Initial experience of platelet glycoprotein IIb/IIIa inhibition with abciximab during carotid stenting: a safe and effective adjunctive therapy

Use of Glycoprotein IIb-IIIa Inhibitors in Patients Undergoing Carotid Artery Stenting in the Vascular Quality Initiative

BACKGROUND

Antiplatelet therapies with thromboxane inhibitors and adenosine 5'-diphosphate antagonists have been widely used following carotid artery stenting (CAS). However, these therapies may not apply to patients who are intolerant or present acutely. Glycoprotein IIb/IIIa inhibitors (GPI) are a proposed alternative therapy in these patients; however, their use has been limited due to concerns of increased risk for intracranial bleeding. Thus, this study aims to assess the safety profile of GPI in patients undergoing CAS.

METHODS

All patients undergoing CAS in the Society of Vascular Surgery - Vascular Quality Initiative database from 2012 to 2021 was included and grouped into GPI versus non-GPI therapy (control). The primary outcome was in-hospital stroke or death, and secondary outcomes included in-hospital stroke/transient ischemic attack (TIA), death, myocardial infarction, and intracranial hemorrhage (ICH)/seizure. Patients were stratified by surgical approach (Transcarotid artery revascularization using flow reversal (TCAR) and transfemoral carotid artery stenting), and stepwise backward logistic regression analysis was conducted to evaluate major primary and secondary outcomes.

RESULTS

A total of 50,628 patients underwent carotid revascularization. Of these, 4.4% of the patients received GPI. Mean age was similar between control versus GPI (71.35(9.67) vs. 71.36(10.20) years). Compared to the control group, patients who receive GPI are less likely to be on optimal medical therapy, including aspirin (83.0% vs. 88.1%), P2Y12 inhibitor (73.0% vs. 82.7%), and statin (82.3% vs. 86.0%) (All P < 0.05). In addition, patients in the GPI group were more likely to undergo TCAR for carotid revascularization (52.2% vs. 48.4%) for emergent/urgent (29.4% vs. 16.8%) and symptomatic indications (55.5% vs. 49.7%) (All P < 0.001). After stratifying by surgical approach, if patients underwent TFCAS and received a GPI, they were at increased odds of developing stroke/death (1.77(1.25-2.51)), death (odds ratio (OR) (95% CI): 1.67(1.07-2.61)), stroke/TIA (OR (95% confidence interval (CI)): 1.65(1.09-2.51)), and ICH/seizure (OR (95% CI): 2.13(1.23-3.68)) (All P < 0.05). No difference was seen in outcomes between the 2 groups if undergoing TCAR.

CONCLUSIONS

Patients who receive GPI were more likely to be symptomatic at presentation and less likely to be medically optimized before their carotid revascularization. Transfemoral access in patients receiving GPI was associated with increased odds of morbidity and mortality. However, this was not observed if undergoing TCAR. TCAR can be considered for its overall favorable results in high-risk patients who are not medically optimized.

Safety and efficacy of prophylactic tirofiban infusion for acute intracranial intraprocedural stent thrombosis

Periprocedural antithrombotic management with glycoprotein IIb/IIIa inhibitors (GPI) for intracranial artery stenting is still controversial. We sought to assess the safety and efficacy of prophylactic tirofiban infusion for acute intracranial intraprocedural stent thrombosis in routine clinical practice. From January 2013 to December 2019, consecutive patients treated with endovascular stenting for symptomatic intracranial atherosclerotic stenosis (ICAS) were identified and dichotomized by whether tirofiban was used. The efficacy and safety outcomes were compared by propensity score matching. A total of 160 consecutive patients in the tirofiban group and 177 patients in the non-tirofiban group were enrolled. Propensity score matching analysis selected 236 matched patients. One acute intraprocedural stent thrombosis (AIST) occurred in patients receiving prophylactic tirofiban, while 8 in the non-tirofiban group. The incidence of AIST in the tirofiban group was significantly lower than that in the non-tirofiban group (0.8% vs 6.8%, P = 0.039). The periprocedural ischemic events (8.5% vs 5.1%, P = 0.424), periprocedural intracranial hemorrhage (4.2% vs 0.8%, P = 0.219) and 30-day total mortality (3.4% vs 0%, P = 0.125) were not statistically different between the two groups. Compared with conventional stenting angioplasty without tirofiban, tirofiban prophylactic infusion can lower the incidence of AIST, without increasing the risk of periprocedural intracranial hemorrhage and 30-day total mortality. However, there is no superiority in reducing periprocedural ischemic events. The current study adds more important insights to the available clinical evidence on the use of tirofiban during stenting of ICAS.

Adjunctive treatment with low dose intra-arterial eptifibatide and intravenous aspirin during carotid stenting: A case series

PURPOSE

According to most guidelines, medical protocol for carotid stenting includes the administration of oral Aspirin and Clopidogrel at least four days before the procedure, with intraprocedural intravenous (IV) heparin. Some publications have also reported the safety of adding glycoprotein 2b/3a inhibitors to the protocol. In this retrospective study, we evaluate the safety of a new medication protocol that includes IV aspirin and intra-arterial Eptifibatide (glycoprotein 2b/3a inhibitor) during carotid stenting. All patients who underwent carotid stenting at Soroka University Medical Center between January 2015 and May 2020 were included (emergent cases were excluded). We divided patients into two groups-patients treated under the standard protocol, and patients treated under the new protocol. In the latter, patients received both the standard protocol regimen, as well as 150 mg IV aspirin immediately before stenting, and a slow intra-arterial injection of 2-3 mg Eptifibatide (glycoprotein 2b/3a antagonist) immediately after stenting. Forty-four patients were treated according to the standard protocol (group 1), and 41 patients were treated according to the new protocol (group 2). In group 1, six patients had complications, while in group 2, no complications of any kind were noted (p = 0.027). The safety and possible efficacy of this novel protocol was preliminarily demonstrated in the present study. Future studies are needed to prove the safety and efficacy of a specific drug regimen that will further reduce the complication rates of carotid stenting.

