Protected carotid stenting in high-surgical-risk patients: The ARCHeR results

Society of vascular surgery vascular registry comparison of carotid artery stenting outcomes for atherosclerotic vs nonatherosclerotic carotid artery disease

OBJECTIVE

The Vascular Registry (VR) on carotid procedures collects long-term outcomes on carotid artery stenting (CAS) and carotid endarterectomy (CEA) patients. The purpose of this report is to describe in-hospital and 30-day CAS outcomes in patients with atherosclerotic carotid artery disease (CAD; atherosclerosis [ATH]) compared to recurrent carotid stenosis (RES) and radiation-induced stenosis (RAD).

METHODS

The VR collects provider-reported data on CAS using a Web-based data management system. For this report, data were analyzed at the preprocedure, procedure, predischarge, and 30-day intervals.

RESULTS

As of November 20, 2008, there were 4017 patients with CAS with discharge data, of which 72% were due to ATH. A total of 2321 patients were available for 30-day outcomes analysis (1623 ATH, 529 restenosis, 119 radiation, 17 dissection, 3 trauma, and 30 other). Baseline demographics showed that ATH occurred in older patients (72-years-old), had the greatest history of coronary artery disease (CAD; 62%), myocardial infarction (MI; 24%), valvular heart disease (8%), arrhythmia (16%), congestive heart failure (CHF; 16%), diabetes mellitus (DM; 35%), and chronic obstructive pulmonary disease (COPD; 20%). RES had a higher degree of baseline stenosis (87.0 vs 85.8 ATH; P = .010), were less likely to be symptomatic (35.5% vs 46.3% ATH; P < .001), but had a greater history of hypertension, peripheral vascular disease (PVD), and smoking. RAD was seen in younger patients (66.6 vs 71.7 ATH; P < .001), were more likely to be male (78.2% vs 60.9% ATH; P < .001), and had less comorbidities overall, with the exception of amaurosis fugax, smoking, and cancer. The only statistically significant difference in perioperative rates was in transient ischemic attack (TIA; 2.7% ATH vs 0.9% RES; P = .02). There were no statistically significant differences in in-hospital death/stroke/MI (ATH 5.4%, RES 3.8%, RAD 4.2%) or at 30 days (ATH 7.1%, RES 5.1%, RAD 5.0%). Even after adjusting for age, gender, symptomatology, CHF, and renal failure, the only statistically significant difference at 30 days was amaurosis fugax between ATH and RAD (odds ratio [OR] 0.13; P = .01).

CONCLUSION

Although patients with ATH have statistically significant comorbidities, they did not have statistically significant increased rates of death/stroke/MI during hospitalization or within 30 days after discharge when compared to RES or RAD. The CAS event rates for ATH vs RES and RAD are similar, despite prior published reports. Symptomatic ATH have statistically significant higher rates of death/stroke/MI compared to asymptomatic cohort. Finally, consistent and accurate entry of long-term data beyond initial hospitalization is essential to fully assess CAS outcomes since a significant number of adverse events occur in the interval from hospital discharge to 30 days.

Stroke prevention: carotid stenting versus carotid endarterectomy

Revascularization of the extracranial carotid arteries is a commonly performed surgical procedure to prevent stroke. Open surgery (i.e., carotid endarterectomy [CEA]) is a well-established stroke prevention procedure but is being ‘challenged' by a less invasive percutaneous procedure (i.e., carotid artery stent [CAS] placement). Clinical trials comparing CAS and CEA for average-surgical-risk patients have demonstrated mixed results, whereas the data for CAS compared with CEA in high-surgical-risk patients have demonstrated non-inferiority. The impending Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) results will have a major impact on the utility of CAS relative to CEA in average-surgical-risk patients.

Randomized trial of predilation versus direct stenting for treatment of carotid artery stenosis

BACKGROUND

A controversial aspect of carotid artery stenting (CAS) is the placement of a stent with or without predilation. The study was designed to test the hypothesis that direct stenting (DS) was not inferior to CAS with predilation.

METHODS

Elective CAS with filter protection was performed in 205 consecutive, unselected patients with carotid artery stenosis (>50% if symptomatic and > or =75% if asymptomatic by Doppler assessment) who were randomly assigned to CAS with predilation (n=100) or direct stenting (DS, n=105). Filter and stent selection were left to the operator's discretion. The study end-point was the angiographic success, defined as < or =30% angiographic residual stenosis after CAS without abnormal angiographic findings in cerebral circulation and without cross-over to predilation in the DS group.

RESULTS

At baseline, patient clinical characteristics and stenosis anatomic features did not differ between groups. Angiographic success was 99% and 97%, p=0.33, in predilation and DS, respectively. No cross-over to predilation occurred in the DS group. Procedural time was shorter in DS as compared to predilation (24.3+/-7% versus 19.9+/-6%, p=0.001) and visible debris were more frequently captured in predilation as compared to DS (50% versus 36%, p=0.003). No peri-procedural and 30-day death or major stroke occurred in both groups. Minor stroke and TIA rates were similar in either group (2% versus 0% and 8% versus 5.7%, p=ns, respectively).

