Acute-phase response after stent implantation in the carotid artery: association with 6-month in-stent restenosis

In-stent restenosis is associated with proliferative skin healing and specific immune and endothelial cell profiles: results from the RACHEL trial

Introduction

In-stent restenosis (ISR) is a major challenge in interventional cardiology. Both ISR and excessive skin healing are aberrant hyperplasic responses, which may be functionally related. However, the cellular component underlying ISR remains unclear, especially regarding vascular homeostasis. Recent evidence suggest that novel immune cell populations may be involved in vascular repair and damage, but their role in ISR has not been explored. The aims of this study is to analyze (i) the association between ISR and skin healing outcomes, and (ii) the alterations in vascular homeostasis mediators in ISR in univariate and integrative analyses.

Methods

30 patients with ≥1 previous stent implantation with restenosis and 30 patients with ≥1 stent without restenosis both confirmed in a second angiogram were recruited. Cellular mediators were quantified in peripheral blood by flow cytometry. Skin healing outcomes were analyzed after two consecutive biopsies.

Results

Hypertrophic skin healing was more frequent in ISR patients (36.7%) compared to those ISR-free (16.7%). Patients with ISR were more likely to develop hypertrophic skin healing patterns (OR 4.334 [95% CI 1.044-18.073], p=0.033), even after correcting for confounders. ISR was associated with decreased circulating angiogenic T-cells (p=0.005) and endothelial progenitor cells (p<0.001), whereas CD4+CD28null and detached endothelial cells counts were higher (p<0.0001 and p=0.006, respectively) compared to their ISR-free counterparts. No differences in the frequency of monocyte subsets were found, although Angiotensin-Converting Enzyme expression was increased (non-classical: p<0.001; and intermediate: p<0.0001) in ISR. Despite no differences were noted in Low-Density Granulocytes, a relative increase in the CD16- compartment was observed in ISR (p=0.004). An unsupervised cluster analysis revealed the presence of three profiles with different clinical severity, unrelated to stent types or traditional risk factors.

Conclusion

ISR is linked to excessive skin healing and profound alterations in cellular populations related to vascular repair and endothelial damage. Distinct cellular profiles can be distinguished within ISR, suggesting that different alterations may uncover different ISR clinical phenotypes.

The preoperative triglyceride-glucose index has a positive effect on predicting the risk of short-term restenosis after carotid artery stenting: a retrospective cohort study

Background

Increasing evidence suggests that insulin resistance is linked to cardiovascular disease and atherosclerosis. The triglyceride-glucose (TyG) index has proven to be a convincing marker to quantitatively evaluate insulin resistance. However, there is no relevant information about the relationship between the TyG index and restenosis after carotid artery stenting.

Methods

A total of 218 patients were enrolled. Carotid ultrasound and computed tomography angiography were used to evaluate in-stent restenosis. A Kaplan-Meier analysis and Cox regression method were performed to analyze the correlation between TyG index and restenosis. Schoenfeld residuals were used to determine the proportional-hazards assumption. A restricted cubic spline method was used to model and visualize the dose-response relationship between the TyG index and the risk of in-stent restenosis. Subgroup analysis was also performed.

Results

Thirty-one participants (14.2%) developed restenosis. The preoperative TyG index had a time-varying effect on restenosis. Within 29 months post-surgery, an increasing preoperative TyG index was linked to a significant increased risk of restenosis (hazard ratio: 4.347; 95% confidence interval 1.886-10.023). However, after 29 months, the effect was decreased, although not statistically significant. The subgroup analysis showed that the hazard ratios tended to be higher in the age ≤ 71 years subgroup (p < 0.001) and participants with hypertension (p < 0.001).

Conclusion

The preoperative TyG index was significantly associated with the risk of short-term restenosis after CAS within 29 months post-surgery. The TyG index may be employed to stratify patients based on their risk of restenosis after carotid artery stenting.

Usefulness of cone-beam computed tomography to predict residual stenosis after carotid artery stenting

OBJECTIVES

The long-term durability of carotid artery stenting (CAS) may be determined by various factors; however, residual stenosis is a known risk factor for in-stent restenosis. The authors of this article utilized cone-beam computed tomography (CBCT) in angiosuite to investigate plaque features affecting the character and quality of stent expansion after CAS.

METHODS

Forty-two CAS cases with both pre- and post-CAS CBCT evaluations were included in this retrospective analysis. Five features derived from pre-CAS images were tested: (1) eccentricity, (2) overballoon, (3) maximum plaque thickness, (4) calcification barrier, and (5) stenotic degree. For post-CAS CBCT, stent configuration was assessed if the stent was expanded and oval or round in shape as well as outward or inward in orientation. Variables were tested if they were associated with oval expansion, outward expansion, and 20% residual stenosis after CAS.

RESULTS

Oval or outward expansion is directly related to residual stenosis. The oval expansion was associated with maximum plaque thickness, and outward expansion was associated with the presence of a calcification barrier. Variables related to > 20% residual stenosis were the maximum plaque thickness, calcification barrier, and pre-CAS stenotic degree.

CONCLUSIONS

CBCT for carotid stenosis may provide valuable information about plaque features, especially calcification features that may interfere with the angioplasty effect, as well as the characteristics and quality of stent expansion. Residual stenosis > 20% was associated with calcification barrier, maximum plaque thickness, and pre-CAS stenotic degree.

Prediction of Carotid In-Stent Restenosis by Computed Tomography Angiography Carotid Plaque-Based Radiomics

In-stent restenosis (ISR) after carotid artery stenting (CAS) critically influences long-term CAS benefits and safety. The study was aimed at screening preoperative ISR-predictive features and developing predictive models. Thus, we retrospectively analyzed clinical and imaging data of 221 patients who underwent pre-CAS carotid computed tomography angiography (CTA) and whose digital subtraction angiography data for verifying ISR presence were available. Carotid plaque characteristics determined using CTA were used to build a traditional model. Backward elimination (likelihood ratio) was used for the radiomics model. Furthermore, a combined model was built using the traditional and radiomics features. Five-fold cross-validation was used to evaluate the accuracy of the trained classifier and stability of the selected features. Follow-up angiography showed ISR in 30 patients. Carotid plaque length and thickness were independently associated with ISR (multivariate analysis); regarding the conventional model, the area under the curve (AUC) was 0.84 and 0.82 in the training and validation cohorts, respectively. The corresponding AUC values for the radiomics-based model were 0.87 and 0.82, and those for the optimal combined model were 0.88 and 0.83. Plaque length and thickness could independently predict post-CAS ISR, and the combination of radiomics and plaque features afforded the best predictive performance.

Balloon Dilation Strategy Does Not Affect Outcomes for Transcarotid Artery Revascularization (TCAR) in Prospective Trials

OBJECTIVES

Strategies of balloon dilation during trans-femoral carotid artery stenting (TFCAS) include pre-stent dilation only (PRE), post-stent dilation only (POST), or both pre- and post- dilation (PRE+POST). Concerns over higher neurological risk have been raised with POST and PRE+POST during TFCAS. Whether these concerns are applicable to Transcarotid Artery Revascularization (TCAR) which utilizes proximal clamping and cerebral blood flow reversal during stent deployment and balloon angioplasty remains unknown. Our aim is to analyze outcomes of PRE, POST or PRE+POST balloon dilation strategies during TCAR.