Antiplatelet Therapy During Emergent Extracranial Internal Carotid Artery Stenting: Comparison of Three Intravenous Antiplatelet Perioperative Strategies

INTRODUCTION

Guidelines for antiplatelet therapy administration, during emergent stenting for extra-cranial internal carotid artery (EC-ICA) occlusion in the setting of acute ischemic stroke (AIS) are lacking. Different antiplatelet regimen are used in association to endovascular therapy (EVT) for the treatment of EC-ICA lesions. We aimed to compare the clinical and radiological effects of three intravenous antiplatelet agents used during emergent EC-ICA stenting.

MATERIAL AND METHODS

Clinical data were collected from January 2015 to December 2019 in a monocentric prospective registry of AIS patients treated by EVT. All patients who underwent emergent EC-ICA stenting were sorted regarding the intravenous antiplatelet agent used during the procedure.

RESULTS

Among 218 patients treated by EVT for an EC-ICA occlusion of the anterior circulation during the study period, 70 underwent an emergent stenting of the EC-ICA. 60 were included in the present study, 9 received intravenous (IV) Cangrelor, 8 IV abciximab and 43 Aspirin. The rate of favorable neurological outcome, defined as modified Rankin Scale (mRS) ≤ 2 at three months were better in the Cangrelor and Aspirin groups (66,7% and 58,1%, respectively) than in the Abciximab group (37,5%), as well as, the rate of any intracranial ICH (22,2% and 37,2% vs 62,5%). The rate of acute stent reocclusion was similar between groups.

CONCLUSION

When used as a rescue treatment during emergent stenting of EC-ICA, Cangrelor and Aspirin present a better safety profile than Abciximab, with less intracranial hemorrhages and a higher rate of good clinical outcome. Additional studies are needed to confirm these findings.

Safety of Glycoprotein IIb-IIIa Inhibitors Used in Stroke-Related Treatment: A Systematic Review and Meta-Analysis

Background:

Endovascular therapy and intravenous thrombolysis with recombinant tissue plasminogen activator are the 2 most recommended treatments for acute ischemic stroke (AIS). Glycoprotein (GP) IIb-IIIa inhibitors are short-acting selective reversible antiplatelet agents that emerged as promising therapeutic agents for AIS about 10 years ago. Given the unclear safety profile and application coverage of GP inhibitors, we conducted this meta-analysis to explore the same.

Methods:

We used GP IIb-IIIa inhibitors, intracranial hemorrhage, and mortality as the key words on Medline, Web of Science, and the Embase databases. Randomized controlled trials, prospective literatures, and retrospective studies in English published between 1990 and 2020 were screened. The outcomes were relative risk (RR) of death and 90-day intracerebral hemorrhage (ICH). We pooled the results in 2 categories and conducted a subgroup analysis stratified by different drugs. The choice of the effects model depended on the value of I².

Results:

In all, 3700 patients from 20 studies were included. No GP IIb-IIIa inhibitors were found to have a remarkable influence on the ICH rate. The RR values of symptomatic ICH for abciximab and eptifibatide were 4.26 (1.89, 9.59) and 0.17 (0.04, 0.69), respectively. Both tirofiban and abciximab could decrease the mortality rate within 90 days. Age > 70 years, National Institutes of Health Stroke Scale > 15, and overall dose > 10 mg are risk factors for ICH events with tirofiban usage. Thrombectomy combined with tirofiban was safe for arterial reocclusion prevention.

Conclusions:

In stroke-related treatment, administration of GP IIb-IIIa inhibitors could be safe, but care should be taken regarding drug species and doses. Abciximab can increase the risk of symptomatic intracranial hemorrhage. Tirofiban and eptifibatide can be considered safe in low doses. Suitable patients should be selected using strict criteria.

Transient Ischemic Attack Due to Early Carotid Stent Thrombosis: Successful Rescue with Rheolytic Thrombectomy and Systemic Abciximab

Purpose:

To describe a successful neurorescue technique in a patient with generalized seizures followed by hemiparesis immediately after carotid artery stenting (CAS) for a postsurgical restenosis.

Case Report:

A 65-year-old man with a symptomatic recurrent high-grade carotid stenosis after carotid endarterectomy was treated with CAS. The procedure was complicated by sudden transient ischemic attack caused by acute carotid stent thrombosis with clot propagation into the cerebral circulation. Percutaneous mechanical thrombectomy was performed with adjunctive infusion of intravenous abciximab, resulting in complete thrombus dissolution and resolution of neurological symptoms.

Conclusions:

Access to a mechanical thrombectomy device was essential for rapid thrombus extraction, and adjunctive abciximab aided in residual clot dissolution. As a result of this combined method of clot removal, a disastrous outcome was averted.

[Endovascular treatment of acute extracranial carotid artery occlusion]

Acute extracranial internal carotid artery (ICA) occlusions resulting in ischemic stroke are different from other forms of acute occlusions of cerebral vessels. The pathophysiological process involved in occlusion of the extracranial ICA is similar to processes observed in acute occlusion of the coronary arteries. The occluded segment of the ICA predominantly consists of an atherosclerotic plaque and a superimposed thrombus. Although the value of endovascular therapy has been established for intracranial occlusions, the acute treatment of extracranial ICA occlusions has not yet been proven in randomized studies. In these patients primary stenting of acute extracranial occlusions of the ICA is a treatment option with good clinical results. This review discusses the endovascular treatment of acute extracranial ICA occlusions.

Current Reperfusion Strategies for Acute Stroke

Stroke is the most common cause of permanent disability, the second most common cause of dementia, and the third most common cause of death in the Western world. The treatment of affected patients is a challenge because intravenous (IV) thrombolysis is often ineffective. IV thrombolysis on its own leads to a favorable clinical outcome in only 15% to 25% in patients with large-artery occlusion. Current reperfusion therapies enable high recanalization rates, high rate of favorable clinical outcome, and low complication rates. However, to achieve good clinical results, appropriate patient selection and the use of optimized stroke management system are obligate.

How Safe is Eptifibatide during Urgent Carotid Artery Stenting?

Background: Glycoprotein IIB/IIIA inhibitors are occasionally utilized during carotid artery stenting (CAS) in the presence or absence of a visualized intra-operative thrombus.

