Long-term Comparative Outcomes of Carotid Artery Stenting Following Previous Carotid Endarterectomy vs De Novo Lesions

Role of carotid duplex in the assessment of carotid artery restenosis after endarterectomy or stenting

Introduction

Redo carotid endarterectomy (CEA) and carotid stenting (CAS) are often performed when there is evidence of post-procedural restenosis. The incidence of restenosis after carotid reconstruction is not negligible, ranging from 5 to 33%. The diagnosis of significant internal carotid artery (ICA) restenosis is usually based on duplex ultrasound (US) criteria, mostly on peak-systolic flow velocity (PSV). However, there have been no generally accepted duplex US criteria for carotid restenosis after CAS or CEA.

Methods

In this systematic review, the PubMed/ Medline and Scopus databases were screened to find trials that reported duplex US criteria for significant restenosis after CEA and/or CAS. Only those reports were analyzed in which the restenoses were also assessed by CT/MR or digital subtraction angiography as comparators for duplex US.

Results

Fourteen studies met the predetermined search criteria and were included in this review. In most studies, PSV thresholds for significant in-stent ICA restenosis after CAS were higher than those for significant stenosis in non-procedurally treated (native) ICA. Many fewer studies investigated the US criteria for ICA restenosis after CEA. Despite the heterogeneous data, there is a consensus to use higher flow velocity thresholds for assessment of stenosis in stented ICA than in native ICA; however, there have been insufficient data about the flow velocity criteria for significant restenosis after CEA. Although the flow velocity thresholds for restenosis after CAS and CEA seem to be different, the large studies used the same duplex criteria to define restenosis after the two procedures. Moreover, different studies used different flow velocity thresholds to define ICA restenosis, leading to variable restenosis rates.

Discussion

We conclude that (1) further examinations are warranted to determine appropriate duplex US criteria for restenosis after CAS and CEA, (2) single duplex US parameter cannot be used to reliably determine the degree of ICA restenosis, (3) inappropriate US criteria used in large studies may have led to false restenosis rates, and (4) studies are required to determine if there is a benefit from redo carotid artery procedure, such as redo-CEA or redo-CAS, starting with prospective risk stratification studies using current best practice non-invasive care alone.

In-stent restenosis and stented-territory infarction after carotid and vertebrobasilar artery stenting

BACKGROUND

Prognosis after vertebrobasilar stenting (VBS) may differ from that after carotid artery stenting (CAS). Here, we directly compared the incidence and predictors of in-stent restenosis and stented-territory infarction after VBS and compared them with those of CAS.

METHODS

We enrolled patients who underwent VBS or CAS. Clinical variables and procedure-related factors were obtained. During the 3 years of follow-up, in-stent restenosis and infarction were investigated in each group. In-stent restenosis was defined as reduction in the lumen diameter > 50% compared with that after stenting. Factors associated with the occurrence of in-stent restenosis and stented-territory infarction in VBS and CAS were compared.

RESULTS

Among 417 stent insertions (93 VBS and 324 CAS), there was no statistical difference in in-stent restenosis between VBS and CAS (12.9% vs. 6.8%, P = 0.092). However, stented-territory infarction was more frequently observed in VBS than in CAS (22.6% vs. 10.8%; P = 0.006), especially a month after stent insertion. HbA1c level, clopidogrel resistance, and multiple stents in VBS and young age in CAS increased the risk of in-stent restenosis. Diabetes (3.82 [1.24-11.7]) and multiple stents (22.4 [2.4-206.4]) were associated with stented-territory infarction in VBS. However, in-stent restenosis (odds ratio: 15.1, 95% confidence interval: 3.17-72.2) was associated with stented-territory infarction in CAS.

CONCLUSIONS

Stented-territory infarction occurred more frequently in VBS, especially after the periprocedural period. In-stent restenosis was associated with stented-territory infarction after CAS, but not in VBS. The mechanism of stented-territory infarction after VBS may be different from that after CAS.