METHODS

We analyzed the prospectively collected data from the ROADSTER1 (pivotal), ROADSTER2 (FDA indicated post-market), and Roadster Extended Access TCAR trials. All trial patients had high risk anatomic or clinical factors for carotid endarterectomy and were included unless they did not undergo stent deployment nor balloon dilation. For trial inclusion, asymptomatic patients had >80% carotid stenosis, and symptomatic patients had >50% stenosis. Primary outcome measures were stroke, death, and myocardial infarction (MI) at 30 days. Data were statistically analyzed with chi-square, ANOVA, and multivariable analysis as appropriate.

RESULTS

There were 851 patients (566 male) who underwent dilation by PRE (N=216), POST (N=249), or PRE+POST (N=386). Patients had carotid stenosis >70% (N=828, 97%), and 207 (24%) were symptomatic. Flow reversal times were longer in the PRE+POST group (PRE 10.2mins, POST 9.8mins, PRE+ POST 13.3mins, P<.001). The 30-day stroke rate for the whole cohort was 1.9%, mortality was 0.5%, and MI rate was 0.94%. Stroke rates for the PRE cohort (1.9%), POST cohort (2.0%), and PRE+POST cohort (1.8%, P=.98) were similar. Also, death rates at 30 days, and composite stroke/death/myocardial infarction rates were similar in the three cohorts. No significant differences in adverse outcomes were noted among the various dilation strategies for both symptomatic and asymptomatic patients.

CONCLUSION

Based on these prospective trial data, there is no difference in neurological complications due to balloon dilation strategy during TCAR. Balloon dilation technique best suited to the patient's specific lesion morphology should be utilized. Further studies are needed to evaluate the relationship of these dilation strategies to long term outcomes including stent patency, restenosis and reintervention.

The association between neutrophil-to-lymphocyte ratio and contrast-induced acute kidney injury in patients with carotid artery stenting

OBJECTIVES

Contrast-induced acute kidney injury (CI-AKI) is a life-threatening complication that leads to comorbidities and prolonged hospital stay lengths in the setting of peripheral interventions. The presence of some CI-AKI risk factors has already been investigated. In this study, we evaluated the predictors of CI-AKI after carotid artery stenting.

METHODS

A total of 389 patients with 50% to 99% carotid artery stenosis who underwent carotid artery stenting were included in this study. Patients were grouped according to CI-AKI status.

RESULTS

CI-AKI developed in 26 (6.6%) patients. Age, baseline creatinine level, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio were higher and estimated glomerular filtration rate, haemoglobin and lymphocyte count were lower in CI-AKI patients. In the multivariate regression analysis, the neutrophil-to-lymphocyte ratio triggered a 1.39- to 2.63-fold increase in the risk of CI-AKI onset (p < 0.001).

CONCLUSIONS

The neutrophil-to-lymphocyte ratio may be a significant predictor of CI-AKI in patients with carotid artery stenting and higher neutrophil-to-lymphocyte ratio values may be independently associated with CI-AKI.

Treatment and Predictors of Recurrent Internal Carotid Artery In-Stent Restenosis

PURPOSE

We aimed to examine the effectiveness of different therapeutic options for and to identify the possible risk factors of recurrent internal carotid artery (ICA) in-stent restenosis (ISR).

METHODS

Forty-six ICA ISRs, which were reintervened at least once, were retrospectively analyzed regarding clinical and imaging characteristics, as well as invasive treatment type (percutaneous transluminal angioplasty [PTA] with a plain balloon, PTA with a drug-eluting balloon [DEB], re-stenting) used.

RESULTS

The median follow-up was 29.5 months (IQR, 8.5-52.8 months) in patients who underwent reintervention for ICA ISR. Stent occlusion occurred in 3 patients (6.5%). One ISR recurrence was noted in 10 patients (21.7%); reintervention was carried out in 7 cases (7/10 [70%]; PTA, N = 5; PTA with a DEB, N = 1; re-stenting, N = 1), while 3 patients (3/10; 30%) received best medical treatment. Two ISR recurrences were observed in 3 patients (6.5%); all of them underwent reintervention (PTA, N = 1; PTA with a DEB, N = 2). Three ISR recurrences were seen in 1 patient (2.2%), who was treated with PTA. No recurrence was observed in those patients, who had DEB treatment. Multiple logistic regression analysis revealed statin therapy to be a protective factor against recurrent ISR (OR, 0.17; 95% CI, 0.03-0.84; P = .029).

CONCLUSION

Our study suggests that PTA with a DEB is the most effective for the treatment of recurrent ISR, and confirms the importance of statin use in patients who have had a carotid reintervention.

The management of carotid restenosis: a comprehensive review

Carotid artery stenosis (CS) is a major medical problem affecting approximately 10% of the general population 80 years or older and causes stroke in approximately 10% of all ischemic events. In patients with symptomatic, moderate-to-severe CS, carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS), has been used to lower the risk of stroke. In primary CS, CEA was found to be superior to best medical therapy (BMT) according to 3 large randomized controlled trials (RCT). Following CEA and CAS, restenosis remains an unsolved problem involving a large number of patients as the current treatment recommendations are not as clear as those for primary stenosis. Several studies have evaluated the risk of restenosis, reporting an incidence ranging from 5% to 22% after CEA and an in-stent restenosis (ISR) rate ranging from 2.7% to 33%. Treatment and optimal management of this disease process, however, is a matter of ongoing debate, and, given the dearth of level 1evidence for the management of these conditions, the relevant guidelines lack clarity. Moreover, the incidence rates of stroke and complications in patients with carotid stenosis are derived from studies that did not use contemporary techniques and materials. Rapidly changing guidelines, updated techniques, and materials, and modern medical treatments make actual incidence rates barely comparable to previous ones. For these reasons, RCTs are critical for determining whether these patients should be treated with more aggressive treatments additional to BMT and identifying those patients indicated for surgical or endovascular treatments. This review summarizes the current evidence and controversies concerning the risks, causes, current treatment options, and prognoses in patients with restenosis after CEA or CAS.

Neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio: novel markers for the diagnosis and prognosis in patients with restenosis following CAS

Aim: In this study, we investigated the effect of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio on restenosis status in patients undergoing carotid angioplasty stenting (CAS). Methodology & results: Clinical imageology and receiver operating characteristic analysis were utilized to study the prognostic significance of NLRs/platelet-to-lymphocyte ratios and their correlation with survival. NLR of restenosis (+) patients was evidently increased after the CAS procedures, while the NLR of restenosis (-) patients before the CAS procedures being the lowest. Area under the curve of pre-CAS NLR or/and post-CAS NLR were all evidently higher than 50%. Also, restenosis incidence was the highest in patients with both high pre-CAS and high post-CAS values. Conclusion: Therefore, NLR can be utilized as an independent prognostic indicator to predict the incidence of restenosis after CAS procedures.

