The Impact of age and outcomes of high-risk patients on carotid revascularization.

OBJECTIVES: To validate the accuracy of high-risk criteria for carotid endarterectomy (CEA) and analyze the correlation between age and outcome of CEA and carotid artery stenting (CAS) in risk groups. METHODS: We reviewed a prospectively managed vascular surgery database in a single tertiary referral center, and 2482 internal carotid arteries (ICAs) had undergone carotid revascularization from November 1994 to December 2021. To validate high-risk criteria for CEA, patients were classified as high risk (Hr) and normal risk (Nr). Subgroup analysis was performed with patients older or younger than 75 years to investigate the relationship between age and outcome in each group. Primary endpoints were 30-day outcomes including stroke, death, stroke/death, myocardial infraction (MI), and major adverse cardiovascular events (MACEs). RESULTS: A total of 2345 ICAs in 2256 patients were enrolled. The number of patients in the Hr group was 543 (24%) and the number in the Nr group was 1713 (76%). CEA and CAS were performed on 1384 (61%) and 872 (39%) patients, respectively. The 30-day stroke/death rate was higher with CAS than CEA in both the Hr (1.1% vs. 3.9%, p = 0.032) and Nr (1.2% vs. 6.9%, p < 0.001) groups. In unmatched logistic regression analysis of the Nr group (n = 1778), the rate of 30-day stroke/death (OR, 5.575; 95% CI, 2.922-10.636; p < 0.001) was higher for CAS than CEA. In propensity score matching of the Nr group, the rate of 30-day stroke/death (OR, 5.165; 95% CI, 2.391-11.155; p < 0.001) was also higher for CAS than CEA. In the age <75 subgroup of the Hr group (n = 428), CAS was associated with higher 30-day stroke/death (OR, 14.089; 95% CI, 1.314-151.036; p = 0.029). In the age ≥75 subgroup of the Hr (n = 139), there was no difference in 30-day stroke/death between CEA and CAS. In the age <75 subgroup of the Nr group (n = 1318), 30-day stroke/death (OR, 6.300; 95% CI, 2.797-14.193; p < 0.001) was higher in CAS. In the age ≥75 subgroup of the Nr group (n = 460), 30-day stroke/death (OR, 6.468; 95% CI, 1.862-22.471; p = 0.003) was higher in CAS. CONCLUSIONS: In patients older than 75 years in the Hr group, there were relatively poor 30-day treatment outcomes in both CEA and CAS. Alternative treatment is needed that can expect better outcomes in older high-risk patients. In the Nr group, CEA has a significant benefit compared with CAS, and CEA should be recommended more to these patients.

Early clinical experience of using the Surpass Evolve flow diverter in the treatment of intracranial aneurysms.

PURPOSE: Here, we presented our early experience with flow diversion procedures using the Surpass Evolve flow diverter (SE, Stryker) and reported the feasibility and safety profile compared to those of a control group treated with other types of flow diverters. METHODS: We included 31 and 53 consecutive flow diversion procedures performed using the SE and other commercial flow diverters, respectively, to treat intracranial aneurysms at our institution. We used two commercial flow diversion systems in the comparison group: the pipeline embolization device and Surpass Streamline. RESULTS: In the SE group, technical failures occurred in three (9.7%) cases, due to either incomplete wall apposition (n = 1, 3.2%) or stent migration (n = 2, 6.5%). Major complications occurred in four (12.9%) cases: delayed rupture of the target aneurysm (n = 1, 3.2%), major ischemic stroke (n = 1, 3.2%), sudden death from an unidentified cause (n = 1, 3.2%), and parent artery occlusion with stent thrombosis (n = 1, 3.2%). Balloon angioplasty was performed in eight (25.8%) cases. On post-procedure MRI, a DWI-positive lesion was detected in three (9.7%) cases. After multivariate adjustment, the SE group was independently associated with less procedural time of ≥ 90 min (adjusted OR, 0.09; 95% CI, 0.03-0.29; p < 0.001), balloon angioplasty (adjusted OR, 0.22; 95% CI, 0.07-0.75; p = 0.015), and DWI-positive lesions (adjusted OR, 0.04; 95% CI, 0.01-0.19; p < 0.001). CONCLUSION: The SE is safe and easy to deploy.

White matter hyperintensity determines ischemic stroke severity in symptomatic carotid artery stenosis.

