bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract TP86: Clinical Significance of Gadolinium Enhancement in Non-Hemorrhagic Intracranial Artery Dissection
Authors: Hashimoto Yukishige , Matsushige Toshinori , Shimonaga Koji , Takahashi Hiroki , Ono Chiaki , Yamashita Hiroshi , Mizoue Tatsuya
Published: June 2021

Background and Purpose:
The mechanisms involved in progression of non-hemorrhagic intracranial artery dissection (IAD) are poorly understood. Contrast enhancement of intracranial saccular aneurysms on magnetic resonance vessel wall imaging (VWI) is thought to predict instability. We investigated the relationship between contrast enhancement of dissecting lesions and progression of IADs based on the hypothesis that this finding might predict instability.

Methods:
A total of 39 IADs in 36 patients (17 women and 19 men; mean age: 49 years) were investigated retrospectively. Three-dimensional T1-weighted fast spin-echo sequences were obtained before and after injection of contrast medium, and the vessel wall/pituitary stalk contrast enhancement ratio (CRstalk) was calculated. Progression of IADs was defined as morphological deterioration; progressive dilatation or stenosis. The relations between IAD progression and potential risk factors, including patient demographic data, IAD morphology, and VWI findings, were investigated by statistical analysis.

Results:
The mean follow-up period was 9.7 months (range: 1-24 months). Progression was detected in 6 of 39 IADs (15%). Five IADs demonstrated aneurysmal dilatation and the other showed stenosis/occlusion. There were no significant differences of demographic factors between the patients with or without IADs progression. IADs with aneurysmal dilation demonstrated significant morphological deterioration (p=0.01). All IADs without contrast enhancement (n=7) improved within one month. Contrast enhancement corresponded to the pseudo-lumen of dissecting lesions. The CRstalk value was significantly higher in IADs with progression than in stable lesions (1.10 ± 0.09 vs. 0.80 ± 0.05, p =0.01).

Conclusions:
The pseudo-lumen of dissecting lesions may be identified by contrast enhancement. Quantitative analysis of contrast enhancement could be useful for predicting instability of IADs during follow-up.
Abstract TP88: Usefulness of High and Standard B-value DWI for Analysis of Pathophysiology in Acute Stage Cerebral Infarction
Authors: Takeishi Yusuke , Yamasaki Fumiyuki , Sakamoto Shigeyuki , Okazaki Takahito , Oshita Jumpei , Ishii Daizo , Hosomi Naohisa , Ueno Hiroki , Aoki Shiro , Nezu Tomohisa , Maruyama Hirofumi , Kurisu Kaoru
Published: June 2021

Introduction:
Standard b-value DWI (sDWI) and high b-value DWI (hDWI) and ADC calculation from each DWI have been widely used for diagnosis of (acute ischemic stroke) AIS. However, diagnosis of AIS subtypes by using hDWI and ADC have not been well investigated.

Hypothesis:
AIS has several pathophysiological subtypes such as lacunar infarction, cardio-embolism(CE), and atherothrombotic brain infarction (ATBI), and so on, and condtion of collateral circulations differ among those subtypes. Several studies have shown that hDWI is relatively dominant in intracellular diffusion, conversely, sDWI is comparatively dominant in extracellular diffusion. Therefore, our hypothesis is that calculation of ADC from sDWI and hDWI could give valuable information for differentiation among AIS subtypes.

Methods:
We evaluated 130 AIS patients from medical records. Pathophysiological diagnoses were made by experienced neurologists. We acquired sDWI and hDWI at 3T MRI in all patients. 321 ADC values were obtained by calculating 200 ischemic lesions sequentially. We used relative ADC (rADC) value to adjust the difference caused by location and age. The rADC values were measured by manually placing regions of interest on the ADC maps at the ischemic lesion defined by DWI high and divided by the ADC values on the contralateral normal brain. For assessment of the AIS (within 30hrs from the onset) relationship between ATBI and CE, we subtract high b-value rADC (hrADC) from standard b-value rADC (srADC) to focus on the extracellular diffusion. To analyze the subacute phase stroke relationship between ATBI and CE, we evaluated the each rADC. And at both phase we conducted Mann-Whitney U test.

