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

Cutting Balloon Angioplasty for Severe In-Stent Restenosis after Carotid Artery Stenting: Long-Term Outcomes and Review of Literature

PURPOSE

Cutting balloon-percutaneous transluminal angioplasty (CB-PTA) is a feasible treatment option for in-stent restenosis (ISR) after carotid artery stenting (CAS). However, the longterm durability and safety of CB-PTA for ISR after CAS have not been well established.

MATERIALS AND METHODS

We retrospectively reviewed medical records of patients with ISR after CAS who had been treated with CB-PTA from 2012 to 2021 in our center. Detailed information of baseline characteristics, periprocedural and long-term outcomes, and follow-up imaging was collected.

RESULTS

During 2012-2021, a total of 301 patients underwent CAS. Of which, CB-PTA was performed on 20 lesions exhibiting severe ISR in 18 patients following CAS. No patient had any history of receiving carotid endarterectomy or radiation therapy. These lesions were located at the cervical segment of the internal carotid artery (n=16), proximal external carotid artery (n=1), and distal common carotid artery (n=1). The median time interval between initial CAS and detection of ISR was 390 days (interquartile range 324-666 days). The follow-up period ranged from 9 months to 9 years with a median value of 21 months. Four patients (22.2%) were symptomatic. The average of stenotic degree before and after the procedure was 79.2% and 34.7%, respectively. Out of the 18 patients receiving CB-PTA, 16 (88.9%) did not require additional stenting, and 16 (88.9%) did not experience recurrent ISR during the follow-up period. Two patients who experienced recurrent ISR were successfully treated with CB-PTA and additional stenting. No periprocedural complication was observed in any case.

CONCLUSION

Regarding favorable periprocedural and long-term outcomes in our single-center experience, CB-PTA was a feasible and safe option for the treatment of severe ISR after CAS.

Clinical trial of carotid artery stenting using dual-layer CASPER stent for carotid endarterectomy in patients at high and normal risk in the Japanese population

BACKGROUND

The dual-layer nitinol CASPER stent was designed to prevent plaque prolapse into its strut and periprocedural stroke.

OBJECTIVE

To conduct a clinical trial for government approval of the device in patients at either high or normal risk for carotid endarterectomy (CEA).

METHODS

Eligible patients had ≥50% symptomatic stenosis or ≥80% asymptomatic stenosis according to the North American Symptomatic Carotid Endarterectomy Trial methods (peak systolic velocity 130 and 230 cm/s on ultrasonography, respectively). The primary endpoint was the lack of major adverse events (MAEs), defined as death, stroke, and myocardial infarction within 30 days, and ipsilateral stroke within 1 year. The performance goal was set at 90.5%. MAE rates were also compared between the CEA high- and normal-risk groups.

RESULTS

140 carotid artery stenting procedures, including 40% of patients at high risk and 60% at normal risk for CEA, were performed in 13 institutes. MAEs occurred in two cases (one intraprocedural and one postprocedural stroke), and the MAE rate was 1.4%. The non-MAE rate was 98.6% according to Kaplan-Meier analysis, which was superior to the previously set performance goal. The deployment success, target lesion revascularization (TLR), in-stent restenosis, and cerebrovascular event rates were 99.3%, 2.4%, 8.5%, and 7.2%, respectively. The MAE rate in patients with normal CEA risk was 1.2%, which was similar to the high-risk CEA group, with no significant difference due to the small number of MAEs.

CONCLUSIONS

The MAE rate following use of the CASPER stent was low (1.4%). The MAE, deployment success, TLR, in-stenosis, and cerebrovascular event rates were similar to those of previous reports.

