Filter-protected Carotid Artery Stenting Research Articles

Randomized Controlled Trial of Conventional Versus MicroNet-Covered Stent in Carotid Artery Revascularization.

The aim of this study was to compare procedure-related ipsilateral cerebral embolism with a conventional (Acculink, Abbott Vascular) versus a MicroNet-covered (CGuard, InspireMD) stent in carotid artery stenting (CAS). The MicroNet-covered stent may reduce periprocedural cerebral embolism in CAS, but level 1 evidence is lacking. A total of 100 consecutive patients were randomized 1:1 to filter-protected CAS using the Acculink or the CGuard device. The study was powered for its primary endpoint of at least 50% reduction in ipsilateral diffusion-weighted magnetic resonance imaging lesion average volume 48 hours postprocedure (blinded external core laboratory analysis). The baseline characteristics of the study groups were similar. Eighty-two (total volume = 18,212mm3) diffusion-weighted magnetic resonance imaging postprocedural cerebral lesions occurred in 26 Acculink-treated patients and 45 lesions (total volume = 3,930mm3; 78.4% reduction) in 25 CGuard-treated patients. New cerebral lesion average volume was 171 mm3 vs 73mm3 (P=0.017) per affected patient and 222 mm3 vs 84mm3 (P=0.038) per lesion (Acculink vs CGuard). In lesion-affected patients, the average sum of lesion volumes was 701 mm3 vs 157mm3 (P=0.007). The Acculink significantly increased the risk for multiple (≥5) cerebral lesions (relative risk: 7.8; 95% CI:1.3-14.9; P=0.021). At 30days, new permanent (fluid-attenuated inversion recovery) lesion prevalence was 3:1 (P<0.001), with total permanent lesion volume 7,474 mm3 vs 574mm3 (92.3% reduction with the CGuard). There were 6 vs 0 new ipsilateral lesions (P=0.030) and 2 versus 0 strokes. The MicroNet-covered stent significantly reduced periprocedural and abolished postprocedural cerebral embolism in relation to a conventional carotid stent. This is consistent with the MicroNet-covered stent's sustained embolism prevention, translating into cerebral protection not only during but also after CAS. The present findings may influence decision making in carotid revascularization. (The SIBERIA Trial [Acculink™ Versus CGuard™]; NCT03488199).

Routine Stent Flushing with Heparinized Saline during Distal Filter-Protected Carotid Artery Stenting: A Technical Modification to Reduce Delayed Embolization

Delayed embolization after filter-protected carotid artery stenting (CAS) may occur because of the protrusion and release of loose atherosclerotic plaque fragments through the stent cells. We describe a technical modification to the standard filter-protected CAS by introducing an extra step, that of washing away the luminal stent surface debris with heparinized saline while the filter is still in place. Aided by the guiding catheter, flushing heparinized saline under manual pressure against the stent will force all loose fragments distally in the internal carotid artery to be captured by the overlying filter. Stent washout with heparinized saline before filter retrieval during filter-protected CAS may potentially increase debris capture and reduce delayed embolization.

Inflammatory Mediators and Cerebral Embolism in Carotid Stenting: New Markers of Risk

