Initial evaluation of carotid angioplasty and stenting with three different cerebral protection devices

The Evolution of Current Management for Carotid Artery Bifurcation Disease

Options for treatment of symptomatic carotid bifurcation disease include carotid endarterectomy (CEA) and carotid artery stenting (CAS). While over the years CEA has established itself as the gold standard for carotid artery revascularization, results from recent trials have shown CAS to be safe and effective in selected patients. This review details the evolution of carotid artery bifurcation disease by highlighting key clinical trials.

A Case of Carotid Sinus Reflex Caused by Manual Aspiration Thrombectomy Using a Balloon Guide Catheter

When starting a mechanical thrombectomy, manual aspiration with balloon guide catheters inserted into the internal carotid artery (ICA) is an efficient method for thrombus aspiration. However, no complications associated with this procedure have been reported. This study describes the case of a 76-year-old man who presented to our hospital with total aphasia and complete right-sided paralysis due to chronic atrial fibrillation and left occlusion of the ICA. When the balloon guide catheter was inserted and inflated at the origin of the left ICA, the patient's systolic blood pressure suddenly decreased from 114 mm Hg to 44 mm Hg. This sudden hypotension may have been caused by the carotid sinus reflex. Hypotension improved following balloon deflation. The procedure was continued, resulting in complete recanalization of the left ICA. The patient died from acute exacerbation of interstitial pneumonia. Although this complication is rare, similar phenomena have been recognized in carotid artery stenting and the use of flow-diverting devices. To the best of our knowledge, this is the first report of a case wherein the carotid sinus reflex was induced by manual aspiration using a balloon guide catheter placed in the ICA. Clinicians should recognize the importance of ensuring that the proximal end of the balloon crosses the carotid sinus when dilating and occluding the ICA with a balloon to avoid the carotid sinus reflex.

A single-center experience of 30-day perioperative and one year clinical outcomes of transcarotid artery revascularization in 100 consecutive patients

BACKGROUND

Transcarotid Artery Revascularization (TCAR) using the ENROUTE system (Silk Road) has been proposed as a safe and effective alternative to both carotid endarterectomy (CEA) and transfemoral carotid artery stenting (TF-CAS). Two large registries (ROADSTER 1 and ROADSTER 2) have shown that TCAR has acceptable/low rates of perioperative stroke/death. This study will analyze the 30-day perioperative and 1-year clinical outcomes from a single-center.

PATIENT POPULATION AND METHODS

This is a retrospective analysis of prospectively collected data from SVS/VQI TCAR surveillance project (TSP) of 100 consecutive patients (102 TCAR procedures) done in our institution. These procedures were done for high-risk patients for CEA, which included anatomical (previous CEA, high cervical lesion, neck radiation, stoma, arch type, etc.), physiological (CHF, severe coronary artery disease, COPD on O2 therapy, etc.) and combined anatomical/physiological reasons. These procedures were done by vascular surgeons after receiving the appropriate training. The perioperative stroke, death, and MI rates were analyzed. Kaplan Meyer analysis was used to estimate rate of freedom from stroke/death and the incidence of ≥50% and ≥80% in-stent restenosis at 1 year.

RESULTS

100 consecutive high-risk patients for CEA included: 38% anatomical, 44% physiological, and 18% combined anatomical and physiological reasons. The mean age was 72.5 years (range 52-90 years). Indications for TCAR were 34% for symptomatic lesions (TIA/stroke) and 66% for asymptomatic lesions. Mean ipsilateral treated stenosis was 80.4%. Contralateral ≥50% stenosis/occlusion was present in 31% of patients. Technical success rate was 100%. 92% had pre-stenting PTA and 26% had post-stenting PTA. The mean flow reversal time was 8.5 min (range 3-26 min). The 30-day perioperative stroke rate was 2.9% (1/67, 1.5% for asymptomatic patients), the stroke/death rate was 2.9%, and stroke/death and MI rate was 3.9% (4/102). Other perioperative complications included cranial nerve injury 3/102 (2.9%), carotid artery dissection (2%), and major hematoma (necessitated operation evacuation) (5.9%). Freedom from stroke rates and stroke/death rates at 1 year were: 90% and 89%. Freedom from ≥50% and ≥80% in-stent restenosis rates at 1 year were 82% and 90%, respectively. None of these restenosis were symptomatic except two (2/13). Freedom from reintervention rate at 1 year was 98%.

CONCLUSION

Although the perioperative events were somewhat higher than what has been reported in previous registries, TCAR for patients who are high-risk for CEA has a low perioperative stroke and stroke/death rates with satisfactory outcome at 1 year. Further long-term data is probably needed to verify long-term outcome.

Alternative Proximal Protection Method during Carotid Artery Stenting Using Combined Transbrachial and Transradial Artery Approaches

Herein, we report a case of carotid artery stenting with proximal flow protection for severe stenosis of the left internal carotid artery using transbrachial and transradial artery approaches. Because an abdominal aortic aneurysm was present, we avoided the transfemoral approach. The procedure was successfully performed with a combination of an 8-Fr balloon guide catheter and microballoon catheter on separate axes. No complications such as pseudoaneurysm, thrombosis, or dissection were observed at the puncture site. The patient was discharged without complications and showed good outcomes at 3 months. This technique may offer a useful alternative for patients with severe stenosis who cannot be treated using a femoral artery approach.

