Embolic protection devices for carotid artery stenting: is there a difference between filter and distal occlusive devices?

Tandem Lesions of the Vertebrobasilar System Treated by Thrombectomy and Vertebral Artery Stenting: A Case Report

Objective

There are few reports on endovascular treatment of tandem lesions in the posterior circulation and no consensus on treatment strategies has been reached. We report a case of tandem lesions of basilar artery occlusion and vertebral artery stenosis treated by thrombectomy and vertebral artery stenting.

Case Presentation

We present the case of a 73-year-old man who developed consciousness disorder and tetraplegia. Head and neck CTA revealed tandem left vertebral artery stenosis and basilar artery occlusion. The patient was treated using a reverse technique, which involves performing thrombectomy first and then vertebral artery stenting, along with Carotid Guardwire PS. Postoperative impairment of consciousness and improvement of tetraplegia were achieved.

Conclusion

The reverse technique combined with Carotid Guardwire PS may be a useful treatment strategy for tandem lesions in the posterior circulation.

Protected versus Unprotected Carotid Artery Stenting : Meta-Analysis of the Current Literature

Objective

To compare peri-operative any symptomatic stroke after carotid angioplasty and stenting (CAS), based on the application or absence of a cerebral protection device.

Methods

A systematic literature review using PubMed, Embase, and the Cochrane Central was done across an online data base from January 1995 to October 2016. Procedures which were performed due to carotid dissection or aneurysm, procedures using covered stents or conducted in an emergency, were excluded. The primary endpoint was perioperative any symptomatic stroke within 30 days after the procedure. A fixed effect model was used in cases of heterogeneity less than 50%.

Results

In the 25 articles included in this study, the number of stroke events was 326 (2.0%) in protected CAS and 142 (3.4%) in unprotected CAS. The use of cerebral protection device significantly decreased stroke after CAS (odds ratio [OR] 0.633, 95% confidence interval [CI] 0.479–0.837, p=0.001). In the publication bias analysis, Egger’s regression test disclosed that the intercept was -0.317 (95% CI -1.015–0.382, p=0.358). Regarding symptomatic patients (four studies, 539 CAS procedures), the number of stroke was six (1.7%) in protected CAS and 11 (5.7%) in unprotected CAS. The protective effect against stroke events by cerebral protection device did not have a statistical significance (OR 0.455, 95% CI 0.151–1.366, p=0.160).

Conclusion

The use of protection device significantly decreased stroke after CAS. However, its efficacy was not demonstrated in symptomatic patients. Routine use of protection device during CAS should be critically assessed before mandatory use.

The Role of Embolic Protection in Carotid Stenting Progress in Cardiovascular Diseases (PCVD)

Embolic protection device (EPD) use has become ubiquitous and is currently mandated by the Centers for Medicare and Medicaid (CMS) for reimbursement in conjunction with carotid artery stenting (CAS). There are two classes of EPD devices: distal filter EPD (f-EPD) and proximal EPD (p-EPD). Measuring the incremental benefit of one strategy over the other remains problematic for several reasons. The first lies in the difficulty of defining an embolic event as transcranial Doppler and diffusion-weighted magnetic resonance imaging abnormalities may not correlate with clinical events. Next, f-EPD is used more frequently than p-EPD making direct comparisons challenging, as analyses to this point have been underpowered. However, there are several promising emerging techniques and technologies that warrant further investigation.

Carotid artery stenting: current and emerging options

Carotid artery stenting technologies are rapidly evolving. Options for endovascular surgeons and interventionists who treat occlusive carotid disease continue to expand. We here present an update and overview of carotid stenting devices. Evidence supporting carotid stenting includes randomized controlled trials that compare endovascular stenting to open surgical endarterectomy. Carotid technologies addressed include the carotid stents themselves as well as adjunct neuroprotective devices. Aspects of stent technology include bare-metal versus covered stents, stent tapering, and free-cell area. Drug-eluting and cutting balloon indications are described. Embolization protection options and new direct carotid access strategies are reviewed. Adjunct technologies, such as intravascular ultrasound imaging and risk stratification algorithms, are discussed. Bare-metal and covered stents provide unique advantages and disadvantages. Stent tapering may allow for a more fitted contour to the caliber decrement between the common carotid and internal carotid arteries but also introduces new technical challenges. Studies regarding free-cell area are conflicting with respect to benefits and associated risk; clinical relevance of associated adverse effects associated with either type is unclear. Embolization protection strategies include distal filter protection and flow reversal. Though flow reversal was initially met with some skepticism, it has gained wider acceptance and may provide the advantage of not crossing the carotid lesion before protection is established. New direct carotid access techniques address difficult anatomy and incorporate sophisticated flow-reversal embolization protection techniques. Carotid stenting is a new and exciting field with rapidly advancing technologies. Embolization protection, low-risk deployment, and lesion assessment and stratification are active areas of research. Ample room remains for further innovations and developments.