Objective: We assess the hemorrhagic and clinical outcomes associated with the use of eptifibatide during CAS.

Methods: A retrospective analysis of prospectively collected data on patients with the diagnosis of carotid artery stenosis underwent CAS in a single center. We identified those who received intravenous eptifibatide intra-operatively and compared to the rest of the cohort. Hemorrhagic outcomes included intracerebral hemorrhage (ICH) or groin hematoma that occurred during the hospital stay.

Results: In this analysis, 81 patients had CAS during a 3-year span; 16 of those had received 15 mg of intravenous eptifibatide intra-operatively. The mean age of the treated and untreated patients was similar (65.6 ± 13.4 versus 65.4 ± 10.2; P = 0.13). One patient (1.2%) in this series had ICH in the perioperative period that occurred in the non-eptifibatide group. Five patients (6.2%) in this series had groin hematoma; only one in the non-eptifibatide group required surgical repair. No mortality was reported and clinical outcomes including discharge modified Rankin scale, NIH stroke scale, as well as discharge destination were similar in both groups. A stratified analysis among those who underwent an urgent CAS showed no significant differences in the risks of hemorrhages or any clinical outcome (P > 0.05).

Conclusion: The use of eptifibatide during CAS is safe. The risk of any hemorrhagic complication is rare in this series; however, a prospective study to validate this observation will be helpful.

Carotid artery stenting in acute stroke

OBJECTIVES

The purpose of this study is to demonstrate the technical success of carotid artery stenting in acute extracranial internal carotid artery (ICA) occlusion as well as the benefit in clinical outcome.

BACKGROUND

Stroke caused by acute occlusion of the ICA is associated with a significant level of morbidity and mortality. For this type of lesion, treatment with standard intravenous thrombolysis alone leads to a good clinical outcome in only 17% of the cases, with a death rate as high as 55%. Recanalization of the occluded ICA can lead to an improvement in acute symptoms of stroke, prevent possible deterioration, and reduce long-term stroke risk. At present, there is no consensus treatment for patients with acute ischemic stroke presenting with severe clinical symptoms due to atherosclerotic occlusion of the extracranial ICA.

METHODS

Carotid artery stenting was performed in 22 patients with acute atherosclerotic extracranial ICA occlusion within 6 h of stroke symptom onset. In 18 patients, there was an additional intracranial occlusion at the level of the terminal segment of the ICA (n = 4) and at the level of the middle cerebral artery (n = 14). Intracranial occlusions were either treated with the Penumbra system or the Solitaire stent-based recanalization system, or a combination of mechanical recanalization and intra-arterial thrombolysis. Recanalization results were assessed by angiography immediately after the procedure. The neurologic status was evaluated before and after the treatment with a follow-up as long as 90 days using the National Institutes of Health Stroke Scale and the modified Rankin Scale.

RESULTS

Successful revascularization of extracranial ICA with acute stent implantation was achieved in 21 patients (95%). There was no acute stent thrombosis. After successful recanalization of the origin of the ICA, the intracranial recanalization with Thrombolysis In Myocardial Infarction flow grade 2/3 was achieved in 11 of the 18 patients (61%). The overall recanalization rate (extracranial and intracranial) was 14 of 22 patients (63%). Nine patients (41%) had a modified Rankin Scale score of ≤2 at 90 days. The mortality rate was 13.6% at 90 days.

CONCLUSIONS

Carotid artery stenting in acute atherosclerotic extracranial ICA occlusion with severe stroke symptoms is feasible, safe, and useful within the first 6 h after symptom onset.

The endovascular management of intracranial vascular disease including the MERCI device

The prompt and aggressive management of acute stroke has become the standard of care as public awareness and the available successful treatment options both increase. The intravenous administration of tissue plasminogen activator within an established treatment window has been determined through large well-designed studies. The endovascular strategies for acute stroke have evolved significantly over the past 5 years and have been prompted by the limits of the intravenous treatment, as well as by the desire to demonstrate improved recanalization rates and improved long-term outcomes. Among these interventional treatment options are the intra-arterial administration of tissue plasminogen activator and newer antiplatelet agents, mechanical thrombectomy with the MERCI device, and intracranial angioplasty and stenting. This article outlines the major studies that have defined the current field of acute stroke management and discusses the basic treatment paradigms that are commonly used today.

Endovascular management of acute ischemic stroke

The management of stroke has progressed significantly over the past 2 decades due to successful treatment protocols including intravenous and intraarterial options. The intravenous administration of tissue plasminogen activator within an established treatment window has been proven in large, well-designed studies. The evolution of endovascular strategies for acute stroke has been prompted by the limits of the intravenous treatment, as well as by the desire to demonstrate improved recanalization rates and improved long-term outcomes. The interventional treatment options available today are the intraarterial administration of tissue plasminogen activator and newer antiplatelet agents, mechanical thrombectomy with the MERCI device and the Penumbra system, and intracranial angioplasty and stent placement. In this review the authors outline the major studies that have defined the current field of acute stroke management and discuss the basic treatment paradigms that are commonly used today.

Rescue use of tirofiban for acute carotid in-stent thrombosis

Carotid artery stenting is widely performed for extracranial carotid artery stenosis. In-stent thrombosis is a rare but potentially devastating complication. We present a case of acute in-stent thrombosis immediately following stent insertion and post-balloon dilatation in a 64-year-old male. Thrombosis was successfully treated by intravenous tirofiban, a glycoprotein IIb/IIIa receptor inhibitor.

Intensive treatment of hypertension decreases the risk of hyperperfusion and intracerebral hemorrhage following carotid artery stenting

OBJECTIVES

To assess the efficacy of a comprehensive blood pressure (BP) management protocol in reducing intracerebral hemorrhage (ICH) following carotid artery stenting (CAS).

BACKGROUND

Following CAS hyperperfusion syndrome (HPS) can lead to significant morbidity and mortality. Hypertension plays an essential role in its development.