INTRODUCTION: The aim of this study is to investigate the influence of white matter hyperintensity (WMH) on stroke severity and prognosis in patients with symptomatic carotid artery stenosis. METHODS: Patients with symptomatic carotid artery stenosis were retrieved from the Samsung Medical Center stroke registry from January 2011 to December 2016. Stroke severity was categorized into three levels according to National Institutes of Health Stroke Scale (NIHSS): transient ischemic attack (TIA) or transient symptoms with infarction (TSI), mild stroke, and moderate to severe stroke. WMH volume was measured with medical image processing and visualization. The clinical outcome was assessed using the modified Rankin scale on the 90th day from which the latest onset of the neurological symptom. Logistic regression was used to predict stroke severity, and ordinal regression was used to compare the clinical outcome. RESULTS: Among 158 patients, the numbers of patients with TIA or TSI, mild stroke, and moderate to severe stroke were 48 (30.4%), 59 (37.3%), and 51 (32.3%), respectively. The larger WMH volume was associated with moderate to severe strokes (TIA/TSI vs. moderate to severe strokes, odds ratio (OR) 2.318, 95% confidence interval (CI) 1.194-4.502, p = 0.007; mild vs. moderate to severe strokes, OR 1.972, 95% CI 1.118-3.479, p = 0.013). Patients with larger volume of WMH showed poorer clinical outcome (cutoff value: 9.71 cm3, OR 2.099, 95% CI 1.030-4.311, p = 0.042). CONCLUSION: Our study showed that larger WMH volume is associated with more severe stroke and poorer prognosis in patients with symptomatic carotid artery stenosis.

Perfusion recovery on TTP maps after endovascular stroke treatment might predict favorable neurological outcomes.

OBJECTIVES: Early recanalization and adequate collateral blood flow are surrogates for functional recovery in endovascular stroke treatment (EVT). We evaluated the prognostic value of pre- and immediate post-thrombectomy perfusion-weighted magnetic resonance imaging (PWI) parameters. METHODS: Consecutive patients with acute ischemic stroke who underwent EVT were enrolled. Lesion volumes and their corresponding changes on diffusion-weighted (DWI) and PWI were assessed. Outcome was measured with modified Rankin Scale (mRS) at 90 days, and early neurological improvement (> 8 points improvement on National Institutes of Health Stroke Scale [NIHSS] or 0 to 1) at 7 days. RESULTS: Fifty-two patients were enrolled. After control of initial NIHSS and recanalization status, post-thrombectomy time-to-peak (TTP) hypoperfused volume and TTP hypoperfused volume change remained independent predictors of favorable functional outcome (odds ratio [OR] = 0.13, 95% confidence interval [CI] = 0.03-0.54, p = 0.005; OR = 1.018, 95% CI = 1.00-1.03, p = 0.017), and early neurological improvement (OR = 0.20, 95% CI 0.07-0.58, p = 0.003; OR = 1.02, 95% CI = 1.00-1.03, p = 0.010). The areas under the curve of post-thrombectomy TTP hypoperfused volume and TTP hypoperfused volume change were 0.90 and 0.82 (cutoff 68 mL and 56 mL) for favorable outcome and 0.86 and 0.82 (cutoff 76 mL and 58 mL) for early neurological improvement, which had better prognostic values than other MR parameters and recanalization grades. CONCLUSIONS: These results suggest a large amount of perfusion recovery on TTP is associated with favorable outcome as well as early neurological improvement after EVT, and may be a useful prognostic marker. KEY POINTS: • A large amount of perfusion recovery on TTP map is associated with favorable outcome and early neurological improvement after EVT. • The best cutoff value for favorable functional outcome was 68 mL for post-EVT TTP hypoperfused volume and 56 mL decrease for TTP hypoperfused volume. • Amount of perfusion recovery on TTP map has better performance on the prediction of favorable functional recovery and early neurological improvement than other diffusion- and perfusion-weighted MRI parameters and recanalization grades.

Balloon Guide Catheter Is Beneficial in Endovascular Treatment Regardless of Mechanical Recanalization Modality.

