Update in the treatment of intracranial atherosclerotic disease

Advancements in imaging of intracranial atherosclerotic disease: beyond the arterial lumen to the vessel wall

Intracranial atherosclerotic disease (ICAD) significantly increases the risk of ischemic stroke. It involves the accumulation of plaque within arterial walls and narrowing or blockage of blood vessel lumens. Accurate imaging is crucial for the diagnosis and management of ICAD at both acute and chronic stages. However, imaging the small, tortuous intracranial arterial walls amidst complex structures is challenging. Clinicians have employed diverse approaches to improve imaging quality, with a particular emphasis on optimizing the acquisition of images using new techniques, enhancing spatial and temporal resolution of images, and refining post-processing techniques. ICAD imaging has evolved from depicting lumen stenosis to assessing blood flow reserve and identifying plaque components. Advanced techniques such as fractional flow reserve (FFR), high-resolution vessel wall magnetic resonance (VW-MR), optical coherence tomography (OCT), and radial wall strain (RWS) now allow direct visualization of flow impairment, vulnerable plaques, and blood flow strain to plaque, aiding in the selection of high-risk stroke patients for intervention. This article reviews the progression of imaging modalities from lumen stenosis to vessel wall pathology and compares their diagnostic value for risk stratification in ICAD patients.

Predictors of successful recanalization following endovascular intervention in non-acute basilar artery occlusion

Objective

This study aims to identify factors influencing successful recanalization following endovascular intervention for non-acute basilar artery occlusion (NABAO).

Background

Endovascular treatment (EVT) is a feasible approach for treating non-acute basilar artery occlusion, but it presents significant technical challenges due to the lack of standardized treatment protocols. Therefore, identifying patients most likely to benefit is critical to minimizing procedural risks.

Methods

A retrospective analysis was conducted on 115 patients with NABAO treated via EVT. Factors associated with successful recanalization, including clinical symptoms, demographic characteristics, procedural outcomes, and imaging findings, were analyzed using multivariate analysis. A scoring system was developed based on independent predictors.

Results

Successful recanalization (defined as modified Thrombolysis in Cerebral Infarction [mTICI] ≥2b) was achieved in 81.7% (94/115) of cases. Multivariate analysis revealed that occlusion duration >3 months (odds ratio [OR]: 0.187, 95% confidence interval [CI]: 0.051-0.688, p = 0.012), blunt-shaped occlusion ends (OR: 0.236, 95% CI: 0.072-0.777, p = 0.018), occlusion length > 30 mm (OR: 0.144, 95% CI: 0.031-0.669, p = 0.013), and insufficient or absent distal compensation (OR: 0.25, 95% CI: 0.075-0.835, p = 0.024) were independent predictors of reduced technical success. The receiver operating characteristic (ROC) curve index for the scoring system, based on these independent predictors, was 0.817 (95% CI: 0.698-0.936, p < 0.001), with a sensitivity of 71.4% and a specificity of 85.4% at a cutoff of 2.5 points.

Conclusion

Longer occlusion duration (>3 months), blunt-shaped occlusion ends, occlusion length > 30 mm, and insufficient distal collateral compensation are independent negative predictors for successful recanalization in patients with NABAO treated via EVT. The proposed scoring system can help screen patients suitable for treatment and optimize treatment strategies, but further validation in prospective cohorts is needed.

Distinguishing stroke from transient ischemic attack using plaque characteristics and arterial transit artifacts

Purpose

We aimed to investigate the differences in plaque characteristics and hemodynamics in patients with ischemic stroke and transient ischemic attack (TIA), comparing the diagnostic abilities of high-resolution magnetic resonance imaging (HRMRI) and arterial spin labeling (ASL) for ischemic stroke.

Methods

This retrospective analysis included patients who underwent HRMRI and ASL between October 2020 and December 2023. We compared clinical risk factors, vascular plaque characteristics, and the presence of arterial transit artifacts (ATAs) at post-labeling delays (PLDs) of 1.5-s and 2.5-s between stroke and TIA groups. Multivariate logistic regression analysis was used to evaluate the diagnostic performance of different prediction models combining clinical factors, differential plaque characteristics, and the presence of ^PLD ATAs.