METHODS

We instituted a comprehensive BP protocol following the last case of ICH complicating a CAS procedure. All patients received comprehensive monitoring of BP and treatment to a BP < 140/90 mm Hg; those with a treated stenosis >or=90%, contralateral stenosis >or=80%, and hypertension (i.e., risk factors for HPS) were treated to a BP < 120/80 mm Hg. Patients who developed HPS received parenteral beta-blockers or nitrates titrated to resolution of symptoms and discharged when asymptomatic and normotensive. Patients and families were instructed to measure BP twice daily for 2 weeks and to call if hypertension or headache developed.

RESULTS

A total of 836 patients had CAS, 266 prior to the comprehensive BP management program and 570 subsequently. The incidence of HPS/ICH was 5/266 (1.9%) patients prior to comprehensive BP management and 3/570 (0.5%) patients afterwards, P = 0.12. The incidence of ICH was 3/266 (1.1%) and 0/570, respectively, P = 0.032. In high-risk patients both HPS and ICH were significantly reduced from 29.4 to 4.2% (P = 0.006) and 17.6-0% (P = 0.006), respectively. There were no complications attributable to the comprehensive program and lengths of hospitalization were similar (2.6 vs. 2.1 days, P = 0.18).

CONCLUSIONS

Comprehensive management of arterial hypertension can lower the incidence of ICH and HPS in high-risk patients following CAS, without additional complications or prolonged hospitalizations.

Glycoprotein IIb/IIIa antagonists during carotid artery stenting:

BACKGROUND

Glycoprotein II b/IIIa antagonists (GPII b/IIIa-A) lower the periprocedural rate of ischemic events during high risk percutaneous coronary interventions. Their clinical impact on carotid artery stenting (CAS) remains to be determined.

METHODS

We analyzed data from the Carotid Artery Stent (CAS) Registry.

RESULTS

From 01/ 2000 to 06/2005 1322 CAS interventions were registered. In 94 (7.1%) procedures a GPII b/IIIa-A was used: abciximab in 8 cases (8.6%), tirofiban in 53 cases (57%) and eptifibatide in 32 cases (34.4%). The use of a GPII b/IIIa-A during CAS decreased significantly over time: from 17.6% in 2000 to 3% in 2005, p for trend <0.0001. The mean use of a GPII b/IIIa-A at the hospitals was 5.2%. More than 50% of the hospitals never used a GPII b/IIIa-A. There were no significant differences in baseline characteristics and concomitant diseases in CAS patients treated with GPII b/IIIa-A compared to those without GPII b/IIIa-A. A bilateral intervention was performed more often in patients treated with GPII b/IIIa-A (2.1 vs 0.2%, p = 0.04), a thrombus was more often visible (27 vs 12.4%, p <0.001) and an ulcer more frequently diagnosed (50 vs 37.5%, p = 0.03). There was no significant difference in the combined death or stroke rate between the two groups (5.3 vs 3.0%, p = 0.22, OR = 1.81, 95% CI: 0.69-4.72), which was confirmed by logistic regression analysis after adjusting for possible confounders (OR = 1.67, 95% CI: 0.62-4.46, p = 0.31).

CONCLUSIONS

Our data neither demonstrate a significant benefit nor a significant risk with the use of GPIIb/IIIa-A during CAS. However, only an adequately sized randomized controlled clinical trial could establish the real value of GPII b/IIIa-A during CAS. Until then, considering the potential increase in cerebral hemorrhage, we should not use GPII b/ IIIa-A routinely during CAS.

The endovascular management of intracranial vascular disease including the MERCI device

The prompt and aggressive management of acute stroke has become the standard of care as public awareness and the available successful treatment options both increase. The intravenous administration of tissue plasminogen activator within an established treatment window has been determined through large well-designed studies. The endovascular strategies for acute stroke have evolved significantly over the past 5 years and have been prompted by the limits of the intravenous treatment, as well as by the desire to demonstrate improved recanalization rates and improved long-term outcomes. Among these interventional treatment options are the intra-arterial administration of tissue plasminogen activator and newer antiplatelet agents, mechanical thrombectomy with the MERCI device, and intracranial angioplasty and stenting. This article outlines the major studies that have defined the current field of acute stroke management and discusses the basic treatment paradigms that are commonly utilized today.

Intracranial Hemorrhage After Carotid Angioplasty:A Pooled Analysis

PURPOSE

To use a pooled analysis of the literature to find the incidence of and characteristics common to intracranial hemorrhage (ICH) associated with carotid artery stenting (CAS).

METHODS

A search of the English-language literature (1996-2005) was performed in PubMed to find cases of CAS-associated ICH. Information was derived from the identified case studies in 5 categories and 19 aspects: (1) incidence of CAS-associated ICH; (2) demographic data (sex, age, symptom presentation, and presence of preexisting hypertension); (3) imaging data (side of lesion, degree of maximal stenosis, lesion location, status of the contralateral carotid artery, collateral circulation, and preprocedural imaging features); 4) procedure-related characteristics (antithrombotic medication, use of cerebral protection devices, residual stenosis, symptoms, interval from the procedure to ICH, type of ICH, and blood pressure changes); and (5) clinical outcome.

RESULTS

Fifty-four cases of CAS-associated ICH were reviewed: 51 cases from 36 published articles and our own 3 cases. The incidence of CAS-associated ICH was 0.63% (95% CI 0.38% to 0.97%) in studies consisting of >100 cases, which was significantly lower (p<0.0001) than that of case series consisting of <100 cases (2.69%, 95% CI 1.75% to 3.94%). Distinctive features included symptomatic lesions, severe stenosis (> or =90%), maximal stenosis in the internal carotid artery (ICA) distal to the bifurcation, and preexisting cerebral infarction.

CONCLUSION

The incidence of CAS-associated ICH was significantly lower in series consisting of >100 cases. More caution should be directed toward patients with symptomatic lesions, severe stenosis, maximal ICA stenosis distal to the carotid bifurcation, and preexisting cerebral infarction.

