Factors related to vessel displacement due to stent retriever retraction: An in vitro study

BACKGROUND

Thrombectomy with a stent retriever (SR) may lead to intracranial hemorrhage due to vessel displacement. We aimed to explore factors related to vessel displacement using an in vitro vessel model.

METHODS

A vessel model mimicking two-dimensional left internal carotid angiography findings was used in this study. Six SR types (Solitaire 3 × 40, 4 × 40, and 6 × 40; Embotrap 5 × 37; Trevo 4 × 41; and Tron 4 × 40) were fully deployed in the M2 ascending, M2 bend, or M1 horizontal portion. Subsequently, the SR was retracted, and the vessel displacement, maximum SR retraction force, and angle of the M2 bend portion were measured. A total of 180 SR retraction experiments were conducted using 6 SR types at 3 deployment positions with 10 repetitions each.

RESULTS

The mean maximum distance of vessel displacement for Embotrap Ⅲ 5 × 37 (6.4 ± 3.5 mm, n = 30) was significantly longer than that for the other five SR types (p = 0.029 for Solitaire 6 × 40 and p < 0.001 for the others, respectively). Vessel displacement was significantly longer in the M2 ascending portion group (5.4 ± 3.0 mm, n = 60) than in the M2 bend portion group (3.3 ± 1.6 mm, n = 60) (p < 0.001) and it was significantly longer in the M2 bend portion group than in the M1 horizontal portion group (1.1 ± 0.7 mm, n = 60) (p < 0.001). A positive correlation existed between the mean maximum SR retraction force or mean angle of the M2 bend portion due to SR retraction (i.e., vessel straightening) and the mean maximum distance of vessel displacement (r = 0.90, p < 0.001; r = 0.90, p < 0.001, respectively).

CONCLUSIONS

Vessel displacement varied with the SR type, size, and deployment position. Moreover, vessel displacement correlated with the SR retraction force or vessel straightening of the M2 bend portion.

Factors related to white thrombi in acute ischemic stroke in cancer patients

OBJECTIVES

Thrombi in cerebral large vessel occlusion associated with active cancer are often fibrin and platelet-rich white thrombi. However, evaluating the thrombus composition in a short time before thrombectomy is often ineffective. We sought to determine factors related to white thrombi in acute ischemic stroke due to large vessel occlusion in cancer patients.

METHODS

Consecutive cancer patients undergoing thrombectomy for acute ischemic stroke due to large vessel occlusion between January 2018 and May 2022 were retrospectively reviewed. The patients were classified into white thrombus and red thrombus groups on the basis of the pathological findings of retrieved thrombi. Patient characteristics and laboratory findings were compared between the two groups.

RESULTS

There were 12 patients in the white thrombus group and 11 patients in the red thrombus group. Active cancer was significantly more in the white thrombus group than in the red thrombus group (91.7% vs. 36.3%, p = 0.0094). Internal carotid artery occlusion was significantly less in the white thrombus group than in the red thrombus group (0% vs. 36.4%, p = 0.037). Among laboratory findings, D-dimer levels were an independent factor associated with white thrombi (odds ratio 8.97 [95% confidence interval 1.71-368.99], p < 0.0001). The cutoff value of D-dimer levels for predicting white thrombi was 3.5 μg/mL (83.3% sensitivity and 100% specificity).

CONCLUSIONS

In acute ischemic stroke in cancer patients, active cancer, no internal carotid artery occlusion, and higher D-dimer levels (≥3.5 μg/mL) may be associated with occlusion with fibrin and platelet-rich white thrombi.

Microcatheter movement in the aneurysm due to low-profile visualized intraluminal support deployment: An in vitro study

BACKGROUND

When a microcatheter is in the aneurysm, it may move due to low-profile visualized intraluminal support (LVIS) deployment. This study was designed to determine this mechanism.

METHODS

Six silicon aneurysm models were created by combining the aneurysm location (side wall or bifurcation) and the parent vessel configuration (straight, ipsilateral bending, or contralateral bending). After adjusting the microcatheter tip position in the aneurysm by pushing or pulling, an LVIS stent was deployed to cover the aneurysm neck, and the changes in the microcatheter tip position was measured. Pushing and pulling were performed 15 times each for each model, for a total of 180 experiments.

RESULTS

In all experiments, the microcatheter tip moved with LVIS deployment. The total movement distance was 3.00±1.59 mm, which was significantly different between the push and pull groups (p = 0.049), between the three side-wall aneurysm models (p<0.0001), and between the three bifurcation aneurysm models (p<0.0001). Backward movement in the aneurysm occurred in 21% (37/180). The frequency of backward movement was significantly different between the side-wall and bifurcation aneurysm models (p = 0.0265) and between the push and pull groups (p<0.0001). The forward movement distance was significantly different between the side-wall (n = 78) and bifurcation (n = 65) aneurysm models (p<0.0001).

CONCLUSIONS

The aneurysm location, the parent vessel configuration, and adjustment of the microcatheter tip position by pushing or pulling may affect the total movement distance and forward/backward movement of the microcatheter tip due to LVIS deployment.

Correlation of Scoring Systems with the Requirement of an External Ventricular Drain in Intraventricular Hemorrhage

BACKGROUND

External ventricular drainage (EVD) is required to resolve acute hydrocephalus associated with intraventricular hemorrhage (IVH). The correlation of scoring systems of IVH with indications for EVD for acute hydrocephalus related to IVH is currently unknown.

METHODS

We identified 213 hypertensive patients with IVH and divided them into 2 groups according to treatment method: 187 patients receiving blood pressure control alone and 26 patients undergoing EVD. The following patients were excluded: pediatric patients, patients undergoing intracranial hematoma removal, patients with fetal status, and patients without sufficient clinical data. We compared the Glasgow Coma Scale score, Graeb score, LeRoux score, Evans index, and bicaudate index values between the 2 groups and determined the prognostication accuracy of each scoring system.

RESULTS

There were significant differences in all 4 scoring systems between the 2 groups (P < 0.001). The cutoff values (sensitivity and specificity) of each scoring system were as follows: Glasgow Coma Scale, 8 (65.4%, 87.7%); Graeb score, 6 (80.8%, 75.4%); LeRoux score, 9 (80.8%, 76.5%); Evans index, 0.245 (80.8%, 67.9%); and bicaudate index, 0.186 (76.9%, 76.5%). The value of the area under the curve of each scoring system (95% confidence interval) was as follows: Glasgow Coma Scale, 0.806 (0.705-0.907); Graeb score, 0.852 (0.779-0.925); LeRoux score, 0.875 (0.812-0.937); Evans index, 0.788 (0.702-0.875); and bicaudate index, 0.778 (0.673-0.883).

CONCLUSIONS

The LeRoux score is better for identifying patients with IVH who are more likely to have EVD.

Rescue therapy for vasospasm following aneurysmal subarachnoid hemorrhage: a propensity score-matched analysis with machine learning

OBJECTIVE

Rescue therapies have been recommended for patients with angiographic vasospasm (aVSP) and delayed cerebral ischemia (DCI) following subarachnoid hemorrhage (SAH). However, there is little evidence from randomized clinical trials that these therapies are safe and effective. The primary aim of this study was to apply game theory-based methods in explainable machine learning (ML) and propensity score matching to determine if rescue therapy was associated with better 3-month outcomes following post-SAH aVSP and DCI. The authors also sought to use these explainable ML methods to identify patient populations that were more likely to receive rescue therapy and factors associated with better outcomes after rescue therapy.

METHODS

Data for patients with aVSP or DCI after SAH were obtained from 8 clinical trials and 1 observational study in the Subarachnoid Hemorrhage International Trialists repository. Gradient boosting ML models were constructed for each patient to predict the probability of receiving rescue therapy and the 3-month Glasgow Outcome Scale (GOS) score. Favorable outcome was defined as a 3-month GOS score of 4 or 5. Shapley Additive Explanation (SHAP) values were calculated for each patient-derived model to quantify feature importance and interaction effects. Variables with high SHAP importance in predicting rescue therapy administration were used in a propensity score-matched analysis of rescue therapy and 3-month GOS scores.

RESULTS

The authors identified 1532 patients with aVSP or DCI. Predictive, explainable ML models revealed that aneurysm characteristics and neurological complications, but not admission neurological scores, carried the highest relative importance rankings in predicting whether rescue therapy was administered. Younger age and absence of cerebral ischemia/infarction were invariably linked to better rescue outcomes, whereas the other important predictors of outcome varied by rescue type (interventional or noninterventional). In a propensity score-matched analysis guided by SHAP-based variable selection, rescue therapy was associated with higher odds of 3-month GOS scores of 4-5 (OR 1.63, 95% CI 1.22-2.17).

CONCLUSIONS

Rescue therapy may increase the odds of good outcome in patients with aVSP or DCI after SAH. Given the strong association between cerebral ischemia/infarction and poor outcome, trials focusing on preventative or therapeutic interventions in these patients may be most able to demonstrate improvements in clinical outcomes. Insights developed from these models may be helpful for improving patient selection and trial design.

Microbleeds and clinical outcome in acute mild stroke patients treated with antiplatelet therapy: ADS post-hoc analysis

BACKGROUND AND PURPOSE

In this post-hoc analysis using acute dual study dataset, the impacts of cerebral microbleeds (MBs) after mild stroke on clinical outcome were investigated.

METHODS

The number of MBs on admission was categorized as 1) no MBs, 2) MBs 1-4, 3) MBs 5-9, and 4) MBs ≥ 10. The efficacy outcome was defined as neurological deterioration and stroke recurrence within 14 days. Safety outcomes included ICH and/or SAH as well as extracranial hemorrhages.