To investigate serological predictors of risk for cerebral embolism after carotid artery stenting (CAS). Twenty consecutive symptomatic and asymptomatic patients (13 men; mean age 74 years) with carotid artery stenosis undergoing standardized filter-protected CAS (Wallstent) were preoperatively evaluated to identify unstable plaque (duplex ultrasound), complicated aortic plaque (transesophageal echocardiography), and inflammatory status [high-sensitivity C-reactive protein (hs-CRP) and serum amyloid-A protein (SAA) serum levels]. Aortic arch type, carotid tortuosity, and complexity of the procedure were considered. Cerebral embolism was evaluated by comparing the number, volume, and side (ipsilateral and non-ipsilateral) of preoperative and postoperative cerebral lesions detected on diffusion-weighted resonance magnetic imaging (DW-MRI) and through light and scanning electron microscopy analysis of cerebral protection filters obtained from CAS. All CAS procedures were completed with no complications. All patients had a negative preoperative DW-MRI, but at least 1 asymptomatic cerebral lesion appeared on DW-MRI after the procedure in 18 (90%) patients. Female gender was associated with a higher number of cerebral lesions (18.2±10.9 vs. 8.3±8.8 for men, p=0.03). Carotid plaque morphology, supra-aortic vessel anatomy, and procedure complexity did not correlate with number or volume of new cerebral lesions. Complicated aortic plaque was associated with a higher volume of non-ipsilateral cerebral lesions than uncomplicated plaque (235.0±259.3 vs. 63.6±63.2 mm(3), respectively; p=0.02). Hs-CRP ≥5 mg/L and SAA ≥10 mg/L were significantly associated with a higher number of new cerebral lesions [16.2±10.7 vs. 4.3±3.4 for hs-CRP <5 mg/L (p=0.02) and 14.8±10.3 vs. 2.8±3.4 for SAA <10 mg/L (p=0.006), respectively]. Hs-CRP ≥5 mg/L and SAA ≥10 mg/L also correlated with greater surface involvement by embolic materials in the protection filters at microscopic analysis [37.0% (5.1%) vs. 26.9% (2.5%) for hs-CRP <5 mg/L, p=0.004; 35.9% (13.5%) vs. 22.2% (6.9%) for SAA <10 mg/L, p=0.02]. In addition to female gender and the presence of complicated aortic plaque, inflammatory status can be a predictor of cerebral embolism in CAS.

Assessing the impact of distal protection filter design characteristics on 30-day outcomes of carotid artery stenting procedures

This study aims to review retrospectively the records of patients treated with carotid artery stenting (CAS) to investigate the potential correlations between clinical variables, distal protection filter (DPF) type and characteristics, and 30-day peri-/postprocedural outcomes. This is a multicenter, single-arm, nonrandomized retrospective study of patients who underwent filter-protected CAS in the Pittsburgh, Pennsylvania, region between July 2000 and May 2011. Analysis of peri-/postprocedural complications included myocardial infarction, transient ischemic attacks (TIA), stroke, death, and a composition of all adverse events (AEs). Filter characteristics for Accunet (Abbott Vascular, Santa Clara, Calif; n= 429 [58.8%]), Angioguard (Cordis Endovascular, Miami Lakes, Fla; n= 114 [15.6%]), FilterWire (Boston Scientific, Natick, Mass; n= 113 [15.5%]), Spider (ev3 Endovascular, Plymouth, Minn; n= 45 [6.2%]), and Emboshield (Abbott Vascular; n= 24 [3.3%]) were previously determined invitro and were used to find correlations with CAS procedural outcomes. Both univariate and multivariate analyses were performed, as well as goodness-of-fit tests to find multivariate correlations with procedural outcomes. In total, 731 CAS procedures using six different DPFs were analyzed. Peri-/postprocedural AEs included 19 TIAs (2.6%), 38 strokes (5.2%), one myocardial infarction (0.1%), 19 deaths (3.6%), and a total of 61 patients with complications (8.3%). Univariate analysis for filter design characteristics showed that the composite of AE was negatively associated withboth vascular resistance (P= .01) and eccentricity (P= .02) and was positively associated with porosity (P= .0007), number of pores (P= .005), and pore density (P= .001). Multivariate analysis and the goodness-of-fit test revealed thatpatients with a history of congestive heart failure, stroke, and TIA (each with odds ratio >1) led to a good-fit model Pvalue of .72 for peri-/postprocedural AEs. Multivariate analysis was inconclusive for all filter design characteristics. The following filter design characteristics are independently significant for minimizing peri-/postprocedural AEs: higher vascular resistance, concentric in shape, greater capture efficiency, lower porosity, lower number of pores, and lower pore density. Lower porosity and smaller wall apposition were also found to be independently significant for minimization of peri-/postprocedural TIAs. This information can be used when considering the desirable design characteristics of future DPFs.).