Pharmacotherapy for patients undergoing carotid stenting

Stroke is the second most common cause of death worldwide [Murray CJ, Lopez AD. Mortality by cause for eight regions of the World: Global Burden of Disease Study, Lancet 1997;349:1269-76. [1]] and remains one of the most common and disabling neurological disorders, particularly in the elderly. Survivors of stroke remain at high risk for developing further vascular events including recurrent strokes, myocardial infarction and vascular deaths. Treatment modalities for such patients include life style modifications, drug therapy and where applicable, surgical or endovascular intervention. Carotid artery disease is implicated in 20-30% of the population as the aetiology for stroke [De Bakey ME. Carotid endarterectomy revisited, J Endovasc Surg 1996;3:4. [2]]. This article examines the pharmacotherapy for patients undergoing carotid stenting. This will be divided into best medical therapy for these patients, and is the same as that that should be given to all patients following transient ischaemic attack (TIA) or stroke. It will provide a concise description of the safety profile, dosage, indications and contraindications of the various drugs that are currently available to reduce the risk of further TIA or stroke. Then the specific drugs used in the peri-procedural period during carotid stenting will be described, along with the evidence supporting their use.

The use of abciximab in the treatment of acute cerebral thromboembolic events during neuroendovascular procedures

BACKGROUND

Recently, a great interest has emerged regarding the use of abciximab for treatment of stroke. Thromboembolic events that occur during neuroendovascular procedures represent a unique subset of stroke patients because definitive angiographic diagnosis and treatment can be performed immediately. The existing literature on this situation suggests excellent results; however, most publications are case reports, and the largest series is 13 cases. We report our experience using abciximab in the treatment of acute thromboembolic events that occur during neuroendovascular procedures.

METHODS

We reviewed the last 1373 consecutive patients who underwent neuroendovascular procedures at the University of Florida from our prospectively maintained clinical database. Of these patients, 29 (2.11%) endovascular cases were complicated by acute cerebral thromboembolic events that were treated with abciximab. Abciximab was administered in less than 1 hour after the onset of the occlusion in every patient. The Thrombolysis In Myocardial Infarction (TIMI) scale was used to measure immediate angiographic outcome, and the Modified Rankin Scale (MRS) was used to measure clinical outcome at the time of follow-up. Independent outcome was defined as an MRS of 3 or less at follow-up.

RESULTS

Angiographic improvement in the TIMI grade was achieved in 29 (81%) of 36 arteries. Three intracerebral hemorrhages occurred with abciximab when administered with concurrent mechanical clot disruption; in two of these hemorrhages, recombinant tissue plasminogen activator (r-tPA) was also administered. The mean follow-up time for the living cohort was 7.54 months. Twenty-four (83%) patients were independent at follow-up, 3 (10%) were dependent at follow-up, and 2 (7%) died.

CONCLUSION

Abciximab appears to be safe and effective in the treatment of acute cerebral thromboembolic complications during neuroendovascular procedures.

Successful Recanalization by In-Stent Percutaneous Transluminal Angioplasty With Distal Protection for Acute Carotid Stent Thrombosis-Case Report-

A 71-year-old male presented with severe left cervical internal carotid artery stenosis manifesting as repeated transient ischemic attacks consisting of right hemiparesis and motor aphasia. Carotid artery stenting (CAS) under distal protection was performed to prevent further ischemic events. This procedure was uneventful. However, the patient exhibited progressive right hemiparesis and motor aphasia 3 days after CAS. Emergent angiography revealed carotid artery occlusion due to in-stent thrombosis. In-stent percutaneous transluminal angioplasty (PTA) was performed under distal protection. The carotid artery was recanalized with small residual thrombus. The neurological deficits almost completely disappeared after PTA. Follow-up angiography 9 months after stenting showed restenosis but no in-stent thrombosis. Carotid thrombosis after CAS can be resolved by in-stent PTA under distal protection and subsequent treatment with antithrombotic agents.

Safety of Abciximab Administration During PCI of Patients with Previous Stroke

OBJECTIVES

To examine the frequency of cerebrovascular complications among patients receiving abciximab (AB) undergoing PCI with prior intracranial hemorrhage (ICH) or recent (< 2 years) ischemic strokes.

BACKGROUND

AB improves clinical outcomes in high-risk patients undergoing percutaneous coronary intervention (PCI); however, the safety of AB in patients with prior stroke has not been adequately studied.

METHODS

A database review of 7,244 consecutive PCIs, from 7/97 to 10/01, identified 6,190 PCIs performed with AB among which 515 interventions were performed in patients with prior stroke history [ICH or recent ischemic stroke, (n = 101) and remote (> 2 years) ischemic stroke, (n = 414)].

RESULTS

The post-PCI stroke rate was significantly higher in patients with prior stroke (2.06% vs. 0.35%, p < 0.001 for all stroke; 0.38% vs. 0.03%, p = 0.023 for ICH). The incidence of ICH among the AB-treated group was 0.065%; a history of prior stroke did not increase the incidence of ICH in the AB-treated group (0.39% vs. 0.0%, p = ns). Moreover, the post-PCI stroke rate was similar between the prior ICH or recent ischemic stroke-group and remote ischemic stroke-group (2 vs. 1.9%; OR: 1.03; 95% CI: 0.21-4.90; p = ns for all strokes; 2% vs. 1.5%; OR: 1.4; 95% CI: 0.27-6.91; p = ns for ischemic stroke). Importantly, no ICH occurred in patients with recent ischemic or any prior ICH stroke.

CONCLUSIONS

Abciximab, in addition to aspirin, heparin and ADP-inhibitors does not increase the risk of stroke in patients with prior stroke undergoing PCI.

Therapeutic potential of platelet glycoprotein IIb/IIIa receptor antagonists in acute ischaemic stroke: scientific rationale and available evidence

Acute ischaemic stroke is the result of an abrupt interruption of focal cerebral blood flow. In the majority of cases, this interruption is caused by an acute thromboembolism. Based on clinical experience in the treatment of acute coronary syndromes, platelet glycoprotein (GP) IIb/IIIa receptor antagonists alone, in combination with reduced doses of thrombolytic agents, or as complementary therapy for short-term mechanical interventions merit consideration as a class of agents with potential use in ischaemic stroke. Research to date and extrapolation from the cardiac literature suggest significant, but as yet unproven, potential for the use of GP IIb/IIIa receptor antagonists in the treatment of acute ischaemic stroke. This potential exists both at the site of the thromboembolic occlusion and at the distal microvascular level. This article reviews the scientific rationale and available evidence for the potential use of platelet GP IIb/IIIa receptor antagonists in acute ischaemic stroke.