History of Carotid Artery Reconstruction around the World and in Japan

Since ancient times, physicians have been aware of correlations between the carotid artery and consciousness; however, carotid stenosis was only recently identified as the cause of atherothrombotic ischemic stroke. In 1658, Wepfer described the first suggestion of a link between symptoms of cerebral arterial insufficiency and carotid pathology. In 1951, Fisher reported details of the symptoms and pathological findings and emphasized that cervical atheromatous lesions induced cerebral infarction with various symptoms. The beginning of carotid artery surgery was ligation of the carotid artery for neck or head injury, but surgeons were aware that this operation induced cerebral symptoms due to lack of blood supply. Carotid endarterectomy (CEA) was first reported by Eastcott et al. in 1954, and in Japan, Kimoto performed a successful CEA in 1962. In 1979, percutaneous transluminal angioplasty (PTA) was performed for patients with fibromuscular dysplasia, and then, carotid artery stenting (CAS) was first performed in 1989 by Mathias. In Japan, Kuwana et al. were the first to perform carotid PTA, in 1981, whereas Yamashita et al. performed the first CAS in 1997. Yoshimura et al. proposed staged carotid stenting to prevent hyperperfusion syndrome. Some issues in carotid reconstruction are still debated today, which include conventional (standard) CEA versus the eversion technique, CEA versus CAS versus medical therapy, and medical economic problems. In the future, we must continue to develop more effective, safer, and less expensive therapeutic methods to prevent carotid stroke, carrying on the efforts of the ancient peoples who pioneered this research.

Thirty-Day Perioperative Clinical Outcomes of Transcarotid Artery Revascularization vs Carotid Endarterectomy in a Single-Center Experience

BACKGROUND

Transcarotid artery revascularization (TCAR) has been proposed as a alternative to carotid endarterectomy (CEA) and transfemoral carotid artery stenting in high-risk patients. Recently Centers for Medicare and Medicaid Services expanded coverage for TCAR to include standard surgical risk patients within the Society of Vascular Surgery Vascular Quality Initiative TCAR Surveillance Project. Few single centers compared the clinical outcome of TCAR with CEA. This study compares 30-day perioperative clinical outcomes between TCAR and CEA.

STUDY DESIGN

This is retrospective analysis of prospectively collected data from the TCAR Surveillance Project of TCAR patients enrolled in our institution and compared with CEAs done in the same time/with the same providers. The primary outcome was stroke and/or death. Secondary outcomes included stroke, death, MI, cranial nerve injury, bleeding, and others. Propensity matching was done to analyze outcomes.

RESULTS

The study analyzed 501 patients (347 CEA, 154 TCAR). There were no significant differences in symptomatic status (43% for CEA vs 38% for TCAR, p = 0.303). TCAR had more patients with hypertension (p = 0.04), coronary artery disease (p = 0.028), and congestive heart failure (p = 0.039). The 30-day perioperative complication rates for CEA vs TCAR were as follows: stroke 1% vs 3% (p = 0.142), stroke/death 1% vs 3% (p = 0.185), MI 0.6% vs 0.7% (p = 1), death 0.6% vs 0% (p = 1), stroke/death/MI 2% vs 4% (p = 0.233), cranial nerve injury 4% vs 2% (p = 0.412), and major hematoma (requiring reintervention) 2% vs 3% (p = 1). After matching 154 CEA patients and 154 TCAR, 30-day perioperative complication rates were as follows: stroke 2% vs 3% (p = 0.723), stroke/death 3% vs 3% (p = 1), death 1.3% vs 0% (p = 0.498), MI 0.7% vs 0.7% (p = 1), and stroke/death/MI 3% vs 4% (p = 0.759).

CONCLUSIONS

This study showed that using propensity match analysis, both CEA and TCAR have similar 30-day perioperative outcomes. Further long-term data are needed.

Transcervical Versus Transfemoral Approach in Carotid Stenting Real World Experience in a Community Hospital

INTRODUCTION

Peri-procedural embolic events are the Achilles' heel of carotid stenting. To overcome this complication, transcervical access to the carotid artery was introduced. In this study we describe our "our life" experience with the transcervical approach in a community hospital.

MATERIAL AND METHODS

All carotid stent procedures between January 2010 and December 2020 were included in this retrospective analysis. The transcervical approach was compared to the transfemoral approach. In both procedures open-cell, closed-cell design and hybrid stents were used. In-hospital stroke was the primary outcome measure.

RESULTS

A total of 340 procedures were performed, in 184 patients the transfemoral approach was used and in 156 patients the transcervical approach was used. In 12 patients (3.5%) an in-hospital stroke was diagnosed, 4 in the transfemoral group (2.2%) and 8 in the transcervical group (5.1%) (P = 0.14). In the multivariate analyses a symptomatic lesion was associated with in-hospital stroke. Neither type of access nor cell design was associated with increased risk of in-hospital stroke.

CONCLUSIONS

In contrast to previous studies, we could not confirm the advantages of the transcervical approach. However, conclusions should be carefully drawn, since this study is retrospective and was performed with multiple surgeon and different kind of stents.

