to a stented carotid artery in long-term follow-up.

Differential effects of carotid artery stenting versus carotid endarterectomy on external carotid artery patency

PURPOSE

To determine the effect of stent coverage of the external carotid artery (ECA) after carotid artery stenting (CAS) compared to eversion endarterectomy of the ECA after carotid endarterectomy (CEA).

METHODS

The records of 101 CAS and 165 CEA procedures performed over 2 years were reviewed. Duplex velocities and history and physical examinations were taken prior to the procedure, at 1 month, and at 6-month intervals subsequently. CAS was performed by extending the stent across the internal carotid artery (ICA) lesion into the common carotid artery (CCA) thereby covering the ECA. CEA was performed with eversion endarterectomy of the ECA.

RESULTS

The mean peak systolic velocities (PSV) in the ICA pre-CAS and pre-CEA were 361 and 352 cm/s, respectively. In terms of CAS, there was a significant increase in ECA velocities versus baseline at 12 (p = 0.009), 18 (p = 0.00001), and 24 (p = 0.005) months. In the CEA group, there was a significant decrease in ECA velocities versus baseline at 1 (p = 0.01) and 6 (p = 0.004) months. There were 2 occluded ECAs in follow-up in the CAS group and none in the CEA group. No significant differences were noted when comparing preprocedural ICA or ECA velocities. However, at the 1-, 6-, and 12-month intervals, the ECA velocities in the CAS group were significantly higher than in the CEA group (p = 0.03, p = 0.001, and p = 0.0004, respectively). There were no neurological symptoms in any patients during the study period.

CONCLUSION

Although progressive stenosis of the ECA is noted during CAS, the ECA usually does not occlude. Furthermore, there are no associated neurological symptoms. Thus, apprehension for progressive ECA occlusion should not be a contraindication to CAS. In addition, concern for ECA coverage should not deter stent extension from the ICA to the CCA during CAS.

Does Free Cell Area Influence the Outcome in Carotid Artery Stenting?

OBJECTIVES

To identify if carotid stent design, especially free cell area, impacts on the 30-day rates for stroke, death and TIA after carotid artery stenting (CAS).

MATERIAL AND METHODS

A CAS database of 3179 consecutive CAS patients was retrospectively assessed. The distribution of neurological complications were analysed for association with the different stent types and designs. Events where subdivided into procedural and postprocedural events.

RESULTS

The overall combined rate of TIA, stroke and death was 2.8% at 30 days (late events 1.9%). The post-procedural event rate analyzed for differences stents varied from 1.2% using BSCI Carotid Wallstent to 5.9% using Medtronic Exponent. The late event rates varied from 1.2% to 3.4% for free cell areas <2.5mm(2) and >7.5mm(2) respectively (p<0.05). Post-procedural event rate was 1.3% for closed cells and 3.4% for open cells. All these differences were highly pronounced among symptomatic patients (p<0.0001).

CONCLUSIONS

After carotid stenting, complication rates vary according to stent type, free cell area and cell design. In the symptomatic population (and also in the total population), post-procedural complication rates are highest for the open cell types and increase with larger free cell area.

Predictors of carotid stent restenosis

OBJECTIVES

We sought to determine the predictors of restenosis after carotid artery stenting and report alternatives for its management.

BACKGROUND

Carotid artery stenting has been increasingly accepted as an alternative to carotid endarterectomy (CEA). Predictors of carotid stent restenosis have not been firmly established, and management of restenotic lesions can be challenging.

METHODS

A retrospective, single-center review was conducted of 399 carotid stent procedures in 363 patients over 9 years, with a mean follow-up of 24 months (range 6-99 months). Clinical variables included age, gender, symptoms, hypertension, diabetes, tobacco use, renal insufficiency, coronary artery disease, hyperlipidemia, peripheral vascular disease, history of CEA, and history of neck radiation (XRT). Angiographic variables included reference vessel diameter, lesion length, post-stenting residual stenosis, stent diameter, type of stent, and number of stents.

