Proximal endovascular occlusion for carotid artery stenting: results from a prospective registry of 1,300 patients

Proximal balloon-guided catheter with flow inversion vs. distal filter protection during the carotid stent placement, a seven years experience in a Colombian reference center

BACKGROUND AND PURPOSE

The carotid stent placement as a therapeutic option for carotid stenosis has been increasing among years; therefore, studies are required to evaluate the security and efficacy of its materials. The purpose of this study was to evaluate the distal filter and the proximal balloon-guided catheter with flow inversion as protection devices during carotid angioplasty and stenting.

METHODS

This is a retrospective, observational study of patients diagnosed with carotid stenosis treated with angioplasty between January 1, 2014, and June 30, 2020; we analyzed a radiology service database to compare the distal filter and the proximal balloon-guided catheter as protection devices during angioplasty.

RESULTS

One hundred seventy-five angioplasties were performed, the distal filter was the most prevalent embolic protection device used (66%), patients baseline characteristics did not differ between groups with different embolic protection devices, except for history of dyslipidemia (p < 0.000). As well, we did not find any significant differences between the groups in the device related complications, intervention time (p = 0.140), unrelated complications (p = 0.693) and functional independence at 90 days (p = 0.096).

CONCLUSIONS

In our study the proximal balloon-guided catheter and the distal filter protection device as protection devices during the carotid stenting didn't show significant differences regarding complications related to the system.

Procedural embolic protection strategies for carotid artery stenting: current status and future prospects

INTRODUCTION

Carotid artery angioplasty and stenting (CAS) is an established procedure to treat carotid artery stenosis for either primary or secondary prevention of stroke. Randomized clinical trials have shown an increased risk of periprocedural cerebrovascular events with CAS compared with carotid endarterectomy (CEA). Several strategies have been proposed to mitigate this risk, including alternative vascular access site, proximal/distal embolic protection devices, and dual-layer stents, among others.

AREAS COVERED

This review provides a general overview of current embolic protection strategies for CAS. The phases of the procedure which can affect the early risk of stroke and how to reduce it with novel techniques and devices have been discussed.

EXPERT OPINION

Innovations in device technologies have dramatically improved the safety and efficacy of CAS. To minimize the gap with surgery, a thorough, patient-oriented approach should be pursued. Endovascular technologies and techniques should be selected on an individual basis to address unique lesion characteristics and vascular anatomies. Meticulous pre-procedural planning, both clinical and anatomical, is needed to assess the embolic risk of each procedure. Only by having an in-depth understanding of the wide range of available endovascular devices and techniques, the operator will choose the most appropriate strategy to optimize CAS results.

Proximal versus distal protection: dissecting clinical trials

Carotid artery stenting (CAS) is a valid alternative to conventional carotid endarterectomy for treatment of carotid artery stenosis. Distal embolization of atherosclerotic debris causing cerebrovascular accidents during CAS has been the most significant concern limiting widespread application of CAS technology. A variety of embolic protection devices (EPDs) with different mechanism of action, have been designed to minimize the risk of major embolization causing stroke and their use is recommended by current guidelines. Two general types of EPDs are available: proximal protection devices (PPDs) and distal protection devices (DPDs). However, there is no convincing clinical evidence of the clinical superiority of one device over another. This review will examine the different types of available devices and also innovative devices and techniques, including strengths and weaknesses of each, and present the available evidence and rationale for their routine use during CAS.

Transradial/brachial carotid artery stenting with proximal protection: technical instructions, acute results and long-term outcomes

BACKGROUND

The aim of this study was to evaluate the feasibility, safety and efficacy of transradial/brachial (TR/TB) carotid artery stenting (CAS) with proximal cerebral protection (PCP) as a first line of treatment of carotid artery stenosis.

METHODS

Among 556 patients with significant (>50% if symptomatic or >70% if asymptomatic by Doppler US) unilateral, lipid-rich carotid artery stenosis undergoing TR/TB CAS, 137 (24.5%) deemed at high-risk for periprocedural cerebral embolization were scheduled for PCP with Mo.MA Ultra or Mo.MA mono-balloon. In patients with very complex anatomy the standard technique was modified loading the Mo.MA catheter without mandrel on two-wire system (so called 'No MAndrel 2 wire' technique, No.MA2) to increase support and deliverability. Device, technical and procedural successes both acute and at follow-up were the main outcomes.

RESULTS

Mean patients' age was 74±7 years (93% male), 15% were symptomatic and 59.6% owned 'high-surgical-risk' features. Stenosis degree was 85±7% with soft composition in all (by CT-angiography). TR and TB approach were selected in 92 (67%) and 45 (33%) patients, respectively. Target carotid axes were right, left bovine and left non bovine in 55%, 38% and 7% of patients. Procedures were successfully completed in all patients (intention-to-treat basis) with the standard Mo.MA Ultra system in 129 patients and the Mo.MA mono-balloon in 8 patients. No.MA2 technique was succesfully used in 16 patients as 'bailout' and in 27 patients as 'first line'). Device and technical success was 97% (133/137 patients) due to crossover to femoral access in 3 cases, and Mo.MA too short to engage the ECA in 1 patient. The procedural success was 96.7% (131/137, two minor strokes). Procedural time and fluoroscopy time were increased with No.MA2 technique. One major vascular complication occurred, in the TB group, while chronic radial occlusion was detected by Doppler ultrasound in 7/92 patients (7.1%) at 372±163 days of follow-up. The event-free survival was 91% and the stroke rate was 0%.

CONCLUSIONS

TR/TB CAS with proximal protection is a feasible, safe and effective strategy and may be considered a first line strategy in all comer patients.

Absolute and relative contraindications to proximal protection: do they really matter? A case-illustrative approach

Carotid artery stenting (CAS) is an established technique to treat carotid artery stenosis. Favorable results have been reported in different subsets of patients in both acute and long-term settings. Among the CAS periprocedural variables the type of cerebral protection - distal filter and proximal protection - play a pivot role to reduce cerebral embolization. Accumulating evidence is in favor of better performance of proximal protection vs. distal filters. However, the rate of worldwide penetration of this devise is low. Potential reasons include a lengthy list of technical issues that may account for the reluctance of filter-oriented operators to change systems. This paper shows how to identify, treat, and overcome these technical obstacles.