Results

A total of 147 patients (mean age, 57.12 ± 13.08 years; 102 men) were initially included in this study, divided into stroke (79) and TIA (68) groups. Significant differences in vascular positive remodeling, intraplaque hemorrhage, enhancement ratio, and the presence of 1.5-s and 2.5-s ATAs (p < 0.05) were observed between groups. Combined HRMRI and ASL performed best in distinguishing ischemic stroke and TIA (area under the curve [AUC], 0.926; 95% confidence interval [CI], 0.885-0.967), with no significant difference in ischemic stroke diagnostic performance between HRMRI and ASL (95% CI, -0.039 to 0.087, Z = 0.742, p = 0.458).

Conclusion

A model combined with plaque characteristics and ATAs showed good diagnostic performance in distinguishing between TIA and stroke in patients with intracranial atherosclerotic stenosis. ASL provides a simpler imaging evaluation method than HRMRI, and ATA evaluation may become a more widely used imaging marker in clinical practice.

Congenital and acquired anomalies of the basilar artery: A pictorial essay

INTRODUCTION

The basilar artery is one of the two cases in our body where an arterial vessel is formed by the union of two others - the vertebral arteries. It provides vascular supply to essential structures for the main vital functions; the posterior cerebral arteries originate from it as terminal branches, and form part of the anastomotic circle of Willis.

IMAGING FINDINGS

Congenital and acquired anomalies of the basilar trunk are described. We provide a schematic and detailed representation of normal anatomical variants - mainly represented by the fenestrated basilar artery or the persistence of carotid-basilar anastomosis; course anomalies are also illustrated, with reference to neuro-vascular conflicts and dolichoectasia. Among congenital anomalies, this pictorial review also shows the variants of the basilar origin, such as in the case of basilar trunk arising from only one of the two vertebral arteries, and the calibre changes - which are represented by aneurysm and hypoplasia. The latter appears to be a risk factor for posterior circulation stroke, when associated with a bilateral posterior foetal variant.Among the acquired forms, this pictorial essay describes some clinical cases of dissections, non-congenital aneurysms, thrombosis and tumour with vascular encasing or compression of basilar artery.

CONCLUSION

CT angiography and MRI allow us to study the posterior intracranial circulation in detail, providing useful pre-treatment information. Therefore, knowledge of congenital or acquired anomalies of the basilar artery is essential for radiologists, neuroradiologists and neurosurgeons.

Enterprise stents for the treatment of symptomatic non-acute intracranial artery stenosis disease: safety and efficiency evaluation

BACKGROUND

Enterprise stent was approved for the treatment of wide-necked intracranial aneurysms. However, it has been widely used in the endovascular treatment of intracranial artery stenosis, which is still controversial. The purpose of this study was to evaluate the safety and efficiency of the Enterprise stent in the endovascular treatment of intracranial artery stenosis disease.

METHODS

We conducted a retrospective case series of 107 patients with intracranial artery stenosis who received Enterprise stent implantation at Nanjing Drum Tower Hospital from January 2020 to December 2022. The rates of recanalization, perioperative complications, in-stent restenosis at 3-12 months and stroke recurrence were assessed for endovascular treatment.

RESULTS

A total of 107 individuals were included in this study, 88 were followed up, and 19 (17.8%) patients were lost to follow-up. The operation success rate was 100%, During the procedure,4（3.7%）patients had vasospasm, and 2(1.9%) patients showed symptomatic bleeding. The overall perioperative complication rate was 5.6%, including 2.8% distal artery embolism, 0.9% in-stent thrombosis, and 1.9% symptomatic bleeding. 88 (82.2%) patients were followed up from 3 to 12 months, of whom 12 (13.6%) had in-stent restenosis, 4 (4.7%) recurrent strokes and 2 died of pulmonary infection caused by COVID-19. Patients were divided into 3 groups according to the cerebral artery, including the middle cerebral artery group, internal carotid artery group, and vertebrobasilar artery group.

CONCLUSIONS

In this study, the placement of the Enterprise stent in patients with symptomatic non-acute intracranial stenosis was successful. However, the occurrence of periprocedural and long-term complications after stenting remains of high concern.

Assessment of paclitaxel drug-coated balloon angioplasty for intracranial atherosclerotic disease based on high-resolution vessel wall magnetic resonance imaging

BACKGROUND

To accurately assess the treatment effect of paclitaxel drug-coated balloon (DCB) angioplasty is essential for intracranial atherosclerotic disease (ICAD) patients. This study aimed to investigate the clinical feasibility of high-resolution vessel wall MRI (HR-VWI) in assessing ICAD with DCB angioplasty.