RESULTS

Of the 1102 patients, 780 (71%) had no MBs on admission, while 230 (21%) had MBs 1-4, 48 (4%) had MBs 5-9, and 44 (4%) had MBs ≥ 10. The number of MBs was not associated with the neurological deterioration and/or stroke recurrence (p = 0.934), ICH and/or SAH (p = 0.743), and extracranial hemorrhage (p = 0.205). Favorable outcome was seem in 84% in the No MBs group, 83% in the MBs 1-4, 94% in the MBs 5-9, and 85% in the MBs ≥ 10 (p = 0.304). Combined cilostazol and aspirin therapy did not alter any rates of efficacy and safety outcomes among the no MBs, MBs 1-4, MBs 5-9, and MBs ≥ 10 groups compared to aspirin alone (all p > 0.05). By multivariate regression analysis, a history of ICH and diastolic blood pressure were the independent parameters to all of the MBs criteria (presence, MBs ≥ 5, and MBs ≥ 10).

CONCLUSIONS

MBs did not alter the clinical outcome at 3 months of onset. Elevated diastolic blood pressure and a history of ICH were the essential parameters related to the MBs.

Factors related to microcatheter passage through the trans-cell approach using a low-profile visualized intraluminal support device: an in-vitro study

BACKGROUND AND PURPOSE

The trans-cell approach using a low-profile visualized intraluminal support (LVIS) device is sometimes used for aneurysm coil embolization. However, factors related to microcatheter passage remain uninvestigated. We aimed to examine in-vitro factors related to microcatheter passage using the trans-cell approach with an LVIS.

METHODS

Silicone vessel models (inner diameter, 4 mm) were created with different bend segments and a 4-mm hole assuming an aneurysm neck on the side of the greater curvature. The LVIS Blue (4.5 × 32 mm) was deployed at the bend segment, and passability on the trans-cell surface was evaluated by passing the microcatheter along the micro guidewire. A total of 800 passage experiments were performed using two types of microcatheter, ten types of silicone vessel, four cell widths, five cells with the same LVIS device, and two micro guidewire directions in the aneurysm.

RESULTS

The Headway Duo microcatheter (35.5%, 142/400) tended to have better passability compared with the Headway 17 microcatheter (29.3%, 117/400) (p = 0.070). As the cell width and angle between the trans-cell surface and microcatheter direction increased, passability significantly increased (p = 0.027 and p < 0.001, respectively). There was no significant difference in passability when the micro guidewire was directed to the proximal side versus the distal side (p = 0.45).

CONCLUSIONS

A large cell width and an obtuse angle between the trans-cell surface and microcatheter direction facilitated good passability. Although statistically marginal, microcatheters with small ledges and small tips had relatively good passability.

Abstract P40: Declining Morbidity From Subarachnoid Hemorrhage in the Last 4 Decades: A Pooled Analysis of 13,343 Patients

Introduction: Subarachnoid hemorrhage (SAH) mortality is decreasing, but data on functional outcomes over time is lacking.

Methods: We created trends of good (Glasgow Outcomes Scale [GOS] of 4 or 5) and optimal (GOS of 5) functional outcomes and mortality (GOS of 1) using linear regression in 15 SAH trials and registries from 1982 to 2014. Models adjusted for age, sex, history of hypertension, World Federation of Neurological Surgeons grade, Fisher grade, aneurysm size, location, and repair modality, and whether data was from a clinical trial or registry. Analyses were repeated separately for the clinical trials and registries. Missing data were handled with multiple imputation.

Results: Overall, 13,343 SAH patients were included. 9,524 (71%) patients had good functional outcome, while 1,608 (12%) died. There was a 0.6% adjusted improvement (95% confidence interval [CI]: 0.5% to 0.7%; p<0.001) per year in good functional outcome and a 0.1% adjusted reduction (95% CI: -0.2% to -0.08%; p<0.001) per year in mortality. For patients enrolled in clinical trials, there was no change good functional outcomes (0%; 95% CI: -0.2% to 0.1%; p=0.923) or mortality (0.0% change per year; 95% CI: -0.09% to 0.1%; p=0.676). Clinical registry patients experienced a 1.2% improvement (95% CI: 1.0% to 1.4%; p<0.001) in good functional outcome and a 0.3% reduction (95% CI: -0.4% to -0.1%; p<0.001) in mortality.

Conclusions: SAH morbidity and mortality decreased from the 1980s to 2010s. This data can be helpful for researchers planning trials, clinicians discussing expected outcomes with patients and family members, and healthcare administrators planning resource utilization.

Cilostazol uncovers covert atrial fibrillation in non-cardioembolic stroke

BACKGROUND

We hypothesized that administration of cilostazol may clarify the occult atrial fibrillation (AF) during hospitalization in mild stroke patients, who has no history of AF.

METHODS

From our prospective non-cardioembolic stroke study, randomized to dual antiplatelet therapy using cilostazol and aspirin or aspirin alone trial (ADS), data on the presence or absence of AF were retrospectively analyzed. In the ADS, during hospitalization, as a routine examination, presence of AF was investigated using electrocardiogram (ECG), ECG monitoring and Holter ECG. Multivariate regression analysis was conducted to evaluate the independent parameters related to the AF. Clinical outcome at 3 months was evaluated using modified Rankin Scale (mRS) score.

RESULTS

Data on 1194 patients (793 [66%] men; median age [interquartile range] of 69 [61-77] years, National Institutes of Health Stroke Scale score 2 [1-4], onset-to-admission 10.8 [4.7-20.5] hours) were retrospectively analyzed. AF was newly detected in 41 (3%) patients (3 by ECG, 21 by the ECG monitoring and 17 by the Holter ECG) during hospitalization. Patients treated with combined cilostazol and aspirin therapy frequently had the AF than those took aspirin alone (5% vs. 2%, p = .007). Multivariate regression analysis showed that cilostazol administration was one of the independent factors for new-AF (odds ratio 2.672, 95%CI: 1.205-5.927, p = .016). The frequency of mRS 0-1 was 68% in the new-AF group and 67% in the non-AF group (p = 1.000).

CONCLUSION

Cilostazol therapy may increase the detectability of AF in acute non-cardioembolic stroke, though the new-AF was not related to clinical outcome at 3 months.

Prediction of Stroke Risk by Detection of Hemorrhage in Carotid Plaques: Meta-Analysis of Individual Patient Data

OBJECTIVES

The goal of this study was to compare the risk of stroke between patients with carotid artery disease with and without the presence of intraplaque hemorrhage (IPH) on magnetic resonance imaging.

BACKGROUND

IPH in carotid stenosis increases the risk of cerebrovascular events. Uncertainty remains whether risk of stroke alone is increased and whether stroke is predicted independently of known risk factors.

METHODS

Data were pooled from 7 cohort studies including 560 patients with symptomatic carotid stenosis and 136 patients with asymptomatic carotid stenosis. Hazards of ipsilateral ischemic stroke (primary outcome) were compared between patients with and without IPH, adjusted for clinical risk factors.

RESULTS

IPH was present in 51.6% of patients with symptomatic carotid stenosis and 29.4% of patients with asymptomatic carotid stenosis. During 1,121 observed person-years, 66 ipsilateral strokes occurred. Presence of IPH at baseline increased the risk of ipsilateral stroke both in symptomatic (hazard ratio [HR]: 10.2; 95% confidence interval [CI]: 4.6 to 22.5) and asymptomatic (HR: 7.9; 95% CI: 1.3 to 47.6) patients. Among patients with symptomatic carotid stenosis, annualized event rates of ipsilateral stroke in those with IPH versus those without IPH were 9.0% versus 0.7% (<50% stenosis), 18.1% versus 2.1% (50% to 69% stenosis), and 29.3% versus 1.5% (70% to 99% stenosis). Annualized event rates among patients with asymptomatic carotid stenosis were 5.4% in those with IPH versus 0.8% in those without IPH. Multivariate analysis identified IPH (HR: 11.0; 95% CI: 4.8 to 25.1) and severe degree of stenosis (HR: 3.3; 95% CI: 1.4 to 7.8) as independent predictors of ipsilateral stroke.

CONCLUSIONS

IPH is common in patients with symptomatic and asymptomatic carotid stenosis and is a stronger predictor of stroke than any known clinical risk factors. Magnetic resonance imaging might help identify patients with carotid disease who would benefit from revascularization.

Abstract TP78: Classification of Ischemic Core Distribution Pattern Using Computed Tomography Perfusion in Anterior Circulation Acute Large Vessel Occlusion

Introduction: The evaluation of ischemic core is important in acute cerebral infarction with large vessel occlusion. The ischemic core is thought to approximate the region that is difficult to receive collateral circulation. We classified the ischemic core distribution pattern into four types on the basis of the tendency of cerebral blood volume (CBV) decrease in the ischemic core, and examined the prognostic ability.

Methods: We included M1 or ICA occlusion which completely recanalized (TICI3) by thrombectomy in our institute from January 2015 to May 2019. The ischemic core was defined as a region where CBV were reduced less than 1.9 ml/100cc. Ischemic core distribution pattern was classified into the following 4 types. Type A: absent of ischemic core. Type B: ischemic core is confined to the basal ganglia and white matter. Type C1: ischemic core is present in the cortex but less than half of MCA region. Type C2: ischemic core is present in the cortex, and more than half of MCA region. The patient characteristics, temporal parameters, ASPECTS and ischemic core distribution pattern were analyzed with mRS0-2 at discharge as a good outcome group.

Results: A total of 47 cases (14 ICA, 33 M1) were included. Ischemic core distribution pattern correlated well with mRS at discharge (p<0.004). Factors that showed a significance in univariate analysis between the good outcome group (n=19) and the poor outcome group (n=28) were age (76 vs 80.5, p=0.037), ASPECTS (10 vs 9, p=0.027), ischemic core distribution type (B vs C1, p=0.002), last known well to recanalization time (191 vs 272.5, p=0.027). Among these factors, multivariate analysis correlated significantly with age (OR, 1.18; 95CI,1.01-1.36), ischemic core distribution pattern (OR, 5.01; 95CI, 1.8-13.9), and recanalization time (OR, 1.46; 95CI, 1.01-2.12).