From surgical clamping to endovascular flow arrest/reversal: the concept behind the system

Carotid artery lesions are frequently composed of friable, thrombotic, ulcerated and/or hemorrhagic materials which can embolize during surgical or endovascular interventions. The use of embolic protection devices (EPD) during carotid angioplasty and stenting (CAS) has been proven to be associated with a reduction of the embolic load. Many studies indicate that the clinical results of CAS are comparable with the best surgical series, when EPD are routinely applied. The proximal EPD work by interrupting or reversing the blood flow in the common carotid artery/internal carotid artery (CCA/ICA). Once established the endovascular flow arrest/reversal, these systems have the advantages of promoting a protected crossing of the lesion and blocking both macro-emboli and micro-emboli. Moreover, proximal neuroprotection implies no manipulation of the device in the distal ICA, neither during device deployment nor during device retrieval, and reduces the risk of arterial spasm, dissection, or intimal damage. The choice between transfemoral and transcervical proximal EPD should account for different factors: local availability, operator expertise, and patient characteristics including anatomical features precluding flow arrest/reversal (e.g., incomplete circle of Willis), femoral access (e.g., unfavorable aortic arch anatomy), or transcervical access (e.g., diseased CCA).

The safety and efficacy of the Mo.Ma system device for carotid artery stenting: A single-center experience from Taiwan

Background

Proximal protection devices, such as the Mo.Ma system provides better neurological outcomes than the distal filter system in the carotid artery stenting (CAS) procedure. This study first evaluated the safety and efficacy of the Mo.Ma system during CAS in a single tertiary referral hospital from Taiwan. The outcomes of distal vs. proximal embolic protection devices were also studied.

Methods

A total of 294 patients with carotid artery stenosis who underwent the CAS procedure were retrospectively included and divided into two groups: 152 patients in the distal filter system group and 142 patients in the Mo.Ma system. The outcomes of interest were compared between the two groups. The factors contributing to occlusion intolerance (OI) in the Mo.Ma system were evaluated.

Results

The procedure success rates were more than 98% in both groups. No major stroke occurred in this study. The minor stroke rates were 2.8% (4/142) and 4.6% (7/152) in the Mo.Ma system and filter system, respectively (p = 0.419). Patients with hypoalbuminemia significantly predicted the risk of stroke with an odds ratio of 0.08 [95% confidence interval (CI), 0.01–0.68, p = 0.020] per 1 g/day of serum albumin in the filter group. A total of 12 patients developed OI in the Mo.Ma system (12/142, 8%). Low occlusion pressure predicted the occurrence of OI in the Mo.Ma group with the hazard ratios of 0.88 (95% CI: 0.82–0.96) and 0.90 (95% CI: 0.84–0.98) per 1 mmHg of occlusion systolic pressure (OSP) and diastolic pressure (ODP), respectively. We further indicated that patients with an OSP of ≥60 mmHg or an ODP of ≥44 mmHg could tolerate the procedure of occlusion time up to 400 s, while patients with an OSP of <49 mmHg or an ODP of <34 mmHg should undergo the procedure of occlusion time less than 300 s to prevent the occurrence of OI.

Conclusion

We have demonstrated the safety and effectiveness of the Mo.Ma system during CAS in an Asia population. By reducing the occlusion time, our study indicated a lower risk of OI in the Mo.Ma system and proposed the optimal occlusion time according to occlusion pressure to prevent OI during the CAS procedure. Further large-scale and prospective studies are needed to verify our results.

Clinical Outcomes of Second- versus First-Generation Carotid Stents: A Systematic Review and Meta-Analysis

Background: Single-cohort studies suggest that second-generation stents (SGS; “mesh stents”) may improve carotid artery stenting (CAS) outcomes by limiting peri- and postprocedural cerebral embolism. SGS differ in the stent frame construction, mesh material, and design, as well as in mesh-to-frame position (inside/outside). Objectives: To compare clinical outcomes of SGS in relation to first-generation stents (FGSs; single-layer) in CAS. Methods: We performed a systematic review and meta-analysis of clinical studies with FGSs and SGS (PRISMA methodology, 3302 records). Endpoints were 30-day death, stroke, myocardial infarction (DSM), and 12-month ipsilateral stroke (IS) and restenosis (ISR). A random-effect model was applied. Results: Data of 68,422 patients from 112 eligible studies (68.2% men, 44.9% symptomatic) were meta-analyzed. Thirty-day DSM was 1.30% vs. 4.11% (p < 0.01, data for SGS vs. FGS). Among SGS, both Casper/Roadsaver and CGuard reduced 30-day DSM (by 2.78 and 3.03 absolute percent, p = 0.02 and p < 0.001), whereas the Gore stent was neutral. SGSs significantly improved outcomes compared with closed-cell FGS (30-day stroke 0.6% vs. 2.32%, p = 0.014; DSM 1.3% vs. 3.15%, p < 0.01). At 12 months, in relation to FGS, Casper/Roadsaver reduced IS (−3.25%, p < 0.05) but increased ISR (+3.19%, p = 0.04), CGuard showed a reduction in both IS and ISR (−3.13%, −3.63%; p = 0.01, p < 0.01), whereas the Gore stent was neutral. Conclusions: Pooled SGS use was associated with improved short- and long-term clinical results of CAS. Individual SGS types, however, differed significantly in their outcomes, indicating a lack of a “mesh stent” class effect. Findings from this meta-analysis may provide clinically relevant information in anticipation of large-scale randomized trials.

Carotid Angioplasty and Stenting for Occlusive Diseases

Stenting for carotid artery stenosis (CAS) was once denied 15 years ago because it failed to prove the non-inferiority to carotid endarterectomy (CEA). However, it is now reevaluated and is thought better due to higher safety and efficacy thanks to the development of devices, strategies, and various protection methods. To achieve the safe CAS, protection methods and stents should be properly selected based on the vessel course and plaque components on the preoperative plaque images. Particularly multiple protection methods including proximal balloon protection and double-layer micromesh stents are useful for the cases with high-risk and fragile plaque. Perioperative anti-platelet management and the control of blood pressure are also important to avoid the ischemic complications and hyperperfusion. Properly protected and tailored CAS based on the risk management has dramatically improved the clinical results and contributed to extend the indication for more difficult lesions.

Carotid artery revascularization using the Walrus balloon guide catheter: safety and feasibility from a US multicenter experience

INTRODUCTION

The Walrus balloon guide catheter (BGC) is a new generation of BGC, designed to eliminate conventional limitations during mechanical thrombectomy.