METHODS

Forty-five patients with intracranial atherosclerotic stenosis ≥ 70% confirmed by digital subtraction angiography (DSA) underwent HR-VWI before and after DCB angioplasty. Postoperative follow-up was performed after 6 months (±1 month). The differences of pre- and postoperative HR-VWI characteristics, including vessel and lumen area at maximal lumen narrowing (MLN), plaque area and length, degree of stenosis, plaque burden (PB), remodeling index, and plaque enhancement amplitude (PEA) were compared. The relationship between stenotic rate obtained using HR-VWI and DSA was evaluated. Each HR-VWI characteristic and clinical factor before DCB angioplasty was separately evaluated for the association with postoperative restenosis.

RESULTS

After six months, lumen area of MLN, plaque length and area, degree of stenosis, PB, and PEA showed a significantly difference relative to the value before DCB angioplasty (all P < 0.05). Spearman correlation coefficients of 0.865 and 0.932 were revealed between DSA and HR-VWI regarding the stenotic rate analysis pre- and post-operation (both P < 0.05). ROC analysis showed PEA, plaque length, and PB before DCB angioplasty separately provided robust prediction of postoperative restenosis (area under the curve = 0.909, 0.814 and 0.743; all P < 0.05). Multivariable analysis revealed that PEA was an independent predictor of prognosis.

CONCLUSIONS

The HR-VWI can accurately assess the treatment effect of DCB and robustly predict prognosis.

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.

Correlation Between Optical Coherence Tomography Angiography Findings at 3 to 6 Weeks and Functional Outcome at 3 Months Following Acute Ischaemic Stroke Due to Extracranial Carotid Artery Atherosclerotic Disease

We wanted to evaluate if optical coherence tomography angiography OCTA findings could predict the functional outcome in extracranial carotid artery atherosclerotic disease (ECAD) associated stroke. This exploratory study was performed on adults with acute ischaemic stroke due to ECAD at 3-6 weeks following stroke onset with risk factor matched controls without carotid artery stenosis. Twenty-three stroke patients (cases) and 23 controls were enrolled. There was significant difference between cases and controls in deep vessel density at the macula (p = .0007) and in radial peripapillary capillary perfusion density (RPCPD) at the optic nerve head (ONH) (p = .0007). Statistically significant difference was noted in the total superficial vessel density (SVD) at the macula (SVD within 1 standard deviation [SD] versus SVD beyond 1 SD of control data) in the ipsilateral eye and functional outcome at 3 months (poor versus very good outcome, modified Rankin scale [mRS] 0-1 versus mRS 2-6, respectively; p = .0361). There was statistically insignificant correlation between the RPCPD at the ONH and the National Institutes of Health Stroke Scale score at admission, mRS at discharge, and mRS at 3 months following stroke onset (r = .33, r = .35, r = .39; p = .11, p = .09, p = .06, respectively). The findings of this exploratory study suggested that OCTA findings may predict 3 month outcomes in cases of ECAD-related stroke and could be useful in decision making in future intervention studies as to whether intervene or not in patients having critical or non-critical ECAD for preventing stroke.

Rescue Stent Placement for Acute Ischemic Stroke with Large Vessel Occlusion Refractory to Mechanical Thrombectomy: A Multiethnic Middle Eastern/African/Asian Cohort

PURPOSE

To investigate the safety and effectiveness of rescue stent placement in patients who experienced acute stroke in whom mechanical thrombectomy failed.

METHODS

This was a retrospective review of a multiethnic stroke database. After stent placement, an aggressive antiplatelet protocol was followed with glycoprotein IIb/IIIa infusion. The primary outcomes were incidence of intracerebral hemorrhage (ICH), recanalization score, and favorable prognosis (modified Rankin score ≤ 2) at 90 days. A comparison was made between patients from the Middle East and North Africa (MENA) region and those from other regions.

RESULTS

Fifty-five patients were included, with 87% being men. The mean age was 51.3 years (SD ±11.8); 32 patients (58%) were from South Asia, 12 (22%) from MENA, 9 (16%) from Southeast Asia, and 2 (4%) from elsewhere. Successful recanalization (modified Thrombolysis in Cerebral Infarction score = 2b/3) was achieved in 43 patients (78%), and symptomatic ICH occurred in 2 patients (4%). A favorable outcome at 90 days was seen in 26 of the 55 patients (47%). Apart from significantly older age-mean, 62.8 years (SD ±13; median, 69 years) versus 48.1 years (SD ±9.3; median, 49 years)-and coronary artery disease burden-4 (33%) versus 1 (2%) (P < .05), patients from MENA had risk factors, stroke severity, recanalization rates, ICH rates, and 90-day outcomes similar to those from South and Southeast Asia.

