Improvement of cerebral blood flow after balloon angioplasty and stenting for symptomatic middle cerebral artery stenosis.

OBJECTIVE: Although reports of endovascular treatment for intracranial arterial stenosis have been increasing recently, their efficacy remains to be elucidated. This study aimed to investigate the changes in cerebral hemodynamics of severe middle cerebral artery (MCA) stenosis patients by performing CT perfusion (CTP) after endovascular treatment. METHODS: Subjects were those who underwent balloon angioplasty and stenting for symptomatic MCA M1 stenosis refractory to medical therapy at our hospital between 2008 and 2022. We included 36 patients (mean age 63.69 ± 15.24 years, 20 males) who underwent CTP before and within three weeks after treatment. The CTP parameters such as relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and relative mean transit time (rMTT) were calculated as ipsilateral values divided by contralateral value. RESULTS: Endovascular treatment consisted of 26 balloon angioplasty and 10 stenting procedures performed at an average of 1 month from onset. CTP was performed at an average of 5.5 days postoperatively. The mean overall stenosis rate decreased from 79.0% to 30.3%. In the balloon angioplasty group, it decreased from 77.6% to 35.3%, and in the stent group, it decreased from 82.7% to 17.5%. After treatment, rCBF and rMTT measured by CTP improved significantly (both p < 0.001), whereas there was no significant change in rCBV. The improvement rates of rCBF and rMTT were mild higher in the stent group, but not significantly so. CONCLUSION: Balloon angioplasty and stenting for symptomatic MCA improved cerebral hemodynamics, resulting in significantly increased rCBF and decreased rMTT.

Ischemic stroke patients with low DWI ASPECTS scores require puncture to recanalization within 30 min for large vessel occlusion.

BACKGROUND: The clinical benefits of faster recanalization in acute large vessel occlusion are well recognized, but the optimal procedure time remains uncertain. The aim of this study was to identify patient characteristics that necessitate puncture-to-recanalization (P-R) time within 30 min to achieve favorable outcome. METHODS: We evaluated the patients from a prospective, multicenter, observational registry of acute ischemic stroke patients. The study included patients who underwent endovascular therapy for ICA or MCA M1 occlusion and achieved successful recanalization. Patients were categorized into subgroups based on pre-treatment characteristics and the frequency of favorable outcomes was compared between P-R time < 30 min and ≥ 30 min. Interaction terms were incorporated into the models to assess the correlation between each patient characteristic and P-R time. RESULTS: A total of 1053 patients were included in the study. Univariate analysis within each subgroup revealed a significant association between P-R < 30 min and favorable outcomes in patients with DWI ASPECTS ≤6, age > 85 and NIHSS ≥16. In the multivariable analysis, NIHSS, age, time from symptom recognition to puncture, and DWI ASPECTS were significant independent predictors of favorable outcomes. Notably, only DWI ASPECTS exhibited interaction terms with P-R < 30 min. The multivariable analysis indicated that P-R < 30 min was an independent predictor for favorable outcome in DWI ASPECTS ≤6 group, whereas not in DWI ≥7. CONCLUSIONS: P-R time < 30 min is predictive of favorable outcomes; however, the effect depends on DWI ASPECTS. Target P-R time < 30 min is appropriate for patients with DWI ASPECTS ≤6.

Long-term outcome and factors associated with restenosis after combination therapy of balloon angioplasty and stenting for symptomatic intracranial stenosis.

BACKGROUND: The optimal treatment for intracranial artery stenosis (ICAS) has not been established. We retrospectively examined the initial and long-term outcomes associated with restenosis of a combination therapy of balloon angioplasty and stenting for symptomatic atherosclerotic ICAS. METHODS: Consecutive patients who underwent balloon angioplasty and/or stenting for ≥ 70% ICAS between 2006 and 2020 were analyzed. Patients within 48 h of stroke onset were excluded. The following procedures were established as standards at our institution: (1) primary balloon angioplasty alone was initially performed; (2) stenting for insufficient dilatation, recoiling, or dissection was conducted; and (3) stenting was considered for restenosis. Intracranial ischemic and hemorrhagic complications within 30 days after treatment were used to evaluate periprocedural safety. Recurrent ischemic events, restenosis and restenosis related factors were used to be evaluate the long-term outcome. RESULTS: A total of 160 patients were recruited. Initial treatment consisted of balloon angioplasty (n = 101) and stenting (n = 59). Intracranial complications within 30 days after treatment were ischemic in five (3.1%) and hemorrhagic in four patients (2.5%). The incidence of these complication was 3.1% in the stenting group and 2.5% in the balloon angioplasty group. The mean follow-up period was 53.9 months. Restenosis was found in 42 patients (26%). Recurrent ischemic events during follow-up were noted in 14 patients (8.8%), of which six patients had TIA and eight patients had ischemic stroke. Restenosis-associated factors included diabetes, coronary artery disease, percent stenosis after treatment, and balloon angioplasty in logistic univariate analysis. Multivariate Cox regression analysis showed that diabetes (HR: 2.084, CI: 1.039-4.180, p = 0.0386), length of lesion (HR; 1.358, CI: 1.174-1.571, p < 0.0001), and balloon angioplasty (HR: 4.194, CI: 1.083-16.239, p = 0.0379) were independent predictors for restenosis. CONCLUSION: Combination therapy of balloon angioplasty and stenting for symptomatic ICAS had a low perioperative stroke rate and may improve long-term outcome. Balloon angioplasty, diabetes, and length of lesion were significantly associated with restenosis.