OBJECTIVE

To report a multi-institutional experience using this BGC for proximal flow control (PFC) in the setting of carotid artery angioplasty/stenting (CAS) in elective (eCAS) and tandem strokes (tCAS).

METHODS

Prospectively maintained databases at 8 North American centers were queried to identify patients with cervical carotid disease undergoing eCAS/tCAS with a Walrus BGC.

RESULTS

110 patients (median age 68, 64.6% male), 80 (72.7%) undergoing eCAS and 30 (27.3%) tCAS procedures, were included (median cervical carotid stenosis 90%; 46 (41.8%) with contralateral stenosis). Using a proximal flow-arrest technique in 95 (87.2%) and flow-reversal in 14 (12.8%) procedures, the Walrus was navigated into the common carotid artery successfully in all cases despite challenging arch anatomy (31, 28.2%), with preferred femoral access (103, 93.6%) and in monitored anesthesia care (90, 81.8%). Angioplasty and distal embolic protection devices (EPDs) were used in 91 (83.7%) and 58 (52.7%) procedures, respectively. tCAS led to a modified Thrombolysis in Cerebral Infarction 2b/3 in all cases. Periprocedural ischemic stroke (up to 30 days postoperatively) rate was 0.9% (n=1) and remote complications occurred in 2 (1.8%) cases. Last follow-up modified Rankin Scale score of 0-2 was seen in 95.3% of eCAS cohort, with no differences in complications in the eCAS subgroup between PFC only versus PFC and distal EPD (median follow-up 4.1 months).

CONCLUSION

Walrus BGC for proximal flow control is safe and effective during eCAS and tCAS. Procedural success was achieved in all cases, with favorable safety and functional outcomes on short-term follow-up.

Mid-term and late results of endovascular treatment for symptomatic carotid artery stenosis under proximal protection

Introduction

Although filters are still preferred during carotid stenting, proximal protection systems (PPS) are increasingly used during these procedures. PPS seem to be safer than distal systems, especially in symptomatic patients, but evidence supporting their use is limited.

Aim

This was a post hoc survey with 30-day mid-term and long-term follow up, which was aimed at assessment of the safety and efficacy of stenting of the internal carotid artery under PPS in symptomatic patients.

Material and methods

We analysed the results of stenting in 120 symptomatic patients presenting with at least 60% stenosis. Patients were aged 67.9 ±9.8 years, and 12 patients were older than 80 years. An occlusion of contralateral artery was found in 5 patients and bilateral stenosis in 26 patients. The primary endpoint of this study was the proportion of patients who had new neurological events, including transient ischemic attack and minor or major stroke in 30-day follow-up. The secondary endpoint was a composite of technical and clinical success. During long-term follow-up we assessed new neurological events and stenoses of implanted stents.

Results

The incidence of new neurological events during 30-day follow-up was 0.8%. The rate of technical success defined by secondary endpoint was 100%. Mean internal carotid artery stenosis before and after stent implantation was 93.8 ±9% and 8.4 ±6.3%, respectively (p < 0.001). Procedural success was achieved in all cases. During long-term follow-up there were two (1.7%) asymptomatic in-stent stenoses and no (0%) new neurological events.

Conclusions

Endovascular management of symptomatic carotid stenosis under PPS is safe, feasible, and appears to be a good alternative to surgical endarterectomy.

Safety and Efficacy of Flow Reversal in Acute and Elective Carotid Angioplasty and Stenting Using the Mo.Ma Device with Short-Term Follow-Up

Objective

To determine the safety and efficacy of flow reversal following proximal flow arrest as an embolic protection strategy for carotid angioplasty and stenting (CAS) with short-term follow-up.

Method

We performed a retrospective review of our CAS database for patients who underwent stent-supported carotid revascularization in the setting of acute/subacute stroke or TIA. We reviewed clinical and radiographic data during a 36-month period. Primary outcome was clinical evidence of ipsilateral stroke in the first 30 days. Secondary outcomes include clinical outcomes and sonographic and/or angiographic follow-up over 6 months, 6-month functional scale, and all-cause mortality.

Results

Fifty-five patients underwent CAS using flow reversal: 26 females and 29 males with a mean age of 69.7 years. Median time to treatment from index event was 3 days. 11% underwent stenting as part of hyperacute stroke therapy. Average luminal stenosis was 86%. The 9-Fr Mo.Ma device was used in combination with Penumbra aspiration in all cases. There were no ipsilateral strokes. Incidence of any ischemic event was 3.64%, but only 1 (1.82%) patient had a postoperative stroke. Clinical follow-up was available for 94.5%, while lesion follow-up was available for 73% of patients. Three patients had evidence of restenosis, but none were symptomatic. Luminal restenosis was ≤30% in all three. Median pre- and post-NIHSS were 1 and 1, respectively.

Conclusion

Flow reversal using the Mo.Ma device is a safe and effective strategy in preventing distal embolization during carotid artery revascularization.

Postoperative ischemic events in patients undergoing carotid artery stenting using algorithmic selection for embolic protection

PURPOSE

Carotid artery stenting (CAS) is a valuable alternative to carotid endarterectomy, especially in high-risk patients. However, the reported incidences of perioperative stroke and death remain higher than for carotid endarterectomy, even when using embolic protection devices (EPDs) during CAS. Our purpose was to evaluate 30-day major adverse events after CAS when selecting the most appropriate EPD.

METHODS

We reviewed the clinical outcomes of 61 patients with 64 lesions who underwent CAS with EPDs. Patients who underwent CAS associated with thrombectomy and who had a preoperative modified Rankin scale score >3 were excluded from the analysis. The EPD was selected based on symptoms, carotid wall magnetic resonance imaging and lesion length, and we analyzed combined 30-day complication rates (transient ischemic attack, minor stroke, major stroke or death).

RESULTS

Forty-nine patients were men and 12 were women. The median age was 72 years (range: 59-89 years) and 44 lesions were asymptomatic. A filter-type EPD was selected in 23 procedures, distal-balloon protection in 14 procedures and proximal-occlusive protection in 27 procedures. Two patients (3.1%) experienced a transient ischemic attack and one patient (1.6%) had a minor stroke within 30 days of the procedure. No patients experienced procedure-related morbidities (modified Rankin score >2) or death.