Impact of plaque dilation before carotid artery stent deployment

OBJECTIVE

Plaque stability is of utmost importance for stroke prevention in the perioperative period (within 24 hours) following carotid artery stenting (CAS). Although carotid plaque is entrapped between stent struts after stent deployment, postdilation can cause a scissoring effect on the plaque, increasing the risk of postprocedural embolic events due to plaque prolapse. Maximum carotid plaque dilation before stent deployment may reduce this risk. This study analyzed the effect of maximum dilation of the carotid plaque before stent deployment (max-pre-SD) or after stent deployment (post-SD) on macroscopic plaque debris, hemodynamic depression (HD), and immediate major adverse events.

METHODS

This prospective nonrandomized multicenter study analyzed patients treated for carotid artery stenosis with CAS from January 2014 to August 2016. Clinical and morphologic characteristics and operative details were analyzed with logistic regression analysis for macroscopic debris and HD. The number of microembolic signals (MESs) was assessed by transcranial Doppler and analyzed.

RESULTS

A total of 309 patients were enrolled and treated with standard CAS performed using a proximal occlusion cerebral embolic protection device; 149 received max-pre-SD and 160 were treated with post-SD. Technical success was achieved in 100% of cases. Macroscopic debris and HD were significantly different between the two groups in favor of max-pre-SD (P < .001). A significant difference in intraprocedural MESs between the groups was detected. Compared with post-SD, max-pre-SD significantly reduced mean MES counts (8.1% vs 68.1%; P < .001). Patients treated with post-SD had a significantly increased risk of MESs in the immediate postoperative period compared with patients treated with max-pre-SD (41.9% vs 1.3%; P < .001).This result was mainly due to the small number of events encountered. Patients treated with post-SD had a 12-fold increased risk of macroscopic debris collection (odds ratio [OR], 12.36; 95% confidence interval [CI], 5.68-26.87; P < .001) and an 18 times increase in HD risk (OR, 17.80; 95% CI, 5.27-60.17; P < .001) compared with patients treated with max-pre-SD. The heterogeneous, mainly echolucent plaque type significantly highly increased the risk of macroscopic debris (OR, 78.45; 95% CI, 8.70-707.09; P < .001) while acting as a protective factor against HD (OR, 0.02; 95% CI, 0.006-0.11; P < .001) along with echogenic or echolucent complex plaques with irregular surface plaque types (OR, 0.10; 95% CI, 0.031-0.336; P < .001). No significant differences between groups (max-pre-SD group and post-SD) were detected in immediate major adverse events (minor stroke, 2.0% and 2.5% [P = .461]; major stroke, 0% and 0.6% [P = .334], respectively).

CONCLUSIONS

Max-pre-SD seems to be a safe and feasible technical modification to the CAS procedure. Macroscopic debris, HD, and MESs are significantly reduced compared with CAS with post-SD. Further research with larger, randomized cohorts of patients is required to establish the superiority of this technical modification.

The incidence of carotid in-stent stenosis is underestimated ≥50% or ≥80% and its clinical implications

BACKGROUND

The incidence of carotid in-stent stenosis has been reported to vary between 1% and 30%. Most published studies have short follow-up, which may lead to underestimation of the incidence of in-stent stenosis. This study analyzed the incidence of ≥50% and ≥80% in-stent stenosis using validated duplex ultrasound criteria and its clinical implications.

METHODS

This is a retrospective analysis of prospectively collected data of 450 carotid artery stenting (CAS) procedures (February 6, 2001-December 19, 2016). All patients had postoperative carotid duplex ultrasound examination, which was repeated at 1 month, 6 months, and every 6 to 12 months thereafter. A Kaplan-Meier analysis was used to estimate rates of freedom from ≥50% in-stent stenosis (internal carotid artery peak systolic velocity of ≥224 cm/s) and ≥80% in-stent stenosis (internal carotid artery peak systolic velocity of ≥325 cm/s), freedom from reintervention, and survival.

RESULTS

The mean age was 68.3 years, with a mean follow-up of 40.3 months. A total of 201 patients (45% [201/450]) had CAS for symptomatic disease. Primary CAS was done in 291 patients (65%); in the remaining 35%, CAS was done for postcarotid endarterectomy (CEA) stenosis. A total of 101 patients (23%) had ≥50% late carotid in-stent stenosis, and of these, 33 (7.4%) had ≥80% in-stent stenosis. Nineteen patients (4.3%) developed late transient ischemic attack and three (0.7%) late stroke. Twenty-three (5.2%) patients had late reintervention. Rates of freedom from ≥50% in-stent stenosis in the whole series were 85%, 79%, 75%, 72%, and 70% at 1 year, 2 years, 3 years, 4 years, and 5 years, respectively. The rates of freedom from ≥50% in-stent stenosis for primary CAS and CAS for post-CEA stenosis were not statistically significant (P = .540). The rates of freedom from ≥80% in-stent stenosis for the whole series were 96%, 95%, 93%, 90%, and 89% at 1 year, 2 years, 3 years, 4 years, and 5 years, respectively. The rates of freedom from ≥80% in-stent stenosis for primary CAS and CAS for post-CEA stenosis were also not statistically significant (P = .516). Rates of freedom from reintervention were 98%, 96%, 93%, 93%, and 91% at 1 year, 2 years, 3 years, 4 years, and 5 years, respectively, and there were no significant differences between primary CAS and CAS for post-CEA stenosis (P = .939). The overall late survival rates were 99%, 97%, 96%, 94%, and 91% at 1 year, 2 years, 3 years, 4 years, and 5 years.

CONCLUSIONS

The incidence of ≥50% in-stent stenosis is relatively high; however, the rates of ≥80% stenosis and late neurologic events are low. Longer follow-up of patients with ≥50% carotid in-stent stenosis may yield higher incidence of ≥80% stenosis.

Neutrophil to Lymphocyte Ratio as a Predictor of Restenosis After Angioplasty and Stenting for Asymptomatic Carotid Stenosis

The inflammatory response plays a vital role in the development of in-stent restenosis (ISR) after carotid angioplasty and stenting (CAS). The neutrophil to lymphocyte ratio (NLR) has been suggested as a sensitive inflammatory marker. We explored the association between NLR and ISR in CAS patients. A total of 427 patients who underwent CAS were enrolled. Neutrophil to lymphocyte ratio was measured before the procedure. Clinical examination and radiographic evaluation were performed at 6 months and annually after the procedure. In-stent restenosis was defined as ≥50% stenosis in the treated lesion. Cox regression was used to identify predictors of ISR after CAS. Of the 459 arteries (in 427 patients) with CAS, 72 (15.7%) were identified with ISR during a mean follow-up of 14.6 (19.1) months (range, 0.7-120.7 months). Increased NLR (≥2.13) was significantly related to ISR in patients with asymptomatic stenosis ( P = .001). However, significance was not observed in symptomatic stenosis. On multivariate analysis, baseline NLR ≥ 2.13 (hazard ratio [HR], 2.74; 95% confidence interval [CI], 1.46-5.14), smoking (HR, 1.99; 95% CI, 1.11-3.58), residual stenosis (HR, 1.12; 95% CI, 1.09-1.15), and baseline glucose level (HR, 1.01; 95% CI, 1.01-1.02) were associated with ISR. Elevated NLR may be a predictor of ISR after CAS for asymptomatic stenosis.