Conclusions: The distribution pattern of ischemic core defined by reduced CBV have good correlation with outcome. There is a possibility that it can be used as a simple tool to predict prognosis using CT perfusion in anterior circulation acute large vessel occlusion.

Abstract WP115: Cilostazol Addition to Aspirin Does Not Alter the Short-Term Neurological Outcome in Each Clinical Subtype of Acute Stroke

Hypothesis: Our previous study, ADS reported that dual antiplatelet therapy (DAPT) using cilostazol and aspirin did not reduce the rate of short-term neurological worsening in non-cardioembolic stroke patients. The aim of the present study is to investigate 1) whether the impact of cilostazol addition to aspirin differ among each stroke subtype, and 2) factors associated with neurological deterioration and/or stroke recurrence in order to find therapeutic target.

Methods: This is a retrospective analysis using the ADS databank. Neurological worsening and the rates of stroke recurrence within 14 day of onset were evaluated. Stroke subtype included large-artery atherosclerosis (LAA), lacunae infarct (LI), branch atheromatous disease (BAD), other, and undetermined.

Results: Data on 1,160 patients (773 [67%] men; median age, 69 [61-77] years, NIHSS score was 2 [1-4]) were analyzed. At discharge, 167 (14%) were diagnoses as having LAA; LI, 532 (46%); BAD, 173 (15%); other, 132 (11%); and undetermined, 156 (14%). Neurological deterioration and/or recurrence were seen in 130 (11%) patients, and the rates were not different between patients treated with DAPT and aspirin in any stroke subtypes: LAA, 19% (DAPT) vs. 11% (aspirin alone), (p=0.185); LI, 4% vs. 3% (p=0.645); BAD, 33% vs.34%, (p=0.872), other, 8% vs.14% (p=0.272); undetermined, 13% vs. 8% (p=0.301). When we evaluated factors related to the deterioration/recurrence, age (p<0.001), NIHSS score (p<0.001), systolic and diastolic blood pressures (p<0.001, and 0.025), whiter matter change (p=0.002), large infarcts >1.5cm (p<0.001), and intracranial stenosis/occlusion (p<0.001) were found. Multivariate regression analysis revealed older age (p=0.003), systolic blood pressure (p=0.013), larger infarct (p=0.001), intracranial stenosis/occlusion (p<0.035) were the independent factors associated with neurological deterioration/stroke recurrence.

Conclusions: Dual antiplatelet therapy using cilostazol and aspirin does not reduce the rate of short-term neurological worsening in each clinical stroke subtype. Improvement of hyperacute therapy targeting the elder patients with elevated blood pressure, large infarct and intracranial stenosis/occlusion should be required.

Branch atheromatous disease has a stronger association with late-onset epileptic seizures than lacunar infarction in Japanese patients

Objective

To evaluate the relationship between late-onset epileptic seizures and non-cortical infarction (namely, lacunar infarction and branch atheromatous disease [BAD]) in Japanese patients.

Methods

We reviewed the medical records and brain magnetic resonance imaging findings of all patients with ischemic stroke admitted to the Departments of Neurology, Neurosurgery, and Stroke Unit at Kurashiki Central Hospital from 1 January 2011 to 31 December 2012. Patients with lacunar infarction and BAD were enrolled; those with cortical and brain stem ischemic lesions were excluded. We analyzed the clinical features of patients who developed late-onset epileptic seizures after cerebral infarction.

Results

Eighty-five patients with lacunar infarction and 99 patients with BAD were enrolled. Four patients with BAD subsequently developed epileptic seizures (2.2% of total patients, 4.0% of patients with BAD), whereas no patients with lacunar infarction developed epileptic seizures. All patients with epileptic seizures had infarction involving the basal ganglia or thalamus. Three of them had multiple cerebral microbleeds, and two had dementia.

Conclusions

Patients with BAD, but not with lacunar infarction, might have a higher risk of developing epileptic seizures than the general population. Non-cortical infarctions with involvement of the basal ganglia or thalamus may increase the risk of subsequent late-onset epileptic seizures.

Acute Aspirin Plus Cilostazol Dual Therapy for Noncardioembolic Stroke Patients Within 48 Hours of Symptom Onset

Background

The aim of the present study was to investigate the efficacy and safety of antiplatelet (aspirin plus cilostazol) dual therapy for patients with noncardioembolic stroke within 48 hours of symptom onset.

Methods and Results

The ADS (Acute Aspirin Plus Cilostazol Dual Therapy for Non‐Cardiogenic Stroke Patients Within 48 Hours of Symptom Onset ) study is an investigator‐initiated, prospective, multicenter (34 hospitals in Japan), randomized, open‐label, and aspirin‐controlled trial. Acute stroke patients with noncardioembolic stroke within 48 hours of onset were studied. The subjects were randomly allocated to combination therapy with aspirin 81 to 200 mg plus cilostazol 200 mg (dual group) and single therapy with aspirin 81 to 200 mg (aspirin group) for 14 days. After the 14 days, all patients took the cilostazol 200 mg for 3 months. A primary efficacy outcome was defined as any one of the following occurring (neurological deterioration, symptomatic stroke recurrence, or transient ischemic attack) within 14 days. A primary safety outcome included intracerebral hemorrhage and subarachnoid hemorrhage. Between May 2011 and June 2017, 1201 patients (796 [66%] men; median age, 69 [61–77] years) randomized 1:1 to either the dual group or the aspirin group were analyzed. Initial National Institutes of Health Stroke Scale score was 2 (1–4) in both groups (P=0.830). A primary efficacy outcome was observed in 11% in the dual group and 11% in the aspirin group (P=0.853). A primary safety outcome occurred in 2 (0.3%) in the dual group and in 1 (0.2%) in the aspirin group (P=0.624).

Conclusions

Dual antiplatelet therapy using cilostazol and aspirin was safe but did not reduce the rate of short‐term neurological worsening.

Clinical Trial Registration

URL: umin.ac.jp/ctr/index/htm. Unique identifier: UMIN000004950.

Abstract WP256: Administration of Cilostazol Clarifies the Burden Atrial Fibrillation in Non-Cardioembolic Stroke

Introduction: The survey of atrial fibrillation (AF) is routinely recommended in acute stroke case, even in patients without AF on admission, because the AF leads to a sever stroke. Cilostazol is often used for stroke patients without AF in Japan; however, it has the adverse events of palpitation due to the vessels dilatation by increased nitric oxide. We hypothesized that administration of cilostazol may clarify the burden AF in stroke patients without AF.

Methods: From our prospective randomized control study, (randomized to dual antiplatelet therapy using cilostazol and aspirin or aspirin alone targeted patients for non-cardioembolic stroke [ADS]), patients assessed the presence of AF were retrospectively analyzed. Presence of AF was detected using ECG monitoring and Holter ECG. All patients were divided into the AF group and the non-AF group and imaging and laboratory findings were compared between the 2 groups. Multivariate regression analysis was conducted to evaluate the independent factors related to new AF.

Results: 1194 patients (793 [66%] men; median age [IQR] of 69 [61-77] years, NIHSS score 2 [1-4], onset-to-admission 10.8 [4.7-20.5] hours) patients were included. AF was newly detected in 41 patients (3 by ECG, 21 by the ECG monitoring and 17 by the Holter ECG) during hospitalization. Patients randomized to the combined cilostazol and aspirin therapy frequently had the AF than those to aspirin alone (29/596 [5%] vs. 12/598 [2%], p=0.007). AF group was older than the non-AF group (76 [72-82] vs. 68 [60-77] years, p<0.001). NIHSS score was similar between AF and non-AF group (5 [3-12] vs. 4 [2-6] p=0.062). Serum brain natriuretic peptide (BNP) level was higher in AF group (65.9 [31.7-145.5] vs. 25.6 [13.1-52.5] ng/ml. p<0.001). Regarding imaging findings, cardio-thoracic ratio (CTR) was elevated (p<0.001), multiple infarcts was frequent (p=0.003) and the infarcts size was larger (>1.5cm) (p<0.001) in AF group. By multivariate regression analysis, cilostazol administration was the independent factor for new AF detection (odds ratio 2.81, 95%CI: 1.30-6.09, p=0.009) adjusting for age, infarct size and number, CTR, BNP, and NIHSS score.

Conclusion: Administration of cilostazol increases the detectability of AF in acute non-cardioembolic stroke.

Abstract WP175: The Significance of Perfusion Computed Tomography in the Prediction of Hyperperfusion After Carotid Endarterectomy

Purpose: Cerebral hyperperfusion syndrome (CHS) is a rare devastating complication associated with hyperperfusion after carotid endarterectomy. Single photon emission computed tomography (SPECT) is usually used with acetazolamide challenge to measure the cerebrovascular reserve (CVR), and a decreased CVR is indicative of a high risk of post CEA hyperperfusion. However, acetazolamide administration can rarely cause serious adverse effects, and thus, alternative methods may be required. Perfusion computed tomography (PCT) is a rapid, more accessible modality, which can be acquired with CT angiography. PCT seems to be useful as a screening tool in identifying groups at high-risk of hyperperfusion, but its usefulness has not sufficiently investigated. Our purpose was to clarify the relationship between hyperperfusion and the preoperative PCT parameters of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT).

Method: We included patients who underwent carotid endarterectomy in our hospital from 2014 December to 2018 April. PCT was obtained preoperatively and on postoperative day 1. Hyperperfusion is defined as a postoperative CBF of the middle cerebral artery area which has increased twice that of the preoperative value. CHS was defined as any symptom and imaging findings related with hyperperfusion, which include headache, seizure, neurological dysfunction, and any intracranial hemorrhage in the related area. Preoperative CBF, CBV, MTT and other patient characteristics are statistically analyzed between a hyperperfusion group and non-hyperperfusion group.