CONCLUSIONS

The perioperative stoke rate was low when we selected a proximal-occlusive-type EPD in high-risk patients with vulnerable carotid artery disease. Our algorithm for EPD selection was an effective tool in the perioperative management of carotid artery stenosis.

Incidence and predictors of acute kidney injury in patients undergoing proximal protected carotid artery stenting

AIMS

Many studies have analysed the occurrence of acute kidney injury (AKI) after percutaneous coronary intervention (PCI) but there are limited data relating to AKI risk in patients undergoing carotid artery stenting (CAS). The aim of this study was to determine the incidence and predictors of AKI in patients undergoing proximal protected CAS.

METHODS AND RESULTS

We analysed 456 patients undergoing proximal protected CAS. A binomial multivariate logistic model was developed including patients' clinical and angiographic/procedural characteristics. AKI (defined as an sCr increase ≥0.3 mg/dl or ≥1.5-fold sCr increase from baseline or more than 50% increase from baseline, within 48 hours post procedure) occurred in 155 patients (34%). AKI patients were more frequently affected by hypertension, diabetes, dyslipidaemia and anaemia, and presented lower renal function at baseline. Higher contrast volume to creatinine clearance ratio (2.40±1.44 vs. 2.08±1.15; p=0.01), lower post-procedural mean arterial pressure (MAP) (94.3±17.7 vs. 99.6±18.5 mmHg; p=0.003) and a more frequent post-procedural systolic pressure drop (∆SBP >50 mmHg) (23.9% vs. 14.3%, p=0.01) were observed in the AKI group of patients. At multivariate analysis, independent predictors of AKI were ∆SBP >50 mmHg, diabetes mellitus and dyslipidaemia.

CONCLUSIONS

AKI can occur quite frequently after proximal protected CAS and is related to clinical and procedural features. These data should be confirmed in larger registries or randomised trials.

Continuous Blood Glucose Monitoring May Detect Carotid Occlusion Intolerance during Carotid Artery Stenting

BACKGROUND

The frequency of the occurrence of adverse events associated with carotid artery stenting (CAS) is usually low, but serious adverse events such as cerebral hyperperfusion syndrome (CHS) may occur. Real-time monitoring is ideal for the early detection of adverse events during the surgical procedure. This study aimed to evaluate continuous blood glucose (BG) monitoring for the detection of adverse events during CAS.

METHODS

Forty patients undergoing scheduled CAS were prospectively enrolled. An artificial pancreas was used for continuous BG monitoring (once per minute), using venous blood extracted at a rate of 2 mL/hr during CAS. The primary endpoint was a correlation between BG change and adverse events.

RESULTS

CAS was discontinued in 1 patient, and BG was not measured in 5 patients (12.5%) because of the inability to extract blood. Among 34 evaluable patients, no patient developed CHS, but 3 patients (9%) experienced carotid occlusion intolerance. During CAS, BG was significantly higher in patients with carotid occlusion intolerance (median: 5 mg/dL) than in patients without carotid occlusion intolerance (median: 0 mg/dL) (P = 0.0221). A cutoff BG value ≥4 mg/dL during CAS showed 50% sensitivity and 100% specificity for the detection of carotid occlusion intolerance. There was no significant correlation between BG change and other adverse events.

CONCLUSIONS

BG elevation may help detect carotid occlusion intolerance although it is still unknown whether BG monitoring can detect CHS. Further studies should validate that a cutoff BG elevation value of ≥4 mg/dL during CAS indicates carotid occlusion intolerance.

Low Common Carotid Artery Systolic Occlusion Pressure and Symptomatic Carotid Artery Stenosis Are Associated with Development of Neurologic Intolerance during Proximal Protected Carotid Artery Stenting

Background and Objectives

Neurologic intolerance (NI) is defined as the occurrence of neurological symptoms during carotid artery stenting (CAS). Because NI is inevitable problem, it may be helpful to anticipate its occurrence. So, we studied factors associated with NI during proximal protected CAS.

Methods

We retrospectively analyzed all consecutive patients underwent proximal protected CAS from August 2012 to January 2017.

Results

We included total 123 patients (109 males, 72±8 years old). The total procedure time was 43±12 minutes, and mean occlusion time was 4.8±1.2 minutes. We divided CAS patients into 2 groups according to presence of NI; neurologic tolerance (NT; n=74, 60%) and NI (n=49, 40%) groups. After the univariate analysis, symptomatic carotid artery stenosis (p=0.003), absence of anterior communicating artery (p=0.015) and low common carotid artery occlusion pressure (CCAOP, p<0.001) were associated with NI. After the multivariate analysis, NI was significantly associated with symptomatic carotid artery stenosis (odds ratio [OR], 5.549; p=0.014) and systolic CCAOP≤42 mmHg (OR, 6.461; p<0.001). In NI group, 43 patients (88%) recovered right after the balloon deflation and 2 patients were normalized within 2 hours. However, 1 had major stroke and 3 had minor strokes in 4 patients with persistent NI ≥24 hours.

Conclusions

About 40% showed NI during the CAS. Most of them (88%, 43 of 49 patients) recovered after the balloon deflation, but stroke incidence was significantly higher in NI group. Symptomatic carotid artery stenosis and systolic CCAOP ≤42 mmHg were significantly associated with the development of NI during proximal protected CAS.

Early results of endovascular treatment of patients with bilateral stenoses of the internal carotid arteries using proximal protection systems at 30-day follow-up

BACKGROUND

Although surgical endarterectomy remains the treatment of choice for carotid artery stenosis, carotid artery stenting (CAS) with use of proximal protection systems (PPS) plays an very important role as alternative treatment modality, especially in patients with critical, symptomatic lesions. This study was single-centre study to evaluate the technical and clinical success of proximal protection devices as the first choice for embolic protection in symptomatic and asymptomatic carotid stenosis in patients with bilateral, advanced lesions of carotid arteries (bilateral stenoses or stenosis and occlusion).

METHODS

This was a post hoc analysis, with 30-day follow up. We analyzed results of treatment of 38 patients who underwent 38 CAS with PPS, 17 such procedures in asymptomatic (group A), and 21 in symptomatic individuals (group B). The GORE^® Flow Reversal System (W.L. Gore, Flagstaff, AZ, USA) was used in 2 patients, and the Mo.Ma Ultra device (Medtronic, Minneapolis, MN, USA) in 36 patients. Mean age was 68±7 years, 65% percent of patient were male.