CONCLUSION

In an unselected, consecutive series of patients submitted to CAS, DS is a feasible technique and is not inferior to CAS with predilation.

Morphological and hemodynamic patterns of carotid stenosis treated by endarterectomy with patch closure versus stenting: a duplex ultrasound study

OBJECTIVES

A duplex ultrasound study was performed to investigate morphological and hemodynamic patterns of carotid stenoses treated by endarterectomy with patch closure versus stenting.

MATERIALS AND METHOD

Twenty-nine carotid stenoses were treated with stenting and 65 with patch closure. Duplex ultrasound parameters (luminal diameter, mm; peak systolic velocity and end-diastolic velocity, cm/s) were measured 24 hours after the procedures and also at 12 months post-procedure. Residual stenoses (immediately postprocedure) and restenoses (within 12 months of procedure) were defined as narrowings of ≥ 50% on duplex ultrasound examination.

RESULTS

In stented patients, the luminal diameter of the proximal internal carotid artery increased in the interval between the 24-hour and 12-month post-procedure studies, while in the patch closure patients, the diameter decreased. Carotid hemodynamics normalized immediately after both patching and stenting and remained relatively stable thereafter up to 12 months. No statistically elevated flow velocities (in the absence of residual stenosis or restenosis) were observed in the patched or stented carotid arteries. No significant differences in residual stenosis rates were observed between the stenting group (3 cases, 10.34%) and the patch closure group (1 case, 1.53%, P = 0.08). At 12 months, 2 stenting patients (6.88%) and 2 patch closure patients (3.07%) had $50% restenosis (P = 0.58). One case of late stroke due to restenosis was observed in the stenting group; the patient died 12 months postoperatively, before receiving new intervention.

CONCLUSION

Measurements over time in luminal diameter signalized differences in arterial remodeling mechanisms between patched and stented carotids. Both stenting and patch closure were associated with carotid patency and flow restoration. This study does not support a general approach to new velocity criteria indiscriminately applied to stented or patched carotids.

Carotid Artery Stenting in the Nation: The Influence of Hospital and Physician Volume on Outcomes

Objectives: To assess national outcomes of carotid artery stenting (CAS) with respect to hospital and practitioner volume.

Methods: The 2005 to 2006 Nationwide Inpatient Sample (NIS) was used to assess CAS with respect to hospital volume, physician volume, and associated complications. Results: Eighteen thousand five hundred ninety-nine CAS interventions were identified. The top 25% was used to define high-volume hospitals (>60 CAS/2 years) and practitioners (>30 CAS/2 years). The stroke rate after CAS was significantly different between low- and high-volume hospitals (2.35% vs 1.78%, respectively; P = .0206). The stroke rate after CAS was also significantly different between low- and high-volume practitioners (2.19% vs 1.51%, P = .0243). Hospital resource use varied significantly between low- and high-volume hospitals (length of stay [LOS]: 1.64 ± 2.10 vs 1.45 ± 11.21, P = .0006; total charges: $32 261 ± 20 562 vs $30 131 ± 19 592, P = .0047) and practitioners (LOS: 1.70 ± 2.14 vs 1.36 ± 1.36; P < .0001; total charges: $33 762 ± 21 081 vs $23 957 ± 19 713; P < .0001). Conclusions: This analysis demonstrates that hospital and physician volume are associated with outcomes and utilization after CAS. High-volume hospitals and practitioners were associated with lower procedure stroke rates and decreased hospital resource utilization.

Carotid revascularization using endarterectomy or stenting systems (CaRESS): 4-year outcomes

PURPOSE

To examine the 4-year outcomes from Carotid Revascularization using Endarterectomy or Stenting Systems (CaRESS) in light of the current reimbursement guidelines for carotid artery stenting (CAS) from the Centers for Medicare and Medicaid Services (CMS).

METHODS

CaRESS was designed as a prospective, nonrandomized comparative cohort study of a broad-risk population of symptomatic and asymptomatic patients with carotid stenosis. In all, 397 patients (247 men; mean age 71 years, range 43-89) were enrolled and underwent carotid endarterectomy (CEA; n = 254) or protected CAS (n = 143). More than 90% of patients had >75% stenosis; two thirds were asymptomatic. The primary endpoints included (1) all-cause mortality, (2) any stroke, and (3) myocardial infarction (MI), as well as the composite endpoints of (4) death and any nonfatal stroke and (5) death, nonfatal stroke, and MI. The secondary endpoints were restenosis, repeat angiography, and carotid revascularization. All patients were classified with respect to surgical risk, symptom status, and stenosis grade based on criteria published by the CMS. In addition, separate analyses were performed comparing genders and octogenarians to those <80 years old.