The PROFI Study (Prevention of Cerebral Embolization by Proximal Balloon Occlusion Compared to Filter Protection During Carotid Artery Stenting): A Prospective Randomized Trial

The objective of this study was to compare the cerebral embolic load of filter-protected versus proximal balloon-protected carotid artery stenting (CAS). Randomized trials comparing filter-protected CAS with carotid endarterectomy revealed a higher periprocedural stroke rate after CAS. Proximal balloon occlusion may be more effective in preventing cerebral embolization during CAS than filters. Patients undergoing CAS with cerebral embolic protection for internal carotid artery stenosis were randomly assigned to proximal balloon occlusion or filter protection. The primary endpoint was the incidence of new cerebral ischemic lesions assessed by diffusion-weighted magnetic resonance imaging. Secondary endpoints were the number and volume of new ischemic lesions and major adverse cardiovascular and cerebral events (MACCE). Sixty-two consecutive patients (mean age: 71.7 years, 76.4% male) were randomized. Compared with filter protection (n = 31), proximal balloon occlusion (n = 31) resulted in a significant reduction in the incidence of new cerebral ischemic lesions (45.2% vs. 87.1%, p = 0.001). The number (median [range]: 2 [0 to 13] vs. 0 [0 to 4], p = 0.0001) and the volume (0.47 [0 to 2.4] cm(3) vs. 0 [0 to 0.84] cm(3), p = 0.0001) of new cerebral ischemic lesions were significantly reduced by proximal balloon occlusion. Lesions in the contralateral hemisphere were found in 29.0% and 6.5% of patients (filter vs. balloon occlusion, respectively, p = 0.047). The 30-day MACCE rate was 3.2% and 0% for filter versus balloon occlusion, respectively (p = NS). In this randomized trial of patients undergoing CAS, proximal balloon occlusion as compared with filter protection significantly reduced the embolic load to the brain.

657 Carotid artery stenting: Cerebral lesions risk and serological markers levels

Microembolization during the carotid artery stenting (CAS) procedure may cause cerebral lesions. Elevated C-Reactive Protein (hsCRP), Vascular endothelial growth factor (VEGF) and serum amyloid A protein (SAA) exert inflammatory activities thus promoting carotid plaque instability. Neuron specific enolase (NSE) is considered a marker of cerebral injury. However their clinical significance on the outcome of revascularization is unknown. This study aims to establish the correlation between embolization and serological markers. Serum hsCRP, SAA and VEGF pre-operatory levels were evaluated in patients with symptomatic carotid stenosis who underwent filter-protected CAS procedure. Patients with hsPCR<5mg/l, SAA<10mg/L and VEGF<500pg/ml were classified in class I or in class II for higher values. Plaques were characterized by grey scale median and classified as homogenous or dishomogenous. Cerebral embolization was evaluated by diffusion weight resonance magnetic imaging (DWI-MR) and through microscopical and ultrastructural analysis of filters, based on percentage of surface involvement (SI) and occluded pore (OP) by embolic material. Results were compared by Fisher's, Student T test and Mann-Whitney U test. Mean hsCRP, SAA and VEGF in 26 patients was respectively 13.43 mg/l, 42.24 mg/l e 509.85 pg/ml. In class I patients, with hsCR P < 5 mg/l, SAA<10mg/L and VEGF<500pg/ml, mean OP was 21.5% versus 35.3% for patients in class II (P < 0.05). In either group, embolic material captured by the filter was identified as atherosclerotic plaque fragments and platelets aggregates. Volume and number of cerebral lesions increased significantly in all patients with hsCRP > 5mg/l and SAA>10mg/l (16.5 vs 2.8 mean number, 3564.6 vs 417.6 mm3 mean volume). All patients presented an increase of 32% of NSE mRNA level expression after the CAS procedure. Finally, patients with indication to CAS had serological values of hsCRP, SAA and NSE three times greater compared to a group of patients submitted to carotid endarterectomy procedure. High hsCRP, SAA and VEGF levels in symptomatic patients are associated with significantly greater embolization during CAS. Cerebral lesions occurred in the group of patients with higher level of inflammation marker and OP. This preliminary data suggest that CAS might not be indicated as a method of revascularization in this specific group of patients.