One-Way Valve Method for Achieving Effective Flow Reversal on Carotid Artery Stenting

Objective

We report a simplified method of manual transfusion with a one-way valve during carotid artery stenting (CAS) with flow reversal.

Case Presentation

A 77-year-old man with cervical internal carotid artery stenosis who developed vulnerable plaques was scheduled for CAS using flow reversal. Blood flow reversal was naturally caused by the arteriovenous pressure gradient, and a method with a one-way valve, which enables simplified manual transfusion using a syringe technique, was used for the patient. CAS was completed without distal embolization.

Conclusion

Manual transfusion can be simplified using a one-way valve in cases of flow reversal during CAS, which often require complicated procedures.

Low-frequency avoidable errors during transcarotid artery revascularization

OBJECTIVE

Transcarotid artery revascularization (TCAR) seems to be a safe and effective alternative to carotid endarterectomy (CEA) and transfemoral carotid artery stenting (TF-CAS). The TCAR system represents a paradigm shift in the management of carotid artery stenosis with potential for a significant decrease in periprocedural morbidity. However, as with CEA or TF-CAS, TCAR is associated with infrequent complications related to user technical error, most of which are preventable. Our goal is to describe these low-frequency events, and to provide guidelines for avoiding them.

METHODS

The U.S. Food and Drug Administration (FDA) requires that all medical device manufacturers create a system for receiving, reviewing, and evaluating complaints (Code 21 of Federal Regulations 820.198). Silk Road Medical, Inc (Sunnyvale, Calif), has established a process by which all feedback, including complaints that may not meet FDA criteria, is captured and stored in a database for detailed analysis. More than 13,300 cases have been performed; submitted complaints were reviewed for incidents of serious injury and periprocedural complications, above and beyond the device-related events that must be reported to the FDA.

RESULTS

A total of 13,334 patients have undergone TCAR worldwide between early 2011 and December 2019 using the SilkRoad device. Reported complications included 173 dissections (1.4% overall rate) of the common carotid artery at the access point, of which 22.5% were managed without intervention or with medical therapy alone and 24.3% were converted to CEA (considered failing safely). Errors in the location of stent deployment occurred in 16 cases (0.13%), with the most common site being the external carotid artery (75%). One wrong side carotid artery stent was placed in a patient with a high midline pattern of the bovine arch. Cranial nerve injury was reported in 11 cases (0.08%), only one of which persisted beyond 3 months. There have been three reported pneumothoraces and one reported chylothorax. Many of these errors can be recognized and prevented with careful attention to detail.

CONCLUSIONS

In high-risk patients requiring treatment for carotid artery stenosis, TCAR has been proven as an alternative to TF-CAS with an excellent safety profile. As with CEA or TF-CAS, this procedure has the potential for infrequent complications, often as a result of user technical error. Although significant, these events can be avoided through a review of the collective experience to date and recognition of potential pitfalls, as we have described.

Recent advances in the treatment of carotid artery disease

Transfemoral carotid stenting has struggled to become a suitable alternative to carotid endarterectomy for the treatment of carotid disease because of higher perioperative stroke risks, even with use of embolic protection devices. To reduce the perioperative stroke rates associated with carotid stenting, several advancements in stent design, embolic protection systems, and technical approaches have been developed. Transcarotid artery revascularization (TCAR) was also recently introduced as a novel carotid artery stenting option which circumvents several of the high embolic-risk maneuvers found in transfemoral carotid stenting and employs a flow reversal system that provides continuous embolic protection throughout the procedure. Early results from this technique have shown low stroke/death rates comparable to carotid endarterectomy while maintaining the minimally invasive benefits of carotid stenting. TCAR has a strong potential to become the preferred method of carotid stenting in the near future and may challenge carotid endarterectomy as the preferred carotid artery revascularization method.

Analysis of the ROADSTER pivotal and extended-access cohorts shows excellent 1-year durability of transcarotid stenting with dynamic flow reversal

OBJECTIVE

We report the 1-year outcomes of the Safety and Efficacy Study for Reverse Flow Used During Carotid Artery Stenting Procedure (ROADSTER) multicenter trial. This trial introduced a novel transcarotid neuroprotection system (NPS), the ENROUTE transcarotid NPS (Silk Road Medical Inc, Sunnyvale, Calif). Postoperative results demonstrated that the use of the ENROUTE transcarotid NPS is safe and effective. The aim of this study was to evaluate the safety of transcarotid artery revascularization (TCAR) and to present the 1-year outcomes.

METHODS

This study is a prospective, single-arm clinical trial. Current enrollment occurs in 14 centers. Primary end points were incidence rates of ipsilateral stroke at 1 year after TCAR. Occurrence of stroke was ascertained by an independent Clinical Events Committee. Patients with anatomic or medical high-risk factors for carotid endarterectomy (CEA) were eligible to be enrolled in the ROADSTER trial.