Carotid Ultrasound Using Superb Microvascular Imaging to Identify Patients Developing In-Stent Restenosis After CAS.

BACKGROUND AND PURPOSE: In-stent restenosis (ISR) caused by in-stent intimal hyperplasia (ISH) may develop after carotid artery stenting (CAS), and often necessitates re-stenting. We investigated whether new ultrasound technique is useful for detecting carotid artery plaques prone to ISR. PURPOSE: Superb micro-vascular imaging (SMI) is a new color Doppler imaging technique for assessing low velocity blood flow such as neovascularization in carotid artery plaques. In this study, we attempted to identify associations between findings from carotid ultrasonography with SMI performed prior to CAS and in-stent restenosis after 6 months of CAS. METHODS: This study investigated 19 patients (18 men; mean age, 72.4 years). Preoperative plaque evaluation was performed by magnetic resonance imaging, ultrasonography, and carotid angiography. Follow up angiography was performed in all patients at 6 months after CAS. ISR was defined as ISH resulting in >50% stenosis based on European Carotid Surgery Trialists criteria. We investigated whether SMI was useful as a predictor of ISR by chi-square test. RESULTS: Preoperative mean stenosis rate according to North American Symptomatic Carotid Endarterectomy Trial methods in 19 patients was 61.3%. Neovascularization was observed on SMI in 10 patients (52.6%). Carotid angiography at 6 months after CAS revealed ISR in 4 patients, all of whom had shown neovascularization on SMI. A significant association was seen between findings of neovascularization on SMI and development of ISR (p = 0.033). In predicting ISR, neovascularization findings on SMI offered 100.0% sensitivity and 60.0% specificity. CONCLUSIONS: Preprocedural plaque characterization by carotid ultrasound with SMI appears useful for predicting ISR at 6 months after CAS.

The Influence of Experience on Gazing Patterns during Endovascular Treatment: Eye-Tracking Study.

Objective: In various fields, differences in eye-gazing patterns during tasks between experts and novices have been evaluated. The aim of this study was to investigate gazing patterns during neuro-endovascular treatment using an eye-tracking device and assess whether gazing patterns depend on the physician's experience or skill. Methods: Seven physicians performed coil embolization for a cerebral aneurysm in a silicone vessel model under biplane X-ray fluoroscopy, and their gazing patterns were recorded using an eye-tracking device. The subjects were divided into three groups according to experience, highly experienced (Expert) group, intermediately experienced (Trainee) group, and less experienced (Novice) group. The duration of fixation on the anterior-posterior (AP) view screen, lateral (LR) view, and out-of-screen were compared between each group. Results: During microcatheter navigation, the Expert and Trainee groups spent a long time on fixation to AP, while the Novice group split their attention between each location. In coil insertion, the Expert group gazed at both the AP and the LR views with more saccades between screens. In contrast, the Trainee group spent most of their time only on the AP view screen and the Novice group spent longer out-of-screen. Conclusion: An eye-tracking device can detect different gazing patterns among physicians with several experiences and skill levels of neuroendovascular treatment. Learning the gazing patterns of experts using eye tracking may be a good educational tool for novices and trainees.

A Case Report of Contrast-Induced Encephalopathy after Repeated Percutaneous Transluminal Angioplasty for Acute Middle Cerebral Artery Occlusion.