Treatment outcomes of carotid artery stenting with two types of distal protection filter device

PURPOSE

Preventing cerebral embolism from debris produced during carotid artery stenting (CAS) is important. This study compared the treatment outcomes of CAS using two types of filter-based embolic protection devices currently in use in Japan.

MATERIALS AND METHODS

We assessed 121 consecutive cases of CAS performed with FilterWire EZ™ between July 2010 and November 2012 and 37 consecutive cases of CAS performed with the Spider FX™ between November 2012 and June 2013. A Carotid Wallstent™ was used in all cases. The incidence of positive lesions on diffusion-weighted magnetic resonance imaging (DWI) and stroke were compared between the groups.

RESULTS

Postoperative DWI-positive lesions were observed in 38 (31.4%) and 14 (37.8%) patients in the FilterWire and Spider groups, respectively. In the FilterWire group, complications were transient ischemic attacks in 3 (2.5%) patients, cerebral infarction in 2 (1.7%) patients (1 patient each with minor and major stroke), and cerebral hemorrhage due to hyperperfusion syndrome in 1 (0.8%) patient. In the Spider group, except for cerebral infarction (minor stroke) in 1 (2.7%) patient, no complications were observed. No significant differences were observed in the incidence of complications between the groups.

CONCLUSION

FilterWire EZ and Spider FX are comparable in terms of treatment outcome.

Double embolic protection during carotid artery stenting with persistent hypoglossal artery

A woman presented with 75% stenosis of the right internal carotid artery (ICA) with extension to the origin of a persistent hypoglossal artery (PHA). The PHA is a rare fetal variant of carotid-basilar anastomosis that elevates the risk of ischemia and embolic infarction within the posterior cerebral circulation in patients with carotid disease proximal to the anastomosis. Our case is highly unique because of the extremely rare nature of the PHA with associated ICA stenosis that extended to the PHA. Additionally, a novel treatment approach was employed by stenting and angioplasty while protecting both the anterior and posterior cerebral circulations.

Use of embolic protective devices in treating acute arterial occlusions: an interventional radiology and vascular surgery collaborative learning experience

A 43-year-old man presented to the emergency department with left leg claudication. CT angiogram confirmed an acute left leg arterial occlusion from a left ventricular thrombus. During intra-arterial thrombolysis, he developed severe abdominal pain and a CT angiogram confirmed an acute occlusive thromboembolism to his left renal artery. Prior to left renal artery intra-arterial embolectomy, temporary intra-arterial occlusion balloons were inflated within his (1) right renal artery to protect this kidney from acute embolism and (2) left iliac artery to protect his left leg from further clot burden. Following the left renal embolectomy, an angiogram demonstrated patent renal arteries, acute occlusion of the right common iliac artery and persistent clot in his left iliac/lower limb. These occlusions were retrieved by surgical embolectomy. Final angiogram demonstrated patent bilateral iliac/lower limb arteries. The patient was discharged on lifelong anticoagulation and remains asymptomatic with bilateral palpable distal pulses and normal serum creatine.

Distal protection filter device efficacy with carotid artery stenting: comparison between a distal protection filter and a distal protection balloon

PURPOSE

This retrospective study aimed to compare the effectiveness of the embolization prevention mechanism of two types of embolic protection device (EPD)-a distal protection balloon (DPB) and a distal protection filter (DPF).