Routine aspiration method during filter-protected carotid stenting: histological evaluation of captured debris and predictors for debris amount

A routine aspiration method in filter-protected carotid artery stenting (CAS) has been reported recently in which the proximal internal carotid artery (ICA) blood column was aspirated using an aspiration catheter after postdilatation regardless of flow state on digital subtraction angiography. We examined the debris particles captured by this method. The routine aspiration method was used in 71 CAS procedures. In two procedures, captured debris particles were examined histologically. In the remaining 69 procedures, the size and number of debris particles were measured under a stereoscopic microscope, and then relationships between the amount of debris particles and clinical variables were evaluated using multivariate regression analysis. Histologically, the captured debris contained platelet-precipitating, thrombotic, lipid-rich fibrous and calcified material. The number of debris particles ≥1 mm was 19.6 ± 12.1 (mean ± SD) in 60 procedures with normal flow and 25.9 ± 17.2 (mean ± SD) in 9 procedures with slow/stop flow. Multivariate regression analysis demonstrated that extension of a proximal ICA angulation was an independent predictor of the amount of debris particles with a maximum diameter of either ≥1 mm or <1 mm but ≥0.5 mm (p < 0.05). The captured debris appeared to originate from atheromatous plaques. If the routine aspiration method had not been used in the present series, the debris might have migrated into intracerebral arteries. Restriction of the extension of a proximal ICA angulation might reduce the amount of debris associated with CAS, especially when the proximal ICA angulation is pronounced.

Filter-Protected versus Unprotected Carotid Artery Stenting: A Randomised Trial

Background: Our aim was to determine whether filter protection reduces embolisation to the brain during carotid artery stenting (CAS). Methods: Thirty patients with symptomatic carotid artery stenosis ≧70% (North American Symptomatic Carotid Endarterectomy Trial) were randomly assigned to filter-protected or unprotected CAS. Diffusion-weighted magnetic resonance imaging (DWI) of the brain was performed before and at 3 time points after CAS. In a subset of patients, high-intensity transient signals on transcranial Doppler (TCD) were recorded with categorisation of emboli. Data were independently reviewed off-site. Results: There were no significant differences in mean age, proportion of octogenarians or presenting symptoms between the groups. On procedural DWI (1–3 and 24 h after stenting), there were 7/24 (29%) and 4/22 (18%) new lesions in protected and unprotected patients respectively (p = 0.38). At 30 days there were 9/33 (26%) and 4/33 (12%) lesions in protected and unprotected patients, respectively (p = 0.1). On TCD there were significantly more signals in total as well as particulate emboli during filter-protected CAS (426.5 and 251.3) than during unprotected CAS (165.2 and 92) – p = 0.01 and 0.03, respectively. Conclusions: Filter-protected CAS is associated with an increase in new lesions on DWI and significantly higher rates of total and particulate microembolisation on TCD than unprotected CAS. The clinical significance of these findings requires further study.

Cervical Access for Filter-protected Carotid Artery Stenting: A Useful Tool to Reduce Cerebral Embolisation

Background Filter-protected transcervical carotid artery stenting (CAS) has been suggested to reduce the intraoperative cerebral embolisation observed during transfemoral CAS. We therefore evaluated clinical outcome and incidence of ischaemic lesions at diffusion-weighted magnetic resonance imaging (DW-MRI) after transcervical and transfemoral CAS. Methods From March 2007 to May 2009, we performed filter-protected CAS in 135 patients with symptomatic (30%) or asymptomatic (70%) carotid stenosis above 70% and below 95%. In 44 patients with risky femoral access or unfavourable aortic arch anatomy, access to common carotid artery was achieved by a small cervical incision. In another 91 procedures we used a classic percutaneous femoral access. Preoperative and postoperative DW-MRI scans were obtained after 111 procedures (82%) – 35 transcervical and 76 transfemoral. Results The incidence of clinical events (transient ischaemic attack (TIA) and stroke) was 2.3% after transcervical CAS and 19.8% after transfemoral CAS ( P < 0.01), without any deaths. DW-MRI disclosed new ischaemic lesions in five patients (5/35, 14.3%) after transcervical CAS and in 28 patients (28/76, 36.8%) after transfemoral CAS ( P = 0.015). All ischaemic lesions depicted after transcervical procedures were ipsilateral to the treated artery. Conclusions Transcervical filter-protected CAS, compared with classic percutaneous procedures, seems to reduce clinical events and DW-MRI ischaemic damage and may be useful in selected patients.