Management of De Novo Carotid Stenosis and Postintervention Restenosis-Carotid Endarterectomy Versus Carotid Artery Stenting-a Review of Literature

The current literature indicates carotid endarterectomy (CEA) as the preferred treatment for symptomatic, moderate to severe carotid artery stenosis. However, recommendations for the management of acute tandem stenosis and complete occlusion, as well as postintervention restenosis of the carotid artery, remain controversial. Here, we review the literature evaluating these conditions and provide suggestions for clinical decision-making. Acute tandem stenosis or occlusion of the common and internal carotid arteries may be treated with angioplasty alone, reserving carotid artery stenting (CAS) or CEA for severe and complex cases. Patients who underwent CEA and developed ipsilateral restenosis may be subjected to angioplasty followed by CAS, which carries a lower risk of cranial nerve injury and subsequent restenosis of the artery. For post-CAS restenosis, current evidence recommends angioplasty and CAS for the management of moderate stenosis and CEA for severe stenosis of the carotid artery. Given the lack of level 1 evidence for the management of these conditions, the abovementioned recommendations may assist clinical decision-making; however, each case and its unique risks and benefits need to be assessed individually. Future studies evaluating and defining the risks and benefits of specific treatment strategies, such as CEA and CAS, in patients with acute tandem stenosis, occlusion, and postintervention restenosis of the carotid artery need to be conducted.

Periprocedural and Long-Term Outcomes of Stent Implantation for De Novo Subclavian Artery Disease

INTRODUCTION

The purpose of the current study was to investigate the periprocedural and long-term outcomes of stent implantation for de novo subclavian artery (SCA) disease.

MATERIAL AND METHODS

We retrospectively investigated consecutive patients with de novo SCA lesions undergoing elective endovascular therapy procedures at our center between April 2004 and September 2015. All patients were included in the analyses of periprocedural outcomes, including procedural and clinical success. Subsequently, patients who completed the clinical follow-up and were assessed with brachial systolic pressure differences between the diseased and the contralateral arms, or angiographic stenosis, after stent implantation with procedural success were included in the analyses of long-term outcomes, including primary patency.

RESULTS

There were 62 patients (median 71.0 years, interquartile range 65.3-76.0 years; 45 men) with 62 de novo SCA lesions included in the analyses of periprocedural outcomes. There were 46 stenoses (74.2%) and 16 occlusions (25.8%). Our results indicated high procedural success rates for overall (95.2%), stenotic (97.8%), and occlusive (87.5%) lesions. Similarly, high clinical success rates were observed for overall (91.9%), stenotic (93.5%), and occlusive (87.5%) lesions. The median follow-up time was 6.0 years (interquartile range, 2.6-8.3 years). There were 48 patients with 48 de novo SCA lesions included in the analyses of long-term outcomes. Primary patency estimates were 97.7% (1 year), 97.7% (3 years), 93.1% (5 years), and 87.6% (7 years). Also, we observed a high estimate for freedom from reintervention for the target vessel (93.8%).

CONCLUSION

Stent implantation for de novo SCA disease can be performed successfully and safely with favorable periprocedural and long-term outcomes.

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.

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.

Efficacy of a Self-Expandable Porous Stent as the Sole Curative Treatment for Extracranial Carotid Pseudoaneurysms

OBJECTIVE

Extracranial carotid pseudoaneurysms are uncommon vascular lesions. Even with conservative management complications can happen, such as delayed cerebral embolization or symptoms due to flow limitation. Although endovascular therapy can be curative, literature demonstrating a preferred technique is scant. Our goal was to evaluate the use of 1 technique only-the deployment of overlapping self-expandable porous stents-to treat a series of extracranial carotid pseudoaneurysms.

METHODS

From 2008 to 2014, 14 consecutive cases of symptomatic extracranial carotid pseudoaneurysms were managed with single or multilayer porous stents at our institution. Each patient underwent a standardized angiographic follow-up at 6 months. Twelve patients also received a follow-up computed tomography angiogram at 12 months, and yearly thereafter (median radiographic follow-up, 38 months). The total clinical follow-up period ranged between 6 and 69 months (median, 46 months).