Objective: We report a case of contrast-induced encephalopathy (CIE) after repeated percutaneous transluminal angioplasty (PTA) for acute middle cerebral artery (MCA) occlusion. Case Presentation: An 88-year-old woman with left hemiparesis was transferred to our hospital by ambulance. MRI revealed acute MCA M1 occlusion. We performed intravenous tissue plasminogen activator therapy and PTA for right MCA occlusion, leading to complete recanalization and improvement in hemiparalysis. After approximately one week, restenosis of right MCA developed and PTA was performed again on day 11. However, her left hemiparesis exacerbated shortly thereafter. CT demonstrated leakage of contrast medium, and an extensive high-intensity area (HIA) on the white matter in the right cerebral hemisphere was noted on MRI FLAIR. The HIA on MRI and neurological deficits gradually improved after conservative treatment, but diffuse atrophy of the right cerebral hemisphere occurred and higher brain dysfunction remained. Conclusion: Repeated ischemia and reperfusion, and the frequent use of contrast media were considered the causes of CIE.

Outcomes of Balloon Angioplasty and Stenting for Symptomatic Intracranial Atherosclerotic Stenosis at a High Volume Center.

PURPOSE: This study investigated the periprocedural complication rates, long-term outcome, and restenosis of endovascular treatment for intracranial atherosclerotic stenosis (ICS) at our hospital. METHODS: We retrospectively analyzed the clinical data of 217 patients comprising 256 endovascular treatments for high-grade symptomatic ICS. The lesion was located in the internal carotid artery in 77, the middle cerebral artery in 111, the basilar artery in 29, and the vertebral artery in 39. Patients were divided into two groups, before (early-phase group, 1999-2013) and after approval of Wingspan (late-phase group, 2014-2017). RESULTS: In the early-phase group (n = 163), 157 lesions were treated by balloon angioplasty and 31 (17%) by coronary stenting. In the late-phase group (n = 54), 33 lesions were treated by balloon angioplasty and 35 (52%) by Wingspan stenting. Overall technical success rates were 96% in the balloon angioplasty and 100% in stenting groups. The 30-day rate of stroke, TIA, and death were 4.8% in the early-phase group and 4.4% in the late-phase group. There was one minor stroke and two TIAs during the follow-up period in the late-phase group. CONCLUSIONS: Endovascular treatment for symptomatic ICS in this study appeared to be safe and effective if patients are properly selected. However, future well-designed randomized trials with different techniques and modified patients selection criteria are certainly warranted.

A Case of Acute Ischemic Stroke Treated with Endovascular Treatment for Tandem Occlusion of the Common Carotid Artery and Internal Carotid Artery Terminal Portion Related to Takayasu Arteritis.

Objective: This report presents a case of mechanical thrombectomy for left internal carotid artery (ICA) terminal portion occlusion performed by left common carotid artery recanalization during hospitalization after diagnosing bilateral common carotid artery occlusion due to Takayasu arteritis. Case Presentation: A 25-year-old woman with fever and cervix pain a few months ago visited our department after repeated transient aphasic attacks. Magnetic resonance imaging (MRI) demonstrated diffuse infarction in the left middle cerebral artery (MCA) area, and she was diagnosed with Takayasu arteritis due to bilateral common carotid artery occlusion and left subclavian artery stenosis. On the 20th day of hospitalization, the terminal portion of the left ICA was occluded and thrombectomy was performed after balloon dilation of the left common carotid artery. Lastly, left common carotid artery stenting was performed. Aphasia and sensory disturbance remained, but she was transferred to a rehabilitation hospital with a modified Rankin Scale (mRS) of 2 on the 65th day of hospitalization. Antithrombotic and immunosuppressive therapy were performed, and restenosis did not develop. Conclusion: Angioplasty and stenting of common carotid artery occlusion can be effective treatments in thrombectomy for intracranial occlusion due to Takayasu disease.

Preprocedural Carotid Plaque Echolucency as a Predictor of In-Stent Intimal Restenosis after Carotid Artery Stenting.