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.

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.

Determinants of In-Stent Restenosis after Carotid Angioplasty: A Case-Control Study

Purpose:

To report a retrospective study that sought to identify clinical factors contributing to the development of in-stent restenosis in the carotid arteries, to profile the patients at greatest risk, and to review the treatment modalities evolved from our experience.

Methods:

Between December 2000 and April 2003, 195 carotid angioplasty/stenting (CAS) procedures (12 bilateral) were performed in 183 patients (131 men; median age 65.9 years, interquartile range 55.2–72.7). Stenting for de novo stenoses was performed in 119 (61%) carotid arteries; 76 (39%) vessels were treated for postsurgical restenosis. Nearly two thirds of the patients (117, 64%) were symptomatic. Patients were evaluated at 3 and 6 months and at 6-month intervals thereafter with duplex ultrasonography. Angiography was used to confirm any recurrent lesion detected on the ultrasound scan.

Results:

Overall perioperative neurological complications included 4 (2.2%) minor strokes, 1 (0.5%) intracranial hemorrhage, and 1 (0.5%) major stroke; both patients with major neurological complications died at 5 and 12 days, respectively, after the procedure. During the 12.5-month follow-up (range 0–27.2), 3 non-procedure-related late deaths and another 9 (4.9%) neurological events occurred (2 strokes and 7 transient ischemic attacks). In-stent restenosis after CAS was present in 10 (5.2%) of 193 carotid arteries (9/181 patients) in follow-up; all but 1 artery had been treated for postsurgical restenosis. All lesions were treated secondarily with endovascular procedures. Statistical analysis demonstrated that postsurgical restenosis was the only predictive factor for the development of in-stent restenosis (OR 15.5, 95% CI 2.05 to 125.6, p = 0.001) in this cohort.

Conclusions:

The present study, far from being exhaustive on the subject, indicates that patients who develop restenosis after carotid endarterectomy are also prone to develop restenosis after CAS; moreover, although strongly recommended for postsurgical restenosis, CAS carries a greater risk of in-stent restenosis in this subgroup, thus reducing the benefits of this procedure.

Follow-up after undersized dilatation of targeted lesions in carotid artery stenting

BACKGROUND AND PURPOSE

We assessed whether intentional undersized dilatation of targeted lesions during carotid artery stenting (CAS) carried a higher risk of in-stent restenosis (ISR) and correlation to subsequent ischemic stroke in qualifying arteries in the follow-up period.

METHODS

Consecutive patients undergoing CAS between April 2003 and May 2010 were retrospectively reviewed. The use of a filter device as a distal embolic protection device (EPD) was first approved by Japanese governmental health insurance in April 2008; previously, transient balloon occlusion was used off-label. Until March 2008 (Group A), the target diameter of balloon dilatation was 80-100% of the normal vessel diameter just distal to the stenotic lesion. Moderately undersized dilatation (70-80% of the normal vessel diameter) using the distal EPD was adopted in April 2008 (Group B) in an attempt to reduce the amount of released plaque debris.

RESULTS

We analyzed 132 CAS procedures (125 patients) in Group A and 53 CAS procedures (52 patients) in Group B. The mean follow-up period was 35.4 months (35.3 months in Group A and 36.0 months in Group B). Eight lesions (4.3%; 7 in Group A and 1 in Group B) developed ISR. None of the patients had symptomatic ISR, and ISR did not increase in Group B (odds ratio, 0.34; 95% confidence interval, 0.04-2.86; p = 0.32).

CONCLUSIONS

Undersized dilatation of targeted lesions did not increase the risk of developing ISR, and we suggest it as a viable treatment option to prevent ischemic events during CAS.

Carotid artery stenting without post-stenting balloon dilatation

PURPOSE

To evaluate the clinical outcome and MRI findings after carotid artery stenting (CAS) without post-dilatation.

METHODS

Between May 2005 and April 2012, a total of 169 consecutive patients (61.4% symptomatic) underwent 176 CAS procedures performed with an embolic protection device (GuardWire, n=116; FilterWire EZ, n=60). All stents were deployed without post-dilatation. Periprocedural complications and mid-term outcomes were analyzed.

RESULTS

The stroke rate was 2.3% within 30 days post-CAS (asymptomatic patients 1.5%; symptomatic patients 2.8%). Cerebral infarction occurred in one asymptomatic patient (1.5%) and one symptomatic patient (0.9%). Intracranial hemorrhage occurred in two symptomatic patients (1.9%). Post-CAS diffusion-weighted imaging (DWI) revealed a high-intensity area in 26 of 176 procedures (14.8%). Ipsilateral stroke after 31 days occurred in two patients (1.1%) and restenosis occurred in six (3.4%). A post-CAS comparison of the embolic protection devices revealed no difference in stroke incidence within 30 days and in DWI high-intensity area.

CONCLUSIONS

Our CAS procedure without post-dilatation is feasible, safe and associated with a low incidence of stroke and restenosis.

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.

Inflammation as a marker for the prediction of internal carotid artery restenosis following eversion endarterectomy--evidence from clinical studies

The role of inflammation is well established in the pathogenesis of atherosclerosis and an increased level of circulating inflammatory markers may predict the future risk of atherosclerosis progression and plaque rupture. C-reactive protein (CRP) identification by hypersensitive methods (high-sensitivity CRP [hsCRP]) has become a clinical and laboratory inflammation marker. Carotid endarterectomy (CEA) is a well-established procedure for carotid stenosis treatment which can reduce stroke rate. Internal carotid artery (ICA) restenosis reduction may be prevented by the anti-inflammatory effect of statins. This review considers the recent findings on the presence of hsCRP and C3 complement concentration and inflammatory plaque composition as well as their effects on ICA restenosis rate, following eversion CEA with emphasis on human studies.

Inflammation and in-stent restenosis: the role of serum markers and stent characteristics in carotid artery stenting

Background

Carotid angioplasty and stenting (CAS) may currently be recommended especially in younger patients with a high-grade carotid artery stenosis. However, evidence is accumulating that in-stent restenosis (ISR) could be an important factor endangering the long-term efficacy of CAS. The aim of this study was to investigate the influence of inflammatory serum markers and procedure-related factors on ISR as diagnosed with duplex sonography.

Methods

We analyzed 210 CAS procedures in 194 patients which were done at a single university hospital between May 2003 and June 2010. Periprocedural C-reactive protein (CRP) and leukocyte count as well as stent design and geometry, and other periprocedural factors were analyzed with respect to the occurrence of an ISR as diagnosed with serial carotid duplex ultrasound investigations during clinical long-term follow-up.