METHODS

Subjects were 164 patients scheduled to undergo carotid artery stenting: a DPB was used in 82 cases (DPB group) from April 2007 until June 2010, and a DPF was used in 82 cases (DPF group) from July 2010 to July 2011. Rates of positive findings on postoperative diffusion-weighted imaging (DWI) and stroke incidence were compared.

RESULTS

Positive postoperative DWI results were found in 34 cases in the DPB group (41.4 %), but in only 22 cases in the DPF group (26.8 %), and there was only a small significant difference within the DPF group. In the DPB group, there was one case of transient ischemic attack (TIA) (1.2 %) and four cases of brain infarction (2 minor strokes, 2 major strokes; 4.9 %), compared to the DFP group with one case of TIA (1.2 %) and no cases of minor or major strokes.

CONCLUSIONS

In this study, significantly lower rates of occurrence of DWI ischemic lesions and intraoperative embolization were associated with use of the DPF compared to the DPB.

New ischemic brain lesions on diffusion-weighted MRI after carotid artery stenting with filter protection: frequency and relationship with plaque morphology

BACKGROUND AND PURPOSE

CAS carries an inherent risk of distal cerebral embolization, precipitating new brain ischemic lesions and neurologic symptoms. Our purpose was to evaluate the frequency of new ischemic lesions found on DWI after protected CAS placement and to determine its association with plaque morphology.

MATERIALS AND METHODS

Fifty patients (mean age 65.13 ± 7.08 years) with moderate and severe internal carotid artery stenosis underwent CAS with distal filter protection. Fibrolipid and fibrocalcified plaque morphology was determined by sonography according to the relative contribution of echogenic and echolucent material, and by multisection CT using plaque attenuation. There were 46.81% of patients with fibrolipid and 53.19% with fibrocalcified plaques. DWI was performed before and 24 hours after CAS.

RESULTS

Seven (14.89%) patients showed new lesions. Four (8.51%) had 6 new lesions inside the treated vascular territory. Three had a single lesion and 1 patient had 3 lesions (mean: 1.5 ± 1). Most lesions (66.66%) were subcortical, with a mean diameter of 9 mm (range 5-15 mm). All lesions occurred in the area supplied by the middle cerebral artery and were clinically silent. A significant relationship was found between plaque morphology and the appearance of new lesions. Patients with fibrolipid plaques had a significantly higher number of new lesions compared with patients with fibrocalcified plaques (P = .041). The absolute risk of new lesions in the fibrolipid group was 18.18%.

CONCLUSIONS

New ischemic lesions were observed in the treated vascular territory in 8.51% of patients. The appearance of new ischemic lesions was significantly related to the plaque morphology. Fibrolipid plaques were associated with higher numbers of new lesions.

Anatomical and technical factors associated with stroke or death during carotid angioplasty and stenting: results from the endarterectomy versus angioplasty in patients with symptomatic severe carotid stenosis (EVA-3S) trial and systematic review

BACKGROUND AND PURPOSE

The purposes of this study were to assess the relationships between anatomic and technical factors and the 30-day risk of stroke or death after carotid angioplasty and stenting in the Endarterectomy versus Stenting in Patients with Symptomatic Severe Carotid Stenosis (EVA-3S) trial and to perform a systematic review of the literature.

METHODS

We included patients from EVA-3S in whom carotid stenting was attempted irrespective of allocated treatment. Two radiologists blinded to clinical data independently assessed the aortic arch and carotid arteries on procedural angiograms. In addition, we performed a systematic review of studies that reported 30-day risk of stroke or death in relation with arterial anatomy and technique. Outcomes were stroke or death and stroke occurring within 30 days of the carotid angioplasty and stenting procedure.

RESULTS

Two hundred sixty-two patients from EVA-3S fulfilled the inclusion criteria (including 1 initially allocated to surgery and 13 in whom stent insertion failed).Within 30 days after the procedure, 25 (9.5%) patients had a stroke or had died. The risk of stroke or death was higher in patients with internal carotid artery-common carotid artery angulation ≥60° (relative risk, 4.96; 2.29 to 10.74) and lower in those treated with cerebral protection devices (relative risk [RR], 0.38; 0.17 to 0.85). In the systematic review (56 studies; 34 398 patients), the risk of stroke or death was higher in patients with left-sided carotid angioplasty and stenting (RR, 1.29; 1.05 to 1.58), increased internal carotid artery-common carotid artery angulation (RR, 3.41; 1.52 to 7.63), and when the target internal carotid artery stenosis was >10 mm (RR, 2.36; 1.28 to 3.38). There was no significant increase in risk of stroke or death in patients with Type III aortic arch, aortic arch calcification, or with ostial involvement, calcification, ulceration or degree of stenosis of the target internal carotid artery stenosis. The use of a cerebral protection device was associated with a lower risk of stroke or death (RR, 0.55; 0.41 to 0.73). Risk was not related with stent or cerebral protection device type.