RESULTS

There were no procedural and during 30-day follow-up neurologic events. Intolerance of occlusion system occurred in 4 patients (11%) in both groups with any later symptoms. Risk factors of this adverse event comprised: lesions of the left internal carotid lesion and coexisiting diabetes mellitus.

CONCLUSIONS

CAS in high risk patients with bilateral lesions of carotid arteries with the use of PPS seems to be a relatively very safe procedure.

Carotid Stenting in Patients With High Risk Versus Standard Risk for Open Carotid Endarterectomy (REAL-1 Trial)

Carotid stenting (CAS) has been mainly offered to those patients considered at "high risk" for open carotid endarterectomy based on available data from large randomized clinical trials. However, several recent studies have called medical "high risk" into question for CAS indication. The REAL-1 trial evaluated the safety and perioperative and long-term effectiveness in patients with significant carotid artery stenosis with "high-risk" criteria treated with CAS and proximal protection device (MOMA) compared with those with standard surgical-risk features. This nonrandomized double-arm registry included 125 patients (40% symptomatic), 71 (56%) with "standard-risk" and 54 (44%) with "high-risk" criteria. The primary end point was the cumulative incidence of any major adverse event, a composite of stroke, myocardial infarction, and death within 30 days after the intervention or ipsilateral stroke after 30 days and up to 4 years. There was no significant difference in primary end point rate at 30 days between patients at "standard risk" and those with "high risk" (1.4% vs 1.9% respectively; hazard ratio for "standard risk" 1.1; 95% CI 0.8 to 1.2, p = 0.77) nor estimated 4-year rate of ipsilateral stroke (1.3% vs 1.8%; hazard ratio for "standard risk" 1.05, 95% CI 0.86 to 1.14, p = 0.9). In conclusion, 4-year postprocedure results demonstrated that CAS with proximal device (MOMA) is safe and effective for patients with and without "high-risk" for carotid endarterectomy.

Transcervical access, reversal of flow and mesh-covered stents: New options in the armamentarium of carotid artery stenting

In the last 25 years, the very existence of carotid artery stenting (CAS) has been threatened on a number of occasions. The initial disappointing results that even lead to the discontinuation of an early randomized controlled trial have improved considerably with time. Novel devices, advanced stent and equipment technology, alternative types of access and several types of filters/emboli protecting devices have been reported to reduce stroke/death rates during/after CAS and improve CAS outcomes. The present review will provide a description of the various technology advances in the field that aim to reduce stroke and death rates associated with CAS. Transcervical access, reversal of flow and mesh-covered stents are currently the most promising tools in the armamentarium of CAS.

Proximal Embolic Protection Devices in Complicated Carotid Artery Stenting

The most frequent complication during carotid artery stenting (CAS) is intraoperative distal embolization. Three categories of embolic protection devices (EPDs) are routinely used through a transfemoral or transcervical approach: distal occlusion devices, distal EPDs with flow preservation using filters, and the proximal occlusive protective systems. We report the case of the internal carotid artery (ICA) plaque rupture during CAS using a proximal EPD (the Mo.Ma system; INVATEC), treated with immediate surgery. The proximal occlusive protective system permitted the common carotid artery and ICA endoclamping for the time necessary to prepare the patient for the carotid endarterectomy. The EPDs should always be chosen considering the patient's and lesion's characteristics. This knowledge allows their use even as "bridge" endovascular devices.

Proximal balloon occlusion versus distal filter protection in carotid artery stenting: A meta-analysis and review of the literature

INTRODUCTION

Carotid artery stenting (CAS) is typically performed using embolic protection devices (EPDs) as a means to reduce the risk of procedure-related stroke. In this study, we compared procedural morbidity and mortality associated with distal (D-EPD) vs. proximal (P-EPD) protection.

METHODS

MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were queried from January 1998 through May 2015. Only studies comparing (D-EPD) and (P-EPD) were included. Two independent reviewers selected and appraised studies and extracted data in duplicate. Random-effects meta-analysis was used to pool outcomes across studies. Heterogeneity of treatment effect among studies was assessed using the I² statistics. Publication bias was assessed using inspection of funnel plots. The primary endpoints included 30-day mortality and stroke. Secondary endpoints included new cerebral lesions on diffusion-weighted magnetic resonance imaging (DW-MRI) and contralateral lesions on DW-MRI.

RESULTS

A total of 12,281 patients were included from 18 studies (13 prospective and 5 retrospective) comparing (D-EPD) and (P-EPD) in the setting of CAS. The mean patient age was 69 years and 64% of patients were male. No evidence of publication bias was detected. There was no significant difference between the two modalities in terms of the risk of stroke (risk difference [RD] 0.0, 95% confidence interval [CI] -0.01 to 0.01) or mortality (RD 0.0, 95% CI -0.01 to 0.01) nor was there any difference in the incidence of new cerebral lesions on DW-MRI or contralateral DW-MRI lesions.

CONCLUSIONS

In patients undergoing CAS, both D-EPD and P-EPD provide similar levels of protection from peri-procedural stroke and 30 days mortality. © 2016 Wiley Periodicals, Inc.

Selective-versus-Standard Poststent Dilation for Carotid Artery Disease: A Systematic Review and Meta-Analysis

BACKROUND

The safety and efficacy of standard poststent angioplasty in patients undergoing carotid artery stent placement have not been well-established.

PURPOSE

We conducted a systematic review of the literature to evaluate the safety and efficacy of carotid artery stent placement and analyzed outcomes of standard-versus-selective poststent angioplasty.

DATA SOURCES

A systematic search of MEDLINE, EMBASE, Scopus, and the Web of Science was performed for studies published between January 2000 and January 2015.

STUDY SELECTION

We included studies with >30 patients describing standard or selective poststent angioplasty during carotid artery stent placement.

DATA ANALYSIS

A random-effects meta-analysis was used to pool the following outcomes: periprocedural stroke/TIA, procedure-related neurologic/cardiovascular morbidity/mortality, bradycardia/hypotension, long-term stroke at last follow-up, long-term primary patency, and technical success.

DATA SYNTHESIS

We included 87 studies with 19,684 patients with 20,378 carotid artery stenoses. There was no difference in clinical (P = .49) or angiographic outcomes (P = .93) in carotid artery stent placement treatment with selective or standard poststent balloon angioplasty. Both selective and standard poststent angioplasty groups had a very high technical success of >98% and a low procedure-related mortality of 0.9%. There were no significant differences between both groups in the incidence of restenosis (P = .93) or procedure-related complications (P = .37).