Results

Over a median of 33.4 months follow-up (IQR: 14.9–53.7) of 210 procedures (mean age of 67.9±9.7 years, 71.9% male, 71.0% symptomatic) an ISR of ≥70% was detected in 5.7% after a median of 8.6 months (IQR: 3.4–17.3). After multiple regression analysis, leukocyte count after CAS-intervention (odds ratio (OR): 1.31, 95% confidence interval (CI): 1.02–1.69; p = 0.036), as well as stent length and width were associated with the development of an ISR during follow-up (OR: 1.25, 95% CI: 1.05–1.65, p = 0.022 and OR: 0.28, 95% CI: 0.09–0.84, p = 0.010).

Conclusions

The majority of ISR during long-term follow-up after CAS occur within the first year. ISR is associated with periinterventional inflammation markers and influenced by certain stent characteristics such as stent length and width. Our findings support the assumption that stent geometry leading to vessel injury as well as periprocedural inflammation during CAS plays a pivotal role in the development of carotid artery ISR.

Periprocedural cilostazol treatment and restenosis after carotid artery stenting: the Retrospective Study of In-Stent Restenosis after Carotid Artery Stenting (ReSISteR-CAS)

Restenosis after carotid artery stenting (CAS) is a critical issue. Cilostazol can reduce restenosis after interventions in coronary or femoropopliteal arteries. We investigated whether periprocedural cilostazol treatment was related to the incidence of in-stent restenosis (ISR) or target vessel revascularization (TVR) after CAS. The study group comprised 553 of 580 patients who underwent CAS between April 2003 and August 2006 and were followed for 30 months after the procedure. ISR was defined as stenosis of at least 50% detected on angiography or ultrasonography. TVR was defined as revascularization of the treated carotid artery. During CAS, 207 patients (37.4%) were treated with cilostazol. Over 30 months, ISR occurred in 23 patients (4.2%), TVR occurred in 16 patients (2.9%), and either ISR or TVR occurred in 25 patients (4.5%). The incidence of ISR or TVR was significantly lower in the cilostazol-treated group than in the untreated group (1.4% vs 6.4%; log-rank P = .006). In a multivariate analysis, cilostazol treatment (hazard ratio [HR], 0.28; 95% confidence interval [CI], 0.08-0.95; P = .041) and stent diameter (HR, 0.73/1-mm increase; 95% CI, 0.54-0.99; P = .044) were independent factors for the occurrence of ISR or TVR. The incidence of a composite of events, including thromboembolism, hemorrhage, death, and TVR, tended to be lower in the cilostazol-treated group than in the untreated group (15.0% vs 19.9%; log-rank P = .17). Periprocedural cilostazol treatment was associated with lower rates of ISR and retreatment after CAS. A prospective randomized controlled trial is needed to clarify the effect of cilostazol on ISR after CAS.

In stent restenosis predictors after carotid artery stenting

Purpose. The long-term efficacy of carotid artery stenting is debated. Predictors of stent restenosis are not fully investigated. Our aim was to assess the incidence of long term restenosis after CAS and to identify some predictors of restenosis. Methods. We retrospectively selected 189 treated patients and we obtained the survival Kaplan-Meier curves for overall survival, for freedom from stroke or death and from restenosis. To correlate clinical, radiological, and procedural variables to stent restenosis, an univariate analysis was performed while to determine independent predictors of restenosis, a multivariate analysis was applied. Results. At 1, 3, and 5 years, the cumulative overall survival rate was 98%, 94%, and 92% with a cumulative primary patency rate of 87%, 82.5%, and 82.5%. The percentage residual stenosis after CAS and multiple stents deployment were independent predictors of restenosis, while diabetes and tumors are suggestive but not significant predictors of restenosis. Conclusions. In our CAS experience, encouraging long-term results seem to derive from both neurological event free rate and restenosis incidence. Adequate recanalization of the treated vessel is important to limit the development of stent restenosis. Multiple stents deployment, and with less evidence, diabetes, or neoplasms has to be considered to facilitate restenosis.

VAST: Vertebral Artery Stenting Trial. Protocol for a randomised safety and feasibility trial

Background

Twenty to 30 percent of all transient ischaemic attacks and ischaemic strokes involve tissue supplied by the vertebrobasilar circulation. Atherosclerotic stenosis ≥ 50% in the vertebral artery accounts for vertebrobasilar stroke in at least one third of the patients. The risk of recurrent vascular events in patients with vertebral stenosis is uncertain and revascularisation of vertebral stenosis is rarely performed. Observational studies have suggested that the risk of subsequent stroke or death in patients with vertebrobasilar ischaemic events is comparable with that in patients with carotid territory events. Treatment of vertebral stenosis by percutaneous transluminal angioplasty has been introduced as an attractive treatment option. The safety and benefit of stenting of symptomatic vertebral stenosis as compared with best medical therapy alone remains to be elucidated in a randomised clinical trial.

Study objectives

The primary aim of the Vertebral Artery Stenting Trial (VAST) is to assess whether stenting for symptomatic vertebral artery stenosis ≥ 50% is feasible and safe. A secondary aim is to assess the rate of new vascular events in the territory of the vertebrobasilar arteries in patients with symptomatic vertebral stenosis ≥ 50% on best medical therapy with or without stenting.

Design

This is a randomised, open clinical trial, comparing best medical treatment with or without vertebral artery stenting in patients with recently symptomatic vertebral artery stenosis ≥ 50%. The trial will include a total of 180 patients with transient ischaemic attack or non-disabling ischaemic stroke attributed to vertebral artery stenosis ≥ 50%. The primary outcome is any stroke, vascular death, or non-fatal myocardial infarction within 30 days after start of treatment. Secondary outcome measures include any stroke or vascular death during follow-up and the degree of (re)stenosis after one year.

Discussion

Improvements both in imaging of the vertebral artery and in endovascular techniques have created new opportunities for the treatment of symptomatic vertebral artery stenosis. This trial will assess the feasibility and safety of stenting for symptomatic vertebral artery stenosis and will provide sufficient data to inform a conclusive randomised trial testing the benefit of this treatment strategy. The VAST is supported by the Netherlands Heart Foundation (2007B045; ISRCTN29597900).

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.

[The effect of carotid stenting on rheological parameters, free radical production and platelet aggregation]

INTRODUCTION

Carotid artery stenting has become a possible treatment of significant carotid stenosis. The risk of stent occlusion and restenosis might be increased by abnormal rheological conditions amplified platelet aggregation and free radical production during the operation.

AIMS

The aim of this study was to assess the changes of the rheologic parameters, platelet aggregation, and oxidative stress after endovascular treatment of carotid stenosis.

METHODS

18 patients (11 men, ages 68 +/- 9 years and 7 women, ages 62 +/- 8 years) suffering from significant carotid stenosis and treated with carotid endovascular intervention were examined. Alteration in hemorrheological parameters as well as epinephrine-, ADP-, and collagen-induced platelet aggregation were evaluated. Oxidative stress was characterized by the determination of catalase activity. The measurements were carried out directly before and after the procedure and 1, 2, 5 days and 1 month following the intervention. Preceding the operation the patients were administered a maximum dose (300 mg) of clopidogrel.