RESULTS

In our series, each of the extracranial carotid pseudoaneurysms appeared to be the result of carotid artery dissection with associated carotid stenosis at the origin of every pseudoaneurysm. Endovascular treatment consisted of 1-3 layers of self-expandable porous stents placed without balloon angioplasty. Immediately after stenting angiographic images were notable for stagnant opacification of the pseudoaneurysm through the stent(s). All pseudoaneurysms were completely obliterated by the 6-month follow-up angiogram and remained so throughout the radiographic follow-up period. Complications were minimal, consisting of 1 patient developing a mild Horner's syndrome after treatment that resolved during clinical follow-up.

CONCLUSIONS

Extracranial carotid pseudoaneurysms can be successfully obliterated with the use of porous, self-expandable stents.

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.

Intracranial Blood Flow Changes After Extracranial Carotid Artery Stenting

BACKGROUND:

Carotid artery stenting is an endovascular treatment option for patients with extracranial carotid stenosis. However, intracranial blood flow changes following stenting have not been established.

OBJECTIVE:

To determine the effects of stenting on intracranial blood flow.

METHODS:

Records of patients who underwent stenting at our institution between 2004 and 2012 and had flow rates obtained pre- and poststenting by the use of quantitative magnetic resonance angiography were retrospectively reviewed. Percentage stenosis, stenosis length, and minimum vessel diameter were measured from cerebral angiography images.

RESULTS:

Eighteen patients were included. Mean age was 65 years with 67% presenting with symptomatic stenosis. Degree of stenosis ranged from 60% to 90%. Internal carotid artery (ICA) mean flow improved significantly poststenting from 174.9 ± 83.6 mL/min to 250.7 ± 91.2 mL/min (P = .011). Ipsilateral middle cerebral artery (MCA) flow, however, was not significantly altered poststenting (107.8 ± 41.6 mL/min vs 114.3 ± 36.3 mL/min; P = .28). Univariate analysis revealed that improved minimum vessel diameter after stenting, but not percentage stenosis (P = .18) or stenosis length (P = .45), is significantly associated with increased ICA flow (P = .02). However, improved percentage stenosis, stenosis length, minimum vessel diameter, and ICA flow poststenting were not significantly associated with increased MCA flow (P = .64, .38, .13, .37, respectively).

CONCLUSION:

ICA flow was compromised at baseline, improving 43% on average poststenting. Increased minimum vessel diameter was the factor most significantly associated with increased flow. Conversely, MCA flow was not significantly compromised at baseline nor altered after stenting, suggesting compensatory intracranial collateral supply prestenting that redistributes following ICA revascularization.

Cilostazol suppression of arterial intimal hyperplasia is associated with decreased expression of sialyl Lewis X homing receptors on mononuclear cells and E-selectin in endothelial cells

BACKGROUND

An inflammatory reaction in vascular tissue is a potential factor linking restenosis after angioplasty. Although cilostazol, a selective phosphodiesterase type 3 inhibitor that is a unique antiplatelet drug and vasodilator, has been reported to be anti-inflammatory, its effect on the inflammatory action of mononuclear cells homing to endothelial cells is not clearly understood. In this study, whether cilostazol inhibits neointimal formation and improves inflammatory actions by inhibiting sialyl Lewis X (SLX) expression on mononuclear cells and E-selectin expression on endothelial cells was evaluated.

METHODS

The effect of cilostazol (1, 3, 10, 30 μM) on expression of E-selectin in human umbilical vein endothelial cells and SLX in rat mononuclear cells stimulated with lipopolysaccharide by immunofluorescence and real-time polymerase chain reaction (n = 3) was studied. Additionally, a double-balloon injury model was used on rat carotid arteries to evaluate vascular intimal hyperplasia. 0.1% cilostazol was administered 3 days before the first balloon injury, and the second balloon injury was performed 7 days after the first injury. Cilostazol administration was continued until rats were sacrificed 14 days after the second angioplasty. The expression of SLX on mononuclear cells and E-selectin on endothelial cells by immunofluorescence (n = 10) and real-time polymerase chain reaction (n = 5) were studied.