CONCLUSIONS

Our results strongly suggest that some technical and anatomic factors, especially extreme angulation of the carotid artery, have an impact on the risks of carotid angioplasty and stenting.

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.

Cerebral ischemic lesions detected with diffusion-weighted magnetic resonance imaging after carotid artery stenting: Comparison of several anti-embolic protection devices

Distal embolism is an important periprocedural technical complication with carotid angioplasty and carotid artery stenting (CAS). We evaluated the safety and efficacy of protection devices used during CAS by detecting new cerebral ischemic lesions using diffusion-weighted magnetic resonance imaging in 95 patients who underwent 98 CAS procedures: 34 using single PercuSurge GuardWire, 31 using double balloon protection, 15 using proximal flow reverse protection devices, 14 using Naviballoon, and 4 using filter anti-embolic devices. Diffusion-weighted imaging was performed preoperatively and postoperatively to evaluate the presence of any new embolic cerebral lesions. Postoperative diffusion-weighted imaging revealed 117 new ischemic lesions. Three patients had new ischemic stroke, two minor and one major, all ipsilateral to the treated carotid artery. The remaining patients had clinically silent ischemia. The incidence of new embolic lesions was lower using the proximal flow reverse protection device than with the double balloon protection (33% vs. 48.4%), but the volume of ipsilateral new ischemic lesions per patient was 136.6 mm(3) vs. 86.9 mm(3), respectively. Neuroprotection with Naviballoon yielded ipsilateral lesions of large volume (86.6 mm(3)) and higher number (5.7 lesions per patient) than using the filter anti-embolic device (34.8 mm(3) and 1 lesion per patient). New cerebral ischemic lesions after neuroprotected CAS are usually silent. The lower incidence of distal ischemia using proximal flow reverse and double balloon protection devices is limited by the larger volume and higher number of ischemic lesions.

Effectiveness and safety of carotid artery stenting for significant carotid stenosis in patients with contralateral occlusion (from the German ALKK-CAS Registry experience)

Data on the safety of carotid artery stenting (CAS) in a large number of unselected patients with contralateral occlusion and significant ipsilateral stenosis are less known. Accordingly, we evaluated 3,137 patients undergoing CAS who were enrolled in a German Registry from 2000 to 2008 and compared the clinical features and in-hospital outcomes of those with and without contralateral carotid occlusion. Contralateral carotid occlusion was present in 191 patients (6.1%) undergoing CAS. Despite the similar age of the patients with and without contralateral carotid occlusion, those with contralateral occlusion had a greater prevalence of co-morbidities, complex carotid stenosis, and greater number of focal neurologic lesions on the contralateral side. The incidence of in-hospital events, including death (1.0% vs 0.5%), ipsilateral major stroke (1.1% vs 1.1%), death or major ipsilateral stroke (1.6% vs 1.4%), ipsilateral transient ischemic attack (2.7% vs 2.5%), myocardial infarction (0.0% vs 0.1%), and reintervention (0.5% vs 1.1%), was low and was not significantly different between those with and without contralateral occlusion (p >0.05 for all comparisons). Among patients with carotid occlusion, major ipsilateral stroke (2.2%), death (2.2%), and a combination of these 2 events (3.3%) were observed exclusively in symptomatic patients with no event in asymptomatic patients. In conclusion, our data from a large number of patients undergoing CAS in a recent contemporary community-based practice attests to the low risk of periprocedural events among patients with contralateral carotid occlusion supporting CAS as an attractive option for the treatment of these patients.