RESULTS

The hematocrit, the plasma fibrinogen concentration (Pfc) and whole blood-, and plasma viscosity (Wbv and Pv) decreased significantly immediately after stenting ( p < 0.001). By the fifth day following the intervention the Pfc, Wdv, Pv, red blood cell (Rbc) aggregation and ADP-induced platelet aggregation increased significantly ( p < 0.0001) compared to values measured after the procedure. At 1 month follow-up these parameters, excepting Wbv, decreased significantly compared to measurements made on the 5th day. On the other hand, catalase activity showed significant elevation by the end of the first month.

CONCLUSION

Hemorrheological parameters and platelet aggregation showed specific changes following carotid stenting. Abnormal changes of the rheological conditions and increasing platelet activation are the most pronounced in the first week following stenting, which may lead to the stent's early occlusion. Oxidative stress production returned to baseline levels only by the end of the first month.

Emerging methods in economic modeling of imaging costs and outcomes a short report on discrete event simulation

RATIONALE AND OBJECTIVES

This short report provides a non-technical overview of one emerging modeling technique, discrete event simulation (DES).

METHODS

A selective review of the literature that has applied DES methods to evaluate imaging technologies.

RESULTS

Mathematical models to evaluate the likely costs and outcomes of health technologies have become increasingly accepted. Increasing experience has also brought a mounting awareness of the limitations of conventional modeling techniques such as decision trees and Markov processes. Patient-level simulation, including DES, may provide a more flexible approach to modeling for economic evaluation of health technologies.

CONCLUSIONS

The strengths of DES suggest that it may have an increasingly important role in the future modeling of annual screening programs, diagnosis, and treatment of chronic recurrent disease and modeling the utilization of imaging equipment.

Restenosis after percutaneous angioplasty: the role of vascular inflammation

Restenosis after endovascular treatment of atherosclerotic lesions in the peripheral, cerebrovascular, and coronary circulation is the major drawback of this minimally invasive technique. Although certain advances have been made during recent years to improve patency rates after percutaneous angioplasty, restenosis remains a challenging clinical problem. Understanding factors that contribute to the pathophysiology of late lumen loss is an effective strategy to improving patients' postangioplasty outcome. Vascular inflammation after balloon angioplasty or stent implantation has been identified as a cornerstone of the restenotic process, and several markers of inflammation have been referred to as potential predictors of outcome. This article reviews recent findings on the issue of inflammation and restenosis after percutaneous angioplasty with special attention given to the role of inflammatory parameters as markers for the restenosis risk in the peripheral vessel area.

Follow-up results of carotid angioplasty with stenting as assessed by duplex ultrasound surveillance

BACKGROUND

Carotid artery stenting (CAS) has become an alternative modality to carotid endarterectomy (CEA) for the treatment of carotid occlusive disease. We report a retrospective review of our institution's experience with CAS versus CEA.

METHODS

Postprocedure surveillance duplex, recurrent symptoms, postprocedure strokes, progression of lesions, and rates of re-operation were analyzed in 46 patients who underwent CAS and 48 patients who underwent CEA. The mean length of follow-up evaluation was 13 months. All CAS procedures included neuroprotection devices.

RESULTS

Statistically significant differences in progression to critical restenosis (2% vs 2%, P = 1.0), rate of subsequent symptoms or stroke (2% vs 10%, P = .1), or rate of re-interventions were not observed between CAS and CEA groups (2% vs 4%, P = .98). Total mortality (0% vs 2%, P = .33), and the occurrence of major adverse events (2% vs 10%, P = .18) also were not significantly different in the CAS compared with the CEA patients. The average rate of increase in internal carotid velocity at 6 to 12 months (-1% vs 1.1%, P = NS) and 12 to 24 months (-5% vs -6.5%, P = NS) also were equivalent.

CONCLUSIONS

Our observed results indicate that CAS may be performed with comparable clinical outcomes and durability of repair comparable with CEA.

Statin Therapy at Carotid Angioplasty and Stent Placement: Effect on Procedure-related Stroke, Myocardial Infarction, and Death

PURPOSE

To retrospectively determine if preprocedural statin treatment is associated with a reduction of cardiovascular events after carotid angioplasty and stent placement (CAS) in patients with symptomatic carotid stenosis.

MATERIALS AND METHODS

A study resulting in a prospective database was approved by the institutional ethics review board; written informed consent was obtained. The approval and informed consent included future retrospective analysis. Consecutive patients (n = 180) from the prospective database underwent CAS for high-grade symptomatic carotid disease. The frequency of cardiovascular complications (composite of stroke, myocardial infarction, and death within 30 days after CAS) between 127 patients without preprocedural statin treatment and that of 53 patients with preprocedural statin treatment at CAS were compared with chi2 and multivariate logistic regression analysis.

RESULTS

The overall 30-day myocardial infarction rate was two of 180 (1%) patients, the minor stroke rate was 16 of 180 (9%) patients, the major stroke rate was one of 180 (0.5%) patients, and the death rate was two of 180 (1%) patients. The incidence of cardiovascular events (composite of stroke, myocardial infarction, and death within 30 days after CAS) was significantly different between patients with preprocedural treatment (4%) and those without preprocedural statin treatment (15%) (P < .05). These higher complication rates among patients without preprocedural statin treatment were not mediated by adjustment for age, sex, other baseline characteristics, degree of carotid stenosis, use of cerebral protection devices, or the year in which CAS was performed.

CONCLUSION

Preprocedural statin therapy appears to reduce the incidence of stroke, myocardial infarction, and death within 30 days after CAS. Future prospective randomized trials are warranted to further assess this potential protective effect of statin drugs during carotid interventions.

Covered Versus Bare Self-Expanding Stents for Endovascular Treatment of Carotid Artery Stenosis:A Stopped Randomized Trial

PURPOSE

To investigate whether filter-protected carotid artery stenting (CAS) using a covered self-expanding stent reduces the risk of cerebral embolization.

METHODS

Fourteen asymptomatic patients (13 men; median age 77 years, IQR 73-83) were enrolled in a randomized pilot trial comparing the rates of cerebral microembolism during and after filter-protected CAS using either a self-expanding covered (n=8) or a bare (n=6) carotid stent. Transcranial Doppler (TCD) monitoring was done during and for 90 minutes after the procedure. Diffusion-weighted magnetic resonance imaging (DW-MRI) was performed before and 24 hours after CAS. Patients were followed for 6 months for neurological events and occurrence of restenosis.

RESULTS

A significant reduction in ipsilateral microembolic signals by TCD was observed with the covered (median 1, IQR 0-4) versus the bare stent (median 6, IQR 3-8; p=0.043). Comparison of the preprocedural and 24-hour postprocedural DW-MRI images showed no new ipsilateral lesions but 1 new lesion in the contralateral hemisphere in the covered stent group, resulting in an overall 7% (95% CI 0%-20%) rate of new ischemic lesions. No neurological complications occurred up to 6 months. Restenosis (>70%) occurred in 3 (38%) of 8 patients with the covered versus none of the bare stents (p=0.21). The trial was stopped when the third restenosis of a covered stent was detected.