RESULTS

Overall, restenosis occurred in 15 patients (3.8%). However, the restenosis occurred in 7 of 35 (20%) patients who had previous XRT, 6 of 57 (10.5%) patients who had previous CEA, and 2 of 9 (22%) patients who previously had both CEA and XRT. The only analyzed variables that were significantly associated with an increased risk of restenosis were previous CEA (OR 4.28, P = 0.008) or XRT (OR 11.3, P <or=<or= 0.0001). Restenosis was most often asymptomatic and detected at routine ultrasound follow-up. Restenotic lesions were successfully treated in 11/11 cases with angioplasty (27%) or stenting (73%). Four patients that are asymptomatic are being monitored closely with ultrasound. No patients required surgical therapy for restenosis.

CONCLUSIONS

Restenosis after carotid stenting is uncommon; however, patients with previous CEA or XRT are at increased risk. Restenotic lesions may be safely treated with further percutaneous interventions.

Plaque Echolucency Is Not Associated With the Risk of Stroke in Carotid Stenting

Background and Purpose— Plaque characteristics are suggested to play a potentially important role as risk factors for poor outcome after carotid artery stenting (CAS). We therefore correlated objectively and subjectively determined carotid plaque morphology with neurological complications after CAS.

Methods— We enrolled 698 consecutive patients undergoing elective CAS from a prospective single-center registry database and classified the preinterventional plaque status according to gray-scale median levels and the standardized Beletsky and Gray-Weale plaque scores. Patients were followed for 30-day neurological complications.

Results— Neurological complications including transient ischemic attack, minor and major stroke occurred in 5.9% (41/698) of the patients. Median gray-scale median, Beletsky and Gray-Weale scores were 45 (interquartile range [IQR] 25 to 70), 3.0 (IQR 2.0 to 3.0) and 2.0 (IQR 2.0 to 3.0), respectively. None of the scores was significantly associated with adverse outcome adjusting for traditional risk factors, medication, preinterventional symptoms, degree of stenosis, contralateral occlusion and use of cerebral protection, neither with respect to all neurological complications nor with respect to stroke and death (all P >0.05).

Conclusions— Plaque echolucency measured by objective and subjective grading did not identify patients with an increased risk of peri-interventional neurological events. Evaluation of plaque echolucency therefore cannot be recommended for risk stratification in CAS patients.

Patient selection for carotid stenting versus endarterectomy: A systematic review

Carotid artery stenting has emerged as an alternative to carotid endarterectomy for the treatment of severe extracranial carotid stenosis in patients with anatomic or clinical factors that increase their risk of complications with surgery, yet there remains a substantial amount of variability and uncertainty in clinical practice in the referral of patients for stenting vs endarterectomy. By undertaking a thorough review of the literature, we sought to better define which subsets of patients with "high-risk" features would be likely to preferentially benefit from carotid stenting or carotid endarterectomy. Although only a single randomized trial comparing the outcomes of carotid stenting with distal protection and endarterectomy has been completed, a wealth of observational data was reviewed. Relative to endarterectomy, the results of carotid stenting seem favorable in the setting of several anatomic conditions that render surgery technically difficult, such as restenosis after prior endarterectomy, prior radical neck surgery, and previous radiation therapy involving the neck. The results of stenting are also favorable among patients with severe concomitant cardiac disease. Carotid endarterectomy, alternatively, seems to represent the procedure of choice among patients 80 years of age or older in the absence of other high-risk features. Overall, existing data support the concept that carotid stenting and endarterectomy represent complementary rather than competing modes of therapy. Pending the availability of randomized trial data to help guide procedural selection, which is likely many years away, an objective understanding of existing data is valuable to help select the optimal mode of revascularization therapy for patients with severe carotid artery disease who are at heightened surgical risk.

Realizing the potential of carotid artery stenting: proposed paradigms for patient selection and procedural technique

Carotid artery stenting, compared with carotid endarterectomy, is emerging as an effective and less invasive method of revascularization for extracranial carotid artery stenosis. Carotid stenting is established as the treatment of choice for certain high-risk patient subsets, and ongoing clinical trials are evaluating this method across a broader clinical spectrum, including asymptomatic patients. For carotid stenting to reach its full potential, an acceptable risk of periprocedural complications, particularly in low-risk patients, must be ensured (the "3% rule"). The present article provides an in-depth review of carotid stenting, with special emphasis on the process of risk stratification pertaining to clinical, anatomic, and procedural considerations necessary to optimize procedural safety and patient outcomes.