RESULTS

No significant differences in the primary outcome measures were found between the CEA and CAS groups in the 4-year analysis. The incidences of any stroke at 4 years were 9.6% for CEA and 8.6% for CAS (p = 0.444); when combined with death, the composite death/nonfatal stroke rates were 26.5% for CEA versus 21.8% for CAS (p = 0.361). The composite endpoint of death, nonfatal stroke, and MI at 4 years was 27.0% in CEA versus 21.7% in CAS (p = 0.273) patients. The secondary endpoints of restenosis (p = 0.014) and repeat angiography (p = 0.052) were higher in the CAS arm. There were no differences in any of the subgroups stratified according the CMS guidelines or in the gender comparison. Four-year incidences of death/nonfatal stroke and death/nonfatal stroke/MI were higher in the CEA arm among patients <80 years of age (p = 0.049 and p = 0.030, respectively). There were no significant differences between these incidences in the octogenarian subgroup.

CONCLUSION

The risk of death or nonfatal stroke 4 years following CAS with distal protection is equivalent to CEA in a broad category of patients with carotid stenosis. There were no significant differences in stroke or mortality rates between high-risk and non-high-risk patients and no differences in outcomes between symptomatic and asymptomatic patients. After 4 years, CAS had a 2-fold higher restenosis rate compared to CEA. The risk of death/stroke or death/stroke/MI appears to be higher following CEA than CAS among patients <80 years of age, yet there is no statistically significant relationship between death, stroke, or MI among octogenarians.

Stent-assisted Percutaneous Angioplasty for Extra-cranial Carotid Disease: Experience at Singapore General Hospital

Introduction: This study aims to analyse the results of carotid stenting in a tertiary referral centre in Singapore. Materials and Methods: Retrospective analysis of all carotid artery stenting (CAS) cases in a single centre from March 1997 to December 2008 was performed. Sixty successful procedures were performed in 61 patients, with bilateral stenting in 1 patient, and 2 failed procedures. The majority were Chinese (78.7%) and males (77.0%), with a high proportion having hypertension (82.0%) and hypercholesterolaemia (78.7%). The majority (91.8%) of patients were high surgical risk candidates, primarily due to cardiac risk factors. Ten patients (16.4%) had prior neck irradiation for nasopharyngeal carcinoma, and 3 patients each (4.9%) had previous endarterectomy and contralateral occlusion. A distal embolic protection device was used in 71.7% of cases. Results: Technical success was 96.8%. The 30-day stroke and death rate was 13.8%, comparable to reported results for this high surgical risk population. Conclusion: CAS is a technically feasible and a relatively safe alternative to endarterectomy to treat extracranial carotid stenosis, especially in patients who are inoperable orat high surgical risk. Keywords: Carotid stenting, High surgical risk

Predictors of clinically significant postprocedural hypotension after carotid endarterectomy and carotid angioplasty with stenting

OBJECTIVES

Significant hypotension after carotid endarterectomy (CEA) and carotid angioplasty with stenting (CAS) has been correlated with adverse outcomes. The objective of this study was to determine risk factors that predict hypotension after patients undergo CEA and CAS.

METHODS

The review included 1474 CEA patients and 157 CAS patients who underwent procedures from 2002 to 2008. Specific patient characteristics, such as comorbid diseases, degree of carotid stenosis, presence of neurologic symptoms, and preprocedure medications, were assessed. Also reviewed were specific postprocedural clinical outcomes, including hypotension requiring pressors, myocardial infarction, stroke, death, and hospital length of stay.

RESULTS

The incidence of clinically significant hypotension was 12.6% in CEA patients and 35% in CAS patients (P < .001). Clinically significant hypotension was correlated with increased postprocedural myocardial infarction (2.1% vs 0.5%, P = .022), increased mortality (2.1% vs 0.1%, P < .001), and length of stay >2 days (46.3% vs 27.4%, P = .01). Hypotension was not associated with increased postprocedural strokes (0.8% vs 0.6%, P = .75) or recurrent neurologic symptoms (0.4% vs 0.3%, P = .55). Preoperative nitrate use predicted a greater incidence of postprocedural hypotension (P = .043). A history of tobacco use was correlated with postprocedure hypotension (P = .033). Preprocedural strokes, the use of calcium channel blockers, beta-blockers, angiotensin-converting enzyme inhibitors, prior myocardial infarction, degree of preprocedural carotid stenosis, type of stent, previous ipsilateral and contralateral interventions, and female gender did not correlate with postprocedural hypotension (P >.05).

CONCLUSIONS

Postprocedural hypotension occurs more commonly with CAS than CEA and is associated with increased postprocedural myocardial infarction and length of stay, and death. Nitrates and tobacco use predict a higher incidence of postprocedural hypotension. High-risk patients should be aggressively managed to prevent the increased morbidity and mortality due to postprocedural hypotension.

Percutaneous versus surgical revascularization for symptomatic carotid artery disease

Stroke is the third leading cause of death worldwide and the number one disease associated with permanent disability. In 2006, the estimated total cost of stroke in the United States was a staggering $60 billion. Significant stenosis of the internal carotid artery is responsible for 10% to 20% of all strokes, and current recommendations suggest that patients with symptomatic carotid artery stenosis undergo revascularization for stroke prevention or risk reduction. Since the 1950s, carotid endarterectomy (CEA) has been the dominant modality of revascularization. However, carotid artery angioplasty, introduced in the 1980s, and subsequent carotid artery stenting (CAS), have greatly improved in recent years and provide a viable alternative to CEA, particularly for certain high-risk patients. Encouraging results from clinical studies of CAS and CEA have played pivotal roles in shaping current practice guidelines. We review the published studies on CAS and discuss appropriate use of this procedure for symptomatic carotid artery disease.