CONCLUSION

Self-expanding covered stents potentially reduce the risk of cerebral microembolism during and after carotid stenting. However, the problem of in-stent restenosis has to be resolved before these devices can be considered for further investigation.

The Role of Antiplatelet Therapy in Carotid Stenting for Ischemic Stroke Prevention

Background and Purpose— Carotid angioplasty and stenting (CAS) is a minimally invasive revascularization procedure that has become a popular and acceptable treatment option in the United States for high surgical risk patients with internal carotid artery atherosclerosis. It is effective and has an acceptable risk profile, but ischemic complications caused by distal embolization and underlying atherothrombosis persist.

Summary of Review— Atherothrombosis is the pathological process that is frequently implicated as the underlying cause of stroke, transient ischemic attacks, and most other ischemic vascular disease. Critical steps in the development of occlusive episodes are the disruption of atherosclerotic plaque and subsequent formation of a platelet-rich mural thrombus. Vascular injury as a result of CAS or any other percutaneous intervention triggers platelet adhesion, activation, and aggregation, resulting in the formation of a mural thrombosis. This risk, in addition to the potential risk of embolization to distal sites, provides a rationale for early antiplatelet therapy with CAS. The risk of late stent (>30 days after stenting) thrombosis in some patients, particularly those receiving drug-eluting stents, provides a rationale for prolonged antiplatelet prophylaxis as well as for prophylaxis against late atherothrombotic events. Because of the systemic and progressive nature of atherothrombosis, protection against ischemic vascular events in other arterial beds expands the benefits of long-term antiplatelet therapy.

Conclusions— As clinical experience with CAS increases, it is likely that it will be used more frequently for patients with occlusive carotid disease. In addition, adjunct antiplatelet therapy will play a key role in the continued development of CAS.

Complications and Follow-up after Unprotected Carotid Artery Stenting

PURPOSE

This prospective study was undertaken to determine the success rate, complications, and outcome of carotid artery stenting (CAS) without the use of cerebral protection devices.

METHODS

During 12 months, 94 high-grade stenoses of the carotid artery in 91 consecutive patients were treated. Sixty-six (70%) of the stenoses were symptomatic and 28 (30%) were asymptomatic.

RESULTS

In all 94 carotid stenoses CAS was successfully performed. During the procedure and within the 30 days afterwards, there were 2 deaths and 3 major strokes in the 66 symptomatic patients, resulting in a combined death and stroke rate of 5 of 66 (7%). Only one of these complications, a major stroke, occurred during the procedure. In the 6-month follow-up, one additional major stroke occurred in a originally symptomatic patient resulting in a combined death and stroke rate of 6 of 66 (10%) for symptomatic patients at 6 months. No major complications occurred in asymptomatic patients during the procedure or in the 6-month follow-up period. At 6 months angiographic follow-up the restenosis rate with a degree of >50% was 3 of 49 (6%) and the rate with a degree of >or=70% was 1 of 49 (2%).

CONCLUSIONS

Cerebral embolization during CAS is not the only cause of the stroke and death rate associated with the procedure. The use of cerebral protection devices during the procedure may therefore not prevent all major complications following CAS.

Management of in-sent restenosis after carotid artery stenting in high-risk patients

BACKGROUND

Carotid artery stenting (CAS) has emerged as an acceptable treatment alternative in patients with carotid bifurcation disease. Although early results of CAS have been promising, long-term clinical outcomes remain less certain. We report herein the frequency, management, and clinical outcome of in-stent restenosis (ISR) after CAS at a single academic institution.

METHODS

Clinical records of 208 CAS procedures in 188 patients with carotid stenosis of 80% or greater, including 48 (26.5%) asymptomatic patients, during a 42-month period were analyzed. Follow-up serial carotid duplex ultrasound scans were performed. Selective angiography and repeat intervention were performed when duplex ultrasound scans showed 80% or greater ISR. Treatment outcomes of ISR interventions were analyzed.

RESULTS

Over a median 17-month follow-up, 33 (15.9%) ISRs of 60% or greater were found, according to the Doppler criteria. Among them, seven patients (3.4%) with a mean age of 68 years (range, 65-87 years) developed high-grade ISR (> or =80%), and they all underwent further endovascular interventions. Six patients with high-grade ISR were asymptomatic, whereas one remaining patient presented with a transient ischemic attack. Five of seven ISRs occurred within 12 months of CAS, and two occurred at 18 months' follow-up. Treatment indications for initial CAS in these seven patients included recurrent stenosis after CEA (n = 4), radiation-induced stenosis (n = 1), and high-cardiac-risk criteria (n = 2). Treatment modalities for ISR included balloon angioplasty alone (n = 1), cutting balloon angioplasty alone (n = 4), cutting balloon angioplasty with stent placement (n = 1), and balloon angioplasty with stent placement (n = 1). Technical success was achieved in all patients, and no periprocedural complications occurred. Two patients with post-CEA restenosis developed restenosis after ISR interventions, both of whom were successfully treated with cutting balloon angioplasty at 6 and 8 months. The remaining five patients showed an absence of recurrent stenosis or symptoms during a mean follow-up of 12 months (range, 3-37 months). By using the Kaplan-Meier analysis, the freedom from 80% or greater ISR after CAS procedures at 12, 24, 36, and 42 months was 97%, 97%, 96%, and 94%, respectively.

CONCLUSIONS

Our study showed that ISR after CAS remains uncommon. Successful treatment of ISR can be achieved by endovascular interventions, which incurred no instance of periprocedural complications in our series. Patients who developed ISR after CEA were likely to develop restenosis after IRS intervention. Diligent ultrasound follow-up scans are important after CAS, particularly in patients with post-CEA restenosis.

Angiotensinogen and Plasminogen Activator Inhibitor-1 Gene Polymorphism in Relation to Renovascular Disease

The present study was designed to evaluate angiotensinogen (AGT) M235T and plasminogen activator inhibitor-1 (PAI-1) (4G/5G) polymorphisims in relation to the occurrence of atherosclerotic renal artery stenosis (ARAS) and recurrent stenosis. In this study, 30 patients were enrolled after angiographic demonstration of ARAS; 100 healthy subjects for AGT polymorphism and 80 healthy subjects for PAI-1 polymorphism were considered the control group. The patients were followed for a mean 46.1 +/- 9.2 months. The patients had significantly higher frequencies of the MT genotype and the T allele than control group (chi(2) = 18.2, p < 0.001 and chi(2) = 11.5 p < 0.001). There were no significant differences in the PAI-1 genotype and allele findings when the data for all patients were compared with that for the controls (chi(2)= 2.45, p = 0.29 and chi(2) = 0.019, p = 0.89). There were no significant differences in the genotype and allele findings for the patients with and without restenosis (p > 0.05). The C-reactive protein (CRP) level was higher in the patients with restenosis than in the patients without restenosis (7.694 +/- 0.39 mg/L and 1.56 +/- 1.08 mg/L) (p = 0.001). Our results suggest that the M235T MT genotype and T allele might be associated with increased risk of atherosclerotic renal artery stenosis. The CRP level might be an independent predictor for recurrent stenosis.