Short- and Mid-Term Outcomes of Stenting in Patients with Isolated Distal Internal Carotid Artery Stenosis or Post-Surgical Restenosis

The aim was to evaluate the outcome of stenting in patients with isolated distal internal carotid artery (ICA) stenosis or post-surgical restenosis, as no data are currently available in the literature. Sixty-six patients (men, N = 53; median age: 66 [IQR, 61–73] years) with ≥50% distal ICA (re)stenosis were included in this single-center retrospective study. The narrowest part of the (re)stenosis was at least 20 mm from the bifurcation in all patients. Patients were divided into two etiological groups, atherosclerotic (AS, N = 40) and post-surgical restenotic (RES, N = 26). Postprocedural neurological events were observed in two patients (5%) in the AS group and in two patients (7.7%) in the RES group. The median follow-up time was 40 (IQR, 18–86) months. Three patients (7.5%) in the AS group had an in-stent restenosis (ISR) ≥ 50%, but none in the RES group. Three patients (7.5%) in the AS group and seven patients (26.9%) in the RES group died. None of the deaths in the RES group were directly related to stenting itself. The early neurological complication rate of stenting due to distal ICA (re)stenoses is acceptable. However, the mid-term mortality rate of stenting for distal ICA post-surgical restenoses is high, indicating the vulnerability of this subgroup.

Carotid Restenosis Rate After Stenting for Primary Lesions Versus Restenosis After Endarterectomy With Creation of Risk Index

PURPOSE

Carotid artery stenting (CAS) is an option for carotid restenosis (CR) treatment with favorable outcomes. However, CAS has also emerged as an alternative to carotid endarterectomy (CEA) for the management of patients with primary carotid stenosis. This study aimed to report CR rates after CAS was performed in patients with primary lesions versus restenosis after CEA, to identify predictors of CR, and to report both neurological and overall outcomes.

MATERIALS AND METHODS

From January 2000 to September 2018, a total of 782 patients were divided into 2 groups: The CAS (prim) group consisted of 440 patients in whom CAS was performed for primary lesions, and the CAS (res) group consisted of 342 patients with CAS due to restenosis after CEA. Indications for CAS were symptomatic stenosis/restenosis >70% and asymptomatic stenosis/restenosis >85%. A color duplex scan (CDS) of carotid arteries was performed 6 months after CAS, after 1 year, and annually afterward. Follow-up ranged from 12 to 88 months, with a mean follow-up of 34.6±18.0 months.

RESULTS

There were no differences in terms of CR rate between the patients in the CAS (prim) and CAS (res) groups (8.7% vs 7.2%, χ²=0.691, p=0.406). The overall CR rate was 7.9%, whereas significant CR (>70%) rate needing re-intervention was 5.6%, but there was no difference between patients in the CAS (prim) and CAS (res) groups (6.4% vs 4.7%, p=0.351). Six independent predictors for CR were smoking, associated previous myocardial infarction and angina pectoris, plaque morphology, spasm after CAS, the use of FilterWire or Spider Fx cerebral protection devices, and time after stenting. A carotid restenosis risk index (CRRI) was created based on these predictors and ranged from -7 (minimal risk) to +10 (maximum risk); patients with a score >-4 were at increased risk for CR. There were no differences in terms of neurological and overall morbidity and mortality between the 2 groups.

CONCLUSIONS

There was no difference in CR rate after CAS between the patients with primary stenosis and restenosis after CEA. A CRRI score >-4 is a criterion for identifying high-risk patients for post-CAS CR that should be tested in future randomized trials.

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.

Propensity-Matched Comparison for Carotid Artery Stenting in Primary Stenosis Versus after Carotid Endarterectomy Restenosis

BACKGROUND

Carotid artery stenting (CAS) has been proposed as the treatment of choice in case of restenosis (RES) after carotid endarterectomy (CEA). The aim of this study was to analyze periprocedural results of CAS for the treatment of post-CEA RES compared with those of CAS performed for primary carotid stenosis (PRS).