Result: There are 73 patients who underwent CEA during the study period, and hyperperfusion was observed in 5 cases, from which 2 were considered as CHS. In the hyperperfusion group, the preoperative CBF was significantly lower (p=0.0008), and the CBV and MTT significantly higher (p=0.0196, p=0.0002). ROC analysis showed that the PCT parameters with the maximal area under the receiver-operating characteristic curve for hyperperfusion was preoperative MTT with an optimal threshold at 8.0 seconds (sensitivity 100%, specificity 100%).

Conclusion: Patient with prolonged preoperative MTT tend to develop hyperperfusion, which is related to CHS.

A Rare Case of Giant Solid Hemangioblastoma Accompanied with Hemophilia Type A

The surgical removal of giant solid hemangioblastoma involves a high risk of perioperative bleeding and requires attentive hemostasis. Here, we present a case of a giant solid hemangioblastoma accompanied with hemophilia which was previously undiagnosed. A 35-year-old man without any past medical history was admitted with diplopia and ocular motility disorder. computed tomography (CT) and magnetic resonance imaging (MRI) revealed obstructive hydrocephalus and a solid giant tumor of more than 4.0 cm in diameter in the right cerebellopontine angle (CPA). Hemangioblastoma was suspected on cerebral angiography. After ventriculoperitoneal shunt for obstructive hydrocephalus, oozing from the skin incision continued for several days. Hemophilia type A was diagnosed based on the result of laboratory blood coagulability examination. Supplemental administration of factor VIII and coil embolization of the feeding arteries of the lesion on the CPA were performed, and the tumor was subtotally resected without hemorrhagic complications. The histopathological diagnosis was hemangioblastoma. We report this case to emphasize the importance not to overlook previously undiagnosed coagulopathy before surgical excision of hemangioblastoma. And, with appropriate perioperative management for coagulopathy, surgical treatment involving a high risk of perioperative bleeding can be safely undertaken.

Pituitary Apoplexy in Long-Term Cabergoline User During Thrombocytopenia Due to Chemotherapy for Chronic Myelocytic Leukemia

BACKGROUND

Pituitary apoplexy (PA) is a life-threatening syndrome. The usage of a dopamine agonist, such as bromocriptine or cabergoline, is considered a predisposing factor for PA, which commonly occurs 1.5 years within commencement.

CASE DESCRIPTION

A 64-year-old female with a >15-year history of cabergoline therapy for pituitary prolactinoma was referred to our department of neurosurgery after complaining of headache, blurred vision, diplopia, and ptosis for 3 days during hospital admission for chemotherapy of chronic myelocytic leukemia. Computed tomography and magnetic resonance imaging revealed findings indicative of PA. As the patient was experiencing thrombocytopenia related to chemotherapy, blood transfusion was preceded, and after a platelet count of 15.0 × 104/μL was confirmed, transnasal neuroendoscopic surgery was performed 5 days from the onset of symptoms. The majority of the prolactinoma was removed, and the prolactinoma in the cavernous sinus was intentionally left. The postoperative course was generally good. The ptosis and diplopia improved, and the blurred vision resolved.

CONCLUSIONS

PA related to dopamine agonist therapy can occur in cases of elevated bleeding tendency, even in long-term users, suggesting that attention should be paid in the administration of a dopamine agonist in the patient experiencing thrombocytopenia. Surgical intervention should be performed after the preoperative platelet number and adequate response to transfusion are confirmed, and the aggressive removal of prolactinoma in the cavernous sinus should be avoided to reduce the risk of hemorrhagic complications.

Metronidazole Induced Encephalopathy Mimicking an Acute Ischemic Stroke Event

Metronidazole induced encephalopathy (MIE), an encephalopathy brought by an antibiotic, is characterized with cerebellar dysfunction, altered mental status and extrapyramidal symptoms. MIE can result in an acute manifestation, but MIE has not been reported as a stroke mimic. An 86-year-old patient undergoing metronidazole therapy for Clostridium difficile enteritis presented to our hospital with sudden disoriented status and motor weakness of the left extremities. Computed tomography (CT) was unrevealing of intracranial hemorrhagic change, and CT angiography did not show any apparent major occlusion or stenosis of the intracranial vessels. However, CT perfusion (CTP) revealed a decrease in peripheral blood flow in the right cerebral hemisphere, and tissue plasminogen activator was administrated for a possible acute ischemic stroke. The findings of follow-up magnetic resonance imaging (MRI) were typical for MIE, revealing areas of hyperintensity on fluid attenuated inversion recovery (FLAIR) signal intensity in the dentate nuclei, the splenium of the corpus callosum, and in the dorsal midbrain. The degree of hyperintensity was stronger in the left dentate nucleus than in the right left dentate on FLAIR and the apparent diffusion coefficient map. The asymmetric findings of the left dentate nucleus on MRI were considered to be responsible for the clinical symptoms and the findings of CTP. We report a rare case of MIE mimicking an acute ischemic stroke, and hypothesize the relationship between the findings of CTP and that of MRI based on the anatomical connection of the dentate nucleus and the cerebral hemisphere.

Primary Intracranial Leiomyosarcoma with Intratumoral Hemorrhage: Case Report and Review of Literature

BACKGROUND

Primary intracranial leiomyosarcoma is a very rare occurrence, and primary leiomyosarcoma with intratumoral hemorrhage has not been described previously. We present a case of a rapidly enlarging primary intracranial leiomyosarcoma with intratumoral hemorrhage.

CASE DESCRIPTION

A 41-year-old female presented with right hemiparesis and gait disturbance. She had a brain tumor on the frontal lobe that was growing rapidly. An intratumoral hemorrhage had occurred suddenly. We removed the tumor after hemorrhage. After the operation, postoperative chemotherapy and radiotherapy were not performed, but the tumor did not recur.

CONCLUSIONS

To the best our knowledge, this is the first report of primary intracranial leiomyosarcoma with intratumoral hemorrhage.

Effect of choice of treatment modality on the incidence of shunt-dependent hydrocephalus after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Shunt-dependent hydrocephalus (SDHC) may arise after aneurysmal subarachnoid hemorrhage (aSAH) as CSF resorptive mechanisms are disrupted. Using propensity score analysis, the authors aimed to investigate which treatment modality, surgical clipping or endovascular treatment, is superior in reducing rates of SDHC after aSAH.

METHODS

The authors' multicenter SAH database, comprising 3 stroke centers affiliated with Kyoto University, Japan, was used to identify patients treated between January 2009 and July 2016. Univariate and multivariate analyses were performed to characterize risk factors for SDHC after aSAH. A propensity score model was generated for both treatment groups, incorporating relevant patient covariates to detect any superiority for prevention of SDHC after aSAH.

RESULTS

A total of 566 patients were enrolled in this study. SDHC developed in 127 patients (22%). On multivariate analysis, age older than 53 years, the presence of intraventricular hematoma, and surgical clipping as opposed to endovascular coiling were independently associated with SDHC after aSAH. After propensity score matching, 136 patients treated with surgical clipping and 136 with endovascular treatment were matched. Propensity score-matched cohorts exhibited a significantly lower incidence of SDHC after endovascular treatment than after surgical clipping (16% vs 30%, p = 0.009; OR 2.2, 95% CI 1.2-4.2). SDHC was independently associated with poor neurological outcomes (modified Rankin Scale score 3-6) at discharge (OR 4.3, 95% CI 2.6-7.3; p < 0.001).

CONCLUSIONS

SDHC after aSAH occurred significantly more frequently in patients who underwent surgical clipping. Strategies for treatment of ruptured aneurysms should be used to mitigate SDHC and minimize poor outcomes.

Effect of intrathecal milrinone injection via lumbar catheter on delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Delayed cerebral ischemia (DCI) is an important complication after aneurysmal subarachnoid hemorrhage (aSAH). Although intrathecal milrinone injection via lumbar catheter to prevent DCI has been previously reported to be safe and feasible, its effectiveness remains unknown. The goal of this study was to evaluate whether intrathecal milrinone injection treatment after aSAH significantly reduced the incidence of DCI.

METHODS

The prospectively maintained aSAH database was used to identify patients treated between January 2010 and December 2015. The cohort included 274 patients, with group assignment based on treatment with intrathecal milrinone injection or not. A propensity score model was generated for each patient group, incorporating relevant patient variables.

RESULTS

After propensity score matching, 99 patients treated with intrathecal milrinone injection and 99 without treatment were matched on the basis of similarities in their demographic and clinical characteristics. There were significantly fewer DCI events (4% vs 14%, p = 0.024) in patients treated with intrathecal milrinone injection compared with those treated without it. However, there were no significant differences between the 2 groups with respect to their 90-day functional outcomes (46% vs 36%, p = 0.31). The likelihood of chronic secondary hydrocephalus, meningitis, and congestive heart failure as complications of intrathecal milrinone injection therapy was also similar between the groups.

CONCLUSIONS

In propensity score–matched groups, the intrathecal administration of milrinone via lumbar catheter showed significant reduction of DCI following aSAH, without an associated increase in complications.