Procedure-Related Complications and Early Neurological Adverse Events of Unprotected and Protected Carotid Stenting:Temporal Trends in a Consecutive Patient Series

PURPOSE

To report procedure-related complications and neurological adverse events of unprotected over-the-wire (OTW) and protected rapid exchange (RX) carotid artery stenting (CAS) in a single-center patient series during an 8-year period.

METHODS

Between 1997 and 2004, 651 consecutive patients (445 men; median age 72 years, interquartile range 64-77) were enrolled in a registry database of carotid stent procedures; from 1997 to 2002, 471 patients underwent unprotected CAS using an OTW technique, while the other 180 patients were treated with protected CAS using RX monorail systems from 2003 to 2004. Technical success and complications (neurological, hemodynamic instability, and access site) up to 30 days post intervention were analyzed.

RESULTS

Technical success improved from 95% with unprotected OTW CAS to 99% with protected RX CAS (p=0.025). Procedure-related complications occurred in 86 (18.3%) of 471 unprotected OTW CAS versus 18 (10.0%) of 180 protected RX CAS procedures (p=0.010). Transient ischemic attacks (3.2% versus 2.8%), minor stroke (1.7% versus 0.6%), and major stroke (2.1% versus 0.6%) showed a trend toward a difference between unprotected OTW and protected RX CAS (p=0.076); combined 30-day stroke/death rates were 3.8% for OTW versus 1.2% for RX CAS (p=0.073). During the 8-year period from 1997 to 2004, the annual rates of procedure-related complications (p=0.002), neurological events (p=0.040), and stroke and death (p=0.14) markedly decreased.

CONCLUSIONS

Carotid stenting became substantially safer in the era of protected RX technology. In addition to a reduction in neurological complications, which may be due to cerebral protection devices, the improved technical success and reduced non-neurological procedure-related complications are likely due to recent technical advances unrelated to cerebral protection.

Angioplasty and stenting of intracranial stenosis

PURPOSE OF REVIEW

The review summarizes recent advances in angioplasty and stenting of intracranial atherosclerotic stenosis.

RECENT FINDINGS

Several single-center studies show that, with the technological advancements in device technology, intracranial stenting is feasible even in the distal internal carotid artery or middle cerebral artery. However, the clinical outcomes vary between moderate and high risk rates for morbidity and mortality. To date, the only prospective multi-center study that has been conducted is the SSYLVIA (Stenting of Symptomatic Atherosclerotic Lesions in the Vertebral or Intracranial Arteries) study, which demonstrated stroke rates of 6.6% and 13.1% at 30 days and 1 year, respectively. A unique feature of this trial is the assessment of restenosis rates and their potential association with clinical symptoms and risks. A promising new concept for stent-assisted procedures in the intracranial vasculature is the use of self-expanding stents. The high flexibility of these stents makes them suitable for treatment of lesions of the distal internal carotid artery and middle cerebral artery that are either inaccessible or difficult to reach with a balloon-mounted stent. Additionally, these self-expanding stents may result in fewer traumas to the parent vessel and in reduced rates of iatrogenic complications and restenosis.

SUMMARY

Intracranial angioplasty with or without stenting is a promising treatment option. Patient selection, careful periprocedural medical management, and a highly skilled neuroendovascular surgeon are all required to perform the procedure with an acceptable risk. If stenting is to be shown to be a safe therapeutic alternative, prospective trials comparing stenting with optimal medical treatment need to be performed.

Current Indications, Results, and Technique of Carotid Angioplasty/Stenting

Carotid endarterectomy (CEA) remains the treatment of choice for most patients with high-grade carotid artery stenosis. Certain patient subsets, including those with severe cardiac and pulmonary disease and those with local/anatomic risk factors (including recurrent stenosis following CEA, cervical radiation therapy, prior radical neck dissection, and surgically inaccessible lesions) are at increased risk of stroke, cranial nerve injury and non-Q myocardial infarction following CEA, and may be better served by carotid angioplasty and stenting (CAS). Procedural success is dependent upon proper patient selection and meticulous attention to detail. The use of cerebral embolic protection appears to reduce the risk of peri-procedural stroke following CAS.

Systematic Review of Early Recurrent Stenosis After Carotid Angioplasty and Stenting

BACKGROUND AND PURPOSE

Carotid angioplasty and stenting (CAS) has emerged as a potential alternative to endarterectomy (CEA) for the treatment of carotid artery disease. Aside from the periprocedural complication rates, the benefits of CAS will be affected by the incidence of recurrent carotid stenosis.

METHODS

We conducted a systematic analysis of all peer-reviewed studies reporting on the rate of restenosis (> or =50%) after CAS based on duplex ultrasound or angiography that were published between January 1990 and July 2004. We identified 34 studies that reported on a total of 4185 patients with a follow-up of 3814 arteries over a median of 13 months (range, 6 to 31 months). The ultrasound criteria and the lower thresholds for defining a recurrent stenosis were very heterogeneous.

RESULTS

The cumulative restenosis rates after 1 and 2 years were approximately 6% and 7.5% in those studies, which used a lower restenosis threshold > or =50% to 70% and approximately 4% in the first 2 years after CAS in those studies, which used a lower restenosis threshold >70% to 80%.

CONCLUSIONS

In reviewing the current literature, the early restenosis rates after CAS compare well with those reported for CEA. However, this analysis of the peer-reviewed literature also indicates that the early restenosis rates after CAS might be higher than previously suggested in observational surveys. Therefore, an active follow-up of all stented arteries seems to be warranted. Moreover, the bulk of endovascular data are derived from small studies with short follow-up periods so that the long-term durability of CAS still needs to be established in large trials. Ideally, these studies should use a clear and uniform definition of restenosis and identical follow-up schedules.

Carotid revascularization for prevention of stroke: carotid endarterectomy and carotid artery stenting

Carotid endarterectomy (CEA) has been used for the past several decades in patients with carotid occlusive disease. Large randomized controlled trials have documented that CEA is a highly effective stroke preventive among patients with carotid stenosis and recent transient ischemic attack or cerebral infarction. In asymptomatic patients with carotid stenosis, clinical trial data suggest that the degree of stroke prevention from CEA is less than among symptomatic patients. However, otherwise healthy men and women with an asymptomatic carotid stenosis of 60% or greater have a lower risk of future cerebral infarction, including disabling cerebral infarction, if treated with CEA compared with those treated with medical management alone. More recently, carotid artery stenting has been performed Increasingly for patients with carotid occlusive disease. As technology has improved, procedural risks have declined and are approaching those reported for CEA. The benefits and durability of CEA compared with carotid artery stenting are still unclear and are being studied in ongoing randomized controlled trials.