Acute and prophylactic endovascular treatment of internal carotid artery stenosis

Stroke is the third most common cause of death in the USA. Up to 20% of all strokes are caused by internal carotid artery (ICA) stenosis. This article reviews the treatment of ICA stenosis, its indication, and its relevance for stroke prevention. The article also discusses the indication of ICA stenosis treatment in an acute stroke situation and offers pathophysiological commentary.

Thirty-Day Outcomes for Carotid Artery Stenting in 6320 Patients From 2 Prospective, Multicenter, High-Surgical-Risk Registries

Background— The American Heart Association has established guidelines for acceptable 30-day death and stroke rates for patients with severe carotid disease undergoing standard-risk carotid endarterectomy: <3% for asymptomatic lesions and <6% for symptomatic lesions. To date, carotid artery stenting has not demonstrated these outcomes in multicenter, prospective assessments of high-surgical-risk patients.

Methods and Results— Data from 2 prospective, multicenter (280 US sites, 672 operators), postmarket surveillance studies in high-surgical-risk patients were analyzed: 2145 patients from the Emboshield and Xact Post Approval Carotid Stent Trial (EX) and 4175 patients from the Carotid ACCULINK/ACCUNET Post Approval Trial to Uncover Rare Events (C2). Both studies had pre- and postprocedure neurological evaluation and independent adjudication of neurological events. The overall 30-day death and stroke rate was 4.1% (95% CI, 3.3% to 5.0%) for EX and 3.4% (95% CI, 2.9% to 4.0%) for C2. In the population comparable with American Heart Association guidelines (<80 years), the combined 30-day death and stroke rate was 5.3% (95% CI, 3.6% to 7.4%) for symptomatic patients and 2.9% (95% CI, 2.4% to 3.4%) for asymptomatic patients, independent of unfavorable risk factors (anatomic or physiologic); in patients ≥80 years, this rate was 10.5% (95% CI, 6.3% to 16.0%) and 4.4% (95% CI, 3.3% to 5.7%), respectively. In subjects with anatomic features unfavorable for surgery, the 30-day death and stroke rates were 1.7% (95% CI, 0.0% to 8.9%) and 2.7% (95% CI, 1.3% to 4.9%) for symptomatic and asymptomatic cohorts, respectively, independent of age.

Conclusions— Outcomes for carotid artery stenting in nonoctogenarian high-surgical-risk patients have improved since the pivotal Food and Drug Administration approval trials, and have achieved American Heart Association standards in both symptomatic and asymptomatic lesions.

Carotid artery stenting: Impact of practitioner specialty and volume on outcomes and resource utilization

OBJECTIVES

A variety of endovascular specialists perform carotid artery stenting (CAS), but little data exist on outcomes and resource utilization among these specialists. We analyzed differences in outcomes after CAS was performed by radiologists (RAD), cardiologists (CRD), and vascular surgeons (VAS).

METHODS

Secondary data analysis of the 2005-2006 State Inpatient Databases for New Jersey were analyzed. Patients with elective admission to the hospital who had CAS procedure <or=2 days after admission were identified. CAS outcomes were analyzed with respect to practitioner specialty and volume, associated complications, and hospital resource utilization.

RESULTS

We identified 625 CAS cases. CRD performed 378 (60.5%), VAS, 199 (31.8%); and RAD, 48 (7.7%). The overall stroke rate was 2.72% and by specialty was CRD, 3.17%; VAS, 2.01%, and RAD, 2.08% (P = .6880). The overall cardiac complication rate was 2.40% (CRD, 2.12%; VAS, 3.02%; RAD, 2.08%; P = .7899). Renal and pulmonary complications were low (0.64% and 0.32%, respectively). Mean hospital length of stay (LOS) in days was significantly shorter for VAS (1.64 +/- 1.40) compared with RAD (2.83 +/- 5.15; P = .0167) and had the same trend compared with CRD (2.14 +/- 3.37; P = .0649). Intensive care unit (ICU) LOS was shorter for VAS (0.52 +/- 0.97) and CRD (0.30 +/- 0.71) than for RAD (2.12 +/- 4.48; P < .0001). The mean total hospital cost was significantly greater for RAD ($20,987 +/- $26,603) and CRD ($18,182 +/- $16,364) than for VAS ($10,000 +/- $4947; P = .0011 and P < .0001, respectively). ICU cost for RAD ($5963 +/- $14,551) was also more than for VAS ($864 +/- $1514; P < .0001) and CRD ($473 +/- $1561; P < .0001). Medical supply costs were significantly greater for CRD ($8772 +/- $9546) than for VAS ($3354 +/- $2261; P < .0001) and RAD ($4964 +/- $2595; P = .0142). Total hospital cost, LOS, and medical supplies were significantly lower for high-volume practitioners vs low-volume practitioners (P < .0001).