Background and Purpose- Based on its mechanism, the use of balloon guide catheters (BGCs) may be beneficial during endovascular treatment, regardless of the type of mechanical recanalization modality used-stent retriever thrombectomy or thrombaspiration. We evaluated whether the use of BGCs can be beneficial regardless of the first-line mechanical endovascular modality used. Methods- We retrospectively reviewed consecutive acute stroke patients who underwent stent retriever thrombectomy or thrombaspiration from the prospectively maintained registries of 17 stroke centers nationwide. Patients were assigned to the BGC or non-BGC group based on the use of BGCs during procedures. Endovascular and clinical outcomes were compared between the BGC and non-BGC groups. To adjust the influence of the type of first-line endovascular modality on successful recanalization and favorable outcome, multivariable analyses were also performed. Results- This study included a total of 955 patients. Stent retriever thrombectomy was used as the first-line modality in 526 patients (55.1%) and thrombaspiration in 429 (44.9%). BGC was used in 516 patients (54.0%; 61.2% of stent retriever thrombectomy patients; 45.2% of thrombaspiration patients). The successful recanalization rate was significantly higher in the BGC group compared with the non-BGC group (86.8% versus 74.7%, respectively; P<0.001). Furthermore, the first-pass recanalization rate was more frequent (37.0% versus 14.1%; P<0.001), and the number of device passes was fewer in the BGC group (2.5±1.9 versus 3.3±2.1; P<0.001). The procedural time was also shorter in the BGC group (54.3±27.4 versus 67.6±38.2; P<0.001). The use of BGC was an independent factor for successful recanalization (odds ratio, 2.18; 95% CI, 1.54-3.10; P<0.001) irrespective of the type of first-line endovascular modality used. The use of BGC was also an independent factor for a favorable outcome (odds ratio, 1.40; 95% CI, 1.02-1.92; P=0.038) irrespective of the type of first-line endovascular modality used. Conclusions- Regardless of the first-line mechanical endovascular modality used, the use of BGC in endovascular treatment was beneficial in terms of both recanalization success and functional outcome.

Outcomes of Stenting versus Endarterectomy for Symptomatic Extracranial Carotid Stenosis: A Retrospective Multicenter Study in Korea.

BACKGROUND: The present multicenter retrospective study aimed to compare the outcome of carotid artery stenting (CAS) versus carotid endarterectomy (CEA) among Korean patients with symptomatic extracranial carotid stenosis. METHODS: Between January 2008 and December 2011, 677 patients underwent either CAS (346, 51.1%) or CEA (331, 48.9%). The primary end point included the occurrence of major adverse cardiovascular events (MACEs), defined as fatal or nonfatal stroke and myocardial infarction, and all-cause mortality during the periprocedural period and within 4 years after CAS or CEA. RESULTS: Although patients undergoing CAS and CEA did not differ significantly in MACE incidence within 4 years (15.3% vs. 11.5%, P = 0.14), CEA showed lower periprocedural MACE incidence than CAS with clinical significance (6.1% vs. 3.0%, P = 0.06). During the periprocedural period, the incidence of any stroke was significantly higher in patients undergoing CAS (5.5% vs. 2.4%, P = 0.04) but not the incidence of myocardial infarction (0.6% vs. 0.3%, P > 0.99). Kaplan-Meier survival analysis showed similar MACE-free (P = 0.16), stroke-free (P = 0.24), and overall survival (P = 0.25) rates in both groups. On subgroup analysis, patients older than 70 years undergoing CAS had a significantly higher incidence of MACE at 4 years (22.7% vs. 13.7%, P = 0.03). CONCLUSIONS: Although the risk of MACE did not differ significantly within 4 years in this Korean population undergoing CAS and CEA, there was a higher risk of stroke with CAS during the periprocedural period.

Cav-1 (Caveolin-1) and Arterial Remodeling in Adult Moyamoya Disease.

Background and Purpose- Moyamoya disease (MMD) is a unique cerebrovascular occlusive disease characterized by progressive stenosis and negative remodeling of the distal internal carotid artery (ICA). We hypothesized that cav-1 (caveolin-1)-a protein that controls the regulation of endothelial vesicular trafficking and signal transduction-is associated with negative remodeling in MMD. Methods- We prospectively recruited 77 consecutive patients with MMD diagnosed via conventional angiography. Seventeen patients with intracranial atherosclerotic stroke and no RNF213 mutation served as controls. The outer distal ICA diameters were examined using high-resolution magnetic resonance imaging. We evaluated whether the degree of negative remodeling in the patients with MMD was associated with RNF213 polymorphism, cav-1 levels, or various clinical and vascular risk factors. We also investigated whether the derived factor was associated with negative remodeling at the cellular level using the tube formation and apoptosis assays. Results- The serum cav-1 level was lower in the patients with MMD than in the controls (0.47±0.29 versus 0.86±0.68 ng/mL; P=0.034). The mean ICA diameter was 2.48±0.98 mm for the 126 affected distal ICAs in patients with MMD and 3.84±0.42 mm for the asymptomatic ICAs in the controls ( P<0.001). After adjusting for confounders, cav-1 levels (coefficient, 1.018; P<0.001) were independently associated with the distal ICA diameter in patients with MMD. In vitro analysis showed that cav-1 downregulation suppressed angiogenesis in the endothelial cells and induced apoptosis in the smooth muscle cells. Conclusions- Our findings suggest that cav-1 may play a major role in negative arterial remodeling in MMD.