Cerebral Embolization during Transcervical Carotid Stenting with Flow Reversal: A Diffusion-Weighted Magnetic Resonance Study

Transfemoral filter-protected carotid artery stenting (CAS) has emerged as a valid alternative to carotid surgery. To overcome the drawbacks of femoral access for CAS and reduce embolic load, some have proposed cervical access with internal carotid artery (ICA) flow reversal. In a series of patients at high risk for femoral access who underwent transcervical CAS with ICA flow reversal, we report clinical outcome and intraoperative embolization rates measured by diffusion-weighted magnetic resonance imaging (DW-MRI). A series of 48 patients were selected for transcervical CAS with carotid flow reversal from September 2004 to July 2007. The indications used for this technique were age >or=80 years, severe aortic and epiaortic vessel tortuosity, widespread calcification of aortic arch or epiaortic vessels, severe aortoiliac occlusive disease, large abdominal aortic aneurysm, and aortobifemoral prosthesis. During the procedure, no adjunctive maneuvers such as external carotid artery balloon occlusion were used. Of the 48 patients, 43 underwent preoperative and postoperative cerebral DW-MRI. The death/stroke rate in the 48 patients was 2.1% (one transient ischemic attack, one minor stroke, and no deaths). None of the procedures led to carotid dissections or access-site complications. Of the 43 patients who underwent DW-MRI, 16 new ischemic lesions were disclosed in six patients (13.9%), four (9.3%) of whom remained asymptomatic. All ischemic lesions were ipsilateral to the treated carotid artery. In patients at high risk for the transfemoral approach, transcervical carotid stenting with flow reversal achieves good technical and clinical results and seems able to reduce the incidence of postoperative DW-MRI ischemic lesions previously reported for transfemoral filter-protected CAS.

Late Evaluation of Silent Cerebral Ischemia Detected by Diffusion-Weighted MR Imaging after Filter-Protected Carotid Artery Stenting

Postoperative diffusion-weighted MR imaging (DWI) often discloses new lesions after carotid artery stent placement (CAS), most of them asymptomatic. Our aim was to investigate the fate of these silent ischemic lesions. We prospectively studied 110 patients undergoing protected transfemoral CAS, 98 of whom underwent DWI before and after the intervention. Patients in whom DWI disclosed silent postoperative lesions also had delayed MR imaging. Preoperative, postoperative, and delayed scans were compared. Of the 92 patients without postoperative symptoms, DWI disclosed 33 new silent ischemic lesions in 14 patients (15.2%), 13 of whom (30 lesions) underwent delayed MR imaging after a mean follow-up of 6.2 months. In 8 of these 13 patients (61%), MR imaging disclosed 12 persistent lesions (12/30, 40%). The reversibility rate depended significantly on the location (cortical versus subcortical) and size (0-5 versus 5-10 mm) of the lesions (P < .05 by chi(2) test). Because many silent ischemic lesions seen on postoperative DWI after CAS reverse within months, the extent of permanent CAS-related cerebral damage may be overestimated.

Flow Impairment During Protected Carotid Artery Stenting:Impact of Filter Device Design

To investigate the impact of filter design on blood flow impairment in the internal carotid artery (ICA) among patients undergoing carotid artery stenting (CAS) using filter-type emboli protection devices (EPD). Between July 2003 and March 2007, 115 filter-protected CAS procedures were performed at an academic institution in 107 consecutive patients (78 men; mean age 68 years, range 38-87). The Angioguard, FilterWire EZ, and Spider filters were used in 68 (59%), 32 (28%), and 15 (13%) of cases, respectively. Patient characteristics, procedural and angiographic data, and outcomes were prospectively entered into an electronic database and reviewed retrospectively along with all angiograms. Flow impairment while the filter was in place was observed in 25 (22%) cases. The presumptive reason of flow impairment was filter obstruction in 21 (18%) instances and flow-limiting spasm at the level of the filter in 4 (4%). In all cases, flow was restored after retrieval of the filter. Flow obstruction in the ICA occurred more frequently with Angioguard (22/68; 32.3%) than with FilterWire EZ (2/32; 6.2%) or Spider (1/15; 6.7%; p = 0.004). No flow occurred in 13 (19%) procedures, all of them protected with Angioguard; no patient treated with other devices experienced this event (p = 0.007). Two (8.0%) strokes occurred in procedures associated with flow impairment, while 1 (1.1%) event was observed in the presence of preserved flow throughout the intervention (p = 0.11). Flow impairment in the ICA during filter-based CAS is common and related to the type of filter used.