RESULTS

Cilostazol effectively inhibited the expression of SLX on mononuclear cells and E-selectin on endothelial cells. Cilostazol inhibited the migration of mononuclear cells in neointimal regions and neointimal hyperplasia after balloon injury. The numbers of macrophages and T-lymphocytes and the hyperplasia area in neointimal regions decreased from 71.06 ± 20.04, 1121 ± 244.4 cells per section, 206,400 ± 96,150 mm(2) to 29.65 ± 16.73, 374.2 ± 124.5 cells per section, and 101,900 ± 16,150 mm(2) due to the administration of cilostazol.

CONCLUSIONS

These results demonstrate that the protective effect of cilostazol against neointimal hyperplasia may be mediated by its anti-inflammatory actions of mononuclear cells homing to endothelial cells by decreasing SLX and E-selectin expression.

CLINICAL RELEVANCE

It is reported that cilostazol inhibits neointimal hyperplasia by decreasing the expression of some cell-adhesion molecules. We evaluated the effects of cilostazol for the expression of sialyl Lewis X (SLX) on mononuclear cells and E-selectin on endothelial cells, which interaction is the first step of inflammation action. Cilostazol was thought to show the anti-inflammatory actions by decreasing SLX and E-selectin expression in addition to decreasing the expression of some cell-adhesion molecules.

Clinical impact and predictors of carotid artery in-stent restenosis

To assess the incidence and clinical significance as well as predictors of in-stent restenosis (ISR) after carotid artery stenting (CAS) diagnosed with serial duplex sonography investigations. We analyzed 215 CAS procedures that had clinical and serial carotid duplex ultrasound investigations. The incidence of in-stent restenosis (ISR) and periprocedural as well as long-term clinical complications were recorded. The influence of an ISR on clinical complication was analyzed using Kaplan-Meier curves and clinical risk factors for the development of an ISR with multivariate logistic regression. During a median follow-up time of 33.4 months (interquartile range 15.3-53.7) an ISR of ≥70% was detected in 12 (6.1%) of 215 arteries (mean age of 68.1 ± 9.8 years, 71.6% male). The combined stroke and death rate during long-term follow-up was significantly higher in the group with an ISR [odds ratio (OR): 3.59, 95% confidence interval (CI): 1.50-8.59, p = 0.004]. After applying multivariate logistic regression analysis contralateral carotid occlusion (OR 10.11, 95% CI 2.06-49.63, p = 0.004), carotid endarterectomy (CEA) restenosis (OR 8.87, 95% CI 1.68-46.84, p = 0.010) and postprocedural carotid duplex ultrasound with a PSV ≥120 cm/s (OR 6.33, 95% CI 1.27-31.44, p = 0.024) were independent predictors of ISR. ISR after CAS during long-term follow-up is associated with a higher proportion of clinical complications. A close follow-up is suggested especially in those patients with the aforementioned independent predictors of an ISR. Against the background of a lacking established treatment of ISR, these findings should be taken into account when offering CAS as a treatment alternative to CEA.

Carotid artery stenting for primary and secondary stroke prevention

BACKGROUND

Carotid artery disease is a major cause of the disability and mortality associated with strokes. Ischemic stroke remains the major cause of adult disability and third-leading cause of adult mortality, and carotid revascularization currently remains the principal surgical tool in the prophylaxis of this disease.

METHODS

The literature representing the current body of evidence for carotid revascularization and the authors' current practices in the management of this disease are summarized in this review.