RESULTS

Overall, 165 patients were included in the long-term follow-up (112 of 141 patients from the pivotal phase and 53 of 78 patients from the extended access). Mean age was 73.9 years (range, 42.1-91.3 years). Patients aged 75 years and older were 43.3% of the cohort. The majority of patients were white (92.7%) and male (75.2%). Most patients were asymptomatic (79.9%). Anatomic risk factors were distributed as follows: contralateral carotid artery occlusion (11.0%), tandem stenosis of >70% (1.8%), high cervical carotid artery stenosis (25.0%), restenosis after CEA (25.6%), bilateral stenosis requiring treatment (4.3%), and hostile neck (14.6%). Medical high-risk criteria included two-vessel coronary artery disease (14.0%) and severe left ventricular dysfunction with ejection fraction <30% (1.8%). In general, 43.3% of patients had at least one anatomic high-risk factor, whereas 29.9% of patients had medical high-risk factors. Both subsets of factors were present simultaneously in 26.8% of the cohort. At 1-year follow-up, ipsilateral stroke incidence rate was 0.6%, and seven patients (4.2%) died. None of the deaths were neurologic in origin.

CONCLUSIONS

TCAR with dynamic flow reversal had previously shown favorable 30-day perioperative outcomes. This excellent performance seems to extend to 1 year after TCAR as illustrated in this analysis. The promising results from the ROADSTER trial likely stem from the novel cerebral protection provided through the ENROUTE transcarotid NPS in comparison to distal embolic protection devices as well as the transcarotid approach's circumventing diseased aortic arch manipulation and minimizing embolization. TCAR offers a safe and durable revascularization option for patients who are deemed to be at high risk for CEA.

Carotid Revascularization with and without the Use of an Embolic Protection Device: A Single-Center Experience from Pakistan

Background

To assess the safety and clinical efficacy of carotid artery stenting with and without an embolic protection device (EPD) in both symptomatic and asymptomatic carotid disease cases.

Methods

Retrospective data of 55 symptomatic (≥50% occlusion by digital subtraction angiography [DSA], ≥70% by ultrasound, computed tomography angiography [CTA], and magnetic resonance angiography [MRA]) and asymptomatic (≥60% by DSA, ≥70% by ultrasound, ≥80% by CTA and MRA) carotid disease cases undergoing carotid stenting/angioplasty revascularization from February 2014 to October 2017 was reviewed. All symptomatic patients either experienced recurrent transient ischemic attacks or one or more stroke attacks. An EPD protocol was designed for its selective use based on plaque morphologies and working diameters. The primary end points at 30 days of follow-up were a periprocedural incidence of any stroke, myocardial infarction or death, and ipsilateral stroke during the follow-up period.

Results

Of the 55 cases, 39 were males and 16 females; mean age was 64.8 years. Fifty-one patients (92.7%) were symptomatic, with a mean stenosis of 80.1%. EPD was used in only 11 cases (20%). Minor stroke rate during the first 30 postoperative days was 1.8% (1 case) with EPD; no myocardial infarction or mortality. No stroke occurred during the median 1.5 years' follow-up.

Conclusion

Based on our single-center experience and findings of a relatively small sample size, carotid revascularization with stenting and angioplasty without EPD in experienced hands was found to be safe and efficacious. In addition, it proves cost-effective for patients by limiting the use of unnecessary disposables. These results are comparable to those reported in major trials and are well within the complication thresholds suggested in current guidelines. These results also show promise and illustrate the need for a larger, randomized controlled trial in order to thoroughly address this aspect of carotid revascularization.

Carotid artery stenting for patients with occipital-vertebral anastomosis

BACKGROUND AND PURPOSE

We report the outcomes of carotid artery stenting for patients with angiographically visible occipital artery-vertebral artery anastomosis.

METHODS

Among 47 consecutive patients who underwent carotid artery stenting from January 2007 to December 2010, seven patients for whom cerebral angiograms clearly showed occipital artery-vertebral artery anastomosis were selected. Four different protection methods were used: distal internal carotid artery protection; carotid flow reversal; seatbelt and airbag technique; and double protection method of protecting both the external and internal carotid artery.

RESULTS

One patient with distal internal carotid artery protection showed a high-intensity lesion at the border of the upper thalamus, internal capsule and lateral ventricle wall after carotid artery stenting. The other patient with the double protection method did not show any high-intensity lesions on postoperative diffusion-weighted imaging in the vertebrobasilar territory. All seven patients with visible occipital artery-vertebral artery anastomosis showed ipsilateral vertebral artery severe stenosis or occlusion.

CONCLUSION

Large occipital artery-vertebral artery anastomosis may be a pathway for embolic materials during carotid artery stenting. External carotid artery protection is recommended for carotid artery stenting in such patients.

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 history of proximal carotid protection and flow reversal to prevent stent angioplasty embolization

Innovation in medicine is often driven by the observations of imaginative physicians who are blessed with insatiable curiosity, coupled with the inability to accept technical boundaries, the status quo of patient care, or the acceptance of procedural morbidity. Few examples illustrate this truism better than the physician-originated clinical research that transformed the safety of carotid stent angioplasty over the last 2 decades. Initial clinical application of carotid stenting suggested that proximal protection may be a better approach to prevent embolic stroke during the angioplasty procedure. The history of how this innovation was developed is particularly relevant as vascular surgeons adopt new endovascular therapies. It has been more than 15 years since Dr Juan Parodi put together a multidisciplinary team of scientists and clinicians to test the "proximal protection" hypothesis. The goal of this overview was to provide Dr Parodi team's perspective on the development of the proximal protection and flow reversal concept to minimize plaque embolization during carotid stent angioplasty procedures.