Intravenous abciximab for parent vessel thrombus during basilar apex aneurysm coil embolization: case report and literature review

BACKGROUND

Parent vessel thrombus formation is a serious complication of intracranial aneurysm embolization. The management of this issue is controversial. Abciximab, a potent platelet inhibitor, has been shown to have thrombolytic effects during coronary interventions. A small number of cases have demonstrated its potential application in neuroendovascular procedures. We review the literature on the management of parent vessel thrombosis during aneurysm coil embolization and report our successful experience with the use of IV abciximab to treat parent vessel thrombus formation related to coil embolization of a basilar apex aneurysm.

CASE DESCRIPTION

A 45-year-old man presented to our center with an incidental basilar apex aneurysm. After being informed of the surgical and endovascular treatment options, he elected to undergo coil embolization of the aneurysm. During the procedure, acute thrombus was noted in the left P1 segment of the posterior cerebral artery. IV abciximab was administered, and an angiogram the following day showed complete dissolution of the clot. The patient had no neurologic sequelae.

CONCLUSIONS

IV abciximab appears to be an effective option in the management of acute parent vessel thrombus encountered during coil embolization of unruptured aneurysms. Sufficient data are lacking regarding its use in the setting of a ruptured aneurysm.

Intracranial Haemorrhage Probably Due to an Angiographically Occult AVM after Carotid Stenting. A Case Report

SUMMARY

Angiographically occult vascular malformations refer to cerebrovascular malformations that are not demonstrable on technically satisfactory cerebral angiography. Authors herein present a very unusual intracranial bleeding complication related to an angiographically occult vascular malformation after extracranial carotid artery stenting procedure. A 52-year-old male patient admitted to the hospital with 2 episodes of amaurosis fugax in the left eye. Cervical carotid angiography and bilateral carotid Doppler ultrasonography revealed a 98% stenosis of the left internal carotid artery just distal to the bifurcation. Post-stenting control cervical carotid angiography revealed neither any residual stenosis nor a developmental venous anomaly. The patient developed left pupil dilatation with loss of consciousness two hours after the neurovascular intervention. Emergent cranial CT showed acute subdural haematoma, intracerebral and subarachnoid haemorrhage with massive midline shift. He underwent an emergent craniotomy with left temporal lobectomy. Abnormal cortical vascular structures with prominent engorgement were remarkable over the posterior temporal cortex. Histopathological studies confirmed the diagnosis of an occult AVM. Classically, these lesions are not visualized with angiography.Our patient's cerebral angiography and MR investigations were all normal. To our knowledge this is the first case in literature in which intracranial haemorrhage (acute subdural haematoma, intracerebral haematoma, SAH) occurred due to hyperperfusion of angiographically occult vascular malformation.

Intravenously Administered Abciximab in the Management of Early Cerebral Ischemia after Carotid Endarterectomy: Case Report

OBJECTIVE AND IMPORTANCE:

Cerebral ischemia is the most worrisome perioperative complication of carotid endarterectomy (CEA). The stroke rate occurring with CEA is estimated to range from 2.3 to 6.3%. Numerous treatment options are available to the neurosurgeon in this scenario, although no “gold standard” exists.

CLINICAL PRESENTATION:

A 61-year-old woman presented with acute left arm weakness 40 minutes after an uneventful CEA for symptomatic carotid stenosis. Emergent angiography demonstrated vascular irregularities in a “moth-eaten” pattern along the arteriotomy closure, suggestive of platelet-fibrin aggregates (“white clot”).

INTERVENTION:

Abciximab was immediately administered intravenously in the angiography suite, with subsequent improvement of the visualized vascular irregularities on a second angiogram performed 12 minutes after infusion and complete resolution of the presumed platelet-fibrin aggregates on a third angiogram performed the next day. The patient had no further episodes of cerebral ischemia. She was discharged home on the fifth postoperative day with improving left arm weakness, which had completely resolved by her 2-month follow-up visit.

CONCLUSION:

To our knowledge, this is the first reported case of abciximab administered intravenously in the setting of acute thromboembolic brain ischemia after CEA. For the unique situation in which an acute thrombus, or white clot, is thought to be the cause of cerebral ischemia, we believe that abciximab may offer an effective and potentially safer alternative than fibrinolytics and may be a more appropriate drug to use from a physiological perspective.

Modulating thrombotic potential in catheter-based percutaneous coronary and peripheral vascular interventions

Thrombosis is an obligatory consequence of all percutaneous vascular interventions. Balloon angioplasty, intravascular stents and other devices routinely used to facilitate dilatation of critical vascular stenoses result in fracture of the intima and exposure of the thrombogenic subendothelium with initiation and perpetuation of platelet activation and aggregation. This not uncommonly results in thrombus formation that may lead to abrupt vessel closure, distal ischemia and tissue infarction, and target organ dysfunction. Fortunately, advances in our understanding of the mechanisms that underlie vascular thrombosis have led to advances in the use of adjunctive pharmacological agents that modulate this pathophysiological response and have led to important reductions in the incidence and severity of thrombotic complications of percutaneous transluminal interventions.

Noncardiac applications of glycoprotein IIb/IIIa inhibitors

Platelet activation and aggregation have become increasingly recognized as the primary processes involved in the cascade that leads to thrombus formation in atherosclerotic vascular disease. Glycoprotein IIb/IIIa receptor inhibitors (GPI) favorably impact thrombus formation and distal embolization by inhibiting the final common pathway of platelet aggregation. Glycoprotein IIb/IIIa inhibitors have been used effectively in a wide variety of clinical scenarios including unstable angina, non-ST segment elevation myocardial infarction, ST segment elevation myocardial infarction, and low and high risk percutaneous coronary interventions with and without intracoronary stenting, however there is limited data regarding the use of these potent antiplatelet agents in the setting of extracardiac vascular disease. This article will review the non-cardiac applications of glycoprotein IIb/IIIa inhibitors in the setting of acute ischemic stroke, carotid and vertebral angioplasty and stenting, acute critical limb ischemia, and percutaneous interventions in peripheral arterial occlusive disease.