OBJECTIVES: In-stent intimal restenosis (ISR) caused by neointimal hyperplasia can develop <24 months after carotid artery stenting (CAS). The utility of plaque imaging by carotid ultrasonography (US) or magnetic resonance imaging (MRI) has been investigated for the prediction of ipsilateral stroke. We aimed to investigate whether these imaging techniques are useful for detecting carotid plaques prone to ISR. MATERIALS AND METHODS: We examined 133 patients (mean age of 72.1 ± 8.4 years old) that received CAS at a single hospital from 2014 to 2018. A pre-CAS carotid plaque evaluation was performed by carotid angiography, duplex carotid US, and black-blood carotid artery MRI (BB-MRI). The mean stenosis rate was 71.0 ± 12.3% by the North American Symptomatic Carotid Endarterectomy Trial (NASCET) methods. Follow-up carotid angiography was performed 6 months after CAS in all patients according to a predefined protocol. ISR was defined as in-stent intimal hyperplasia more than 50% stenosed based on the NASCET criteria. The selection of the stent type was at the discretion of the treating physician. Predictors of ISR were determined by multivariate logistic regression analysis. RESULTS: Follow-up angiography demonstrated ISR in 33 patients (24.8%). In 44 patients, more than two stents were deployed. Univariate logistic regression analyses demonstrated echolucent lesion, floating plaque, complete occlusive or pseudo-occlusive lesion, and closed-cell stent use as significantly associated with ISR (>50%). Multivariate logistic regression analysis demonstrated that echolucent lesion (OR 4.667, 95% CI 1.849-11.779) and closed-cell stent use (OR .378, 95% CI .148-.968) were significantly associated with ISR. CONCLUSIONS: Preprocedural plaque characterization by carotid US appeared to be useful to predict ISR 6 months after CAS.

Effects of Aspiration and Re-transfusion Technique with Carotid Artery Stenting.

Objective: Embolic stroke is the most serious complication after carotid artery stenting (CAS). The incidence rate of embolic stroke is reduced by the use of embolic protection devices (EPDs); however, there is no consensus on which EPD is the most effective. The aspiration and re-transfusion technique (ART) with CAS under distal balloon protection was adopted at our center to reduce the incidence of embolic complications. This retrospective study investigated the effects of ART. Methods: From November 2010, 243 consecutive patients treated by CAS under distal balloon protection were included. ART was performed on 202 patients (ART group) and the other 40 patients only received distal balloon protection (non-ART group). In ART, the blood from the aspiration catheter was continuously returned through a filter to the femoral vein. The amount of debris was assessed intermittently using a small blood sample and the rest was returned. We investigated the diffusion-weighted imaging (DWI)-positive rate and symptomatic ischemic stroke one day after CAS. Results: Compared with the non-ART group, the incidence of DWI-positive lesions (22.7% vs 37.5%, P = 0.07) and frequency of symptomatic ischemic stroke (0.9% vs 5.0%, P = 0.12) were reduced in the ART group. The hemoglobin reduction rate was significantly reduced by ART (11.1% vs 14.9%, P <0.01). In the ART group, the frequency of multiple lesions (more than 5) and large lesions (more than 10 mm) was lower than that in the non-ART group (P <0.01, P = 0.14). Conclusion: CAS under distal balloon protection with ART was effective at reducing the incidence of DWI-positive lesions and may be useful to reduce the incidence of symptomatic ischemic stroke.

Contrast-enhanced carotid ultrasonography and MRI plaque imaging to identify patients developing in-stent intimal hyperplasia after carotid artery stenting.

AIM: In-stent intimal hyperplasia (ISH) observed after carotid artery stenting (CAS) may lead to in-stent restenosis. We aimed to investigate whether contrast-enhanced carotid ultrasonography (CEUS) and magnetic resonance imaging (MRI) plaque imaging prior to CAS are predictive for ISH at 6 months after CAS. MATERIAL AND METHOD: A total of 14 patients (13 men, 1 woman; mean age, 74.2 years) were prospectively enrolled. CEUS and MRI plaque imaging were performed before CAS. ISH was diagnosed by carotid angiography at 6 months after CAS. Patients were divided into two groups based on the thicknessof ISH and age, risk factors, enhancement in CEUS, MRI plaque imaging and number of replaced stents were compared between groups. RESULTS: Carotid angiography at 6 months after CAS revealed ISH in 10 patients. Plaque enhancement on CEUS was observed in 6 patients, all of whom showed ISH. A significant association was seen between plaque enhancement on CEUS and development of ISH (χ2 test, CEUS enhancement (+) 100% vs. CEUS enhancement (-) 50% p=0.040). Carotid plaques in 12 patients were diagnosed as unstable by MRI plaque imaging. Presence of ISH was significantly associated with unstable plaque diagnosed by MRI plaque imaging (χ2 test, unstable 83% vs. stable 0%; p=0.016). CONCLUSION: Carotid plaque MRI and CEUS may be useful to predict ISH after CAS.

Intraplaque Microvascular Flow Signal in Superb Microvascular Imaging and Magnetic Resonance Imaging Carotid Plaque Imaging in Patients with Atheromatous Carotid Artery Stenosis.