CONCLUSION

Stroke rates after CAS did not vary significantly among practitioner specialties. Hospital resource utilization did vary significantly: Vascular surgeons had the lowest utilization of hospital resources for performing CAS. High practitioner volume was associated with lower hospital resource utilization. Elucidation of factors creating resource utilization disparities among endovascular practitioners may lead to improved patient outcomes and permit significant future cost savings for carotid interventions.

Acute cerebral rescue during carotid artery stenting: a stroke of good fortune?

Major stroke is a potentially devastating complication of carotid artery revascularization. Carotid artery stenting, unlike endarterectomy, offers the opportunity to attenuate this complication by allowing for the instantaneous detection and early endovascular treatment of neurologic defects complicating the procedure. We report a case that highlights the utility of aggressive endovascular cerebral rescue during a carotid artery stent procedure.

Open-cell versus closed-cell stent design differences in blood flow velocities after carotid stenting

OBJECTIVE

The differential effect of open-cell vs closed-cell stent design configuration on carotid velocities detected by duplex ultrasound (DUS) imaging has not been established. To identify possible stent design differences in carotid velocities, we analyzed DUS studies obtained before and immediately after carotid artery stenting (CAS).

METHODS

In a series of 141 CAS procedures performed during a 3-year period, data from the first postinterventional DUS images and carotid angiograms were evaluated for each patient. Peak systolic velocities (PSV), end-diastolic velocities (EDV), and internal carotid artery/common carotid artery (ICA/CCA) PSV ratios were compared according to stent design. Differences in carotid velocities were analyzed using nonparametric statistical tests.

RESULTS

Completion angiograms revealed successful revascularization and <30% residual stenosis in each case. The 30-day stroke-death rate in this series was 1.6% and was unrelated to stent type. Postintervention DUS images were obtained a median of 5 days (interquartile range [IQR], 1-25 days) after CAS. Closed-cell stents were used in 41 procedures (29%) and open-cell stents in 100 (71%). The median PSV was 95.9 cm/s (IQR, 77-123 cm/s) for open-cell stents and 122 cm/s (IQR, 89-143 cm/s) for closed-cell stents, which was significantly higher (P = .007). Closed-cell stents also had significantly higher median EDVs (36 vs 29 cm/s; P =.006) and ICA/CCA PSV ratios (1.6 vs 1.1; P =.017). By DUS criteria, the carotid velocities in 45% of closed-cell stents exceeded the threshold of 50% stenosis for a nonstented artery compared with 26% of open-cell stents (P =.04). Closed-cell stents had a 2.2-fold increased risk of yielding abnormally elevated carotid velocities after CAS compared with open-cell stents (odds ratio, 2.2; 95% confidence interval, 1.02-4.9).

CONCLUSIONS

Carotid velocities are disproportionately elevated after CAS with closed-cell stents compared with open-cell stents. This suggests that the velocity criteria for quantifying stenosis may require modification according to stent design. The importance of these differences in carotid velocities related to stent design and the potential relationship with recurrent stenosis remains to be established.

Safety of carotid stenting for stroke prevention: need of an independent outcome assessor

Safety and efficacy of carotid artery stenting have still to be fully established. We propose a standardized registry of carotid artery stenting in use at our hospital to evaluate whether the presence of an independent neurologist performing basal, procedural and post-procedural observation increases the accuracy of outcome assessment. We collected a cohort of patients receiving carotid stenting. An external neurologist supervised the endovascular intervention and monitored the patient's clinical conditions during procedure and follow-up time (12 months). The procedure was carried out successfully in all cases. We registered two intra-procedural strokes and two strokes within 24 h. The risk of major complications in our study was 9.1% at 30 days. Our complication rate is higher than in previous studies. These findings could be partly explained by the unemployment of distal protection devices, but also by the presence of an independent observer that might have increased the accuracy of neurological evaluation.

Carotid artery stenting versus carotid endarterectomy: current status

Carotid occlusive disease remains an important cause of ischemic stroke. The results of large, randomized, clinical trials have established the benefit of surgical revascularization in patients with symptomatic or asymptomatic carotid stenosis. The introduction of balloon angioplasty and stenting of the extracranial carotid artery as a potential alternative to surgery has been received with enthusiasm by patients and physicians. Whether or not this enthusiasm is justified fully has yet to be determined. This article reviews established and emerging data from clinical trials evaluating the safety and efficacy of carotid endarterectomy, carotid angioplasty, and stenting.

Cutting balloon angioplasty in percutaneous carotid interventions

PURPOSE

To report a prospective feasibility study of cutting balloon angioplasty (CBA) applied in the predilation phase of carotid artery stenting (CAS) in highly calcified lesions.