Subarachnoid Hemorrhage from Vertebral Arteriovenous Fistula without Perimedullary Drainage: Rare Stroke Hemorrhagic Event in a Patient of Neurofibromatosis Type 1

Vertebral arteriovenous fistula (VAVF), which can cause subarachnoid hemorrhage (SAH) when having a perimedurally drainage, has been reported as a rare vascular abnormality in patients with neurofibromatosis type 1 (NF-1). In addition, extracranial vertebral aneurysm (EVAn) coexisting with VAVF and NF-1 is considered rare, and further complication with SAH is extremely rare in patients. There is only one reported case of NF-1 complicated with SAH from VAVF with an EVAn. Here, we present a case of a middle-aged patient with NF-1. The VAVF accompanied by an EVAn was detected with an episode of SAH. The VAVF with an EVAn in our case was accompanied with an epidural varix, lacking of perimedullary drainage, which could be a cause for SAH. We speculate the mechanism of SAH from the VAVF with an EVAn lacking of perimedurally drainage, focusing on hemodynamic stress of the VAVF and the tissue fragility related to NF-1.

Association of plasma D-dimer level with thromboembolic events after endovascular coil treatment of ruptured cerebral aneurysms

OBJECTIVE

Although endovascular therapy is favored for acutely ruptured intracranial aneurysms, hematological factors associated with acute subarachnoid hemorrhage (SAH) may predispose to procedure-related ischemic complications. The aim of this study was to evaluate whether an elevated level of plasma D-dimer, a parameter of hypercoagulation in patients with acute SAH, is correlated with increased incidence of thromboembolic events during endovascular coiling of ruptured aneurysms.

METHODS

The authors analyzed data from 103 cases of acutely ruptured aneurysms (in 103 patients) treated with endovascular coil embolization at a single institution. Factors associated with elevated D-dimer level on admission were identified. The authors also evaluated whether D-dimer elevation was independently correlated with increased incidence of perioperative thromboembolic events.

RESULTS

An elevated D-dimer concentration (≥ 1.0 μg/ml) on admission was observed in 70 (68.0%) of 103 patients. Increasing age (p < 0.001, Student t-test) and poor initial neurological grade representing World Federation of Neurosurgical Societies (WFNS) grade IV or V (p = 0.0018, chi-square test) were significantly associated with D-dimer elevation. Symptomatic thromboembolic events occurred in 11 cases (10.7%). Elevated D-dimer levels on admission (OR 1.34, 95% CI 1.10-1.62, p = 0.0029) independently carried a higher risk of thromboembolic events after adjustment for potential angiographic confounders, including wide neck of the aneurysm and large aneurysm size.

CONCLUSIONS

Elevated D-dimer levels on admission of patients with acute SAH were significantly associated with increased incidence of thromboembolic events during endovascular coiling of ruptured aneurysms.

Flexible endoscopically assisted evacuation of acute and subacute subdural hematoma through a small craniotomy: preliminary results

BACKGROUND

The first choice to treat acute subdural hematoma (SDH) is a large craniotomy under general anesthesia. However, increasing age or comorbid burden of the patients may render invasive treatment strategy inappropriate. These medically frail patients with SDH may benefit from a combination of small craniotomy and endoscopic hematoma removal, which is less invasive and even available under local anesthesia. Although hematoma evacuation with a rigid endoscope for acute or subacute SDHs has been reported in the literature, use of a flexible endoscope may have distinct advantages. In this article, we attempted to clarify the utility of small craniotomy evacuation with a flexible endoscope for acute and subacute SDH in the elderly patients.

METHOD

Between November 2013 and September 2016, a total of 17 patients with acute SDH (15 patients), subacute SDH (1 patient), or acute aggravation of chronic SDH (1 patient) underwent hematoma evacuation with a flexible endoscope at our hospital and were enrolled in this retrospective study. Either under local or general anesthesia, the SDH was removed with a flexible suction tube with the aid of the flexible endoscope through the small craniotomy (3 × 4 cm). Hematoma evacuation rate, improvement of clinical symptoms, and procedure-related complications were evaluated.

RESULTS

Hematoma evacuation rate was satisfactory, and statistically significant clinical improvement was observed in postoperative Glasgow Coma Scale in all cases compared to the preoperative assessment. No procedure-related hemorrhagic complications were observed.

CONCLUSIONS

The results reported here suggest that small craniotomy evacuation with a flexible endoscope is a safe, effective, and minimally invasive treatment for acute and subacute SDH in selected cases.

Abstract TP138: The Clinical Features and the Long-Term Outcomes of Carotid Symptomatic Low-Grade Stenosis

Background: Ischemic events caused by carotid artery stenosis are affected not only by stenosis but also by the instability of plaque. In symptomatic low-grade stenosis cases medical treatment is generally performed, but there are cases with repeated recurrence. The purpose of this study is to clarify the clinical features and long-term outcomes in cases of symptomatic low-grade stenosis.

Methods: We included seventy-one symptomatic patients with carotid low-grade stenosis (<NASCET 50%) who were admitted to our hospital from 2005 to 2016. The relative plaque signal intensity (rSI) with reference to muscle and expansive remodeling rate (ERR) were measured using carotid MRI. Antiplatelet therapy and treatment for atherosclerosis risk factors were administered in all cases. Carotid endarterectomy (CEA) was performed when ischemic symptoms appeared or the stenosis rate progressed despite medical treatment.

Results: The mean stenosis rate, rSI and ERR on admission were 20.4, 1.75 and 1.96, respectively. Seventy percent of cases involved intraplaque hemorrhage and positive remodeling. During a mean of 52-months follow-up, a recurrence of ischemic events was confirmed in 33 cases (46%), from which the duration until recurrence was within 7 days (33%), 3 months (18%), 1 year (18%), 2 years (21%), and over 2 years (15%). Nine cases had impending stroke, 3 of which were associated with major artery occlusion. CEA was performed in 28 cases (39%) for impending stroke (25%), recurrence of ischemic events (46%), asymptomatic infarction (7%), and stenosis rate progression (11%). During a mean of 47-months follow-up after CEA, 2 cases of death (fetal intracerebral hemorrhage, asphyxia) and one case of brain stem lacunar infarction were observed, but an ipsilateral ischemic event was not observed.

Conclusion: Most of the symptomatic patients with low-grade stenosis had both intraplaque hemorrhage and positive remodeling. The risk of recurrence and stenosis progression was high. CEA might have had a preventive effect against ischemic events in low-grade stenosis.

Abstract 159: Acute Aspirin Plus Cilostazol Dual Therapy for Non-cardioembolic Stroke Study (ADS)

Hypothesis: The aim of the present study was to investigate the efficacy and safety of antiplatelet (aspirin plus cilostazol) dual therapy for non-cardioembolic stroke patients within 48 h of symptom onset.

Methods: ADS is an investigator initiated, a prospective, multicenter (34 hospitals in Japan), randomized, and an aspirin-controlled study. Acute stroke patients with non-cardioembolic stroke within 48 hours of onset were studied. Only patients with preadmission mRS score 0-2 were included. Subjects were randomly allocated to the combination therapy with aspirin 81-200mg plus cilostazol 200mg (Dual group) and the single therapy with aspirin 81-200mg (Aspirin group) for 14 days. After the 14 days, all patients took the cilostazol 200mg for 3 months. Primary outcomes include 1) the neurological worsening within 14 day of onset; and 2) the rates of transient ischemic attack (TIA), stroke recurrence, intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH) within 14 days of onset. Secondary outcome included mRS score at 3 months after stroke.

Results: 1,201 patients (796 [66%] men; median age [interquartile range], 69 [61-77] years) were randomized 1:1 to either the dual group or the aspirin group. Initial National Institutes of Health Stroke Scale score was similar as 2 (1-4) in both groups (p=0.617). As a primary outcome, the neurological worsening within 14 days was similarly observed in the dual and in the aspirin group (10.5% vs. 9.7%, P=0.701). The rates of TIA and stroke recurrence in the dual and in the aspirin group were also similar as 0.2% vs. 0.2% (p=1.000), and 1.2% vs. 1.3% (p=1.000), respectively. As a safety outcome, each group had one patient with ICH (0.2% vs. 0.2%, p=1.000). Only 1 patient (0.2%) in the dual group complained of SAH within 14 days of stroke onset, though it was asymptomatic (p=1.000). Regarding the secondary outcome, although preadmission mRS score of 0 was infrequent in the dual group (84% vs. 89%, p=0.054), the rate of mRS 0-1 at 3 months seemed to be frequent in the dual group than aspirin group (69% vs. 64% p=0.075).

Conclusions: Dual antiplatelet therapy using cilostazol and aspirin does not reduce the rate of short-term neurological worsening. However, this combined therapy may improve the clinical outcome at 3 months of onset.

Development and validation of outcome prediction models for aneurysmal subarachnoid haemorrhage: the SAHIT multinational cohort study

OBJECTIVE

To develop and validate a set of practical prediction tools that reliably estimate the outcome of subarachnoid haemorrhage from ruptured intracranial aneurysms (SAH).

DESIGN

Cohort study with logistic regression analysis to combine predictors and treatment modality.

SETTING

Subarachnoid Haemorrhage International Trialists' (SAHIT) data repository, including randomised clinical trials, prospective observational studies, and hospital registries.

PARTICIPANTS

Researchers collaborated to pool datasets of prospective observational studies, hospital registries, and randomised clinical trials of SAH from multiple geographical regions to develop and validate clinical prediction models.

MAIN OUTCOME MEASURE

Predicted risk of mortality or functional outcome at three months according to score on the Glasgow outcome scale.

RESULTS

Clinical prediction models were developed with individual patient data from 10 936 patients and validated with data from 3355 patients after development of the model. In the validation cohort, a core model including patient age, premorbid hypertension, and neurological grade on admission to predict risk of functional outcome had good discrimination, with an area under the receiver operator characteristics curve (AUC) of 0.80 (95% confidence interval 0.78 to 0.82). When the core model was extended to a "neuroimaging model," with inclusion of clot volume, aneurysm size, and location, the AUC improved to 0.81 (0.79 to 0.84). A full model that extended the neuroimaging model by including treatment modality had AUC of 0.81 (0.79 to 0.83). Discrimination was lower for a similar set of models to predict risk of mortality (AUC for full model 0.76, 0.69 to 0.82). All models showed satisfactory calibration in the validation cohort.