Number of Stent Retriever Passes Associated With Futile Recanalization in Acute Stroke.

Background and Purpose- Stent retriever (SR) thrombectomy has become the mainstay of treatment of acute intracranial large artery occlusion. However, it is still not much known about the optimal limit of SR attempts for favorable outcome. We evaluated whether a specific number of SR passes for futile recanalization can be determined. Methods- Patients who were treated with a SR as the first endovascular modality for their intracranial large artery occlusion in anterior circulation were retrospectively reviewed. The recanalization rate for each SR pass was calculated. The association between the number of SR passes and a patient's functional outcome was analyzed. Results- A total of 467 patients were included. Successful recanalization by SR alone was achieved in 82.2% of patients. Recanalization rates got sequentially lower as the number of passes increased, and the recanalization rate achievable by ≥5 passes of the SR was 5.5%. In a multivariable analysis, functional outcomes were more favorable in patients with 1 to 4 passes of the SR than in patients without recanalization (odds ratio [OR] was 8.06 for 1 pass; OR 7.78 for 2 passes; OR 6.10 for 3 passes; OR 6.57 for 4 passes; all P<0.001). However, the functional outcomes of patients with ≥5 passes were not significantly more favorable than found among patients without recanalization (OR 1.70 with 95% CI, 0.42-6.90 for 5 passes, P=0.455; OR 0.33 with 0.02-5.70, P=0.445 for ≥6 passes). Conclusions- The likelihood of successful recanalization got sequentially lower as the number of SR passes increased. Five or more passes of the SR became futile in terms of the recanalization rate and functional outcomes.

Rescue Stenting for Failed Mechanical Thrombectomy in Acute Ischemic Stroke: A Multicenter Experience.

BACKGROUND AND PURPOSE: Effective rescue treatment has not yet been suggested in patients with mechanical thrombectomy (MT) failure. This study aimed to test whether rescue stenting (RS) improved clinical outcomes in MT-failed patients. METHODS: This is a retrospective analysis of the cohorts of the 16 comprehensive stroke centers between September 2010 and December 2015. We identified the patients who underwent MT but failed to recanalize intracranial internal carotid artery or middle cerebral artery M1 occlusion. Patients were dichotomized into 2 groups: patients with RS and without RS after MT failure. Clinical and laboratory findings and outcomes were compared between the 2 groups. It was tested whether RS is associated with functional outcome. RESULTS: MT failed in 148 (25.0%) of the 591 patients with internal carotid artery or middle cerebral artery M1 occlusion. Of these 148 patients, 48 received RS (RS group) and 100 were left without further treatment (no stenting group). Recanalization was successful in 64.6% (31 of 48 patients) of RS group. Compared with no stenting group, RS group showed a significantly higher rate of good outcome (modified Rankin Scale score, 0-2; 39.6% versus 22.0%; P=0.031) without increasing symptomatic intracranial hemorrhage (16.7% versus 20.0%; P=0.823) or mortality (12.5% versus 19.0%; P=0.360). Of the RS group, patients who had recanalization success had 54.8% of good outcome, which is comparable to that (55.4%) of recanalization success group with MT. RS remained independently associated with good outcome after adjustment of other factors (odds ratio, 3.393; 95% confidence interval, 1.192-9.655; P=0.022). Follow-up vascular imaging was available in the 23 (74.2%) of 31 patients with recanalization success with RS. The stent was patent in 20 (87.0%) of the 23 patients. Glycoprotein IIb/IIIa inhibitor was significantly associated with stent patency but not with symptomatic intracranial hemorrhage. CONCLUSIONS: RS was independently associated with good outcomes without increasing symptomatic intracranial hemorrhage or mortality. RS seemed considered in MT-failed internal carotid artery or middle cerebral artery M1 occlusion.

Collateral status affects the onset-to-reperfusion time window for good outcome.