METHODS

From January 2003 to February 2007, 178 consecutive patients (109 men; mean age 73.1+/-7.3 years) with highly calcified carotid lesions underwent CAS with CBA applied as a pre-specified strategy in the predilation phase of the procedure. All steps in the procedure were performed under cerebral filter protection. The cutting balloon ranged in diameter from 3 to 4 mm and was inflated at nominal pressures in the target lesion. Pre-CBA dilation with a low-profile coronary balloon was performed only when the cutting balloon was not able to cross the lesion. Selection of the filters and stents was at the operator's discretion. Primary endpoints were the all stroke and death rates at 30 days and 6 months. Secondary endpoints included cutting balloon success (positioning and full balloon inflation), CAS technical success (residual angiographic stenosis <30%), CAS procedural success (technical success and no complications), and in-hospital major complications.

RESULTS

Cutting balloon success was achieved in all 178 patients. In 32 (18.0%), pre-CBA dilation was necessary due to inability to cross the lesion with the cutting balloon initially. CAS technical success was achieved in all patients. One (0.6%) patient suffered transient neurological intolerance due to flow cessation from massive debris in the distal filter; this event was completely resolved after the filter was removed (CAS procedural success 99.4%). One patient suffered a major stroke at day 15 (0.6% 30-day all stroke and death rate). At the 6-month follow-up, 174 (97.7%) patients were evaluated; 1 patient died from myocardial infarction at day 35, and 2 patients died from non-neurological or cardiac causes at days 103 and 158. The cumulative all stroke and death rate was 2.2%.

CONCLUSION

These data suggest that CBA performed during the predilation phase of CAS in highly calcified lesion is a safe and useful method to prepare this lesion subset for stenting.

Carotid stenting with embolic protection: evolutionary advances

Stroke is one of the most significant causes of death and morbidity worldwide. Atherosclerotic stenosis of the extracranial internal carotid artery has been invoked as a common causative factor for stroke in over 20% of patients. Although medical therapy can help to prevent the onset and progression of carotid arteriosclerosis, open surgical carotid endarterectomy has been the gold standard for treating severe blockage. Carotid artery stenting has recently demonstrated efficacy in stroke prevention from atherosclerosis, and in high-risk surgical subgroups, has been shown to be associated with a reduction in the risk of myocardial infarction. The controversy for carotid stenting surrounds the incidence of periprocedural stroke. Will embolic protection devices (EPDs) decrease this risk? EPDs continue to evolve with various engineering strategies directed at increasing the efficiency of protection. There are two major categories of EPDs: distal occlusion, either with balloons (e.g., Percusurge, Medtronic Corporation, MN, USA); or distal filtration (e.g., Angioguard, Cordis Corporation, NJ, USA). The second method is proximal protection (e.g., MoMA device, Invatec Corporation, Brescia, Italy). We review the results of trials currently evaluating carotid stenting with both distal and proximal embolic protection.

Periprocedural Drug Therapy in Carotid Artery Stenting: The Need for More Evidence

Carotid artery stenting (CAS) is a widely accepted alternative for patients at high risk for carotid endarterectomy (CEA). However, the role, indications, and evidence for many pharmacologic agents that are used adjunctively in the periprocedural setting have not been established. Several drugs are commonly used before, during, and after CAS, but their uses have not been standardized. Large prospective cohort studies with good validity or randomized trials are needed to demonstrate efficacy, predict outcome, and determine the optimal use of these medications in patients undergoing CAS to improve patient care and obtain optimal outcomes. Several conclusions can be made: (1) dual-antiplatelet therapy (aspirin and clopidogrel) is commonly used for CAS; (2) the most commonly used regimen is aspirin 325 mg and clopidogrel 75 mg per day, but the optimal time of therapy is unknown; and (3) the dose and regimen of other agents used for CAS are not established.

LOW INCIDENCE OF SYMPTOMATIC STROKES AFTER CAROTID STENTING WITHOUT EMBOLIZATION PROTECTION DEVICES FOR EXTRACRANIAL CAROTID STENOSIS

OBJECTIVE

Carotid angioplasty and stenting (CAS) remains the primary modality of treating individuals with carotid stenosis and significant comorbidities or anatomically difficult lesions. The use of embolization protection devices (EPD) has been mandated by the cerebrovascular community even though the ability of these devices to prevent symptomatic strokes is not supported by the current literature. Our goal was to assess the clinical and radiological outcomes of patients who underwent CAS without EPDs at our hospital from 1996 to 2006.

METHODS

We performed a retrospective chart analysis of all patients who underwent CAS without EPDs at the Jefferson Hospital for Neuroscience in Philadelphia, PA. The clinical and angiographic outcomes of these patients were studied retrospectively using chart reviews and operative, angiographic, and radiological reports. The mean clinical and radiological follow-up period was 18.6 months.

RESULTS

One hundred five patients (97.2%) had clinical follow-up at 1 month. During this period, the following complications were observed: cerebrovascular accidents in 2 patients (1.9%), myocardial infarctions in 2 patients (1.9%), femoral hematoma in 1 patient (0.9%), retroperitoneal hematomas in 3 patients (2.8%), and cervical carotid dissections in 4 patients (3.7%); 2 patients (1.9%) died. Seventy-six patients (80.9%) had a mean clinical follow-up period of 18.6 months. During this period, 2 patients (2.6%) had cerebrovascular accidents, 1 of which was fatal. The long-term morbidity and mortality rate was 2.6%. In the same follow-up period, the restenosis (&gt;50% stenosis from baseline) rate was 9.2% (7 patients). Three (3.9%) of these patients went on to require repeat CAS.