CONCLUSION

The prediction models reliably estimate the outcome of patients who were managed in various settings for ruptured intracranial aneurysms that caused subarachnoid haemorrhage. The predictor items are readily derived at hospital admission. The web based SAHIT prognostic calculator (http://sahitscore.com) and the related app could be adjunctive tools to support management of patients.

Healthcare resource utilization and clinical outcomes associated with acute care and inpatient rehabilitation of stroke patients in Japan

Objective

To investigate healthcare resource utilization and changes in functional status in stroke patients during hospitalization in an acute hospital and a rehabilitation hospital.

Design

Retrospective cohort study.

Setting

One acute and one rehabilitation hospital in Japan.

Participants

Patients who were admitted to the acute hospital due to stroke onset and then transferred to the rehabilitation hospital (n = 263, 56% male, age 70 ± 12 years).

Main outcome measures

Hospitalization costs and functional independence measure (FIM) were evaluated according to stroke subtype and severity of disability at discharge from the acute hospital.

Results

Median (IQR) costs at the acute hospital were dependent on the length of stay (LOS) and implementation of neurosurgery, which resulted in higher costs in subarachnoid hemorrhage [$52 413 ($49 166-$72 606) vs $14 129 ($11 169-$19 459) in cerebral infarction; and vs $15 035 ($10 920-$21 864) in intracerebral hemorrhage]. The costs at the rehabilitation hospital were dependent on LOS, and higher in patients with moderate disability than in those with mild disability [$30 026 ($18 419-$39 911) vs $18 052 ($10 631-$24 384)], while those with severe disability spent $25 476 ($13 340-$43 032). Patients with moderate disability gained the most benefits during hospitalization in the rehabilitation hospital, with a median (IQR) total FIM gain of 16 (5-24) points, compared with a modest improvement in patients with mild (6, 2-14) or severe disability (0, 0-5).

Conclusions

The costs for in-hospital stroke care were substantial and the improvement in functional status varied by severity of disability. Our findings would be valuable to organize efficient post-acute stroke care.

External Ventricular Drainage Preceding the Removal of a Nail from the Intracranial Space as a Safe Management Strategy for Predicted Secondary Intraventricular Hemorrhage

BACKGROUND

Intracranial nail gun injury is a rare traumatic event and can result from a suicide attempt. Cerebral angiography is essential in the evaluation of damage to the intracranial vessels, and surgical removal of nails is generally the optimal treatment. Intraventricular hemorrhage can happen after removal of intracranial nails. Endovascular surgery or intraoperative computed tomography has been reported to be useful for detection and treatment of intraventricular hemorrhage. After the surgical removal of nails, attention should be paid for complications such as pseudoaneurysm and infection.

CASE DESCRIPTION

A 63-year-old man with a history of depression was transferred to our hospital in an unconscious state. Physical examination showed 2 nails puncturing his left thorax, and computed tomography revealed a nail puncturing the intracranial space. No damage to these intracranial vessels was observed on computed tomography angiography and venography. After drainage for potential intraventricular hemorrhage, the nails were removed. Postoperatively, prophylactic antibiotic therapy was administrated for secondary infection. Computed tomography angiography did not detect any postoperative pseudoaneurysms. The patient also underwent therapy from a psychiatrist and was transferred to another hospital.

CONCLUSIONS

As for treatment of a case of intracranial nail gun injury, our case shows that preoperative cerebral angiography is not always needed in intracranial nail gun injury when there is no apparent damage to the intracranial vessels and emergent removal of nails is required. External ventricular drainage preceding the removal of a puncture object can be an effective management strategy for secondary intraventricular hemorrhage.

Asymptomatic Carotid T1-High-Intense Plaque as a Risk Factor for a Subsequent Cerebrovascular Ischemic Event

Background: Intraplaque hemorrhage, detected as a high-signal intensity on carotid MRI, is also strongly associated with ischemic events in symptomatic patients. However, in asymptomatic patients, the relationship of the T1-high intense plaque and the subsequent stroke is not clear. The aim of this study is to test the hypothesis that asymptomatic carotid T1-high intense plaque is a risk factor for a subsequent cerebrovascular ischemic event. Methods: Of the 1,353 consecutive patients, who underwent head and carotid MRI as part of their annual medical check-up, the imaging quality of 13 was poor and 150 did not present for follow-up examination, thus leaving 1,190 subjects for evaluation. Of the 1,190 patients, 96 patients had findings of high-signal intensity on carotid MRI and 1,094 patients did not. Cerebrovascular events were retrospectively evaluated. Results: During a mean follow-up period of 53 months, 4 patients with high-signal intensities on carotid MRI (4%) and 3 with no findings (0.3%) had a cerebrovascular ischemic event, with the occurrences significantly higher in the high-signal-intensity group. (p < 0.01) Cox regression analysis indicated that the presence of the high-intense plaque on carotid MRI (hazard ratio [HR] 4.2; 95% CI 1.0-17.1; p = 0.04), age (HR 1.1; 95% CI 1.0-1.2; p = 0.003), and diabetes mellitus (HR 7.2; 95% CI 1.8-27.4; p = 0.004) were associated with the occurrence of subsequent ischemic cerebrovascular events. Conclusions: Asymptomatic carotid T1-high-intense plaque might be a potential high-risk factor for a subsequent cerebrovascular ischemic event.

Short-Term Results of Carotid Endarterectomy and Stenting After the Introduction of Carotid Magnetic Resonance Imaging: A Single-Institution Retrospective Study

OBJECTIVE

Although carotid artery stenting (CAS) has been gaining popularity as an alternative to carotid endarterectomy (CEA), perioperative stroke rate following contemporary CAS remains significantly higher than stroke rate after CEA. The purpose of this study was to assess perioperative (within 30 days) therapeutic results in patients with carotid stenosis (CS) after introduction of preoperative carotid magnetic resonance imaging plaque evaluation in a single center performing both CEA and CAS.

METHODS

Based on prospectively collected data for patients with CS who were scheduled for carotid revascularization, retrospective analysis was conducted of 295 consecutive patients with CS. An intervention was selected after consideration of periprocedural risks for both CEA and CAS. Concerning risk factors for CAS, results of magnetic resonance imaging plaque evaluation were emphasized with a view toward reducing embolic complications.

RESULTS

CAS was performed in 114 patients, and CEA was performed in 181 patients. Comparing baseline characteristics of the 295 patients, age, T1 signal intensity of plaque, symptomatic CS, urgent intervention, and diabetes mellitus differed significantly between CAS and CEA groups. Among patients who underwent CAS, new hyperintense lesions on diffusion-weighted imaging were confirmed in 47 patients. New hyperintense lesions on diffusion-weighted imaging were recognized in 21.4% of patients who underwent CEA (n = 39), significantly less frequent than in patients who underwent CAS.

CONCLUSIONS

The overall short-term outcome of CEA and CAS is acceptable. Preoperative carotid magnetic resonance imaging evaluation of plaque might contribute to low rates of ischemic complications in CAS.

Abstract TP417: Plasma D-dimer Elevation Predicts Poor Functional Outcomes Through Systemic Complications After Aneurysmal Subarachnoid Hemorrhage

Introduction: Plasma D-dimer levels elevate during acute stage of aneurysmal subarachnoid hemorrhage (SAH) and are associated with poor functional outcomes. However, the mechanism in which D-dimer elevation on admission affects functional outcomes remains unknown.

Hypothesis: We hypothesize that D-dimer levels on admission are correlated with systemic complications rather than neurological complications, and therefore have an additive predictive value on conventional risk factors for poor functional outcomes.

Methods: A total of 187 patients with aneurymal SAH were retrospectively analyzed from a single center, observational cohort database. Correlations of plasma D-dimer levels on admission with patients’ characteristics, initial presentation, neurological complications, and systemic complications were identified. We also evaluated additive value of D-dimer elevation on admission for poor functional outcomes by comparing predictive models with and without D-dimer.

Result and Conclusions: D-dimer elevation on admission was associated with increasing age, women, and severity of SAH. Patients with higher D-dimer levels had increased likelihood of nosocomial infections (OR 1.22 [95% CI 1.07-1.39], p = 0.004), serum sodium disorders (OR 1.11 [95% CI 1.01-1.23], p = 0.033), and cardiopulmonary complications (OR 1.20 [95% CI 1.04-1.37], p = 0.01) by multivariable analysis. D-dimer elevation was an independent risk factor of poor functional outcomes (modified Rankin scale 3-6, OR 1.50 [95% CI 1.15-1.95], p = 0.003). A novel prediction model with D-dimer had significantly better discrimination ability for poor outcomes than conventional models without D-dimer, evaluated by C statistics, net reclassification improvement, and integrated discrimination improvement methods. These results suggest that elevated D-dimer levels on admission were independently correlated with systemic complications, and had an additive value for outcome prediction on conventional risk factors after aneurysmal SAH.

The role of alternative anastomosis sites in occipital artery–posterior inferior cerebellar artery bypass in the absence of the caudal loop using the far-lateral approach

OBJECTIVE

Occipital artery–posterior inferior cerebellar artery (OA-PICA) bypass is a technically challenging procedure for posterior fossa revascularization. The caudal loop of the PICA is considered the optimal site for OA-PICA anastomosis, however its absence can increase the technical difficulty associated with this procedure. The use of the far-lateral approach for accessing alternative anastomosis sites in OA-PICA bypass in patients with absent or unavailable caudal loops of PICA is evaluated.