CONCLUSION

Rescue stent placement showed good outcomes and a low risk of clinically significant bleeding in a multiethnic cohort of patients from MENA and South and Southeast Asia, similar to that in published literature.

Advances in Acute Ischemic Stroke Treatment: Current Status and Future Directions

The management of acute ischemic stroke has undergone a paradigm shift in the past decade. This has been spearheaded by the emergence of endovascular thrombectomy, along with advances in medical therapy, imaging, and other facets of stroke care. Herein, we present an updated review of the various stroke trials that have impacted and continue to transform stroke management. It is critical for the radiologist to stay abreast of the ongoing developments to provide meaningful input and remain a useful part of the stroke team.

Neurotoxicity of Paclitaxel and Rapamycin in a Rat Model with Transient Blood-Brain Barrier Opening

Objective

Drug-eluting stents and balloons are occasionally used to reduce restenosis in medically intractable intracranial atherosclerotic stenosis. The authors aimed to determine whether such drugs can cause neurotoxicity due to local effects in a rat model.

Methods

Intra-arterial catheters were placed in the right common carotid artery of rats. Mannitol was injected to transiently open the brain-blood barrier (BBB), followed by high-dose drug (paclitaxel and rapamycin) injection. The optimal time interval of transient BBB opening for maximal drug penetration was determined to be 10 minutes. Paclitaxel and rapamycin were intraarterially administered in various doses. All the rats were neurologically evaluated, and their brain tissues were histologically examined.

Results

Neither neurological deficits nor histological abnormalities were observed in all the rats.

Conclusion

Paclitaxel and rapamycin did not cause neurotoxicity in a rat model with transient BBB opening.

Outcome of Wingspan Stent Using Aggressive Post-stent Balloon Dilation for Intracranial Atherosclerosis Stenosis

Background: Wingspan stent has gained interest for better long-term outcomes for intracranial atherosclerosis disease (ICAD). However, in-stent restenosis still presents as a problem and may cause postoperative neurological events. We aimed to find a way to prevent in-stent restenosis.

Method: Patients with stenosis >70% ICAD were treated with wingspan stent and were retrospectively reviewed. The patients were separated into two groups: one with post-dilation and the other without post-dilation. The outcomes of wingspan stenting were compared immediately after the surgery and at a 1-year follow-up.

Results: Overall, 28 patients were included for analysis, with 15 patients undergoing post-dilation and 13 patients not undergoing the procedure. The extent of stenosis was significantly lower in the post-dilation group than in the no post-dilation group, both immediately after the surgery (14.8 ± 10.2 vs. 28.5 ± 14.5%, p < 0.01) and at 1-year follow-up (25.8 ± 18.0 vs. 50.1 ± 23.2%, p < 0.01). The post-dilation method immediately expanded the stent diameter (2.89 ± 0.48 vs. 3.05 ± 0.44 mm, p < 0.001), and the diameter still increased at 1-year follow-up (3.05 ± 0.44 vs. 3.12 ± 0.43 mm, p < 0.01) due to the self-expandable property of the wingspan. Similarly, in the no post-dilation group, the stent size was also increased (2.70 ± 0.67 vs. 2.80 ± 0.64 mm, p < 0.01). However, at 1-year follow up, the luminal diameter was stationary in the post-dilation group (2.36 ± 0.73 vs. 2.46 ± 0.82 mm, p = 0.88) and decreased in the no post-dilation group (2.24 ± 0.56 vs. 1.60 ± 0.79 mm, p < 0.01). The periprocedural complication rate was similar between the groups.

Conclusion: The post-dilation method can be feasibly performed and can offer better stent expansion and apposition in the wingspan system. By applying this technique, we might prevent in-stent restenosis and improve neurological outcomes.

Non-compliant and compliant balloons for endovascular rescue therapy of cerebral vasospasm after spontaneous subarachnoid haemorrhage: experiences of a single-centre institution with radiological follow-up of the treated vessel segments

BACKGROUND

For endovascular rescue therapy (ERT) of cerebral vasospasm (CVS) due to spontaneous subarachnoid haemorrhage (sSAH), non-compliant (NCB) and compliant (CB) balloons are used with both balloon types bearing the risk of vessel injury due to specific mechanical properties. Although severe delayed arterial narrowing after transluminal balloon angioplasty (TBA) for CVS has sporadically been described, valid data concerning incidence and relevance are missing. Our aim was to analyse the radiological follow-up (RFU) of differently TBA-treated arteries (CB or NCB).