CONCLUSION

Our experience reveals that CAS can be performed safely with risks similar to those reported in series in which EPDs were used. Any procedure or device that adds risk and cost to the patient should be evaluated with a randomized, controlled trial to evaluate its efficacy, especially in situations in which published data provide conflicting results. The use of EPDs should be no exception to this paradigm.

Clinical trials: past, present, and future

Carotid stenting has been in evolution for the past 15 years. Initially limited by a lack of dedicated equipment, pivotal trials using both dedicated stent technology and embolic protection filters in patients at high risk for surgical endarterectomy have been largely completed, and results have compared favorably to both direct and historical surgical controls. While this has led to Food and Drug Administration approval of at least six carotid stent systems in the US, European randomized trials in standard surgical risk patients have had mixed results and confused the perception of the place of this technology in the care of patients with carotid stenosis. Current US trials are in progress, one nearing completion, and they will further contribute an understanding as to the place of stent therapy in the standard surgical risk patient, regardless of symptomatic status.

Carotid artery stenting has increased rates of postprocedure stroke, death, and resource utilization than does carotid endarterectomy in the United States, 2005

OBJECTIVE

Carotid endarterectomy (CEA) remains the procedure of choice for treatment of patients with severe carotid artery stenosis. The role of carotid artery stenting (CAS) in this patient group is still being defined. Prior single and multicenter studies have demonstrated economic savings associated with CEA compared with CAS. The purpose of this study was to compare surgical outcomes and resource utilization associated with these two procedures at the national level in 2005, the first year in which a specific ICD-9 procedure code for CAS was available.

METHODS

All patient discharges for carotid revascularization for the year 2005 were identified in the Nationwide Inpatient Sample based on ICD9-CM procedure codes for CEA (38.12) and CAS (00.63). The primary outcome measures of interest were in-hospital mortality and postoperative stroke; secondary outcome measures included total hospital charges and length of stay (LOS). All statistical analyses were performed using SAS version 9.1 (Cary, NC), and data are weighted according to the Nationwide Inpatient Sample (NIS) design to draw national estimates. Univariate analyses of categorical variables were performed using Rao-Scott chi(2), and continuous variables were analyzed by survey weighted analysis of variance (ANOVA). Multivariate logistic regression was performed to evaluate independent predictors of postoperative stroke and mortality.

RESULTS

During 2005, an estimated 135,701 patients underwent either CEA or CAS nationally. Overall, 91% of patients underwent CEA. The mean age overall was 71 years. Postoperative stroke rates were increased for CAS compared with CEA (1.8% vs 1.1%, P < .05), odds ratio (OR) 1.7; (95% confidence interval [CI] 1.2-2.3). Overall, mortality rates were higher for CAS compared with CEA (1.1% vs 0.57%, P < .05) this difference was substantially increased in regard to patients with symptomatic disease (4.6% vs 1.4%, P < .05). By logistic regression, CAS trended toward increased mortality, OR 1.5; (95% CI .96-2.5). Overall, the median total hospital charges for patients that underwent CAS were significantly greater than those that underwent CEA ($30,396 vs $17,658 P < .05).

CONCLUSIONS

Based on a large representative sample during the year 2005, CEA was performed with significantly lower in-hospital mortality, postoperative stroke rates, and lower median total hospital charges than CAS in US hospitals. As the role for CAS becomes defined for the management of patients with carotid artery stenosis, clinical as well as economic outcomes must be continually evaluated.

Safety and Efficacy of Carotid Angioplasty/Stenting in 100 Consecutive High Surgical Risk Patients: Immediate and Long-Term Follow-up

Background/purpose. This study analyzes the safety and efficacy of carotid angioplasty/stenting (CAS) with embolic protection devices in high surgical risk (HSR) patients. Patient population/methods. This study includes 100 consecutive HSR patients, who were followed prospectively, and had carotid duplex ultrasounds at 1 month and every 6 months thereafter. A Kaplan—Meier lifetable analysis was used to estimate survival rates, rates of freedom from stroke, and freedom from ≥50% in-stent restenosis. Results. Mean age was 69.6 years. There were 59 men and 41 women. Mean follow-up was 26.1 months (range, 1-50). Indications for CAS were symptomatic ≥50% stenosis in 47% and ≥80% asymptomatic stenosis in 53%. Procedure success rate was 100%. HSR includes 33% with restenosis and cardiac comorbidity, 21% with restenosis and cardiac/medical comorbidities, 13% with restenosis only, and 33% with cardiac/medical comorbidities. The 30-day perioperative stroke rate was 2% with no perioperative deaths or MI. Stroke-free survival rates were 95%, 91%, 83%, 79%, and 73% at 1, 2, 3, and 4 years, respectively. There were no late strokes. Stroke-free rate was 98% at 1, 2, 3, and 4 years, respectively. Freedom from ≥50% in-stent restenosis was 98%, 93%, 90%, and 79% at 1, 2, 3, and 4 years, respectively. Six patients had asymptomatic ≥80% in-stent restenosis; 3 underwent reintervention (percutaneous transluminal angioplasty). The incidence of in-stent restenosis was not statistically significant between patients who had restenosis after carotid endarterectomy and patients with primary stenting ( P = .21). Conclusions. CAS with embolic protection devices in HSR patients is safe and effective.