METHODS

Data from consecutive patients submitted to CAS at our institution from 2008 to 2016 were retrospectively reviewed. Patients with in-stent RES were excluded. Initially, preoperative risk factors, demographics, intraoperative variables, and perioperative outcomes were analyzed according to the indication groups (PRS and RES). Then, propensity score matching was performed obtaining 2 homogeneous groups of patients. Covariates included were age, gender, hypertension, hyperlipidemia, cardiac disease, chronic renal disease, symptomatic carotid plaque, and positive ipsilateral brain computed tomography scan. Intraoperative data and perioperative outcomes were then compared between the 2 matched groups.

RESULTS

Of 480 included patients, 300 (62.5%) underwent CAS for PRS, and 180 (37.5%) for RES. After propensity score analysis (158 patients/group), no significant difference was observed in terms of technical success, number, and type of stent used, except for need of intraoperative atropine administration that was higher in the PRS group (38.6% vs. 13.3%, respectively; P < 0.001). In the perioperative period, composite neurologic event was significantly higher in the PRS group (7.6% vs. 1.9%; P = 0.017). Moreover, need of ionotropic support was higher in the PRS group (8.9% vs. 1.9%; P = 0.0069). Myocardial infarction rate and 30-day mortality were similar in both groups (P = 0.317; P = 1, respectively).

CONCLUSIONS

In a large single-center experience, CAS for post-CEA RES was associated with a significantly lower risk of any neurologic event and hemodynamic instability in the perioperative period compared with CAS performed for primary carotid lesions. Our results confirm that post-CEA RES may represent an elective indication for CAS.

Risk Factors for Restenosis After Carotid Revascularization: A Meta-Analysis of Hazard Ratios

BACKGROUND

Carotid artery restenosis after carotid endarterectomy (CEA) or carotid artery stenting (CAS) will occur in 3%-30% of cases. Restenosis can lead to more frequent clinical and imaging monitoring and the potential for reoperation. We sought to define the demographic, clinical, and radiographic characteristics that influence the restenosis risk after carotid revascularization.

METHODS

The present study was performed in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. A random effects model meta-analysis of hazard ratios (HRs) was conducted.

RESULTS

Eighteen studies with 17,106 patients were included. Diabetes (HR, 1.68; 95% confidence interval [CI], 1.00-2.83; I², 76.7%), dyslipidemia (HR, 1.77; 95% CI, 1.08-2.91; I², 22.5%), female gender (HR, 1.50; 95% CI, 1.14-1.98, I², 0%), chronic kidney disease (HR, 4.15; 95% CI, 1.69-10.19; I², 44.5%), hypertension (HR, 1.99; 95% CI, 1.07-3.72; I², 68%), smoking (HR, 1.65; 95% CI, 1.15-2.37; I², 54.3%), and pretreatment stenosis >70% (HR, 1.04; 95% CI, 1.0-1.08; I², 0%) showed a statistically significant increase in restenosis risk after carotid revascularization. Subgroup analyses of CEA and CAS showed that female gender and smoking status were significantly associated with recurrent stenosis after CEA but not after CAS. In contrast, hypertension was associated with restenosis after CAS but not after CEA. Patch endarterectomy (HR, 0.33; 95% CI, 0.22-0.50; I², 0%) and symptomatic status at presentation in the CAS group (HR, 0.61; 95% CI, 0.41-0.90; I², 0%) were associated with a decreased risk of restenosis. Antiplatelet use and coronary artery disease were not associated with restenosis risk.

CONCLUSIONS

Diabetes, dyslipidemia, female gender, renal failure, hypertension, and smoking were associated with an increased risk of restenosis, and patch endarterectomy and symptomatic status at presentation were associated with a decreased risk of carotid restenosis. Both female gender and current smoking status were only associated with recurrent stenosis after CEA, and hypertension was only associated with restenosis after CAS.