OBJECTIVE: To characterise the time window in which endovascular thrombectomy (EVT) is associated with good outcome, and to test the differential relationship between functional outcome and onset-to-reperfusion time (ORT), depending on collateral status. METHODS: This was a retrospective analysis of clinical and imaging data of 554 consecutive patients, who had recanalisation success by EVT for anterior circulation large artery occlusion, from the prospectively maintained registries of 16 comprehensive stroke centres between September 2010 and December 2015. The patients were dichotomised into good and poor collateral groups, based on CT angiography. We tested whether the likelihood of good outcome (modified Rankin Scale, 0-2) by ORT was different between two groups. RESULTS: ORT was 298 min±113 min (range, 81-665 min), and 84.5% of patients had good collaterals. Age, diabetes mellitus, previous infarction, National Institutes of Health Stroke Scale, good collaterals (OR 40.766; 95% CI 10.668 to 155.78; p<0.001) and ORT (OR 0.926 every 30 min delay; 95% CI 0.862 to 0.995; p=0.037) were independently associated with good outcome. The drop in likelihood of good outcome associated with longer ORT was significantly faster in poor collateral group (OR 0.305 for every 30 min; 95% CI 0.113 to 0.822) than in good collateral group (OR 0.926 for every 30 min; 95% CI 0.875 to 0.980). CONCLUSIONS: Earlier successful recanalisation was strongly associated with good outcome in poor collateral group; however, this association was weak during the tested time window in good collateral group. This suggests that the ORT window for good outcome can be adjusted according to collateral status.

Early rebleeding of intracranial dural arteriovenous fistulas after an intracranial hemorrhage.

BACKGROUND: The aim of this study was to evaluate the clinical and angiographic characteristics of dural arteriovenous fistulas (DAVF) presenting with intracranial hemorrhage (ICH), with a focus on early rebleeding according to the initial hemorrhage type. METHOD: The clinical and radiologic features of 21 dAVFs that presented with intracranial hemorrhage were retrospectively reviewed. The hemorrhage type was classified as pure intraparenchymal hemorrhage (pIPH) and subarachnoid or subdural hemorrhage with IPH (non-pIPH). RESULTS: There were 13 patients with pIPH and 8 with non-pIPH. The median follow-up period was 30 months (range, 1-116 months), and the median interval from hemorrhage to treatment was 4 days (range, 0-72 days). Rebleeding occurred in 8 (38.1%) of 21 patients. Four (50%) of eight patients with non-pIPH suffered from early rebleeding within 3 days, while there was no early rebleeding in patients with pIPH. There was a significantly higher rate of early rebleeding in the non-pIPH group (p = 0.012). Angiographically, venous ectasia (p = 0.005) and direct cortical venous drainage (dCVD) (p = 0.008) showed a significantly higher proportion in the non-pIPH group than in the pIPH group. CONCLUSIONS: DAVFs with ICH is likely to rebleed after the first hemorrhage. Thus, early treatment can be needed in all DAVFs with ICH. In addition, DAVFs that presenting with non-pIPH and containing venous ectasia or dCVD on initial angiography may have a higher risk of early rebleeding. Therefore, cautious attention and urgent treatment are necessary for these patients.

Multiparametric MR imaging of tumor response to intraarterial chemotherapy in orthotopic xenograft models of human metastatic brain tumor.

The purpose of our study was to investigate the therapeutic efficacy of intraarterial (IA) chemotherapy via multiparametric magnetic resonance imaging (MRI) analysis in orthotopic mouse brain tumor models. Stereotactic-guided intracranial inoculation of MDA-MB-231 cells was performed in nude mice. Thirty tumor bearing mice were randomized into three groups, and each group received either IA docetaxel administration (n = 10), intravenous (IV) docetaxel administration (n = 10), or IA solvent injection (n = 10) as control. Treatment response was monitored by diffusion-weighted imaging and dynamic contrast enhanced-MRI obtained 1 day before and 8 days after therapy initiation. Imaging results were correlated with histopathology. In the results, IA chemotherapy showed a significant decrease in tumor volume (86.5 ± 15.6 %) compared to the IV chemotherapy (121.1 ± 39.6%) and control (126.2 ± 22.0%) 8 days after therapy (p < 0.05). Furthermore, IA chemotherapy resulted in a significant increase in mean tumor apparent diffusion coefficient (ADC) values (116.8 ± 44.9%); in contrary IV chemotherapy (66.6 ± 26.9%) and control (69.1 ± 29.5%) showed a significant decrease in ADC values corresponding to further tumor growth (p < 0.05). However, there was no significant difference in perfusion parameters including initial area under the curve, K(trans), K(ep), and V(e) between the groups (p > 0.05). Histopathology confirmed necrosis and necroptosis in the tumors after IA chemotherapy. In conclusion, IA chemotherapy may lead to effective inhibition of tumor cell proliferation and offer potential benefit of inducing higher degree of treatment response than IV chemotherapy.