[Stent-assisted angioplasty for atherosclerotic stenosis of the carotid artery. An overview]

For symptomatic stenosis of the carotid artery the invasive options for treatment (by means of stent or operation) are superior to conservative medical treatment. Recent multi-center randomized controlled trials, which will be presented here, indicate that stenting in the treatment of symptomatic carotid stenosis is neither safer nor more effective than carotid endarterectomy. When carried out by an experienced interventionalist stent-assisted angioplasty (CAS) is an alternative to carotid endarterectomy. Subgroup-analysis indicates that for patients older than 70 years of age invasive techniques should be the method of choice. In the case of contralateral high-grade stenosis or occlusion, CAS is the method of choice. For patients treated by stenting, the periprocedural complication rate is not influenced by the use of protection systems. The present results on symptomatic carotid stenosis should not be transferred to the therapy of asymptomatic carotid stenosis. A 3-armed study (SPACE2) on the comparison of the best medical treatment with the invasive treatment modalities (CAS or CEA) is in preparation and will be started in 2 months.

Results using a self-expanding stent alone in the treatment of severe symptomatic carotid bifurcation stenosis

Object

Conventional endovascular therapy for carotid stenosis involves placement of an embolic protection device followed by stent insertion and angioplasty. A simpler approach may be placement of a stent alone. The authors determined how often this approach could be used to treat patients with carotid stenosis, and assessed which factors would preclude this approach.

Methods

Over a period of 6 years, 97 patients with symptomatic carotid stenosis were treated with the intention of using a “stent-only” approach. Arteries in 77 patients (79%) were treated with stents alone, 13 required preinsertion balloon dilation, 6 postinsertion dilation, and 1 both pre- and postinsertion dilation.

Results

The mean stenosis according to North American Symptomatic Carotid Endarterectomy Trial criteria was reduced from 82 to 40% in the stent-only group and from 89 to 37% in the stent and balloon angioplasty group. The 30-day stroke and death rate was 7.2%. Patients were followed for a mean of 15 months. In the stent-alone group, the mean preoperative Doppler peak systolic velocity (PSV) was 409 cm/second, with an internal carotid artery/common carotid artery (ICA/CCA) ratio of 7.2. At follow-up review, the PSV decreased to 153 cm/second and the ICA/CCA ratio to 2.1. In the angioplasty group the mean preoperative PSV was 496 cm/second and the ICA/CCA ratio was 9.2, decreasing to 163 cm/second and 2, respectfully, at follow-up evaluation. Restenosis occurred in 12.8% of patients at 6 months and in 15.9% at 1 year. One stroke occurred during the follow-up period in each group. Using multivariable analysis, factors precluding the “stent-only” approach were as follows: severity of stenosis, circumferential calcification, and no history of hyperlipidemia.

Conclusions

Balloons may not be required to treat all patients with carotid stenosis. A stent alone was feasible in 79% of patients, and 79% of patients were alive and free from ipsilateral stroke or restenosis at 1 year. Restenosis rates with this approach are higher than with conventional angioplasty and stent insertion. Carotid arteries with very severe stenoses (> 90%) and circumferential calcification may be more successfully treated with angioplasty combined with stent placement.

The Angioguard embolic protection device

Endovascular management of cardiovascular disease is quickly becoming a more popular treatment. The effectiveness in using embolic protection devices (EPDs), such as the Angioguard XP filter, during carotid artery stenting (CAS) is a topic of ongoing controversy and scrutiny. Early clinical results indicate that EPDs can reduce complications associated with CAS. However, the incidence of stroke and postprocedural embolic events are statistically similar when comparing CAS with the gold standard in carotid stenosis repair, carotid endarterectomy (CEA). The focus of this manuscript is the critical evaluation of Angioguard XP with respect to numerous in vitro and ex vivo experiments, and clinical trials that have been conducted by the authors and other researchers to investigate the efficacy of EPDs with the objective of suggesting engineering design considerations for future generations of these devices. Angioguard XP has had mixed performance outcomes in in vitro testing reported in the literature. In our laboratory, this device had undesirable measures of performance in bench-top testing protocols using in vitro flow models. Technical considerations relevant to design of EPDs, such as ideal pore size, effective wall apposition in tortuous geometry and maximization of capture efficiency have not been addressed adequately in the literature. It is likely that in the future both CAS and CEA will coexist as potential forms of treatment in the clinical management of cerebrovascular disease.