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.

Transcarotid Artery Revascularization With Flow Reversal

Purpose: To report a study evaluating the safety and efficacy of stenting via direct carotid access with flow reversal using the ENROUTE Transcarotid Neuroprotection System. Methods: Between March 2009 and June 2012, 75 patients (mean age 72.6 years; 45 men) underwent carotid artery stenting with the ENROUTE System; the majority of patients (63, 84%) were asymptomatic. The primary safety endpoint was the composite of major stroke, myocardial infarction, or death at 30 days. Efficacy outcomes included acute device success, procedure success, and tolerance to flow reversal. Fifty-six (74.7%) patients underwent diffusion-weighted magnetic resonance imaging (DW-MRI) before and after the procedure to assess the development of new ischemic brain lesions. Results: Acute device and procedure success were achieved in 68 (90.6%) patients. The reverse flow circuit was established in 71 (94.6%) patients; only 5 patients demonstrated transient intolerance to flow reversal that did not interfere with completion of the procedure. The mean time on flow reversal was 19.1 minutes. In the DW-MRI substudy, 10 (17.9%) of 56 patients had ipsilateral new white lesions with a mean volume of 0.17 mL. At 30 days, no major stroke, myocardial infarction, or death occurred; 1 patient had experienced a minor stroke that was adjudicated as not related to either the device or procedure. Conclusion: Results of the PROOF study demonstrate the safety and efficacy of transcarotid revascularization with the ENROUTE Transcarotid Neuroprotection System.

Secondary Prevention of Ischemic Cerebrovascular Disease. What Is the Evidence?

Patients who had a transient ischemic attack or stroke are at increased risk of experiencing recurrent cerebrovascular events. For this reason, secondary prevention of ischemic cerebrovascular disease is essential. Several modifiable, lifestyle-associated risk factors have been implicated, such as physical activity, smoking, and alcohol consumption. Established and emerging vascular risk factors are associated with an increased risk of stroke. Pharmacologic treatment, including the use of antiplatelet, antihypertensive, and lipid-lowering agents, has also been shown to reduce the risk of secondary cerebrovascular events. Surgical intervention, either open or endovascular, may be the preferred therapeutic option in well-defined subsets of patients. It is important to establish specific measures for the early detection and prevention of recurrent cerebrovascular disease. Therefore, further research and greater awareness in this field are needed.

Carotid artery stenting for vulnerable plaques on MR angiography and ultrasonography: utility of dual protection and blood aspiration method

Background

Carotid artery stenting (CAS) for internal carotid artery (ICA) stenosis with vulnerable plaques is controversial. We analyzed the effect of a dual protection and blood aspiration method during CAS in patients with vulnerable plaques.

Methods

A total of 111 patients with ICA stenosis underwent CAS using the dual protection (simultaneous flow reversal and distal filter) and blood aspiration method. In 103 of 111 patients, preoperative carotid plaque was estimated by both 3 T MRI and ultrasonography (US). ICA plaques with a high intensity signal on time-of-flight-MR angiography (TOF-MRA) and/or mobile component on US were defined as vulnerable plaques. We assessed major adverse events (MAE) (ie, major stroke, myocardial infarction, and death) and hyperintense spots on diffusion-weighted images (DWI) after CAS. We then evaluated the visible debris captured by dual protection and blood aspiration during CAS.

Results

The preoperative ICA plaque on TOF-MRA and US was judged to be vulnerable in 48.5% (50/103 patients). The success rate of the CAS procedure was 100% with no MAE within 30 days. DWI showed small hyperintense spots in 18% (9/50 patients) and 18.9% (10/53 patients) in the vulnerable and non-vulnerable plaque groups, respectively. Visible debris was captured in 68% (34/50 patients) and 45.3% (24/53 patients) in the vulnerable and non-vulnerable plaque groups, respectively (p=0.0286).

Conclusions

The combination of dual protection and blood aspiration could provide effective distal embolic protection although vulnerable plaques on TOF-MRA and US had a high incidence of debris during CAS. Thus, CAS using dual protection and blood aspiration is safe in patients with vulnerable plaques.

Usefulness of dual protection combined with blood aspiration for distal embolic protection during carotid artery stenting

BACKGROUND

We describe dual protection (simultaneous flow reversal and distal filter) combined with blood aspiration as a novel technique to provide distal embolic protection during carotid artery stenting (CAS).

METHODS

Between July 2011 and August 2014, 190 patients with internal carotid artery (ICA) stenosis underwent 190 CAS procedures as follows. After post-dilation of the stent using dual protection, the aspiration catheter was placed between the distal filter and the proximal end of the stent, and the blood was aspirated several times from the ICA. We assessed hyper-intensity spots in diffusion-weighted images (DWI), and major adverse events (MAE) defined as major stroke, myocardial infarction and death after CAS. We then assessed visible debris captured in aspirated blood, the distal filter and a blood filter during flow reversal.