Clinical Features of Superficially Located Brain Arteriovenous Malformations with Transdural Arterial Communication.

BACKGROUND: Contrary to deeply located brain arteriovenous malformations (AVMs), superficially located AVMs are more likely to have transdural arterial communications (TACs). However, the clinical and radiologic characteristics of patients presenting with AVMs and TACs are poorly understood. The purpose of this study is to determine whether clinicoradiological features of cerebral AVMs differ according to TAC. METHODS: Between 2002 and 2012, 438 consecutive patients with a brain AVM were treated in our hospital. Among them were 124 patients with superficially located brain AVMs who met the inclusion and exclusion criteria of our study. We retrospectively reviewed the clinicoradiological features of their TACs to explore the variation in characteristics. RESULTS: Thirty-two of the 124 patients with a superficially located AVM (25.8%) had TAC. Radiologic findings of brain AVM images with TAC showed that TAC occurred significantly more frequently among larger AVMs (with vs. without TAC, 11.2 vs. 4.0 ml) and among diffuse AVMs (56.3 vs. 28.3%, p = 0.004). Clinical findings indicate that TAC was associated with chronic headache (43.8 vs. 12.0%, p < 0.001) and older age (43.1 vs. 36.6 years, p = 0.037). CONCLUSIONS: Brain AVM with TAC seems to be accompanied by distinctive clinical features, such as chronic headache and older age. Larger size and diffuseness of the AVM were also associated with TAC. Findings from this study and the prognostic significance of TAC should be further explored in a large prospective study.

Morphological risk factors for the rupture of anterior communicating artery aneurysms: the significance of fenestration.

INTRODUCTION: The purpose of this study was to evaluate morphological factors associated with rupture in anterior communicating artery (AcomA) aneurysms and to investigate the significance of AcomA fenestration as a risk factor for aneurysm rupture. METHODS: The clinical and radiologic findings of 255 patients with AcomA aneurysms treated with coil embolization between January 2005 and March 2014 were retrospectively reviewed. We performed univariate and multivariate analyses to evaluate the associations between morphological variables and rupture status. RESULTS: The number of patients with AcomA fenestration was 17 out of 255 (6.6 %). There were no statistically significant differences between the fenestration group and non-fenestration group in clinical and morphological characteristics. Multivariate logistic regression tests showed that superior direction of aneurysm dome (OR 2.802, p = 0.023), presence of a bleb (OR 5.998, p < 0.001), high aspect ratio (OR 3.138, p = 0.009), size greater than 7 mm (OR 3.356, p = 0.013), and AcomA fenestration (OR 4.135, p = 0.026) were significantly associated with AcomA aneurysm rupture. CONCLUSIONS: The results of this study demonstrated that a fenestrated AcomA is associated with risk of aneurysm rupture. Therefore, AcomA fenestration can be considered as an important morphological risk factor for rupture, along with other known risk factors such as the direction of aneurysm dome, a bleb, high aspect ratio, and size.

Safety and efficacy of antiplatelet response assay and drug adjustment in coil embolization: a propensity score analysis.

INTRODUCTION: The purpose of this study was to explore the safety and efficacy of an antiplatelet response assay and drug adjustment to prevent delayed thromboembolic events after stent-assisted coil embolization. METHODS: A total of 370 patients were enrolled in this study between December 2005 and July 2014. Of these, 124 patients were placed into the drug resistance test (DRT) group with drug adjustment according to response to an antiplatelet agent, and 246 patients comprised the control group with a standard antiplatelet regimen. The response to the antiplatelet agent was evaluated with the VerifyNow Rapid Platelet Function Assay. Propensity score matching analysis was performed with one-to-multiple matching. RESULTS: Among 370 patients, delayed thromboembolic events occurred in 28 (7.6 %) patients including 25 (10.2 %) in the control group and three (2.4 %) in the DRT group. Antiplatelet response test (p = 0.012), diabetes mellitus (DM) (p = 0.014), and hypertension (HTN) (p < 0.001) were associated with delayed infarction in multivariate analysis. In propensity score matching analysis, 331 patients were matched (control group (n = 229) vs. DRT group (n = 103)), and antiplatelet response (hazard ratio 0.247, 95 % confidence interval 0.070-0.868, p = 0.029) was correlated with delayed infarction. Conversely, the two groups were not significantly different with regard to total (p = 0.368) or major hemorrhagic complications (p = 0.108). CONCLUSION: Antiplatelet drug adjustment according to the results of an antiplatelet response assay might be associated with a decreased risk of delayed thromboembolic infarction compared with the standard antiplatelet regimen.

