Endovascular Management of Intracranial Atherosclerosis

Multimodal imaging approach for the diagnosis of intracranial atherosclerotic disease (ICAD): Basic principles, current and future perspectives

PURPOSE

To review the different imaging modalities utilized in the diagnosis of Intracranial Atherosclerotic Disease (ICAD) including their latest development and relevance in management of ICAD.

METHODS

A review of the literature was conducted through a search in google scholar, PubMed/Medline, EMBASE, Scopus, clinical trials.gov and the Cochrane Library. Search terms included, "imaging modalities in ICAD," "ICAD diagnostic," "Neuroimaging of ICAD," "Evaluation of ICAD". A summary and comparison of each modality's basic principles, advantages and disadvantages were included.

RESULTS

A total of 144 articles were identified and reviewed. The most common imaging used in ICAD diagnoses were DSA, CTA, MRA and TCD. They all had proven accuracy, their own benefits, and limitations. Newer modalities such as VWI, IVUS, OCT, PWI and CFD provide more detailed information regarding the vessel walls, plaque characteristics, and flow dynamics, which play a tremendous role in treatment guidance. In certain clinical scenarios, using more than one modality has been shown to be helpful in ICAD identification. The rapidly evolving software related to imaging studies, such as virtual histology, are very promising for the diagnostic and management of ICAD.

CONCLUSIONS

ICAD is a common cause of recurrent ischemic stroke. Its management can be both medical and/or procedural. Many different imaging modalities are used in its diagnosis. In certain clinical scenario, a combination of two more modalities can be critical in the management of ICAD. We expect that continuous development of imaging technique will lead to individualized and less invasive management with adequate outcome.

Endovascular Therapy for Symptomatic Intracranial Artery Stenosis: a Systematic Review and Network Meta-analysis

Intracranial artery atherosclerotic stenosis (ICAS) is one of the most common causes of stroke. Endovascular therapy including balloon angioplasty alone (BA), balloon-mounted stent (BMS), or self-expanding stent (SES) was an important alternative to treat symptomatic ICAS refractory to medical treatment, while none of the three subtypes has been established to be the primary option. We conducted a systematic review and network meta-analysis to determine both the safety and efficacy and establish a hierarchy of different endovascular therapies on symptomatic ICAS. Major databases including MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for studies comparing outcomes of three different endovascular approaches and other comparable non-endovascular therapies for symptomatic ICAS patients published from 1 January 2000 to 1 November 2021. Primary outcomes included short-term mortality or stroke rate (peri-procedural, or mean follow-up ≤ 3 months), and long-term mortality or stroke rate (mean follow-up ≥ 6 months). Pairwise and network meta-analyses based on the above systematic review were conducted. A total of 19 eligible studies involving 3386 patients treated with 4 different approaches (BA, SES, BMS, and medical treatment) were analyzed. For primary outcome, BA had the highest ranking (SUCRA value 78), followed by BMS (SUCRA value 21.5) and SES (SUCRA value 13.1). The short-term mortality or stroke rate was significantly lower in the BA group compared to SES (OR = 2.50; 95% CI 1.12 to 5.57; p = 0.026) or BMS (OR = 0.43; 95% CI 0.19 to 0.96; p = 0.038). Other primary and secondary outcomes were no different among all three types of endovascular therapy. Overall, the studies were of good methodological quality and the consistency was acceptable across all network meta-analyses. BA offers the highest level of safety outcomes in terms of short-term mortality or stroke in treating symptomatic patients with intracranial artery stenosis, compared to SES and BMS, which needs to be confirmed in future studies. Trial registration in PROSPERO database: CRD42018084055.

Effects of mechanical thrombectomy for acute stroke patients with etiology of large artery atherosclerosis

AIMS

Atherosclerosis is more prevalent in Asian population. This distinct etiology of stroke might disadvantage Asian patients when applying. mechanical thrombectomy (MT). The purpose of this research was to evaluate the efficacy and safety of MT in a cohort of Chinese patients with acute ischemic stroke. due to large artery atherosclerosis (LAA).

METHODS AND RESULTS

A total of 649 patients treated with MT were included. Patients were classified according to etiology of stroke as LAA and cardioembolism ones. Successful revascularization was defined as modified Thrombolysis in Cerebral Infarction (mTICI) grade ≥ 2b. Favorable outcome was defined as modified Rankin Scale (mRS) score ≤ 2 at 90 days. Logistic regression was used to identify predictors for functional outcomes. The patients with stroke of LAA etiology had significantly higher rate of favorable functional outcome (50.2% vs 36.5%, p < .001) and good collateral (grade of ASITN/SIRI: 2-3) (58.8% versus 43.2%, p < .001), and lower median baseline National Institutes of Health Stroke Scale score (NIHSS) (15.6 versus 18.2, p < .001), compared to patients with stroke of cardioembolism etiology. There was no significant difference in the rate of successful postprocedural mTICI between groups (84.5% versus 83.2%, p = .671). Rates of symptomatic intracranial hemorrhage (20.0% versus 11.7%, p = .004) and mortality (31.8% versus 18.8%, p < .001) within 3 months were notably higher in the cardioembolism group than that in the LAA group.