RESULTS

The overall technical success rate was 100 %, and all stenoses were dilated. Hyper-intense spots were found in 33 (17.3 %) of 190 DWI. The rate of MAE within 30 days was 1.05 % (2/190). Visible debris in 175 of 190 CAS procedures was captured in 92 (52.5 %) of these 175. In 25 (27.2 %) of these 92, visible debris was captured in all of aspirated blood, the distal filter and the blood filter during flow reversal, only the blood filter during flow reversal (n = 19; 20.7 %), only the distal filter (n = 14; 15.2 %), only aspirated blood (n = 11; 12 %), aspirated blood and the blood filter during flow reversal (n = 10; 10.8 %), aspirated blood and the distal filter (n = 7; 7.6 %) and the distal filter and blood filter during flow reversal (n = 6; 6.5 %).

CONCLUSIONS

Adding a distal filter and blood aspiration to flow reversal during CAS could provide effective distal embolic protection.

Proximal protection with the Gore PAES can reduce DWI lesion size in high-grade stenosis during carotid stenting

AIMS

The aim was to determine the incidence of new ischaemic lesions on diffusion-weighted MR imaging (DWI) in a non-randomised cohort of patients after protected and unprotected carotid artery stent placement using the Parodi Anti-Emboli System (PAES).

METHODS AND RESULTS

A retrospective review was conducted on 269 patients who received DWI prior to, and 24-72 hours after, stent placement. All patients were enrolled in one centre. Forty patients stented with the PAES device were matched with 229 patients stented without protection (control group). New diffusion restriction on DWI was detected in 25.8% (PAES) versus 32.3% (control group); p=0.64. On average there were 0.7 lesions (PAES) versus 0.8 lesions (control group) per patient. The area of lesions was 1.7 (PAES) versus 5.6 mm2. In a subanalysis of patients (32 PAES, 148 non-protected) with >80% stenosis, the area of restricted diffusion was less when proximal protection was used (p<0.05). The number and area of DWI lesions did not differ on the contralateral, non-stented side. When the PAES system was used, patients were more likely not to have any lesion at all (p=0.028).

CONCLUSIONS

In high-grade stenosis, the use of the Gore PAES device significantly reduced the area of new DWI lesions and patients were more likely not to have any new DWI lesion at all.

Carotid Artery Stenting Versus Carotid Endarterectomy for Treatment of Asymptomatic Carotid Disease

In patients with asymptomatic carotid artery stenosis the optimal strategy to reduce the risk for stroke remains controversial. Although carotid endarterectomy was traditionally considered the gold standard for revascularization, emerging data suggest that carotid artery stenting is an appropriate alternative in many asymptomatic patients. This article summarizes the evidence base and related controversies regarding carotid endarterectomy versus carotid artery stenting for the revascularization of carotid disease in asymptomatic patients.

[Carotid artery stenting technique]

Over the past 25 years carotid artery stenting (CAS) has emerged as an alternative to carotid endarterectomy (CEA). Most of all younger patients and symptomatic patients with contralateral carotid artery occlusion particularly benefit from CAS. To achieve an optimal result with CAS, patient selection and even more important, knowledge and experience of the interventionist is crucial. The periprocedural complication rate of CAS in large experienced centers is lower (2-3%) than those in randomized trials. Several different devices are now available which allow the procedure to be tailored according to patient anatomy and lesion complexity. Complications like hyperperfusion syndrome and intracerebral bleeding, rupture of side branches of the external or internal carotid artery as well as problems caused by slow flow can be widely avoided by adequate experience.

Microembolization during carotid artery stenting in patients with high-risk, lipid-rich plaque. A randomized trial of proximal versus distal cerebral protection

OBJECTIVES

The goal of this study was to compare the rate of cerebral microembolization during carotid artery stenting (CAS) with proximal versus distal cerebral protection in patients with high-risk, lipid-rich plaque.

BACKGROUND

Cerebral protection with filters partially reduces the cerebral embolization rate during CAS. Proximal protection has been introduced to further decrease embolization risk.

METHODS

Fifty-three consecutive patients with carotid artery stenosis and lipid-rich plaque were randomized to undergo CAS with proximal protection (MO.MA system, n = 26) or distal protection with a filter (FilterWire EZ, n = 27). Microembolic signals (MES) were assessed by using transcranial Doppler during: 1) lesion wiring; 2) pre-dilation; 3) stent crossing; 4) stent deployment; 5) stent dilation; and 6) device retrieval/deflation. Diffusion-weighted magnetic resonance imaging was conducted before CAS, after 48 h, and after 30 days.

RESULTS

Patients in the MO.MA group had higher percentage diameter stenosis (89 ± 6% vs. 86 ± 5%, p = 0.027) and rate of ulcerated plaque (35% vs. 7.4%; p = 0.019). Compared with use of the FilterWire EZ, MO.MA significantly reduced mean MES counts (p < 0.0001) during lesion crossing (mean 18 [interquartile range (IQR): 11 to 30] vs. 2 [IQR: 0 to 4]), stent crossing (23 [IQR: 11 to 34] vs. 0 [IQR: 0 to 1]), stent deployment (30 [IQR: 9 to 35] vs. 0 [IQR: 0 to 1]), stent dilation (16 [IQR: 8 to 30] vs. 0 [IQR: 0 to 1]), and total MES (93 [IQR: 59 to 136] vs. 16 [IQR: 7 to 36]). The number of patients with MES was higher with the FilterWire EZ versus MO.MA in phases 3 to 5 (100% vs. 27%; p < 0.0001). By multivariate analysis, the type of brain protection was the only independent predictor of total MES number. No significant difference was found in the number of patients with new post-CAS embolic lesion in the MO.MA group (2 of 14, 14%) as compared with the FilterWire EZ group (9 of 21, 42.8%).