Current role of emboli protection devices in percutaneous coronary and vascular interventions

After the observation that distal embolization is a frequent complication of coronary and vascular interventions, mechanical emboli protection devices (EPD) have been developed and tested in different vascular territories. The most frequently used device type incorporates a guidewire with a filter that is placed distal to the target lesion, unfolded, and then retrieved at the end of the procedure. Alternative approaches are based on transient flow obstruction using proximal or distal balloon occlusion. The procedure is then performed under flow reversal or flow arrest and the blood column is evacuated prior to restoration of flow. The efficacy of EPD in reducing major adverse cardiac events among patients undergoing percutaneous intervention of aortocoronary bypass grafts has been demonstrated in a randomized trial. In the acute myocardial infarction setting, EPD failed to improve outcomes. Although randomized data in carotid artery stenting are lacking, a broad, but not unanimous, consensus supports the use of these devices. While a small randomized trial showed disappointing results of emboli protection in renal stenting, no data are available for lower extremity interventions.

Cerebral ischemia detected with diffusion-weighted MR imaging after protected carotid artery stenting: comparison of distal balloon and filter device

Objective

The aim of this study was to examine the incidence of ischemia during protected carotid artery stenting (CAS) as well as to compare the protective efficacy of the balloon and filter devices on diffusion-weighted MR imaging (DWI).

Materials and Methods

Seventy-one consecutive protected CAS procedures in 70 patients with a severe (> 70%) or symptomatic moderate (> 50%) carotid artery stenosis were examined. A balloon device (PercuSurge GuardWire) and a filter device (FilterWire EX/EZ, Emboshield) was used in 33 cases (CAS-B group) and 38 cases (CAS-F group) to prevent distal embolization, respectively. All the patients underwent DWI within seven days before and after the procedures. The number of new cerebral ischemic lesions on the post-procedural DWI were counted and divided into ipsilateral and contralateral lesions according to the relationship with the stenting side.

Results

New cerebral ischemic lesions were detected in 13 (39.4%) out of the 33 CAS-Bs and in 15 (39.5%) out of the 38 CAS-Fs. The mean number of total, ipsilateral and contralateral new cerebral ischemic lesion was 2.39, 1.67 and 0.73 in the CAS-B group and 2.11, 1.32 and 0.79 in the CAS-F group, respectively. No statistical differences were found between the two groups (p = 0.96, 0.74 and 0.65, respectively). The embolic complications encountered included two retinal infarctions and one hemiparesis in the CAS-B group (9.09%), and one retinal infarction, one hemiparesis and one ataxia in the CAS-F group (7.89%). There was a similar incidence of embolic complications in the two groups (p = 1.00).

Conclusion

The type of distal protection device used such as a balloon and filter does not affect the incidence of cerebral embolization after protected CAS.

Spasm induced by protection balloon during carotid artery stenting

PURPOSE

The PercuSurge system is a distal balloon embolic protection device used for carotid artery stenting (CAS). We performed a retrospective study on the prognosis and clinical effects of spasms induced by the PercuSurge GuardWire system (PercuSurge-induced spasm).

MATERIALS AND METHODS

We performed CAS in 118 carotid stenoses using the PercuSurge system. Of the 118 procedures, 31 (26.3%) of the patients experienced PercuSurge-induced spasm, and all underwent postoperative follow-up studies by cerebral angiography and antiplatelet treatment.

RESULTS

On follow-up angiograms obtained a mean of 5.2 months (range 3-10 months) after CAS, all 31 PercuSurge-induced spasms had disappeared, and no delayed stenosis was found at the sites where the spasms had occurred. No ischemic events due to the spasms occurred during a mean follow-up of 13 months (range 3-32 months).

CONCLUSION

In the hands of physicians experienced in endovascular surgery, CAS using the PercuSurge system is a safe method with which to treat patients with carotid stenosis. Our study demonstrated that PercuSurge-induced spasms had no morphological or clinical adverse effects.

The type of embolic protection does not influence the outcome in carotid artery stenting

OBJECTIVES

The goal of this study was to review our experience with embolic protection devices (EPDs) during carotid artery stenting (CAS). Specifically, we aimed to verify their clinical effectiveness and to compare clinical outcomes between specific devices and types of EPDs.