Differential Vascular Pathophysiologic Types of Intracranial Atherosclerotic Stroke: A High-Resolution Wall Magnetic Resonance Imaging Study.

BACKGROUND AND PURPOSE: Intracranial atherosclerotic stroke (ICAS) has various stroke mechanisms, including branch occlusive disease (BOD), subcortical infarcts caused by parent arterial disease occluding the perforator's orifice, and non-BOD, infarcts beyond the subcortical area caused by artery-to-artery embolism. To test whether these 2 types of ICAS had different vascular pathophysiologies, we compared the high-resolution magnetic resonance imaging characteristics between BOD and non-BOD ICAS. METHODS: Eighty patients with acute infarcts caused by ICAS of proximal middle cerebral artery or basilar artery without carotid/cardiac embolic sources or nonatherosclerotic causes were enrolled (36 BOD and 44 non-BOD patients). The steno-occlusive intracranial artery at the maximal stenosis was analyzed for vascular remodeling and wall enhancement. RESULTS: BOD had distinct radiological features in terms of vascular morphology and enhancement. BOD showed a milder stenosis than non-BOD (P<0.001). Positive remodeling was more frequently observed in non-BOD than in BOD (P=0.005). Wall area index was also lower in BOD. Plaque enhancement was observed in all but one non-BOD patient and in one fourth of BOD patients (P=0.003). Although both types showed an eccentric enhancement, this enhancement was more frequently distributed in the BOD group on the side where the perforators arose. As the number of asymptomatic intracranial stenosis increased, the degree of stenosis (rho=0.513, P=0.003) increased in the BOD group, whereas enhanced plaque area (rho=0.343, P=0.030) increased in the non-BOD group. CONCLUSIONS: Our data indicate that BOD is a common and unique form of ICAS, distinct from non-BOD. These 2 types of ICAS have different vascular pathophysiologies in terms of vascular remodeling and plaque characteristics.

A novel magnetic resonance imaging approach to collateral flow imaging in ischemic stroke.

OBJECTIVE: Dedicated magnetic resonance (MR) imaging (MRI) sequences for evaluation of collaterals can be generated using MR perfusion (MRP) source data. We compared a novel collateral flow imaging technique with digital subtraction angiography (DSA) for determining collateral circulation in acute stroke and evaluated the ability of MR-based collateral flow maps to predict outcomes after recanalization therapy. METHODS: Consecutive patients who were candidates for endovascular treatment were enrolled. A collateral flow map derived from MRP source data was generated by manual or automatic postprocessing. Collateral grading based on the collateral flow map was performed and compared with grading based on DSA. Clinical and radiological outcomes were evaluated according to MR-based collateral grading and early reperfusion (ER) status. RESULTS: There was good correlation between MRI-based and DSA-based collateral grades (weighted κ-coefficient = 0.70). Collateral status and achievement of ER were the 2 main determinants of a favorable functional outcome and neurological improvement, in addition to infarct growth. Regardless of achievement of ER, better collaterals were significantly associated with a lower modified Rankin score at day 90 (p < 0.001 for trend in both ER(-) and ER(+) ). Most symptomatic intracranial hemorrhages occurred in patients with a poor collateral grade and ER(+) , whereas no patient with excellent collaterals suffered symptomatic intracranial hemorrhage or died. INTERPRETATION: MRI techniques to assess collaterals are rapidly being developed, and may provide insight into collateral perfusion. The combination of collateral images derived from pretreatment MRP source data and reperfusion status is a robust predictor of outcomes in acute ischemic stroke.

Long-term results of ethanol sclerotherapy with or without adjunctive surgery for head and neck arteriovenous malformations.