METHODS

Twelve patients with utilisation of either NCB or CB for CVS were retrospectively analysed for clinical characteristics, ERT, functional outcome after 3 months and RFU. Compared with the initial angiogram, we classified delayed arterial narrowing as mild, moderate and severe (<30%, 30%-60%, respectively >60% calibre reduction).

RESULTS

Twenty-three arteries were treated with CB, seven with NCB. The median first RFU was 11 months after TBA with CB and 10 after NCB. RFU was performed with catheter angiography in 18 arteries (78%) treated with CB and in five (71%) after NCB; magnetic resonance angiography was acquired in five vessels (22%) treated with CB and in two (29%) after NCB. Mild arterial narrowing was detected in three arteries (13%) after CB and in one (14%) after NCB. Moderate or severe findings were neither detected after use of CB nor NCB.

CONCLUSION

We found no relevant delayed arterial narrowing after TBA for CVS after sSAH. Despite previous assumptions that CB provides for more dilatation in segments adjacent to CVS, we observed no disadvantages concerning long-term adverse effects. Our data support TBA as a low-risk treatment option.

Association of Mortality with Antiplatelet Treatment in Patients with Stent Placement or Angioplasty: A Population-Based Nested Case-Control Study

PURPOSE

Antiplatelet drugs are essential in patients with cardiovascular disease who undergo stent placement. We hypothesized that risks of mortality would differ according to adherence to antiplatelet agents, number of antiplatelet agents, and antiplatelet regimens in patients undergoing stent placement or angioplasty.

MATERIALS AND METHODS

Between 2002 and 2013, we initially enrolled 8671 subjects who underwent stent placement or angioplasty in the National Health Insurance Service-National Sample Cohort in Korea. Using the International Classification of Diseases, 10th revision, the incidence of all-cause death, including cardiovascular disease, cerebrovascular disease, and cancer, was defined. Using a nested case-control study design, controls were matched to cases at a ratio of 4:1, and a total of 5415 subjects were eligible for this study.

RESULTS

During a median follow-up period of 3.51 years, the incidence rate of all-cause death was 40 per 1000 person-years. We found that adherence to antiplatelet monotherapy significantly decreased risk of death by cerebro-cardiovascular disease, compared with discontinuation of antiplatelets [adjusted odds ratio (OR) 0.62, 95% confidence interval (CI) (0.41-0.96)]. Compared with dual antiplatelet therapy (DAPT), aspirin and clopidogrel monotherapy significantly reduced death by cerebro-cardiovascular disease [adjusted OR 0.65, 95% CI (0.44-0.95) and adjusted OR 0.58, 95% CI (0.35-0.96), respectively]. There was no significant difference of mortality between aspirin monotherapy and clopidogrel monotherapy.

CONCLUSION

Our study demonstrated that adherence to antiplatelet therapy and antiplatelet monotherapy, compared with DAPT, in patients with stent placement or angioplasty may have a beneficial effect on mortality in cerebro-cardiovascular disease.

Quantitative and Qualitative Analysis of Atherosclerotic Stenosis in the Middle Cerebral Artery Using High-Resolution Magnetic Resonance Imaging

PURPOSE

We analyzed and compared the imaging characteristics of the vessel wall of the middle cerebral artery (MCA) in symptomatic and asymptomatic patients using a 3.0-T high-resolution magnetic resonance imaging (HR-MRI) protocol, including a 3-dimensional T1-sampling perfection with application-optimized contrasts using different flip angle evolutions sequence.

METHODS

Fifty-three patients with atherosclerotic stenosis of the MCA underwent 3.0-T HR-MRI examinations. The characteristics of atherosclerotic plaques in 53 patients (28 symptomatic, 25 asymptomatic) were analyzed, including plaque distribution and signal intensity. Plaque burden (PB), stenosis degree, and the remodeling index were measured and compared between symptomatic and asymptomatic patients.

RESULTS

The PB of the symptomatic group was significantly higher than that of the asymptomatic group (P = .006), and moderate-severe stenosis was more common (P = .01). The remodeling index of the symptomatic group was also lower (P = .015) and negative remodeling (NR) was more common (P = .043). Binary logistic regression analysis showed that stenosis degree was a risk factor in symptomatic patients (odds ratio = 135, P = .023).

CONCLUSION

There is a trend that some characteristics of plaques and vessels, including the moderate-severe stenosis, larger PB, and NR, were observed more frequently among patients with symptomatic atherosclerotic stenosis of the MCA than among asymptomatic patients.