LIMITATIONS

No comparison to a patient group without poststent dilation could be performed.

CONCLUSIONS

Our meta-analysis demonstrated no significant difference in angiographic and clinical outcomes among series that performed standard poststent angioplasty and those that performed poststent angioplasty in only select patients.

Carotid Artery Stenting With Proximal Embolic Protection via a Transradial or Transbrachial Approach: Pushing the Boundaries of the Technique While Maintaining Safety and Efficacy

PURPOSE

To compare the feasibility and safety of proximal cerebral protection to a distal filter during carotid artery stenting (CAS) via a transbrachial (TB) or transradial (TR) approach.

METHODS

Among 856 patients who underwent CAS between January 2007 and July 2015, 214 (25%) patients (mean age 72±8 years; 154 men) had the procedure via a TR (n=154) or TB (n=60) approach with either Mo.MA proximal protection (n=61) or distal filter protection (n=153). The Mo.MA group (mean age 73±7 years; 54 men) had significantly more men and more severe stenosis than the filter group (mean age 71±8 years; 100 men). Stent type and CAS technique were left to operator discretion. Heparin and a dedicated closure device or bivalirudin and manual compression were used in TR and TB accesses, respectively. Technical and procedure success, crossover to femoral artery, 30-day major adverse cardiovascular/cerebrovascular events (MACCE; death, all strokes, and myocardial infarction), vascular complications, and radiation exposure were compared between groups.

RESULTS

Crossover to a femoral approach was required in 1/61 (1.6%) Mo.MA patient vs 11/153 (7.1%) filter patients mainly due to technical difficulty in engaging the target vessel. Five Mo.MA patients developed acute intolerance to proximal occlusion; 4 were successfully shifted to filter protection. A TR patient was shifted to filter because the Mo.MA system was too short. CAS was technically successful in the remaining 55 (90%) Mo.MA patients and 142 (93%) filter patients. The MACCE rate was 0% in the Mo.MA patients and 2.8% in the filter group (p=0.18). Radiation exposure was similar between groups. Major vascular complications occurred in 1/61 (1.6%) and in 3/153 (1.96%) patients in the Mo.MA and filter groups (p=0.18), respectively, and were confined to the TB approach in the early part of the learning curve. Chronic radial artery occlusion was detected by Doppler ultrasound in 2/30 (6.6%) Mo.MA patients and in 4/124 (3.2%) filter patients by clinical assessment (p=0.25) at 8.1±7.5-month follow-up.

CONCLUSION

CAS with proximal protection via a TR or TB approach is a feasible, safe, and effective technique with a low rate of vascular complications.

Proximal occlusion versus distal filter for cerebral protection during carotid stenting: updated meta-analysis of randomised and observational MRI studies

AIMS

Proximal occlusion (PO) and distal filter (DF) serve for cerebral embolic protection during carotid artery stenting (CAS). New cerebral lesions at diffusion-weighted magnetic resonance imaging (DW-MRI) represent a surrogate endpoint for embolisation, though their clinical impact is controversial. We performed a meta-analysis of randomised and observational DW-MRI studies comparing PO and DF during CAS.

METHODS AND RESULTS

We searched electronic scientific databases. The primary endpoint was the incidence of new cerebral lesions at DW-MRI; secondary endpoints were the incidence of new ipsilateral and new contralateral cerebral lesions at DW-MRI and death/cerebrovascular events (CVE). A total of 392 patients (seven studies) received CAS. At DW-MRI after 48 hours 178 patients (48.3%) presented new cerebral lesions. The use of PO versus DF reduced neither the risk of new cerebral lesions (OR [95% confidence interval] 0.65 [0.28-1.52], p=0.32) nor the risk of death/CVE (0.59 [0.22-1.60], p=0.30). Diabetes, baseline stenosis and symptoms significantly modified the risk estimates for new cerebral lesions.

CONCLUSIONS

In this meta-analysis, one half of patients receiving protected CAS developed new embolic cerebral lesions at DW-MRI, although the overwhelming majority were asymptomatic. Cerebral protection with PO versus DF neither reduced cerebral embolisation nor impacted on clinical outcomes.

Evaluation of cerebrovascular reserve in patients undergoing carotid artery stenting and its usefulness in predicting significant hemodynamic changes during temporary carotid occlusion

We investigated the usefulness of cerebrovascular reserve (CVR) testing to predict severe hemodynamic changes during proximally protected carotid artery stenting. Of 90 patients referred, 63 eligible underwent complete evaluation of the extent of carotid artery disease and transcranial Doppler ultrasound (TCD) assessment of CVR by means of a breath-holding test and ophthalmic artery flow pattern evaluation. Periprocedural TCD monitoring of the ipsilateral middle cerebral artery flow was performed in 24 patients undergoing proximally protected procedure (requiring induction of flow arrest within internal carotid artery). Abnormal CVR was significantly less common in patients with unilateral compared to bilateral carotid artery disease (26.3 % vs. 76.9 %, p=0.02), while ophthalmic artery flow reversal was rare in patients with unilateral carotid artery disease (2.5 % vs. 42.9 %, p<0.01). During the induction of carotid flow arrest, the average mean flow velocity drop following external carotid artery occlusion was low (3.5 %, p=0.67) compared to the induction of complete flow arrest (32.8 %, p<0.01). Six patients had a total mean flow velocity drop >50 %, including 2 patients with normal pre-procedural CVR. Our results suggest that TCD evaluation of CVR is not a reliable predictor of hemodynamic changes induced during proximally protected carotid artery stenting in patients with unilateral carotid artery disease.

Clinical Analysis Comparing Efficacy between a Distal Filter Protection Device and Proximal Balloon Occlusion Device during Carotid Artery Stenting

OBJECTIVE

The main concern during transfemoral carotid artery stenting (CAS) is preventing cerebral embolus dislodgement. We compared clinical outcomes and intraprocedural embolization rates of CAS using a distal filter protection device or proximal balloon occlusion device.

METHODS

From January 2011 to March 2015, a series of 58 patients with symptomatic or asymptomatic internal carotid artery stenosis ≥70% were treated with CAS with embolic protection device in single center. All patients underwent post-CAS diffusion-weighted magnetic resonance imaging (DW-MRI) to detect new ischemic lesions. We compared clinical outcomes and postprocedural embolization rates.