RESULTS

We provide an evidence-based narration of the development and current status of carotid artery stenting (CAS) by reviewing 1) the evidence for carotid revascularization from early carotid endarterectomy (CEA) trials; 2) the randomized trials comparing CEA and CAS, with a special emphasis on the recently published results of the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST), which have been a "game-changer," tipping the balance towards accepting CAS as a safe, equally effective, and durable alternative to CEA for all patients requiring carotid revascularization; and 3) the technical advances in CAS after enrollment of patients in the CREST.

CONCLUSIONS

CAS and CEA are complementary procedures. Judicious selection of the procedure is made on a case-by-case basis.

Cerebral artery restenosis following transluminal balloon angioplasty for vasospasm after subarachnoid hemorrhage

Background:

Although percutaneous transluminal angioplasty (PTA) is a widely used less invasive method to treat coronary artery stenosis, 10% of treated patients experience restenosis. Restenosis also occurs in approximately 5% of patients subjected to carotid artery stenting. Animal and human data suggested that restenosis is a response to injury incurred during PTA. As PTA has come into wide use to manage symptomatic cerebral vasospasm after subarachnoid hemorrhage (SAH) we studied the incidence of restenosis after PTA for cerebral vasospasm.

Methods:

Our study population consisted of 32 patients who had undergone PTA. They were followed by cerebral or 3DCT angiography or MRA for 6 126 months post-PTA (mean 48.65 months) to diagnose restenosis of the cerebral artery. We compared the size of the cerebral artery on the PTA and the contralateral side.

Results:

All 32 patients underwent successful PTA of 38 vascular territories and all manifested angiographic improvement of vasospasm. None suffered restenosis during the follow up period.

Conclusion:

PTA resulted in a significant improvement in the vessel diameter in patients with vasospasm after SAH and they did not suffer restenosis in the course of prolonged follow-up.

Follow-up Outcomes of Self-Expanding Stents for Carotid Artery Angioplasty at a Single Hospital

Carotid artery angioplasty and stent placement (CASP) is widely accepted as a valuable alternative to carotid endarterectomy, particularly among high-risk patient populations. We analyzed the follow-up data of patients who underwent CASP with self-expanding stents for carotid lesions. Since 2001, self-expanding stents have been deployed in 59 lesions in 56 patients. Forty-seven patients were male, and nine were female. The median age was 73 years, ranging 50 to 83 years. There were 31 asymptomatic lesions and 28 symptomatic lesions. The median follow-up period was 27 months, ranging six to 102 months. All lesions received stents and technical success was achieved in 58 (98.3%) out of 59 lesions. The 30-day transient ischemic attack rate was 8.6%, the stroke rate was 3.4%, and the death rate was 0%. No ischemic attack was observed on the ipsilateral side after 30 days. Recurrent stenosis (>50%) was observed in three patients (5.1%) and in two (3.4%) of these, revascularization was performed. Kaplan-Meier analysis showed that the rates for one year and two year freedom from any stroke or death were 93.1% and 90.9%, respectively. The incidence of recurrent carotid stenosis is acceptably low after CASP. CASP is effective to prevent ipsilateral ischemic stroke in symptomatic and asymptomatic patients.

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.

The hostile neck does not increase the risk of carotid endarterectomy

INTRODUCTION

Hostile neck anatomy is assumed to be associated with increased surgical risk for patients undergoing carotid endarterectomy (CEA) and is often considered a reason to choose carotid stenting or medical management. This retrospective case-control study evaluated whether, and how much, anatomically hostile necks represent a condition of higher surgical risk of early and late mortality and major or minor morbidity.

METHODS

The data for 966 homogeneous CEA patients was prospectively entered in a computer database. Seventy-seven had a hostile neck anatomy due to previous oncologic surgery or neck irradiation, restenoses after CEA, high carotid bifurcation, or bull-like and inextensible neck. A case-control matched-pair cohort study considered sex, age (5-year intervals), and year of operation. Regional anesthesia was used for all operations for atherosclerotic stenosis >or=70%, conforming to the European Carotid Surgery Trial (ECST) in symptomatic and asymptomatic patients, at a single center and by one surgeon or under his direct supervision.