Cerebral Ischemia after Filter-Protected Carotid Artery Stenting Is Common and Cannot Be Predicted by the Presence of Substantial Amount of Debris Captured by the Filter Devic

Cerebral Ischemia after Filter-Protected Carotid Artery Stenting Is Common and Cannot Be Predicted by the Presence of Substantial Amount of Debris Captured by the Filter Devic

Carotid Stents: Unleashed, Unproven

Primarily on the basis of data derived from the Stenting and Angioplasty With Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial,1 the US Food and Drug Administration (FDA) has approved the use of carotid stents (CASs) in high-risk patients. The SAPPHIRE trial was published and much heralded as a randomized trial demonstrating that CASs were not inferior to carotid endarterectomy (CEA). Yet, the more recent Endarterectomy Versus Angioplasty in Patients with Symptomatic Carotid Stenosis randomized trial of CASs compared with CEA had to be stopped because the stroke rate with stents was so high that it triggered the safety guidelines of the study design.2 How can we explain the striking difference in outcome between these 2 studies, and how did it happen that the FDA was so convinced of the quality and validity of the SAPPHIRE trial that it granted approval for CASs? An examination of the SAPPHIRE trial—its conduct, data collection and analysis, the circumstances of publication, the presentation to the FDA Advisory Panel, and its consequent approval—is the primary focus of this article. This is a case study of the flaws in our system for the evaluation and approval of medical devices that warrant serious reflection on our ability to properly create and act on accurate information and live up to our commitment to evidence-based decision making. Response by Samuelson et al p 1601 As it now stands, existing studies leave us with the unfortunate but not unreasonable conclusion that no scientific basis exists for the use of CASs as approved by the FDA, and in the absence of change, there is every reason to doubt the capability of our current system to protect the public from unnecessary risk in the future. Although this article focuses on just 1 example of how our systems …

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

To investigate whether filter-protected carotid artery stenting (CAS) using a covered self-expanding stent reduces the risk of cerebral embolization. Fourteen asymptomatic patients (13 men; median age 77 years, IQR 73-83) were enrolled in a randomized pilot trial comparing the rates of cerebral microembolism during and after filter-protected CAS using either a self-expanding covered (n=8) or a bare (n=6) carotid stent. Transcranial Doppler (TCD) monitoring was done during and for 90 minutes after the procedure. Diffusion-weighted magnetic resonance imaging (DW-MRI) was performed before and 24 hours after CAS. Patients were followed for 6 months for neurological events and occurrence of restenosis. A significant reduction in ipsilateral microembolic signals by TCD was observed with the covered (median 1, IQR 0-4) versus the bare stent (median 6, IQR 3-8; p=0.043). Comparison of the preprocedural and 24-hour postprocedural DW-MRI images showed no new ipsilateral lesions but 1 new lesion in the contralateral hemisphere in the covered stent group, resulting in an overall 7% (95% CI 0%-20%) rate of new ischemic lesions. No neurological complications occurred up to 6 months. Restenosis (>70%) occurred in 3 (38%) of 8 patients with the covered versus none of the bare stents (p=0.21). The trial was stopped when the third restenosis of a covered stent was detected. Self-expanding covered stents potentially reduce the risk of cerebral microembolism during and after carotid stenting. However, the problem of in-stent restenosis has to be resolved before these devices can be considered for further investigation.