METHODS

The CAS databases at four participating centers were reviewed. Adverse events were defined as death, stroke (>24 hours), or transient ischemic attack (TIA) (<24 hours). We compared the risk of procedural and 30-day events between patients treated with and without an EPD. We also compared these risks between different EPDs and between the different types of EPDs.

RESULTS

A total of 3160 CAS procedures using nine EPDs were analyzed. The risk of a procedural adverse event was 0.9% in protected and 2.3% in unprotected procedures (P = .12). Compared with the most frequently used device (FilterWire, Boston Scientific, Natick, Mass), there was no significant difference in the risk of procedural adverse events for any of the other EPDs. There was, however, an increased risk of 30-day adverse events with the Accunet (Abbott Vascular, Redwood, Calif) filter compared with the FilterWire (relative risk [RR] 2.67, confidence interval [CI] 1.41 to 5.04, P = .005). Pairwise comparison of proximal occlusion balloons to filters, distal occlusion balloons to filters, and proximal to distal occlusion balloons revealed no significant difference in the risk of procedural or 30-day adverse events. There was no significant difference in risk of procedural events between eccentric and concentric filters, however, the relative risk of eccentric compared with concentric filters at 30 days was 0.59 (unadjusted, CI 0.38 to 0.92, P = .04). This difference was still apparent after adjustment for risk factors (RR 0.61, CI 0.39 to 0.95, P = .06), but not after adjustment for risk factors and stent-type [(open-cell vs closed-cell) RR 0.76, CI 0.47 to 1.22, P = .51].

CONCLUSION

The use of EPDs is associated with a low risk of procedural adverse events. We were unable to detect significant differences in risks of procedural adverse events between different devices or types of devices. We speculate that the observed differences seen at 30 days are largely attributable to differences in stent-type used.

Current Treatment of Peripheral Arterial Disease

Despite advances in medical therapies to help prevent the development of atherosclerosis and improve the management of patients with established peripheral arterial disease (PAD), the prevalence of PAD and associated morbidity remains high. Over the past decade, percutaneous revascularization therapies for the treatment of patients with PAD have evolved tremendously, and a great number of patients can now be offered treatment options that are less invasive than traditional surgical options. With the surgical approach, there is significant symptomatic improvement, but the associated morbidity and mortality preclude its routine use. Although newer percutaneous treatment options are associated with lower procedural complications, the technical advances have outpaced the evaluation of these treatments in adequately designed clinical studies, and therapeutic options are available that may not have been rigorously investigated. Therefore, for physicians treating patients with PAD, an understanding of the various therapies available, along with the inherent benefits and limitations of each treatment option is imperative as a greater number of patients with PAD are being encountered.

Technical Limitations of Carotid Filter Embolic Protection Devices

Improved carotid artery stenting (CAS) results are credited to the development of embolic protection devices (EPDs). Reported are outcomes and technical failures of two classes of EPDs: distal balloon occlusion and distal filtration. We present a retrospective review of 206 CAS procedures from April 2001-September 2005. Filters (AccuNet, Angioguard, Filterwire, or Emboshield) were used in 98 cases (48%), distal balloon occlusion (PercuSurge) in 94 (46%), and no protection in 14. Data include demographics and procedural records. Mean age was 70 years (76% men, 24% women). At 30 days, there were no deaths, no myocardial infarctions, two major ipsilateral strokes (1%), two minor posterior strokes (1%), four transient ischemic attacks (2%), and one major access site complication (0.5%). Major neurologic events were equally divided between balloon occlusion and filters. Mean balloon occlusion time was 12 min, with only two patients (2%) manifesting reversible neurologic intolerance during flow arrest. In the last 100 cases, filter devices were preferentially used due to preserved antegrade flow. However, 11 cases (11%) necessitated intraoperative switching to balloon occlusion because of either extreme tortuosity or severe stenosis of the target lesion precluding passage of the filter element. CAS-specific equipment has improved procedural results. Despite theoretic advantages of filter EPDs, up to 10% of lesions are either too narrow or tortuous to allow safe passage of the filter element. Switching to a distal balloon occlusion system, which is well tolerated, may be preferred to unprotected predilation. Practitioners of CAS should be versed in both.