RESULTS

The hostile neck patients and the control group were matched for age, sex, carotid-related symptoms, degree of stenoses, and main risk factors for cardiovascular diseases. Intraoperative variables were substantially equivalent in the two groups; however, procedure length and clamping time were, respectively, about 22 minutes (P = .0001) and 7 minutes longer (P = .01) in the hostile neck group. Rates of postoperative mortality and neurologic events were equivalent. Peripheral nerve lesions were multiple and significantly more frequent in the hostile neck patients (21% with >or=1 cranial nerve lesion vs 7% of controls, P = .03), yet all were transient and limited to a few months. The subgroups of patients with hostile neck, restenoses, and bull-like inextensible necks required the longest operative and clamping time, and those with bull-like and high bifurcation had the most frequent cranial nerve dysfunctions. At the respective follow-up of 47 and 45 months, survival curves (P = .48) and the incidence of restenoses and fatal and nonfatal strokes were similar (5 and 4, respectively).

CONCLUSIONS

Hostile necks led to more complex CEA procedures but without substantial consequences in early and late morbidity and mortality. Most patients with hostile neck can undergo CEA at low risk, with the benefit of effective long-lasting stroke prevention similar to standard patients. In our opinion, the more frequent but temporary cranial nerve dysfunctions that occur are not sufficient to consider hostile neck patients noneligible for CEA.

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.

Simple new method for making a rat carotid artery post-angioplasty stenosis model

A simple new method for making a rat post-angioplasty stenosis model was developed using a single-lumen compliant balloon catheter/guidewire system and no special diet. This technique was applied to 10 9-week-old Wistar rats fed a normal diet. The catheter/guidewire system was inserted from the external carotid artery and advanced retrogradely into the common carotid artery. The balloon was inflated six times with rotation through 60 degrees . After angioplasty, the external carotid artery was ligated. Homogeneous stenoses due to intimal hyperplasia were demonstrated in cross sections of all cases. This simple and gentle method allows an easily reproducible post-angioplasty stenosis model.

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.

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.

Intracranial Hemorrhage After Carotid Angioplasty:A Pooled Analysis

PURPOSE

To use a pooled analysis of the literature to find the incidence of and characteristics common to intracranial hemorrhage (ICH) associated with carotid artery stenting (CAS).

METHODS

A search of the English-language literature (1996-2005) was performed in PubMed to find cases of CAS-associated ICH. Information was derived from the identified case studies in 5 categories and 19 aspects: (1) incidence of CAS-associated ICH; (2) demographic data (sex, age, symptom presentation, and presence of preexisting hypertension); (3) imaging data (side of lesion, degree of maximal stenosis, lesion location, status of the contralateral carotid artery, collateral circulation, and preprocedural imaging features); 4) procedure-related characteristics (antithrombotic medication, use of cerebral protection devices, residual stenosis, symptoms, interval from the procedure to ICH, type of ICH, and blood pressure changes); and (5) clinical outcome.

RESULTS

Fifty-four cases of CAS-associated ICH were reviewed: 51 cases from 36 published articles and our own 3 cases. The incidence of CAS-associated ICH was 0.63% (95% CI 0.38% to 0.97%) in studies consisting of >100 cases, which was significantly lower (p<0.0001) than that of case series consisting of <100 cases (2.69%, 95% CI 1.75% to 3.94%). Distinctive features included symptomatic lesions, severe stenosis (> or =90%), maximal stenosis in the internal carotid artery (ICA) distal to the bifurcation, and preexisting cerebral infarction.

CONCLUSION

The incidence of CAS-associated ICH was significantly lower in series consisting of >100 cases. More caution should be directed toward patients with symptomatic lesions, severe stenosis, maximal ICA stenosis distal to the carotid bifurcation, and preexisting cerebral infarction.