RESULTS

CAS was performed in all 61 patients. Distal filter protection success rate was 96.6% (28/29), whose mean age was 70.9 years, and mean stenosis was 81%. Their preprocedural infarction rate was 39% (11/28). Subsequent DW-MRI revealed 96 new ischemic lesions in 71% (20/28) patients. In contrast, the proximal balloon occlusion device success rate was 93.8% (30/32), whose mean age was 68.8 years and mean stenosis was 86%. Preprocedure infarction rate was 47% (14/30). DW-MRI revealed 45 new ischemic lesions in 57% (17/30) patients. Compared with distal filter protection device, proximal balloon occlusion device resulted in fewer ischemic lesions per patient (p=0.028). In each group, type of stent during CAS had no significant effect on number of periprocedural embolisms. Only 2 neurologic events occurred in the successfully treated patients (one from each group).

CONCLUSION

Transfemoral CAS with proximal balloon occlusion device achieves good results. Compared with distal filter protection, proximal balloon occlusion might be more effective in reducing cerebral embolism during CAS.

Predicting Hemodynamic Changes of Cerebral Blood Flow during Temporal Carotid Occlusion: A Review of Current Knowledge with Implication for Carotid Artery Stenting

Carotid artery disease (CAD) plays an important role in the stroke development and its prevalence increases with aging of the population. Its wide variability of clinical manifestation ranges from incidental asymptomatic finding to devastating or fatal stroke, although cerebral collateral circulation is considered one of the major modifying factors. Over time, carotid artery stenting (CAS) has evolved into a reputable method for the treatment of patients with severe CAD. With expanding use of proximal protection systems resembling surgical clamp, there is an increasing demand to understand collateral cerebral circulation to protect patients from periprocedural hypoperfusion, which increases the risk of cerebral events. Transcranial Doppler ultrasound (TCD) is a useful tool allowing monitoring in real time during procedure patient́s cerebral hemodynamic status providing the operator with valuable information. Its role in predicting periprocedural hypoperfusion is, however, less well established. In this article, we discuss the role of cerebral collateral circulation, summarize the current knowledge regarding its evaluation with TCD and suggest future implications for CAS.

Follow-up after undersized dilatation of targeted lesions in carotid artery stenting

BACKGROUND AND PURPOSE

We assessed whether intentional undersized dilatation of targeted lesions during carotid artery stenting (CAS) carried a higher risk of in-stent restenosis (ISR) and correlation to subsequent ischemic stroke in qualifying arteries in the follow-up period.

METHODS

Consecutive patients undergoing CAS between April 2003 and May 2010 were retrospectively reviewed. The use of a filter device as a distal embolic protection device (EPD) was first approved by Japanese governmental health insurance in April 2008; previously, transient balloon occlusion was used off-label. Until March 2008 (Group A), the target diameter of balloon dilatation was 80-100% of the normal vessel diameter just distal to the stenotic lesion. Moderately undersized dilatation (70-80% of the normal vessel diameter) using the distal EPD was adopted in April 2008 (Group B) in an attempt to reduce the amount of released plaque debris.

RESULTS

We analyzed 132 CAS procedures (125 patients) in Group A and 53 CAS procedures (52 patients) in Group B. The mean follow-up period was 35.4 months (35.3 months in Group A and 36.0 months in Group B). Eight lesions (4.3%; 7 in Group A and 1 in Group B) developed ISR. None of the patients had symptomatic ISR, and ISR did not increase in Group B (odds ratio, 0.34; 95% confidence interval, 0.04-2.86; p = 0.32).

CONCLUSIONS

Undersized dilatation of targeted lesions did not increase the risk of developing ISR, and we suggest it as a viable treatment option to prevent ischemic events during CAS.

Fifteen-year experience with carotid artery stenting (from the carotid artery stenting-registry of the Arbeitsgemeinschaft Leitende Kardiologische Krankenhausärzte)

To date only sparse data are available on trends and changes in indications, patient's characteristics, and clinical outcome of patients undergoing carotid artery stenting (CAS) in clinical practice. From February 1996 to December 2010, 6,116 CAS procedures were performed in 5,976 patients at 36 hospitals within the prospective, multicenter CAS registry of the Arbeitsgemeinschaft Leitende Kardiologische Krankenhausärzte. Median age of patients was 71 years, 71.6% were men; a symptomatic stenosis was treated in 50.3% and an embolic protection device (EPD) was used in 82.5% of the patients. The overall hospital mortality or stroke rate was 3.1%. Stroke or in-hospital death occurred in 4.0% in symptomatic patients and in 2.2% in asymptomatic patients. In a logistic regression model, independent predictors of in-hospital death or stroke were heart failure (odds ratio [OR] 2.03, 95% confidence interval [CI] 1.22 to 3.36, p = 0.006), symptomatic stenosis (OR 1.52, 95% CI 1.05 to 2.18, p = 0.03), and age (OR per 10 years 1.46, 95% CI 1.17 to 1.81, p <0.001). The use of an EPD was significantly associated with a lower rate of death or stroke in the registry (OR 0.45, 95% CI 0.26 to 0.78, p = 0.004). From 1996 to 2010, mean age of patients increased by 4.1 years (p <0.001), the proportion of male patients decreased from 82.4% to 70.2% (p = 0.07), the proportion of symptomatic stenoses decreased (84.6% to 24.7%, p <0.001), and the use of EPDs increased from 1.4% to 97.2% (p <0.001). Comparing 2 periods from 1996 to 2003 and 2004 to 2010, a numeric decrease in the in-hospital stroke or death rate was seen in symptomatic (4.7% vs 3.5%, p = 0.11), and in asymptomatic patients (2.9% vs 2.1%, p = 0.27) undergoing CAS, which did not reach statistical significance. In conclusion, the proportion of symptomatic carotid artery stenoses decreased significantly; EPDs established as a standard tool and a numeric decrease of in-hospital stroke or death was seen in asymptomatic and symptomatic patients undergoing CAS in clinical practice over the last 15 years.