CONCLUSIONS

In patients with high-risk, lipid-rich plaque undergoing CAS, MO.MA led to significantly lower microembolization as assessed by using MES counts.

Endovascular intervention for acute cervical carotid artery occlusion

BACKGROUND

Acute cervical carotid artery occlusion presents with a severe neurological deficit and is associated with unfavorable outcomes. In this study, the authors report their experience with patients having had acute ischemic stroke due to cervical carotid occlusion, who underwent endovascular intervention.

METHOD

Sixteen acute cervical carotid occlusion patients (15 males and 1 female; mean age 67.7 years) were treated by endovascularly between January 2009 and November 2012. Clinical, procedural, and angiographic data were retrospectively evaluated. Successful intracranial recanalization was based on thrombolysis in cerebral infarction score of 2B-3. A favorable outcome was defined as a modified Rankin Scale score of 0-2 at 90 days.

FINDINGS

The average score of National Institutes of Health Stroke Scale before treatment was 15.9. Ten of 16 patients (63 %) were associated with intracranial tandem occlusion. Ten (63 %) cases were caused by atherosclerotic, 4 (25 %) by atrial fibrillation (AF), and 2 (13 %) by dissection. Thirteen of 16 (81 %) achieved successful cervical recanalization and 7 of 16 (44 %) patients obtained sufficient cervical and intracranial perfusion. As a result, 5 of 16 (31 %) patients demonstrated favorable outcomes. Five of seven patients (71 %) with successful cervical and intracranial recanalization presented favorable outcomes. In contrast, none of the patients without cervical or intracranial recanalization presented favorable outcomes. Three of 6 (50 %) patients initially without intracranial occlusion showed favorable outcomes, but only 2 of 10 (20 %) patients associated with intracranial occlusion had favorable outcomes. On the aspect of etiology, in atherosclerotic cases, 4 of 10 (40 %) showed favorable outcomes. However, all four AF cases deteriorated into poor outcomes.

CONCLUSIONS

This study demonstrated the feasibility of endovascular intervention for acute cervical carotid artery occlusion. Although treatment for tandem occlusion and AF cases is an issue that should be resolved, intervention must be encouraged. Successful cervical and intracranial revascularization will be essential for favorable outcomes.

Off-label use of drugs and devices in the neuroendovascular suite

SUMMARY

The off-label use of drugs and devices in neuroendovascular procedures is common. Neurointerventionalists should be well aware of the level of evidence available in support of the off-label use of drugs and devices in their practice and some of the potential adverse events associated with them. These uses are categorized as I or II if they have been evaluated as primary or ancillary interventions in prospective trials/registries of neuroendovascular procedures and III if they were evaluated in case series. Category IV use is based on evaluation as primary or ancillary interventions in prospective trials/registries of non-neuroendovascular procedures. Physicians are allowed to use off-label drugs and procedures if there is strong evidence that they are beneficial for the patient. The neurointerventional professional societies agree that off-label use of drugs and devices is an important part of the specialty, but practicing providers should base their decisions on sound evidence when using such drugs and devices.

Initial experience with a reversal-of-flow cerebral protection device in carotid angioplasty

PURPOSE: To report initial findings with the GORE Flow Reversal System®, with a focus on major/minor adverse events in the 30 first postoperative days. METHODS: The first 24 patients submitted to carotid angioplasty using the GORE system, from June 2010 to May 2012, were retrospectively assessed with regard to indications, anatomic details, technical difficulties, and early clinical outcomes, including major (stroke, death, acute myocardial infarction) and minor (hematoma) adverse events. RESULTS: Systemic hypertension was present in 100% of the patients, diabetes mellitus in 58.3%, and coronary disease in 37.5%. Type II aortic arch was encountered in 62.5% of the patients and atherosclerotic lesion predominantly at the carotid bifurcation affecting the internal and common carotid arteries in 79.2%. Angiographic data revealed contralateral carotid arteries with <50% stenosis in 95.8% of cases and preservation of cerebral blood flow in 95.8%. All procedures but one were technically successful. Mean cerebral flow reversal time was 14.9 minutes, with a statistically significant difference between the first 12 (17.9 minutes) and the last 12 patients treated (11.6 minutes) (p<0.001). Intolerance to flow reversal was observed in 17.4% of the cases. Technical difficulties were experienced in 1 patient (4.2%). Clinical outcomes included 4.2% of stroke and 12.5% of hematomas at arterial puncture sites. CONCLUSION: The system was technically effective. A significant reduction in cerebral flow reversal time was observed, and the rates of early major/minor adverse events were within acceptable limits, suggesting that the device is safe and effective.