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.

Cervical carotid revascularization: the case for carotid angioplasty with stenting

Carotid artery angioplasty with or without stent placement has evolved as an alternative to carotid endarterectomy, particularly for those patients in whom carotid endarterectomy is associated with a higher risk of complications. This article summarizes the selection criteria for participation in and the results of several carotid intervention trials, reviews the relative indications and limitations for both surgical and endovascular revascularization approaches, and describes the technique for and results associated with carotid stenting. The discussion is presented from the vantage of neurosurgeons who are experienced in both revascularization approaches.

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.

Surgical management of acute carotid thrombosis after carotid stenting: a report of three cases

We report three cases of symptomatic acute carotid thrombosis occurring after carotid artery stenting (CAS). CASE 1: A patient presented with crescendo transient ischemic attacks on the second day after CAS. Ultrasound images demonstrated incomplete in-stent thrombosis due to plaque protrusion. The urgent surgical procedure consisted of stent removal and carotid thromboendarterectomy. CASE 2: A case of complete thrombosis of a carotid stent occurred 4 days after implantation in a patient with essential thrombocythemia diagnosed by chance. The surgical strategy included stent removal and carotid thromboendarterectomy. CASE 3: Cardiac multiple embolisms in a patient with chronic atrial fibrillation caused concomitant leg ischemia and acute carotid stent occlusion 2 hours after CAS. Cerebral reperfusion was established by embolectomy, without removing the stent. At the same time, the right leg ischemia was resolved by a thromboembolectomy with a Fogarty catheter. These three cases demonstrate that acute thrombosis after carotid stenting can be managed successfully with emergent surgical intervention. Thromboendarterectomy with stent removal or in selected cases, simple thromboembolectomy, can minimize neurologic sequelae in patients suffering from acute post-stenting carotid thrombosis.

In-stent Restenosis After Carotid Angioplasty and Stenting: A Challenge for the Vascular Surgeon

PURPOSE

This study aims to review the incidence of in-stent restenosis (ISR), the factors which determine restenosis, and to evaluate the use of various endovascular techniques for the management of ISR following carotid artery stenting (CAS).

METHODS

Four hundred and seven patients (334 men, mean age 63 years, range 46-86, median 65 years) were treated with CAS between December 2000 and March 2004. Three hundred and seventy-two (89%) patients had at least one ultrasound evaluation performed 6 months after procedure (range 6-40). Recurrent stenosis >80% detected with duplex ultrasound scans were further evaluated by angiography and treated with repeat endovascular procedure.

RESULTS

CAS was performed successfully in all cases with a Carotid WallStent (Boston Scientific) using a cerebral protection device (filter). Perioperative complications included four (0.9%) minor and two (0.4%) major strokes these latter two patients died at 5 and 12 days after the operation. No other deaths occurred. A total of 15 carotid arteries (3.6%) in 14 patients had ISR. All ISR were treated with a repeat endovascular procedure: three balloon angioplasty alone, eight angioplasty and secondary stenting, four angioplasty with cutting balloon. Postsurgical restenosis was confirmed to be the only predictive factor for the development of in-stent restenosis (OR 14.5, 95% CI 2.3-113.4, p=0.005). Endovascular treatment of ISR achieved technical success without periprocedurale complications and the absence of significant restenosis over a median follow up time of 12.4 months (range 3.5-30.7).

CONCLUSION

Our experience with a large cohort of CAS showed an encouragingly low incidence of ISR (3.6%) and successful treatment by repeat endovascular intervention. We recommend attempting all endovascular possibilities before performing stent removal.

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.