Comparison of in-hospital outcomes of patients with versus without previous carotid endarterectomy undergoing carotid stenting (from the German ALKK CAS Registry)

Repeat carotid endarterectomy (CEA) for recurrent stenosis remains a challenging treatment option associated with high morbidity and mortality. Carotid artery stenting (CAS) is an attractive alternative management option for these patients. However, data about the effectiveness and safety of CAS in a large number of unselected patients are less known. We evaluated 3,070 patients who underwent CAS enrolled in a German registry from 1996 to 2006 at 31 sites. We compared clinical and angiographic features and in-hospital outcomes of patients with and without previous CEA who underwent CAS. Of 3,070 patients in the registry, 223 (7.3%) underwent CAS for restenosis after previous CEA. Median age was similar in patients with and without previous CEA (70 years, interquartile range 64 to 76 vs 71 years, interquartile range 65 to 76). Ipsilateral neurologic symptoms occurred in approximately 1/2 the patients in both groups. Other co-morbid conditions and angiographic or procedural factors did not differ between the 2 groups. In-hospital events including death (0% vs 0.4%), ipsilateral major stroke (1.4% vs 1.5%), death or major ipsilateral stroke (1.4% vs 1.7%), ipsilateral transient ischemic attack (1.9% vs 2.8%), myocardial infarction (0.4% vs 0.1%), and reintervention (0.7% vs 0.4%) were all low and not significantly different between those with and without previous CEA (p >0.05 for all comparisons). In conclusion, our data for a large number of patients who underwent CAS in a recent contemporary community-based practice attests to the low risk of periprocedural events in patients with recurrent stenosis after previous CEA. This low risk along with the less invasive nature of the procedure should make CAS an attractive and perhaps preferred option for the treatment of these patients.

Double-Wire Technique in Balloon-Protected Carotid Artery Stenting

OBJECTIVES

To evaluate the safety and efficacy of a double-wire technique in carotid artery stenting (CAS) with a distal occlusion balloon system, PercuSurge GuardWire.

METHODS

Fifty-one consecutive patients with 53 de novo lesions were scheduled to undergo balloon-protected CAS with the "double-wire technique," the use of two wires, one for independent predilatation and the other for stent implantation.

RESULTS

Fifty consecutive patients underwent a total of 52 balloon-protected CAS except for 1 patient with one lesion that could not be accessed. The use of a 1.5-mm coronary balloon was necessary in only 2 cases (3.8%) to let the PercuSurge GuardWire cross critically stenotic lesions. The placement of the PercuSurge GuardWire into the internal carotid artery was successful in all cases. Technical success was obtained in all cases. Fifty lesions (96.2%) were treated with one inflation of the distal occlusion balloon during the entire procedure consisting of predilatation, stent implantation, and aspiration, and among them three lesions (5.8%) required postdilatation. The mean occlusion time of cerebral blood flow for 50 lesions was 266 +/- 37 seconds. Out of 50 procedures, 45 (90.0%) had occlusion times of 300 seconds or less. Neurological intolerance requiring intravenous anesthesia was seen in 4 cases (7.7%) and periprocedural neurological complication in 2 cases (3.8%).

CONCLUSIONS

The "double-wire technique" is safe and effective for the shortening of occlusion time during predilatation, stent implantation, and aspiration, leading to satisfactory technical and clinical outcomes, in most cases. This technique should be considered for balloon-protected CAS using the PercuSurge GuardWire.

Transcranial Doppler monitoring during stenting of the carotid bifurcation: evaluation of two different distal protection devices in preventing embolization

PURPOSE

To compare the efficacy of 2 emboli protection devices in preventing embolization during carotid artery stenting (CAS).

METHODS

The GuardWire distal occlusion system (n=19) and the distal FilterWire EX (n=12) were compared in 31 consecutive patients (24 men; mean age 71+/-10 years) monitored with transcranial Doppler for microembolic signals before, during, and after CAS. The choice of the protection device was based on availability and on the patency of the contralateral carotid artery.