Assessment of reverse flow as a means of cerebral protection during carotid artery stent placement with diffusion-weighted and transcranial Doppler imaging

PURPOSE

To assess the effectiveness of flow reversal as an alternative means of cerebral protection by using transcranial Doppler recordings and diffusion-weighted imaging (DWI) as surrogate markers of brain injury.

MATERIALS AND METHODS

Eighteen patients with symptomatic carotid artery disease were recruited. Magnetic resonance imaging was performed before the intervention and at 3 and 24 hours and 30 days after the intervention to detect new ischemic lesions with DWI. Transcranial Doppler recordings were made during the procedure to assess for microembolic signals (MESs). Data were compared against data from a historical control cohort of patients who underwent CAS placement with or without filter protection (n = 15 each) under the same protocol in a different study.

RESULTS

There were fewer periprocedural new lesions on DWI in the reverse-flow cohort compared with the historical control cohort with filter protection (P = .084). Reverse flow revealed significantly fewer MESs during the whole procedure compared with the filter-protected group (P = .01) but not the unprotected group (P = .55). There was a marked decrease in MES counts for reverse flow protection during the embologenic stages of the procedure (P = .004).

CONCLUSIONS

Use of the reverse flow device was associated with fewer overall lesions on DWI and proportionately fewer positive scans compared with the use of filter-type devices (P = .08, not significant). Transcranial Doppler recordings demonstrated a significant reduction in embolization to the brain during carotid artery stent placement with the use of reverse-flow cerebral protection.

Direct Relationship between Angiographic Characteristics of Carotid Atherosclerotic Plaque and Filling Defect in the Cerebral Protection Filters : Based on the Conventional Angiography

Objective

Neurologic complications during carotid artery stenting (CAS) are usually associated with distal embolic event. These embolic incident during CAS are highly associated with the carotid plaque instability. The current study was undertaken to identify the angiographic characteristics of carotid plaque vulnerability, which was represented as filling defect in the cerebral protection filters during CAS.

Methods

A total of 107 patients underwent CAS with use of a distal protection filter. Angiographic carotid plaque surface morphology was classified as smooth, irregular, and ulcerated. To determine predictable factors of filling defect in the protection filters, 11 variables were retrospectively analyzed which might influence filling defect in the protection filters during CAS.

Results

Filling defects during CAS were presented in the 33 cerebral protection filters. In multivariate analysis, angiographic ulceration [odds ratio (OR), 6.60; 95% confidence interval (CI) : 2.24, 19.4; p=0.001], higher stenosis degree (OR, 1.06; 95% CI : 1.00, 1.12; p=0.039), and coexistent thrombus (OR, 7.58; 95% CI : 1.69, 34.05; p=0.08) were highly associated with filling defect in the cerebral protection devices during CAS. Among several variables, angiographic surface ulceration was the only significant factor associated with flow stagnation during CAS (OR, 4.11; 95% CI : 1.33, 12.72; p=0.014).

Conclusion

Plaque surface morphology on carotid angiography can be a highly sensitive marker of plaque instability during CAS. The independent risk factors for filling defect in the filter devices during CAS were plaque ulceration, stenosis degree, and coexistent thrombus.

Carotid artery stenting for primary and secondary stroke prevention

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Safety and feasibility of a novel transcervical access neuroprotection system for carotid artery stenting in the PROOF Study

BACKGROUND

Randomized controlled trials have shown that periprocedural rates of stroke and death are higher with carotid artery stenting (CAS) than with carotid endarterectomy (CEA) in the treatment of carotid artery stenosis. Diffusion-weighted magnetic resonance imaging (DW-MRI) has shown higher rates of clinically silent new ischemic brain lesions when CAS is performed as compared with CEA. The Silk Road Medical Embolic PROtectiOn System: First-In-Man (PROOF) Study is a single-arm first-in-man study using the MICHI Neuroprotection System (Silk Road Medical Inc, Sunnyvale, Calif), a novel transcervical access and cerebral embolic protection system. This system enables stent implantation under controlled blood flow reversal of the carotid artery, also known as Flow Altered Short Transcervical Carotid Artery Stenting (FAST-CAS).

METHODS

Between March 2009 and February 2010, a total of 44 subjects were enrolled into the study. The primary composite endpoint was major stroke, myocardial infarction, or death within 30 days. Forty-three patients (97.7%) completed the study through the 30-day endpoint. One patient was lost to follow-up. In a subgroup of consecutive subjects, DW-MRI examinations were performed preprocedure and within 24 to 48 hours after the stent implantation. Blinded independent neuroradiologists reviewed all DW-MRI studies and confirmed the absence or presence of new ischemic brain lesions.

RESULTS

All enrolled patients were successfully treated, and no major adverse events were seen through the follow-up period. Thirty-one subjects had DW-MRI examinations. Of these, five patients (16%) had evidence of new ischemic brain lesions but no clinical sequelae. Transient intolerance to reverse flow was reported in 9% of cases, but in all cases, a stent was successfully placed, and the intolerance was managed by minimizing the duration of reverse flow during the procedure.

CONCLUSION

In this first-in-man experience, FAST-CAS using the MICHI Neuroprotection System was shown to be a safe and feasible method for carotid revascularization. DW-MRI findings suggest controlled reverse flow provides cerebral embolic protection similar to that seen with CEA.