METHODS

A morphometric analysis of OA-PICA bypass with anastomosis on each segment of the PICA was performed on 5 cadaveric specimens through the conventional midline foramen magnum and far-lateral approaches. The difficulty level associated with anastomoses at each segment was qualitatively assessed in each approach for exposure and maneuverability by multiple surgeons. A series of 8 patients who underwent OA-PICA bypass for hemodynamic ischemia or ruptured dissecting posterior fossa aneurysms are additionally reviewed and described, and the clinical significance of the caudal loop of PICA is discussed.

RESULTS

Anastomosis on the caudal loop could be performed more superficially than on any other segment (p < 0.001). A far-lateral approach up to the medial border of the posterior condylar canal provided a 13.5 ± 2.2–mm wider corridor than the conventional midline foramen magnum approach, facilitating access to alternative anastomosis sites. The far-lateral approach was successfully used for OA-PICA bypass in 3 clinical cases whose caudal loops were absent, whereas the midline foramen magnum approach provided sufficient exposure for caudal loop bypass in the remaining 5 cases.

CONCLUSIONS

The absence of the caudal loop of the PICA is a major contributing factor to the technical difficulty of OA-PICA bypass. The far-lateral approach is a useful surgical option for OA-PICA bypass when the caudal loop of the PICA is unavailable.

[Indocyanine Green Videoangiography-Guided Target Bypass for Surgical Trapping of Distal Middle Cerebral Artery Aneurysm:A Technical Case Report]

Intraoperative indocyanine green(ICG)videoangiography is simple, less invasive, and enables real-time observation of hemodynamics during neurovascular surgery. In this article, we describe a case of ruptured distal middle cerebral artery aneurysm, which was unclippable and required parent artery occlusion with extracranial-intracranial bypass. Under temporary clipping of the proximal vessel, ICG videoangiography demonstrated the proper target vessel for bypass through delayed and retrograde filling of the dye. In this operation, ICG videoangiography contributed to simpler and less invasive procedures, by avoiding dissection of the tight cerebral fissure and intraoperative angiography.

Acute Compressive Myelopathy Caused by Spinal Subarachnoid Hemorrhage: A Combined Effect of Asymptomatic Cervical Spondylosis

BACKGROUND

Patients with subarachnoid hemorrhage (SAH) by hemorrhagic arteriovenous fistulas (AVFs) usually presents with meningeal signs, including headache and nausea, and focal neurologic deficit is found in rare cases. In this article, we report a case of acute compressive cervical myelopathy caused by hemorrhagic AVF at the craniocervical junction.

CASE DESCRIPTION

A 73-year-old woman was transferred to our hospital for sudden headache and subsequent left hemiparesis. Head computed tomography scan showed SAH exclusively in the posterior fossa, and catheter angiography revealed a perimedullary arteriovenous fistula at the craniocervical junction as a source of the SAH. Detailed neurologic examination showed the sensory disturbance of bilateral upper extremities and bladder and rectal disturbance, suggesting concurrent cervical myelopathy. Magnetic resonance imaging of the cervical spine showed disk herniation at the C4-5 level, spinal SAH deposition above the C4-5 level, and accompanying myelomalacia. No intramedullary hemorrhage was found.

CONCLUSIONS

Spinal SAH alone rarely causes focal neurologic deficit. However, this case suggests spinal SAH can cause acute compressive myelopathy when complicated with preexisting spinal canal stenosis.

Plasma D-dimer may predict poor functional outcomes through systemic complications after aneurysmal subarachnoid hemorrhage

OBJECTIVE Plasma D-dimer levels elevate during acute stages of aneurysmal subarachnoid hemorrhage (SAH) and are associated with poor functional outcomes. However, the mechanism in which D-dimer elevation on admission affects functional outcomes remains unknown. The aim of this study is to clarify whether D-dimer levels on admission are correlated with systemic complications after aneurysmal SAH, and to investigate their additive predictive value on conventional risk factors for poor functional outcomes. METHODS A total of 187 patients with aneurysmal SAH were retrospectively analyzed from a single-center, observational cohort database. Correlations of plasma D-dimer levels on admission with patient characteristics, initial presentation, neurological complications, and systemic complications were identified. The authors also evaluated the additive value of D-dimer elevation on admission for poor functional outcomes by comparing predictive models with and without D-dimer. RESULTS D-dimer elevation on admission was associated with increasing age, female sex, and severity of SAH. Patients with higher D-dimer levels had increased likelihood of nosocomial infections (OR 1.22 [95% CI 1.07-1.39], p = 0.004), serum sodium disorders (OR 1.11 [95% CI 1.01-1.23], p = 0.033), and cardiopulmonary complications (OR 1.20 [95% CI 1.04-1.37], p = 0.01) on multivariable analysis. D-dimer elevation was an independent risk factor of poor functional outcome (modified Rankin Scale Score 3-6, OR 1.50 [95% CI 1.15-1.95], p = 0.003). A novel prediction model with D-dimer had significantly better discrimination ability for poor outcomes than conventional models without D-dimer. CONCLUSIONS Elevated D-dimer levels on admission were independently correlated with systemic complication, and had an additive value for outcome prediction on conventional risk factors after aneurysmal SAH.

Carotid artery plaque assessment using quantitative expansive remodeling evaluation and MRI plaque signal intensity

OBJECT

Plaque characteristics and morphology are important indicators of plaque vulnerability. MRI-detected intraplaque hemorrhage has a great effect on plaque vulnerability. Expansive remodeling, which has been considered compensatory enlargement of the arterial wall in the progression of atherosclerosis, is one of the criteria of vulnerable plaque in the coronary circulation. The purpose of this study was risk stratification of carotid artery plaque through the evaluation of quantitative expansive remodeling and MRI plaque signal intensity.

METHODS

Both preoperative carotid artery T1-weighted axial and long-axis MR images of 70 patients who underwent carotid endarterectomy (CEA) or carotid artery stenting (CAS) were studied. The expansive remodeling ratio (ERR) was calculated from the ratio of the linear diameter of the artery at the thickest segment of the plaque to the diameter of the artery on the long-axis image. Relative plaque signal intensity (rSI) was also calculated from the axial image, and the patients were grouped as follows: Group A = rSI ≥ 1.40 and ERR ≥ 1.66; Group B = rSI< 1.40 and ERR ≥ 1.66; Group C = rSI ≥ 1.40 and ERR < 1.66; and Group D = rSI < 1.40 and ERR < 1.66. Ischemic events within 6 months were retrospectively evaluated in each group.

RESULTS

Of the 70 patients, 17 (74%) in Group A, 6 (43%) in Group B, 7 (44%) in Group C, and 6 (35%) in Group D had ischemic events. Ischemic events were significantly more common in Group A than in Group D (p = 0.01).

CONCLUSIONS

In the present series of patients with carotid artery stenosis scheduled for CEA or CAS, patients with plaque with a high degree of expansion of the vessel and T1 high signal intensity were at higher risk of ischemic events. The combined assessment of plaque characterization with MRI and morphological evaluation using ERR might be useful in risk stratification for carotid lesions, which should be validated by a prospective, randomized study of asymptomatic patients.

Abstract TP232: Symptomatic Plaque with Low-grade Stenosis Which Retains Hyperintensity After an Ischemic Event may Indicate a High Risk of a Subsequent Ipsilateral Ischemic Event

Introduction: Intraplaque hemorrhage (IPH) has been reported to be a characteristic feature of a vulnerable plaque, indicated by an area of high signal intensity on carotid MRI. It has been reported that symptomatic low-grade stenosis with IPH is strongly associated with ischemic events, but there are limited data regarding the dynamics of the carotid plaque signal. The aim of this study was to assess the time-dependent change of carotid plaque in the symptomatic patient with low-grade stenosis.

Methods: Thirty-eight symptomatic patients with carotid low-grade stenosis (0.31 between time points was considered significant. We then investigated changes in rSI and subsequent ipsilateral ischemic events.

Result: Of the 38 patients, there were strong-positive and positive plaque at baseline in 22 and 12 patients, respectively. During a mean follow-up period of 42.5 months, 26 positive plaques (74%) at baseline kept an rSI of >1.25, and all of 4 negative plaques at baseline changed positive. Strong-positive plaques at baseline showed a lower tendency to be negative than positive plaque (p=0.08). Twenty-one of the 38 patients (55%) experienced a total of 26 recurrent ischemic events. In patients who experienced recurrent ischemic events, 19 plaques (73%) were strong-positive and 5 plaques (19%) were positive. Compared to the most recent carotid MRI, rSI at the event was stable in 18 patients (69%) and increased in 8 patients (31%).

Conclusions: Most symptomatic plaque with low-grade stenosis retained its hyperintensity after ischemic events and had a high rate of subsequent ipsilateral ischemic events. A sustaining high signal intensity might be associated with an increased risk of subsequent ischemic events. Follow-up observation by carotid MRI has the potential to increase the accuracy of stroke risk stratification in the management of carotid low-grade stenosis.

Impact of Aneurysm Projection on Intraoperative Complications During Surgical Clipping of Ruptured Posterior Communicating Artery Aneurysms

BACKGROUND:

Surgical clipping of ruptured posterior communicating artery (PCoA) aneurysms is a well-established procedure to date. However, preoperative factors associated with procedure-related risk require further elucidation.

OBJECTIVE:

To investigate the impact of the direction of aneurysm projection on the incidence of procedure-related complications during surgical clipping of ruptured PCoA aneurysms.

METHODS:

A total of 65 patients with ruptured PCoA aneurysms who underwent surgical clipping were retrospectively analyzed from a single-center, prospective, observational cohort database in this study. The aneurysms were categorized into lateral and posterior projection groups, depending on direction of the dome. Characteristics and operative findings of each projection group were identified. We also evaluated any correlation of aneurysm projection with the incidence of procedure-related complications.