Outcome of Carotid Stenting Versus Endarterectomy

Background and Purpose— To compare perioperative and midterm results of carotid artery stenting (CAS) versus carotid endarterectomy (CEA) in similar cohorts of patients, a retrospectively matched case-control study was performed.

Methods— Three hundred and one case subjects undergoing CAS with cerebral protection and 301 concurrent matched-controls undergoing CEA were examined. Matching was by sex, age (±2 years), symptoms and coronary disease.

Results— The 30-day disabling stroke/death rate was 2.6% in the CAS group versus 1.3% in the CEA group (odds ratio [OR] 2; 95% CI, 0.54 to 9.35; P =0.4). CAS patients had a significantly higher risk of periprocedural stroke (7.9% versus 2.3%; OR, 5.2; 95% CI, 1.7 to 18; P =0.001) than CEA patients. However, there was a decreasing trend in 30-day neurological event rates for the last 201 CAS matched cases: 5.4% versus 1.9% (OR 2.8; 95% CI, 0.8 to 10.2; P =0.1). Fifty percent of CAS disabling strokes occurred during cannulation of epiaortic vessels before placement of cerebral protection. Conditional multivariate analysis revealed CAS as a predictor of 30-day stroke (hazard ratios [HR] 3.9; 95% CI, 1.6 to 9.4; P =0.002) but not of 30-day disabling stroke/death (HR 3.6; 95% CI, 0.93 to 13.9; P =0.06). Restenosis free intervals at 36 months were 93.6% versus 92.1% for CAS and CEA, respectively, ( P =0.6).

Conclusions— When comparing CAS with CEA, the risk of any neurological events is still higher, particularly during catheterism and ballooning. The effect of the learning curve related to technical expertise and patient selection may influence the outcome of CAS versus CEA. In the midterm the restenosis rate of CAS compares favorably to CEA.

Filter-Protected Carotid Stenting Via a Minimal Cervical Access With Transitory Aspirated Reversed Flow During Initial Passage of the Target Lesion

PURPOSE

To evaluate the preliminary results of filter-protected carotid artery stenting (CAS) via a minimal cervical access, with temporary common carotid artery (CCA) occlusion and aspiration in selected high-risk candidates for carotid endarterectomy.

METHODS

Since February 2002, 26 patients (17 men; mean age 73.7 years, range 54-98) at high surgical risk according to the SAPPHIRE eligibility criteria underwent 29 transcervical CAS procedures under filter protection. Under general anesthesia, a 6-F short introducer sheath was directly mounted in the CCA through a small (2-4 cm) laterocervical cutdown. The CCA was briefly clamped, and blood was aspirated while the filter device was positioned above the target lesion. With the filter in place and the clamp released, nitinol stents were deployed under filter protection. Hemostasis was achieved by direct suture.

RESULTS

Twenty-eight (96%) interventions were technically successful; 1 complex lesion could not be crossed and was converted to surgery. Mean clamping time was 1.7 (range 1.0-3.5) minutes. Combined 30-day stroke/mortality was 0%. Ultrasound surveillance demonstrated a < 60% asymptomatic in-stent restenosis in 1 (4%) patient with radiation-induced arteritis after 28 months. During a mean follow-up of 11.6 months (range 3-38), 1 (4%) minor ipsilateral stroke was noted at 6 months in a patient whose antiplatelet therapy was transitorily interrupted.

CONCLUSION

Our preliminary observations from this small early experience suggest that this variant CAS technique is feasible and probably diminishes the neuroembolic risk during initial navigation of the ICA target stenosis.

Blunt carotid injury

Blunt carotid injury (BCI) is an uncommon disorder, occurring in trauma patients as a result of cervical hyperextension, hyperflexion, or direct blow. BCI is commonly present in initially asymptomatic patients who subsequently develop devastating thromboembolic complications of their injury. Although clinical predictors of injury have been developed, they are of limited accuracy. Nevertheless, employment of clinical screening criteria is of value in identifying at-risk patients in need of diagnostic testing. Liberalized screening of these trauma patients with angiography or the latest generation (64-multidetector) CT angiography facilitates early diagnosis and provides opportunity for timely intervention in asymptomatic victims. Anticoagulation and/or antithrombotic therapy in specific categories of these patients reduces neurologic morbidity and mortality. Endovascular stenting shows promise as a treatment modality for specific subsets of individuals with BCI. Surgery remains a therapeutic option for some surgically accessible lesions.