Comparison of periprocedure complications resulting from direct stent placement compared with those due to conventional and staged stent placement in the basilar artery

OBJECT

Medically refractory, symptomatic atherosclerotic disease of the basilar artery (BA) portends a poor prognosis. Studies have shown morbidity rates following placement of stents in these lesions to be quite variable, ranging from 0 to 30%. The authors review their experience with BA stent placement for severe atherosclerotic disease to determine whether an increase in neurological morbidity is associated with direct stent placement (that performed without predilation angioplasty) compared with conventional stent placement (that performed immediately after predilation angioplasty) or staged stent placement (angioplasty followed > or = 1 month later by stent placement with or without repeated angioplasty).

METHODS

The authors retrospectively reviewed the medical records from a consecutive series of 10 patients who underwent stent placement for medically refractory, symptomatic atherosclerotic disease of the BA between February 1999 and November 2002. Patient records were analyzed for symptoms at presentation, percentage of angiographically visible stenosis, devices used, procedure-related morbidity, and clinical and radiographic outcomes. Patients with symptomatic intracranial vertebral artery stenosis but without concomitant severe (> 50%) BA stenosis were excluded from the study. Four patients were treated with direct stent placement, three with a staged procedure (these were included in a previous publication), and three with conventional stent placement. In the group treated with direct stent placement, a dense quadriparesis developed in two patients after the procedure. Computerized tomography or magnetic resonance imaging revealed infarction of the ventral pons in these patients. In the staged stent placement group, no permanent neurological complications occurred after the procedure and, in the conventional stent placement group, one of three patients experienced a neurological complication involving homonymous hemianopsia.

CONCLUSIONS

Direct stent placement in the BA is associated with a relatively high complication rate, compared with a staged procedure. Complications may result from an embolic shower following disruption of atheromatous plaque debris attained using high-profile devices such as stents, as demonstrated by the postoperative imaging appearance of acute pontine infarctions. Additionally, displacement of debris by the stent into the ostia (snowplowing) of small brainstem perforating vessels may be responsible for the complications noted. Although direct stent placement in peripheral and coronary vessels has been shown to be safe, the authors suggest that direct stent placement in the BA should be avoided to minimize the risk of periprocedure morbidity.

Carotid Artery Stenting in a Community Setting: Experience Outside of a Clinical Trial

Carotid artery angioplasty and stenting (CAS) currently represents a less invasive percutaneous alternative to conventional endarterectomy for the treatment of carotid occlusive disease. We report here the results and complication rates of CAS performed by a team of interventionalists at a non-clinical trial center utilizing a standardized CAS protocol. CAS was attempted in 51 arteries in 48 patients (mean age 71 +/- 9 years, range 53-90). Fifteen (29%) of 48 patients were symptomatic. Indications for CAS were previous ipsilateral endarterectomy (15/51, 29%), previous neck radiation therapy (1/51, 2%), or significant coronary artery disease (30/51, 59%). SMART((R)) stents were deployed via percutaneous femoral artery access, with anticoagulation (heparin, abciximab, aspirin, clopidogrel) and temporary transvenous cardiac pacemakers employed in all patients. Neuroprotection was not used. Neurological examination and duplex scans were performed in follow-up. CAS was successfully performed in 96% of cases (49 lesions/46 patients) with angiographic stenoses of 88 +/- 8%. Neurological complications included one (2%) minor stroke that occurred 12 hr after CAS. There were no periprocedural mortalities. Clinically significant bradycardia or asystole occurred in 11/49 (22%) procedures, necessitating short-term ventricular pacing. All stented vessels remained patent during 12.2 +/- 10.1 (range 1-37) months follow-up period. One asymptomatic restenosis (>70%) occurred at 3 months, which was successfully reangioplastied; we thus had 1-year angiographic restenosis rate of 2%. Patients selected for CAS may represent a subset of patients with carotid disease who have considerable comorbidities or unfavorable anatomy compared to those undergoing conventional endarterectomy. CAS may be performed safely outside of a clinical trial with results similar to those of published series from trial centers using a standardized protocol.

Hyperperfusion Syndrome: Toward a Stricter Definition

OBJECTIVE

Hyperperfusion syndrome is a rare and potentially devastating complication of carotid endarterectomy or carotid artery angioplasty and stenting. With the advent of new imaging techniques, we reviewed our experience with this phenomenon.

METHODS

This report is a retrospective review of 129 consecutive cases of carotid endarterectomy performed between June 1, 2000, and May 31, 2002, and 44 consecutive cases of carotid artery angioplasty and stenting performed between January 1, 1997, and May 31, 2002. We specifically searched for examples of patients who developed postprocedural nonthrombotic neurological deficits that typified the hyperperfusion syndrome.

RESULTS

Seven cases of hyperperfusion syndrome occurred, four after endarterectomy (3.1% of carotid endarterectomy cases) and three after stenting (6.8% of stenting cases). The cases of hyperperfusion were classified as presenting with 1) acute focal edema (two cases with stroke-like presentation, attributable to edema immediately after revascularization), 2) acute hemorrhage (two cases of intracerebral hemorrhage immediately after stenting and one case immediately after endarterectomy), or 3) delayed classic presentation (two cases with seizures, focal motor weakness, and/or late intracerebral hemorrhage at least 24 hours after endarterectomy).

CONCLUSION

Hyperperfusion syndrome may be more common and more variable in clinical presentation than previously appreciated.

Use of abciximab during infrainguinal peripheral vascular interventions: initial experience

PURPOSE

To investigate the use of abciximab as an adjunct during infrainguinal angioplasty.