Cumulative incidence of restenosis in the endovascular treatment of extracranial carotid artery stenosis: a meta-analysis

OBJECTIVE

To assess the cumulative incidence of restenosis and stroke after stenting for cervical carotid artery stenosis.

METHODS

We reviewed PubMed, ScienceDirect, and Scopus and included all studies reporting restenosis after stenting. The cumulative incidence of restenosis at 6 and 12 months was calculated. We also estimated the cumulative incidence of ipsilateral stroke within 30 days after stenting. Random effect meta-analysis and meta-regression were performed using relevant study level covariates. Sources of heterogeneity were investigated.

RESULTS

Among 7765 records, 40 studies were selected. 15 943 patients and 16 337 carotid arteries were considered. The overall pooled cumulative incidence of restenosis >50% at 12 months was 5.7% (95% CI 3.8% to 8.6%), >70% at 12 months was 5.2% (95% CI 3.3% to 8.2%), >50% at 6 months was 3.9% (95% CI 2.2% to 6.8%), and ipsilateral stroke within 30 days after stenting was 1.6% (95% CI 1.0% to 2.5%) without association with the use of an embolic protection device. We did not identify any relevant source of heterogeneity of the cumulative incidence of restenosis >50% at 12 months. Mean age explained 80.9% (R²=80.9%, p=0.01) of heterogeneities of restenosis >70% at 12 months. The presence of hostile neck explained 53.9% (R²=53.9%, p=0.03) of heterogeneities of restenosis >50% at 6 months.

CONCLUSION

This meta-analysis showed a low cumulative rate of restenosis at 12 months and ipsilateral stroke within 30 days after stenting. Older patients and those with hostile neck present a lower risk of in-stent restenosis. The use of an embolic protection device was not associated with a lower risk of stroke.

Perioperative outcomes after reoperative carotid endarterectomy are worse than expected

OBJECTIVE

Reoperative carotid endarterectomy (CEA) can be technically challenging because of significant scarring as a consequence of the initial CEA procedure. There are limited data that describe outcomes after reoperative CEA, and as such, our goal was to determine the effect of reoperative CEA on perioperative outcomes.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was queried for patients undergoing index and reoperative CEA between 2005 and 2014. Multivariate analysis was performed to assess the effect of reoperative CEA on outcomes including stroke, major adverse cardiovascular event, and procedure time.

RESULTS

There were 75,943 index and 140 reoperative CEAs identified. No differences were found in baseline demographics or comorbidities except that the reoperative group had a higher incidence of patients with end-stage renal disease (3.6% vs 1.1%; P = .004). Prior stroke with deficit (20.8% vs 15.4%; P = .137) and without deficit (11.5% vs 9.1%; P = .43) were similar between reoperative and index CEA groups. Both the reoperative and index initial CEA cohorts had comparable rates of surgical site infection (0.7% vs 0.3%; P = .462), return to the operating room (3.6% vs 4%; P = .816), readmission with 30 days (2.1% vs 6.9%; P = .810), myocardial infarction (2.1% vs 0.9%; P = .125), and perioperative death (0.7% vs 0.9%; P = .853). The reoperative cohort had a significantly higher rate of perioperative stroke (5.0% vs 1.6%; P = .002) and a longer operative duration (137 ± 54 vs 116 ± 49 minutes; P < .001). Multivariate analysis revealed that reoperative CEA was an independent factor for postoperative stroke (odds ratio, 3.71; 95% confidence interval [CI], 1.61-8.57; P = .002), major adverse cardiovascular event (odds ratio, 2.76; 95% CI, 1.32-5.78; P = .007), and longer procedure time (means ratio, 1.21; 95% CI, 1.12-1.30; P < .001).

CONCLUSIONS

Reoperative carotid surgery is associated with a longer operative time and higher risk for perioperative stroke compared with index CEA. This information informs the risk-benefit analysis for reoperation.

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.