Carotid artery atherosclerosis is one of the major risk factors for ischemic stroke. Intraplaque neovascularization (IPN) is one of the steps toward the development of vulnerable plaque. Superb microvascular imaging (SMI) is a new ultrasonographic technique for visualizing low-velocity and microvascular flow by clutter suppression to extract flow signals from large to small vessels and enables visualization of intraplaque microvascular flow (IMVF) without echo contrast media. We aimed to investigate the association between IMVF signal in SMI and MRI plaque imaging among patients with atherosclerotic carotid stenosis. We prospectively enrolled patients (>18 years old) with mild to severe carotid stenosis (more than 50% in cross-sectional area) diagnosed by carotid ultrasonography between August 2017 and April 2018, irrespective of sex and history of stroke. A total of 40 patients (31 men, 9 women; mean age, 75.1 ± 10.0 years) were enrolled. SMI revealed IPN findings in 21 patients. SMI clearly visualized the direction of pulsatile flow movement in microvessels and IPN was easily classified into the two types of Type V (n=2) and Type E (n=19). Multivariate logistic regression analysis presented that microvascular flow signal in carotid plaque on SMI was identified as a significant predictor of intraplaque hemorrhage as evaluated by MRI (OR, 8.46; 95%CI, 1.44-49.9; p=0.018). This study demonstrated a significant association between the presence of IMVF signal in SMI and intraplaque hemorrhage characterized by high-intensity lesions on MRI T1-FFE images.

Association between paroxysmal atrial fibrillation and the left atrial appendage ejection fraction during sinus rhythm in the acute stage of stroke: a transesophageal echocardiographic study.

BACKGROUND: This study aimed to investigate whether left atrial appendage (LAA) dysfunction evaluated by transesophageal echocardiography (TEE) during sinus rhythm is predictable of paroxysmal atrial fibrillation (PAF) as an embolic source in the acute stage of stroke. METHODS AND RESULTS: We measured and analyzed LAA flow velocity (LAA-FV) and LAA ejection fraction (LAA-EF) in 300 acute ischemic stroke patients by TEE. We divided the acute ischemic stroke patients into 3 groups. The atrial fibrillation (AF) group (n=58) comprised patients whose TEE was performed during AF rhythm. The PAF group (n=42) comprised patients with a history of AF but with normal sinus rhythm when TEE was performed. The normal sinus (sinus) group (n=200) did not have any history of AF. We found that mean LAA-FV and LAA-EF values in the PAF group were significantly lower than those in the sinus group (P<.001). The diagnostic accuracy of LAA-FV for the diagnosis of PAF calculated as the area under receiver operating characteristic curves was low (.582, 95% confidence interval [CI]=.498-.665) but that of LAA-EF was modest (.721, 95% CI=.653-.789), with an optimal cutoff point of 49.1%. CONCLUSIONS: LAA dysfunction as determined by TEE (LAA-EF<49.1%) in the acute stage of stroke is predictive of PAF with moderate accuracy. Long-term electrocardiographic monitoring is recommended for cryptogenic stroke patients with LAA dysfunction.

Association between inflammatory biomarkers and progression of intracranial large artery stenosis after ischemic stroke.

BACKGROUND: Proinflammatory state has been implicated as a pathogenetic mechanism in the progression of intracranial large artery atherosclerosis (ILA). High levels of inflammatory biomarkers in healthy populations and in patients with acute stroke or acute coronary syndrome are known to be associated with subsequent stroke events. This study investigated the relationship between circulating biomarkers measured early after stroke onset and future ILA progression. METHODS: In 48 patients with acute ischemic stroke, high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), IL-18, tumor necrosis factor-α, matrix metalloproteinase (MMP)-2 and MMP-9 were measured within 48 hours after onset. Baseline severity and ILA progression were assessed by serial magnetic resonance angiography (MRA). The median follow-up period for MRA was 3.1 years. Hazard ratio (HR) was calculated using the Cox proportional hazard model adjusted for traditional risk factors, and accuracy of predicted ILA progression was analyzed by receiver operating characteristic (ROC) curve analysis. RESULTS: ILA progression was observed in 6 of 48 patients (12.5%). After adjusting for age, sex, and presence of hypertension, baseline ILA severity score (HR 2.814; 95% confidence interval [CI] 1.172-6.754) and IL-6 (HR 1.215; 95% CI 1.002-1.473) were significantly associated with ILA progression. Area under the ROC curve (AUC) for prediction of ILA progression by traditional risks, baseline ILA severity score and IL-6, was 0.647. When IL-6 was removed from this model, AUC remained at 0.631. CONCLUSIONS: In addition to traditional risk factors and baseline radiologic findings, circulating levels of IL-6 measured soon after stroke onset are associated with future ILA progression.