MATERIALS AND METHODS

Abciximab was used in conjunction with recanalization techniques and angioplasty to treat stenoses or occlusions in 16 patients: 10 patients had high-grade stenoses or occlusions longer than 5 cm in the superficial femoral artery and popliteal artery, and six patients had stenoses or occlusions below the popliteal artery. All patients received a bolus of heparin after arterial access was achieved. Abciximab was administered by means of a weight-base nomogram that consisted of an initial bolus followed by an overnight infusion. Technical success was defined as a less than 30% residual stenosis after angioplasty. Patients were carefully followed up for possible postprocedural complications. Platelet counts were monitored for 24 hours.

RESULTS

Technical success was achieved in 15 (94%) of 16 patients. One occlusion of the superficial femoral artery could not be crossed. There was a mean postprocedural increase of 0.23 in the ankle-brachial index. There was no significant effect on platelet count. Two minor complications occurred. One major complication occurred; this was a groin hematoma, which required a blood transfusion.

CONCLUSION

The use of abciximab as an adjunct during complex infrainguinal arterial interventions appears promising, on the basis of initial experience.

Evaluation of glycoprotein IIb/IIIa inhibitors in carotid angioplasty and stenting

PURPOSE

To review the immediate neurological and bleeding complications associated with the use of glycoprotein (GP) IIb/IIIa inhibitors in patients undergoing extracranial carotid artery stent placement.

METHODS

A retrospective review was performed of 550 patients (321 men; mean age 71.1 years, range 28-91) who underwent carotid artery angioplasty and stent placement. Glycoprotein IIb/IIIa inhibitors were given prophylactically along with heparin to 216 patients, whose outcomes were compared to a control group of 334 patients who received intravenous heparin alone. Primary endpoints were the immediate and 30-day neurological complications, including transient ischemic attacks (TIAs), minor and major strokes, and neurologically-related deaths. The secondary endpoint was any abnormal bleeding.

RESULTS

The all stroke/neurological death rate in 216 patients treated with heparin and GP IIb/IIIa inhibitors was 6.0% (13 events) compared 2.4% (8 events) in the 334 patients in the heparin-only control group (p=0.0430). Two of the 4 neurologically-related deaths in the GP IIb/IIIa inhibitor group resulted from intracranial hemorrhages; there were no intracranial hemorrhages in the heparin-only group. There was 1 episode of extracranial bleeding in the GP IIb/IIIa inhibitor group treated with embolization. The incidences of significant puncture-site bleeding requiring transfusion were similar in the groups.

CONCLUSIONS

Neurological complications following percutaneous carotid artery interventions have been relatively few. The neurological sequelae in carotid stent patients receiving glycoprotein IIb/IIIa inhibitors were more numerous and consequential, which suggests that the use of GP IIb/IIIa inhibitors in carotid stenting should be discouraged.

Staged stent-assisted angioplasty for symptomatic intracranial vertebrobasilar artery stenosis

OBJECT

Medically refractory symptomatic vertebrobasilar atherosclerotic disease has a poor prognosis. Studies have shown that longer (> or = 10 mm), eccentric, high-grade (> 70%) stenoses portend increased procedure-related morbidity. The authors reviewed their experience to determine whether a staged procedure consisting of angioplasty followed by delayed (> or = 1 month later) repeated angioplasty and stent placement reduces the morbidity associated with endovascular treatment of symptomatic basilar and/or intracranial vertebral artery (VA) stenoses.

METHODS

The authors retrospectively reviewed the medical records in a consecutive series of eight patients who underwent planned stent-assisted angioplasty for medically refractory, symptomatic atherosclerotic disease of the intracranial posterior circulation between February 1999 and January 2002. Staged stent-assisted angioplasty was planned for these patients because the extent and degree of stenosis of the VA and/or basilar artery (BA) lesion portended an excessive procedure-related risk. The degree of stenosis, recent onset of symptoms (unstable plaque), vessel tortuosity, and lesion length and morphological feaures were contributing factors in determining procedure-related risk. Patient records were analyzed for location and degree of stenosis, preprocedural regimen of antiplatelet and/or anticoagulation agents, devices used, procedure-related complications, and clinical and radiographic outcomes. Among the patients in whom staged stent-assisted angioplasty was planned, vessel dissection, which necessitated immediate stent placement, occurred during passage of the balloon in one of them. In a second patient, the stent could not be maneuvered through the tortuous VA. In a third patient, the VA and BAs remained widely patent after angioplasty alone, and therefore stent placement was not required. Significant complications among the eight patients included transient aphasia and hemiparesis in one and a groin hematoma that necessitated surgical intervention in another; there was no permanent neurological morbidity. The mean stenosis before treatment was 78%, which fell to 54% after angioplasty, and the mean residual stenosis after stent placement was 30%. At the last follow-up examination, none of the treated patients had further symptoms attributable to the treated stenosis.

CONCLUSIONS

The novel combination of initial angioplasty followed by delayed endoluminal stent placement may reduce the neurological morbidity associated with endovascular treatment of long, high-grade stenotic lesions. Attempting to cross high-grade stenoses with higher-profile devices such as stents may result in an embolic shower. Furthermore, neointimal proliferation and scar formation after angioplasty result in a thickened fibrous layer, which may be protective during delayed stent deployment. Larger-scale studies involving multiple centers are needed to elucidate further the lesion morphological characteristics and patient population most likely to benefit from staged procedures.

Embolization in atherosclerosis

Much has been learned about microembolization in the last two decades. The promising blood markers for brain injury will further enhance our future understanding of microembolic events. New surgical techniques, drugs, and devices have substantially reduced microembolization during carotid angioplasty, CEA, and CABG.

Stent-assisted endoluminal revascularization for the treatment of intracranial atherosclerotic disease

Since the inception of intravascular stents in the 1960s, marked technological advancements have yielded stents that can be navigated through tortuous cerebral vessels. Numerous applications for intracranial stenting are being developed at an exciting pace. One such application that has shown promise in several small series is the use of stents for endoluminal revascularization of severe intracranial stenosis that is refractory to medical therapy. Prior to the introduction of endovascular approaches for this condition, complex bypass procedures were often necessary to restore adequate blood flow to hypoperfused parenchyma. In the following article, we review endovascular techniques for stenting of intracranial atherosclerotic disease. Patient selection, vascular access, medical management, and future directions are discussed.