Anatomical and Technical Factors Influence the Rate of In-Stent Restenosis following Carotid Artery Stenting for the Treatment of Post-Carotid Endarterectomy Stenosis

Background

Carotid artery stenting (CAS) has been advocated as an alternative to redo surgery for the treatment of post-carotid endarterectomy (CEA) stenosis. This study analyzed the efficacy of CAS for post-CEA restenosis, focusing on an analysis of technical and anatomical predictive factors for in-stent restenosis.

Methods

We performed a retrospective monocentric study. We included all patients who underwent CAS for post-CEA restenosis at our institution from July 1997 to November 2013. The primary endpoints were the technical success, the presence of in-stent restenosis >50% or occlusion, either symptomatic or asymptomatic, during the follow-up period, and risk factors for restenosis. The secondary endpoints were early and late morbidity and mortality (TIA, stroke, myocardial infarction, or death).

Results

A total of 153 CAS procedures were performed for post-CEA restenosis, primarily because of asymptomatic lesions (137/153). The technical success rate was 98%. The 30-day perioperative stroke and death rate was 2.6% (two TIAs and two minor strokes), and rates of 2.2% (3/137) and 6.2% (1/16) were recorded for asymptomatic and symptomatic patients, respectively. The average follow-up time was 36 months (range, 6–171 months). In-stent restenosis or occlusion was observed in 16 patients (10.6%). Symptomatic restenosis was observed in only one patient. We found that young age (P = 0.002), stenosis > 85% (P = 0.018), and a lack of stent coverage of the common carotid artery (P = 0.006) were independent predictors of in-stent restenosis.

Conclusion

We identified new risk factors for in-stent restenosis that were specific to this population, and we propose a technical approach that may reduce this risk.

Hybrid approach in a difficult case of pseudoaneurysm of right common carotid artery

We present the case of a 65-year-old gentleman, who presented with a symptomatic pseudoaneurysm of the right common carotid artery. Because of high surgical risk, endovascular approach was decided upon. However, taking hardware across the lesion via the aortic arch provided us with insurmountable difficulties. Therefore, a hybrid approach was resorted to, in which an arteriotomy was done in the carotid artery followed by direct implantation of the stent. We were thus able to create a favorable trade-off between the high surgical risk of a full surgical procedure and the peri-operative benefit of an endovascular approach.

The myth of restenosis after carotid angioplasty and stenting

BACKGROUND AND PURPOSE

Reported rates of in-stent restenosis after carotid artery stenting (CAS) vary, and restenosis risk factors are poorly understood. We evaluated restenosis rates and risk factors, and compared patients with 'hostile-neck' carotids (a history of ipsilateral neck surgery or irradiation) and atherosclerotic lesions.

METHODS

Demographic, clinical, and radiological characteristics of patients undergoing cervical CAS between 1995 and 2010 with at least 1 month of follow-up were reviewed. Patients with substantial (≥50%) radiographic restenosis were compared with those without significant restenosis to identify restenosis risk factors.

RESULTS

The analysis included 121 patients with 133 stented vessels; 91 (68.4%) lesions were symptomatic. Indications for stent placement included hostile-neck lesions, substantial surgical comorbidities, inclusion in a randomized carotid stenting trial, acute carotid occlusion, tandem stenosis, large pseudoaneurysm, high carotid bifurcation, and contralateral laryngeal nerve palsy. Procedures were technically successful in all but one lesion (99.2%). Perioperative stroke occurred in four cases (3.0%). Mean follow-up was 38 months (range 1-204 months), during which 23 vessels (17.3%) developed restenosis. Hostile-neck carotids (n=57) comprised 42.9% of all vessels treated and were responsible for 15 of 23 restenosis cases, resulting in a significantly higher restenosis rate than that of primary atherosclerotic lesions (26.3% vs 10.5%, p=0.017). By univariate analysis, the presence of calcified plaque was significantly associated with the incidence of in-stent restenosis (p=0.02).

CONCLUSIONS

Restenosis rates after carotid angioplasty and stenting are low. Patients with a history of ipsilateral neck surgery or irradiation are at higher risk for substantial radiographic and symptomatic restenosis.