RESULTS

The baseline characteristics were similar in the patients treated under protection from either device. Placement and retrieval of the protection device, stenting, and postdilation were technically successful in all patients. Two patients suffered a transient ischemic attack shortly after the procedure; no other adverse cardiovascular events occurred at 30 days. Compared to the GuardWire, the use of the FilterWire was associated with more microembolic signals during stent deployment (77.4+/-33.5 versus 1.07+/-1.94, p<0.0001), postdilation (63.9+/-21.0 versus 2.06+/-2.58, p<0.0001), and retrieval of the protection device (21.4+/-15.4 versus 10.9+/-8.3, p=0.051). Consequently, the total amount of microembolic signals during the procedure was higher when the filter device was employed (183.0+/-42.1 versus 31.7+/-12.0, p<0.0001).

CONCLUSION

The distal occlusion device appears to be more effective than the filter in reducing distal embolization detected by transcranial Doppler monitoring.

Comparison of embolization protection device-specific technical difficulties during carotid artery stenting

BACKGROUND

Embolic protection devices (EPDs) consisting of an internal carotid artery (ICA) filter or balloon occlusion are typically used during carotid artery stenting (CAS). This study compares the technical difficulties encountered using these two types of EPD.

METHODS

A retrospective review was conducted of patients undergoing CAS using a balloon occlusion EPD (balloon group: PercuSurge GuardWire) or filter EPD (filter group: Accunet, AngioGuard, or FilterWire). Complications were defined as minor stroke, National Institutes of Health (NIH) stroke scale <3; major stroke, NIH stroke scale > or =3; transient ischemic attack (TIA), reversible focal neurologic impairment; technical, reversible neurologic compromise during EPD deployment, inability to cross lesion, ICA spasm requiring treatment, EPD-related factors that prolonged CAS.

RESULTS

CAS (n = 141) was performed in 133 patients (82% men) with a mean age of 72 of years. Comorbidities included diabetes, 35%; coronary artery disease, 75%; hypertension, 82%; and renal insufficiency, 15%. Indication was previous cerebrovascular accident in 10%, TIA in 29%, and asymptomatic >80% stenosis in 61%. Primary lesions were treated in 83% vs restenosis in 17%. The 30-day event rate was 1.4% major stroke, 2.1% minor stoke, 1.4% myocardial infarction, and 0.7% death. The overall combined 30-day stroke, death, and myocardial infarction rate was 5.6%. The 30-day stroke and death rate was 4.0% in the balloon group (n = 99) and 4.6% in the filter group (n = 42, P = .51). EPD-related technical difficulties occurred in 15% of the balloon group and 31% of the filter group (P < .05). Technical difficulties included a 10% incidence of reversible neurologic compromise during balloon deployment compared with 0% in the filter group (P = .002) and 12% incidence of inability to cross the lesion before predilation in the filter group compared with 0% in the balloon group (P = .001).

CONCLUSIONS

During CAS, both balloon occlusion and filter devices provide acceptable results and appear complimentary. Filters can be used preferentially to avoid a 10% incidence of reversible neurologic compromise associated with balloon occlusion, except in critically narrowed or tortuous lesions when balloon occlusion may be preferred because of a 12% need for unprotected predilatation with filters.

Current status of carotid artery stenting

This Clinical Update summarizes the results of larger case series, industry-sponsored registries, and randomized trials of carotid artery stenting (CAS). In >20 case series that studied >24,000 patients undergoing CAS, 51% of patients were symptomatic, most procedures (97%) resulted in successful stent deployment, and 30-day stroke rates varied from 1% to 8%, with a trend toward lower rates as experience and embolic protection device (EPD) use increased. In 12 industry-sponsored registries (none were published in peer-reviewed journals), 30-day stroke rates varied from 2% to 7%, and 30-day combined adverse events, including stroke, death, and myocardial infarction, were 3% to 9%. More than 12 randomized trials comparing CAS and carotid endarterectomy (CEA) have been initiated since 1998. Results have varied over time, depending on the population studied and the technology used. However, the largest and most recent results of the completed SAPPHIRE trial in high-risk patients undergoing CAS with the use of EPDs demonstrated that CAS is at least not inferior to CEA, with a 1-year combined adverse event rate of 12% for CAS and 20% for CEA (P = .05). Other ongoing trials will address not only whether CAS could be superior to CEA in high-risk patients but also, more importantly, whether CAS is beneficial in other subgroups, such as low-risk and asymptomatic patients.