CONCLUSION

Mechanical thrombectomy may be more efficacious in treating acute ischemic stroke of LAA etiology than that of cardioembolism etiology.

Endovascular treatment for symptomatic intracranial artery stenosis: protocol for a systematic review and network meta-analysis

INTRODUCTION

Atherosclerotic intracranial artery stenosis (ICAS) is one of most common causes of stroke, which is the second-leading cause of death worldwide. Medical, surgical and endovascular therapy are three major treatments for ICAS. Currently, medical therapy is considered as the standard of care for most patients with ICAS, while extracranial to intracranial bypass is only used in rare situations. Balloon angioplasty alone, balloon-mounted stent and self-expanding stent, collectively called endovascular treatment, have shown promising potentials in treating specific subgroups of patients with symptomatic ICAS; however, their comparative safety and efficacy is still unclear. Therefore, a systematic review with network meta-analysis is needed to establish a hierarchy of these endovascular treatments.

METHODS AND ANALYSIS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols was followed to establish this protocol. The search will be limited to studies published from 1 January 2000 to the formal search date. Major databases including Cochrane Library, MEDLINE, EMBASE, Chinese Biomedical Literature Database, conference proceedings and grey literature database will be searched for clinical studies comparing at least two interventions for patients with symptomatic ICAS. Primary outcomes include short-term and long-term mortality or stroke rate. Random effects pairwise and network meta-analyses of included studies will be performed on STATA (V.14, StataCorp, 2015). The surface under the cumulative ranking curve and mean rank will be calculated in order to establish a hierarchy of the endovascular treatments. Evaluation of the risk of bias, heterogeneity, consistency, transitivity and quality of evidence will follow the recommendations of the Cochrane Handbook for Systematic Reviews of Interventions.

ETHICS AND DISSEMINATION

Ethics approval is not needed as systematic review is based on published studies. Study findings will be presented at international conferences and published on a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42018084055; Pre-results.

Spanning from the West to East: An Updated Review on Endovascular Treatment of Intracranial Atherosclerotic Disease

Ischemic stroke is a major cause of morbidity and mortality, incurring significant cost. Intracranial atherosclerotic disease (ICAD) accounts for 10-15% of ischemic stroke in Western societies, but is an underlying pathology in up to 54% of ischemic strokes in Asian populations. ICAD has largely been treated with medical management, although a few studies have examined outcomes following endovascular treatment. Our objective was to summarize the major trials that have been performed thus far in regard to the endovascular treatment of ICAD and to provide direction for future management of this disease process. Systematic review of the literature from 1966 to 2015, was conducted in regard to intracranial angioplasty and stenting. Studies were analyzed from PubMed, American Heart Association and Society of Neurointerventional Surgery databases. SAMMPRIS and VISSIT are the only randomized controlled trials from which Western guidelines of intracranial stenting have been derived, which have displayed the superiority of medical management. However, pooled reviews of smaller studies and other nonrandomized trials have shown better outcomes with endovascular therapy in select patient subsets, such as intracranial vertebrobasilar stenosis or in the presence of robust collaterals. Suboptimal cases, including longer lesions, bifurcations and significant tortuosity tend to fair better with medical management. Medical management has been shown to be more efficacious with less adverse outcomes than endovascular therapy. However, the majority of studies on endovascular management included a diverse patient population without ideal selection criteria, resulting in higher adverse outcomes. Population analyses and selective utilization of endovascular therapy have shown that the treatment may be superior to other management in select patients.

The contemporary management of intracranial atherosclerotic disease

Intracranial atherosclerotic disease is the most common cause of cerebral vasculopathy and an important stroke etiology worldwide, with a higher prevalence in Asian, Hispanic and African ethnicities. Symptomatic intracranial atherosclerotic disease portends a recurrent stroke risk as high as 18% at one year. The key to secondary prevention is an understanding of the underlying stroke mechanism and aggressive control of conventional cardiovascular risks. Contemporary treatment includes antiplatelet therapy, optimal glycemic and blood pressure control, statin therapy and lifestyle modifications. For patients with high-grade (70-99%) symptomatic steno-occlusion, short-term dual antiplatelet therapy with aspirin and clopidogrel followed by life-long single antiplatelet therapy may reduce the recurrent risk. Current evidence does not advocate percutaneous transluminal angioplasty and stenting as an initial treatment. External counterpulsation, encephaloduroarteriosynangiosis and remote limb ischemic preconditioning are treatments under investigation. Future studies should aim at predicting patients prone to recurrence despite of medical therapies and testing the efficacy of emerging therapies.