RESULTS:

Patients with ruptured PCoA aneurysms with posterior projection more likely presented with good-admission-grade subarachnoid hemorrhage (P = .01, χ2 test) and were less to also have intracerebral hematoma (P = .01). These aneurysms were found to be associated with higher incidence of intraoperative rupture (P = .02), complex clipping with fenestrated clips (P = .02), and dense adherence to PCoA or its perforators (P = .04) by univariate analysis. Aneurysms with posterior projection were also correlated with procedure-related complications, including postoperative cerebral infarction or hematoma formation (odds ratio, 5.87; 95% confidence interval, 1.11-31.1; P = .04) by multivariable analysis.

CONCLUSION:

Ruptured PCoA aneurysms with posterior projection carried a higher risk of procedure-related complications of surgical clipping than those with lateral projection.

Reflux of Anterior Spinal Artery Predicts Recurrent Posterior Circulation Stroke in Bilateral Vertebral Artery Disease

BACKGROUNDS AND PURPOSE

Predictive value of reflux of anterior spinal artery for recurrent posterior circulation ischemia in bilateral vertebral arteries steno-occlusive disease was evaluated.

METHODS

We retrospectively reviewed 55 patients with symptomatic posterior circulation stroke caused by bilateral stenotic (>70%) lesions of the vertebral artery. We investigated any correlation of clinical and angiographic characteristics including collateral flow patterns, with recurrent stroke. Risk factors for poor 3-month functional outcome were also evaluated.

RESULTS

Recurrent posterior circulation stroke was observed in 15 (27.3%) patients. Multivariable analysis using Cox proportional hazards model showed anterior spinal artery reflux as a significant risk factor for stroke recurrence (adjusted hazard ratio, 19.3 [95% confidence interval, 5.35-69.9]; P<0.001). Anterior spinal artery reflux was also correlated with poor functional outcome (modified Rankin Scale score, 3-6; adjusted odds ratio, 7.41 [95% confidence interval, 1.24-44.4]; P=0.028).

CONCLUSIONS

In patients with symptomatic bilateral vertebral artery occlusive disease, anterior spinal artery reflux predicted recurrent posterior circulation stroke and poor functional outcome.

Endovascular Therapy for Ruptured Cerebral Aneurysms in the Elderly: Poor Accessibility of the Guiding Catheter and Use of Local Anesthesia as the Predictors of Procedure-Related Rupture

BACKGROUND

Endovascular therapy is favored for ruptured intracranial aneurysms in the elderly. However, poor accessibility to the aneurysm through the parent artery and use of local anesthesia in this age group may predispose to intraprocedural complications.

OBJECTIVE

To evaluate whether age-related poor access to the ruptured target aneurysm and use of local anesthesia are associated with increased incidence of procedure-related rupture during endovascular embolization.

METHODS

A total of 117 patients with 117 ruptured aneurysms underwent endovascular embolization at a single institution. Correlation of increasing age with poor accessibility of the guiding catheter was analyzed. In addition, the distance from the aneurysm to the guiding catheter was investigated to identify an association with incidence of procedure-related rupture. Correlation of local anesthesia with procedure-related rupture was also evaluated in the multivariable analysis.

RESULTS

Increasing age was significantly associated with poor accessibility of the guiding catheter (P = .001, Mann-Whitney U test). Procedure-related rupture occurred in 9 of 117 aneurysms (7.7%). Longer distance between distal aneurysms and low-positioned guiding catheters carried a higher risk of procedure-related rupture than a shorter distance between proximal aneurysms and high-positioned guiding catheters (odds ratio, 19.3; 95% confidence interval, 1.84-201; P = .01, multivariable analysis). Use of local anesthesia was also a significant risk factor of procedure-related rupture by multivariable analysis.

CONCLUSION

Increasing age was correlated with poor accessibility of the guiding catheter in endovascular embolization of ruptured intracranial aneurysms. Distally located aneurysms treated through a low-positioned guiding catheter and use of local anesthesia increased the risk of procedure-related rupture.

The association between expansive arterial remodeling detected by high-resolution MRI in carotid artery stenosis and clinical presentation

OBJECT

The purpose of the present study was to investigate the association between carotid artery (CA) expansive remodeling (ER) and symptoms of cerebral ischemia.

METHODS

One hundred twenty-two consecutive CAs scheduled for CA endarterectomy (CEA) or CA stent placement (CAS) were retrospectively studied. After excluding 22 CAs (2 were contraindicated for MRI, 8 had near-occlusion, 6 had poor image quality, and 6 had restenosis after CEA or CAS), there were 100 CAs (100 patients) included in the final analysis. The study included 50 symptomatic patients (mean age 73.6 ± 8.9 years, 6 women, mean stenosis 68.5% ± 21.3%) and 50 asymptomatic patients (mean age 72.0 ± 5.9 years, 5 women, mean stenosis 79.4% ± 8.85%). Expansive remodeling was defined as enlargement of the internal carotid artery (ICA) with outward plaque growth. The ER ratio was calculated by dividing the maximum distance between the lumen and the outer borders of the plaque perpendicular to the axis of the ICA by the maximal luminal diameter of the distal ICA at a region unaffected by atherosclerosis using long-axis, high-resolution MRI.

RESULTS

The ER ratio of the atherosclerotic CA was significantly greater than that of normal physiological expansion (carotid bulb; p < 0.01). The ER ratio of symptomatic CA stenosis (median 1.94, interquartile range [IQR] 1.58–2.23) was significantly greater than that of asymptomatic CA stenosis (median 1.52, IQR 1.34–1.81; p = 0.0001). When the cutoff value of the ER ratio was set to 1.88, the sensitivity and specificity to detect symptoms were 0.6 and 0.78, respectively. The ER ratio of symptomatic patients was consistently high regardless of the degree of stenosis.

CONCLUSIONS

There was a significant correlation between ER ratio and ischemic symptoms. The ER ratio might be a potential indicator of vulnerable plaque, which requires further validation by prospective observational study of asymptomatic patients.

Intrasylvian hematoma caused by ruptured middle cerebral artery aneurysms predicts recovery from poor-grade subarachnoid hemorrhage

OBJECT

Intrasylvian hematoma (ISH) is a subtype of intracranial hematoma caused by aneurysmal rupture and often presents with a poor initial neurological grade; it is not well studied. The aim of this study was to elucidate outcomes of aneurysmal subarachnoid hemorrhage (SAH) with ISH.

METHODS

Data for 97 patients with poor-grade SAH (World Federation of Neurosurgical Societies Grade IV or V) were retrospectively analyzed from a single-center, prospective, observational cohort database. Ultra-early surgical clipping, removal of hematoma, external decompression for brain swelling, and prevention of vasospasm by cisternal irrigation with milrinone were combined as an aggressive treatment. Characteristics and clinical courses of SAH with ISH were identified. The authors also evaluated any correlations between poor admission-grade SAH and ISH with good functional outcome.

RESULTS

Patients with poor admission-grade SAH and with ISH were more likely to have initial cerebral edema (p < 0.001, Mann-Whitney U-test), which significantly resolved overtime (p < 0.001, Mann-Whitney U-test). These patients had a better chance of functional survival (modified Rankin Scale scores of 1-3; OR 5.75; 95% CI 1.36-24.3; p = 0.017) at 6 months after hospital discharge, after adjustment for potential confounders such as younger age and better initial neurological grade by multivariable analysis.

CONCLUSIONS

ISH predicted good functional recovery from poor-grade aneurysmal SAH.

[De novo distal superior cerebellar artery aneurysm after embolization of a ruptured aneurysm at the bifurcation of the contralateral basilar and superior cerebellar arteries]

The formation of de novo aneurysms in the posterior fossa after successful treatment of a previous aneurysm in the same fossa is rare. Here we describe a case of a de novo generated aneurysm at the distal superior cerebellar artery(SCA)7 years after the successful obliteration of an aneurysm at the contralateral basilar artery(BA)-SCA bifurcation. The treatment of the original posterior fossa aneurysm may lead to hemodynamic changes that may contribute to the formation of a de novo aneurysm at another vulnerable point in the posterior fossa circulation. We conclude that a close surveillance is required after the initial treatment of posterior fossa aneurysms in order to detect the possible formation of de novo aneurysms.

Reduced cerebrovascular reserve is associated with an increased risk of postoperative ischemic lesions during carotid artery stenting

Background

Reduced cerebrovascular reserve (CVR) is associated with increased risk of ischemic events in carotid steno-occlusive diseases.

Objective

To determine whether pretreatment CVR can predict postoperative ischemic lesions after carotid artery stenting (CAS) by retrospective analysis.

Methods

We retrospectively reviewed the medical records of 46 patients (42 men; mean age 74.2±8.3 years) who underwent CAS and preprocedural cerebral blood flow measurement by quantitative single-photon emission CT. Ischemic lesions were evaluated by diffusion-weighted image (DWI) within 72 h after the intervention. We also evaluated plaque characteristics using black-blood MR plaque imaging.

Results

New ipsilateral DWI-positive lesions were found in 11 cases (23.9%). Patients were classified into two groups based on the presence or absence of new DWI-positive lesions, and no significant differences in characteristics were found between the DWI-positive and DWI-negative groups, except for age and CVR of the ipsilateral middle cerebral artery (MCA) territory. The DWI-positive group was significantly older than the DWI-negative group (79.7±4.1 vs 72.5±8.6 years; p=0.0085) and had lower average regional CVR (1.4±18.2% vs 22.4±25.8%; p=0.016). MR plaque imaging showed no significant difference in relative overall plaque MR signal intensity between the two groups (1.53±0.37 vs 1.34±0.26; p=0.113). In multivariate logistic regression analysis, lower CVR of the ipsilateral MCA territory (<11%) was the only independent risk factor for new ischemic lesions following CAS (OR=6.99; 95% CI 1.17 to 41.80; p=0.033).

Conclusions

Impaired pretreatment CVR was associated with increased incidence of new infarction after CAS.