INTRODUCTION: Ethanol sclerotherapy has shown favorable short-term efficacy in managing head and neck arteriovenous malformation (AVM) which is well known for high recurrence rate after treatment. The purpose of this study was to report immediate treatment results and long-term follow-up results of ethanol sclerotherapy in patients with head and neck AVMs. METHODS: We performed a retrospective review of 45 patients with head and neck AVMs treated between April 1997 and December 2013 by using ethanol sclerotherapy with or without adjunctive surgery. The degree of AVM eradication was analyzed, and complications per treatment session were recorded. Long-term treatment effectiveness was assessed with clinical and imaging follow-up. RESULTS: In total, 132 sclerotherapies were performed in the 45 patients, with a total angiographic eradication rate of 17.8% (n = 8). Partial resolution was achieved in 34 patients, and three patients showed no response. Mean follow-up period was 56.6 months (range, 13-144 months). The long-term recurrence rate was 11.1% (5/45), and all recurrences occurred more than 3 years after the treatment with interval disease-controlled period. The major complication rate was 3.8% (5/132), and 34 minor complications (25.8%) occurred. CONCLUSIONS: Ethanol sclerotherapy is effective for achieving long-term durable cure of head and neck AVMs. In patients with non-curable disease, it is also effective for symptom palliation and long-term disease control. However, given recurrence after interval disease-controlled period, long-term follow-up should be required to detect recurrence in patients with any residual lesion after treatment.

Spontaneous angiographic changes in venous drainage patterns related to symptom changes in patients with untreated cavernous sinus dural arteriovenous fistula.

INTRODUCTION: We evaluated the relationship between symptomatic and angiographic changes in untreated cavernous sinus dural arteriovenous fistulas (CSdAVFs), focusing on venous drainage patterns. METHODS: The clinical and radiologic features of 34 cases of untreated CSdAVF were retrospectively reviewed. We classified venous drainage patterns as type I (only antegrade drainage), type II (combined antegrade drainage and venous reflux), type III (venous reflux without antegrade drainage), or type IV (stasis or occlusion of venous reflux). Symptom changes were categorized as improvement, aggravation of initial symptoms, or symptom pattern change. RESULTS: Twenty-one patients (61 %) showed symptom changes during follow-up (median, 12; range, 3-151 months). In the symptom improvement group (n = 10), patients who underwent follow-up angiography (n = 4) exhibited spontaneous occlusion. In the symptom aggravation group (n = 4), new venous reflux developed in 2 patients (type I to type II) and spontaneous occlusion in 2 patients (type III to spontaneous occlusion). In the symptom pattern change group (n = 7), 2 patients showed new venous reflux (type I to type II), and 5 showed stasis or occlusion of an engorged ophthalmic vein (type II or III to type IV). Angiographic regression was observed in all type III and IV patients, and cortical venous reflux (CVR) developed in 1 type I patient. CONCLUSION: Symptom changes correlated with chronological angiographic changes. Without treatment, most CSdAVFs behaved benignly and had a low incidence of CVR. Therefore, close observation is a possible protocol for managing CSdAVFs that have tolerable symptoms, no CVR, and no antegrade drainage despite aggravation or fluctuation in symptoms.

High-resolution magnetic resonance wall imaging findings of Moyamoya disease.

BACKGROUND AND PURPOSE: Diagnosis of Moyamoya disease (MMD) is based on the characteristic angiographic findings. However, differentiating MMD from intracranial atherosclerotic disease (ICAD) is difficult. We compared vessel wall imaging findings on high-resolution magnetic resonance imaging between MMD and ICAD. METHODS: High-resolution magnetic resonance imaging was performed on 32 patients with angiographically proven MMD and 16 patients with acute infarcts because of ICAD. Bilateral internal carotid arteries and steno-occlusive middle cerebral artery were analyzed for wall enhancement and remodeling. RESULTS: Enhancement patterns and distribution were different. Most patients with MMD (90.6%) showed concentric enhancement on distal internal carotid arteries and middle cerebral arteries, whereas focal eccentric enhancement was observed on the symptomatic segment in ICAD. MMD was characterized by middle cerebral artery shrinkage; the remodeling index and wall area were lower in MMD than in ICAD (remodeling index, 0.19±0.11 versus 1.00±0.43; wall area, 0.32±0.22 versus 6.00±2.72; P<0.001). CONCLUSIONS: MMD was characterized by concentric enhancement on bilateral distal internal carotid arteries and shrinkage of middle cerebral artery, regardless of symptoms.