Long-term results of carotid stenting are competitive with surgery

OBJECTIVE

The feasibility of carotid stenting (CS) is no longer questionable, although its indications remain debatable. Until the results of randomized trials are available, personal series and registries should help in the comparison of long-term results of CS with those of endarterectomy. We report here the long-term results of a large series of CS in our department with a long follow-up. This retrospective study reviews a single surgeon's 11-year experience with CS. Our results are compared with those of conventional surgery emanating from our own series and the North American Symptomatic Carotid Endarterectomy Trial (NASCET), European Carotid Surgery Trial (ECST), and Asymptomatic Carotid Atherosclerosis Study (ACAS).

MATERIALS AND METHODS

CS has been performed in our department in a single, semi-private institution for 12 years. Patients with high lesions, and postradiotherapy and postendarterectomy stenoses were treated with CS, as were patients at high risk for surgery. The others were operated on with conventional endarterectomy. During the study, we performed 221 CS procedures on 193 patients (150 men and 43 women). The average follow-up was 2.7 years (1 month to 9.3 years). We analyzed the late results in terms of prevention from stroke, the freedom from new neurologic events, and also patency rates of the treated carotid vessels. We also identified predictors for neurologic complication and in-stent restenosis by using univariate analysis.

RESULTS

Life-table analyses at 10 years gave a 96% (confidence interval [CI] = 3%) rate for stroke freedom, a 98% (CI = 2%) rate for fatal stroke freedom, and a primary assisted patency rate of 95% (CI = 3%). Predictors for neurologic complication were [corrected] age >70 ( P = .041), and [corrected] potential renal insufficiency ( P = .056 [corrected] In-stent restenosis occurrence extended from 2 months to 4.5 years after the procedure. The restenosis rates at 6 months, 1, 2, and 4.5 years were, respectively, 1.4%, 2.3%, 3.7%, and 5.9% (13/221). No factors were found to be strong predictors of in-stent restenosis [corrected]

CONCLUSION

These long-term results show that CS is competitive with conventional surgery. A more accurate selection for CS or surgery might reduce the rate of complications after carotid stenosis repair.

Frequency and management of recurrent stenosis after carotid artery stent implantation

Object. To determine the rate of hemodynamically significant recurrent carotid artery (CA) stenosis after stent-assisted angioplasty for CA occlusive disease, the authors analyzed Doppler ultrasonography data that had been prospectively collected between October 1998 and September 2002 for CA stent trials.

Methods. Patients included in the study participated in at least 6 months of follow-up review with serial Doppler studies or were found to have elevated in-stent velocities (> 300 cm/second) on postprocedure Doppler ultrasonograms. Hemodynamically significant (≥ 80%) recurrent stenosis was identified using the following Doppler criteria: peak in-stent systolic velocity at least 330 cm/second, peak in-stent diastolic velocity at least 130 cm/second, and peak internal carotid artery/common carotid artery velocity ratio at least 3.8. Follow-up studies were obtained at approximate fixed intervals of 1 day, 1 month, 6 months, and yearly. Angiography was performed in the event of recurrent symptoms, evidence of hemodynamically significant stenosis on Doppler ultrasonography, or both. Treatment was repeated because of symptoms, angiographic evidence of severe (≥ 80%) recurrent stenosis, or both of these.

Stents were implanted in 142 vessels in 138 patients (all but five patients were considered high-risk surgical candidates and 25 patients were lost to follow-up review). For the remaining 112 patients (117 vessels), the mean duration of Doppler ultrasonography follow up was 16.42 ± 10.58 months (range 4–54 months). Using one or more Doppler criteria, severe (≥ 80%) in-stent stenosis was detected in six patients (5%). Eight patients underwent repeated angiography. Six patients (three with symptoms) required repeated intervention (in four patients angioplasty alone; in one patient conventional angioplasty plus Cutting Balloon angioplasty; and in one patient stent-assisted angioplasty).

Conclusions. In a subset of primarily high-risk surgical candidates treated with stent-assisted angioplasty, the rates of hemodynamically significant restenosis were comparable to surgical restenosis rates cited in previously published works. Treatment for recurrent stenosis incurred no instance of periprocedure neurological morbidity.