Filter-Protected Carotid Stenting Via a Minimal Cervical Access With Transitory Aspirated Reversed Flow During Initial Passage of the Target Lesion

To evaluate the preliminary results of filter-protected carotid artery stenting (CAS) via a minimal cervical access, with temporary common carotid artery (CCA) occlusion and aspiration in selected high-risk candidates for carotid endarterectomy. Since February 2002, 26 patients (17 men; mean age 73.7 years, range 54-98) at high surgical risk according to the SAPPHIRE eligibility criteria underwent 29 transcervical CAS procedures under filter protection. Under general anesthesia, a 6-F short introducer sheath was directly mounted in the CCA through a small (2-4 cm) laterocervical cutdown. The CCA was briefly clamped, and blood was aspirated while the filter device was positioned above the target lesion. With the filter in place and the clamp released, nitinol stents were deployed under filter protection. Hemostasis was achieved by direct suture. Twenty-eight (96%) interventions were technically successful; 1 complex lesion could not be crossed and was converted to surgery. Mean clamping time was 1.7 (range 1.0-3.5) minutes. Combined 30-day stroke/mortality was 0%. Ultrasound surveillance demonstrated a < 60% asymptomatic in-stent restenosis in 1 (4%) patient with radiation-induced arteritis after 28 months. During a mean follow-up of 11.6 months (range 3-38), 1 (4%) minor ipsilateral stroke was noted at 6 months in a patient whose antiplatelet therapy was transitorily interrupted. Our preliminary observations from this small early experience suggest that this variant CAS technique is feasible and probably diminishes the neuroembolic risk during initial navigation of the ICA target stenosis.

Invited commentary

Using diffusion-weighted magnetic resonance imaging (DWI), Hammer et al have demonstrated an alarming rate (40%) of new microinfarcts after filter-protected carotid artery stenting (CAS). These data support previous studies that have demonstrated new microinfarcts in 20% to 43% of patients after CAS.1Schluter M. Tubler T. Steffens J.C. Mathey D.G. Schofer J. Focal ischemia of the brain after neuroprotected carotid artery stenting.J Am Coll Cardiol. 2003; 42: 1007-1013Abstract Full Text Full Text PDF PubMed Scopus (130) Google Scholar, 2Flach H.Z. Ouhlous M. Hendriks J.M. et al.Cerebral ischemia after carotid intervention.J Endovasc Ther. 2004; 11: 251-257Crossref PubMed Scopus (112) Google Scholar They are to be commended on their overall results: there were only two (4%) minor strokes that resolved completely, no myocardial infarctions, and no deaths. The pattern of these cerebral infarcts suggests that they are not due to failure of the embolic protection device. Ipsilateral DWI infarcts occurred with equal frequency in cases with and without visible debris captured in the filter. More importantly, the DWI lesions frequently involved the contralateral cerebral hemisphere, thus suggesting that many occurred before cannulation of the target carotid artery. The occurrence of these DWI lesions seems, on the basis of Hammer and associates’ analysis, to correlate with difficult arch anatomy, supra-aortic carotid torutuosity, and the performance of contralateral brachiocephalic selective catheterization. Thankfully, most of these lesions seem clinically silent, but this would be better evaluated with formal neuropsychiatric testing. These results argue against routine contraleral diagnostic arteriography as part of a CAS procedure, especially because one of the two strokes did occur in the contralateral occipital lobe. In our center, like many, we are careful to minimize manipulations in the aortic arch and attempt to cannulate only the target carotid artery during CAS. Proper patient selection and technical skill will be critical in decreasing CAS neurologic event rates to those seen with carotid endarterectomy, especially in older patient populations, in which CAS stroke and death rates have exceeded 12%.3Hobson II, R.W. Howard V.J. Roubin G.S. et al.Carotid artery stenting is associated with increased complications in octogenarians 30-day stroke and death rates in the CREST lead-in phase.J Vasc Surg. 2004; 40: 1106-1111Abstract Full Text Full Text PDF PubMed Scopus (503) Google Scholar We use computed tomographic angiography to screen patients for difficult arch anatomy, evaluate aortic arch plaque burden, and evaluate the carotid lesion length and calcification. We have used this information to exclude some patients from further consideration for CAS on the basis of anatomic concerns. This study by Hammer et al supports the concepts that minimal, focused catheter manipulation within the aortic arch and careful patient selection based on evaluation of aortic arch/carotid anatomy will limit the incidence of neurologic events during CAS. CorrectionJournal of Vascular SurgeryVol. 42Issue 6PreviewFor the article “Interval Gangrene Complicating Superficial Femoral Artery Stent Placement” published in J Vasc Surg 2005:42;564-66, one author was inadvertently left off, Dr. Neal Cayne. The correct order of authors should read: Full-Text PDF Open Archive