Carotid artery stenting: an update

In patients with carotid disease, the purpose of carotid artery revascularization is stroke prevention. For >50 years, carotid endarterectomy has been considered the standard treatment for severe asymptomatic and symptomatic carotid stenoses. Carotid artery stenting (CAS) has emerged in the last 15 years as minimally invasive alternative to surgery. However, the value of the endovascular approach in the management of carotid disease patients remains highly controversial. The aims of this review are to elucidate the current role of CAS, to describe the major technology advancements in the field, and to speculate about the future of this therapy.

Safety and efficacy assessment of carotid artery stenting in a high-risk population in a single-centre registry

Introduction

Ischaemic stroke is the primary cause of long-term disability and the third most common cause of death. Internal carotid artery stenosis is an important risk factor for stroke and transient ischaemic attack (TIA). European Society of Cardiology (ESC) and American Heart Association (AHA) guidelines allow carotid artery stenting (CAS) as an alternative to endarterectomy in centres with low rates of death or stroke.

Aim

To assess the safety and efficacy of CAS in a single-centre observation.

Material and methods

We performed a retrospective analysis of all patients treated with CAS between March 2008 and July 2012. Clinical data and outcomes in both asymptomatic and symptomatic patients were analysed.

Results

A total of 214 consecutive patients were included in the registry. Symptomatic patients accounted for 57% of the study group and were more likely to have a history of stroke and/or TIA that occurred more than 6 months before the procedure (50% vs. 8%, p < 0.001). Asymptomatic patients were more likely to have a history of coronary artery disease (88% vs. 61%, p < 0.001), and the rates of previous acute coronary syndrome and revascularisation were also higher in this group (58% vs. 41% and 71% vs. 52%, respectively, both p < 0.05). The symptomatic group had higher incidence of stroke in periprocedural and 30-day observation (4% vs. 0%, p < 0.05). There was no difference in incidence of adverse events in long-term observation.

Conclusions

Carotid artery stenting is a safe and efficacious procedure. Every centre performing CAS should monitor the rate of periprocedural complications.

Cerebral embolic lesions detected with diffusion-weighted magnetic resonance imaging following carotid artery stenting: a meta-analysis of 8 studies comparing filter cerebral protection and proximal balloon occlusion

OBJECTIVES

The aim of this meta-analysis was to evaluate and compare the efficacy of the 2 different neuroprotection systems in preventing embolization during carotid artery stenting (CAS), as detected by diffusion-weighted magnetic resonance imaging (DW-MRI).

BACKGROUND

Data from randomized and nonrandomized studies comparing both types of embolic protection devices revealed contrasting evidence about their efficacy in neuroprotection, as assessed by the incidence of new ischemic lesions detected by DW-MRI.

METHODS

Eight studies, enrolling 357 patients, were included in the meta-analysis. Our study analyzed the incidence of new ischemic lesions/patient, comparing filter cerebral protection and proximal balloon occlusion.

RESULTS

Following CAS, the incidence of new ischemic lesions/patient detected by DW-MRI was significantly lower in the proximal balloon occlusion group (effect size [ES]: -0.43; 95% confidence interval [CI]: -0.84 to -0.02, I(2) = 70.08, Q = 23.40). Furthermore, following CAS, the incidence of lesions at the contralateral site was significantly lower in the proximal protection group (ES: -0.50; 95% CI: -0.72 to -0.27, I(2) = 0.00, Q = 3.80).

CONCLUSIONS

Our meta-analysis supports the concept that the use of proximal balloon occlusion compared with filter cerebral protection is associated with a reduction of the amount of CAS-related brain embolization. The data should be confirmed by a randomized clinical trial.

Endarterectomy or carotid artery stenting: the quest continues part two

BACKGROUND

Although randomized trials on carotid artery stenting (CAS) could not establish its equivalence to carotid endarterectomy (CEA) in patients with symptomatic carotid disease, CAS is rapidly evolving. Data on long-term outcome after CAS from randomized trials have now become available and ongoing, prospectively held registries frequently publish their results in increasing numbers of patients. We have therefore reviewed the currently available literature and provide an update of our previous article on this topic.

DATA SOURCES

PubMed literature searches were performed to identify relevant studies regarding current status of CEA and stenting for symptomatic carotid stenosis.

CONCLUSIONS

The efficacy of CAS in patients with symptomatic carotid artery stenosis remains unclear because of varying results in randomized trials. Although multiple registries do report promising results after CAS, peri-interventional stroke/death rates still exceed those rates currently found after CEA. Therefore, CEA remains the "gold standard" in treating these patients.

Influence of carotid artery stenting on cognition of elderly patients with severe stenosis of the internal carotid artery

Background

The aim of this study was to investigate the influence of carotid artery stenting (CAS) on the cognition and quality of life of elderly patients with severe stenosis of the internal carotid artery.

Material/Methods

65 elderly patients with symptomatic severe stenosis of internal carotid artery were recruited into 2 groups: the pharmacotherapy group (n=29) and the CAS group (n=36). Before surgery and 1, 3, 6, and 12 months after surgery, Montreal cognitive assessment (MoCA) was used for the evaluation of cognition and WHOQOL-BREF was used for the assessment of quality of life.

Results

At 12 months after surgery, total MoCA score and WHOQOL-BREF score in the pharmacotherapy group was significantly reduced when compared with those before surgery (P<0.05). In the CAS group, the total MoCA score, scores of attention and delayed recall, and WHOQOL-BREF score increased significantly at different time points after surgery when compared with those before surgery (P<0.05). Moreover, in CAS group, the MoCA score and WHOQOL-BREF markedly increased gradually over time (P<0.05). Compared with the pharmacotherapy group, cognition and quality of life in the CAS group were improved dramatically during the follow-up period (P<0.05).

Conclusions

Severe stenosis of the internal carotid artery is a cause of cognition impairment, and CAS may improve cognition and quality of life.

State of the art in carotid artery stenting: trial data, technical aspects, and limitations

The volume of carotid artery stenting (CAS) safety and efficacy data has grown exponentially over the last decade. Recent comparative data with carotid endarterectomy, the utility of embolic protection devices, peri-procedural medications, basic technical aspects of CAS, developments in carotid stent design, potential complications of CAS, and complication risk factors are discussed in this review.

Complications and Solutions with Carotid Stenting

Complications of carotid stenting can be classified as neurologic, cardiovascular, death, carotid, access site, device malfunctions, and general and late complications. The risk of most complications is related to readily identifiable patient and anatomic factors. Management and outcome of complications require immediate recognition and a team-based approach to patient care.