Results:
In superacute phase, hDWI more clearly showed hyper-intense signal than sDWI. From the onset, rADC of CE was lower than that of ATBI (median srADC-hrADC: ATBI/CE =0.0699/0.0244) (P=0.0445), this might imply the poor collateral status in CE. Contrary, for subacute phase, CE rapidly underwent necrosis in the ischemic core, rADC was higher than ATBI rADC (median ATBI/CE:0.5939/0.6480) (P=0.0011).

Conclusions:
We found that quantitative assessment of hrADC and srADC could give valuable information for differential diagnoses of AIS subtypes.
Abstract TP91: Unfavorable Baseline Hypoperfusion Intensity Ratio is Associated With Infarct Growth and Poor Outcome in Patients With Distal MCA Occlusions
Authors: MacLellan Adam , Mlynash Michael , Kemp Stephanie , Christensen Soren , Marks Michael , Lansberg Maarten , Albers Greg
Published: June 2021

Background:
A low hypoperfusion intensity ratio (HIR) predicts good collateral vessel status and correlates with infarct growth and functional outcome in early window patients with proximal large vessel anterior circulation occlusions. Its performance in predicting clinical and radiologic outcome has not been assessed in patients with more distal occlusions. In this retrospective analysis of the CT Perfusion to Predict Response to Recanalization in Ischemic Stroke (CRISP) study, we hypothesized that a favorable baseline HIR would predict less infarct growth in patients with distal middle cerebral artery (MCA) occlusions.

Methodology:
Patients with occlusions of an M2 or M3 branch of the MCA on catheter angiography were included; all patients underwent mechanical thrombectomy with TICI2B/3 reperfusion. Baseline ischemic core volume and HIR (Tmax >10s / Tmax >6s) were assessed with RAPID software; late follow-up infarct volumes (>36 hours from initial CT perfusion) were manually determined from DWI MRI. Excellent functional outcome was defined as a modified Rankin score of 0-1.

Results:
Fourteen patients with baseline perfusion and late follow-up imaging were included; nine patients presented with M2 occlusions, and 5 with M3 occlusions. The mean baseline HIR of 0.48 was used to dichotomize patients into favorable or unfavorable baseline profiles. Patients with a favorable baseline HIR had significantly smaller baseline ischemic core volumes (0 mL [IQR 0-3.3] vs. 14.0 mL [IQR 8.7-22.1], p=0.01), smaller final infarct volumes (16.1 mL [IQR 12.7-41.2] vs. 71.4 mL [IQR 43.8-113.5], p=0.01) and less infarct growth (16.1 mL [IQR 9.4-31.9] vs. 49.0 mL [IQR 31.1-100.8], p=0.03). Excellent functional outcome was achieved in 6/6 (100%) of those with favorable baseline HIR, versus 3/8 (37.5%) with unfavorable baseline profile (p=0.03).

Conclusion:
In patients with distal MCA occlusions, poor collateral status at baseline as demonstrated by a high HIR score is associated with more infarct growth and worse clinical outcomes. HIR may be helpful for guiding thrombectomy decisions in patients with distal occlusions and warrants further prospective study in this population.
Abstract WMP100: Excessive Blood Pressure Reduction Increases the Risk of Acute Kidney Injury After Intracerebral Hemorrhage
Authors: Irie Kenichi , Miwa Kaori , Tanaka Kanta , Ikenouchi Hajime , Ihara Masafumi , Toyoda Kazunori , Koga Masatoshi
Published: June 2021

Background:
Elevated blood pressure (BP) in the first 24 hours of admission of acute intracerebral hemorrhage (ICH) has been the focus of intensive therapeutic investigation, although early intensive BP lowering addresses a concern about development of acute kidney injury (AKI). However, it is unclear as to the effect of BP measure including the absolute BP reduction and increased BP variability on AKI in patients with acute ICH.

Methods:
We retrieved data of consecutive patients with acute ICH from our prospective stroke registry between July 2015 and August 2017. We excluded patients with preexisting end-stage renal disease or in-hospital death within 24 hours. The primary outcome was AKI within 7days after admission defined using the AKI Network criteria. We recorded BP on emergency department arrival and for every 1 hour from 1 to 24 hours after admission (25 measurements). We measured mean systolic BP (SBP) and maximum minus minimum SBP within both 12 hours and 24 hours, and also quantified SBP variabilities (SBPV) including standard deviation, coefficient of variation, successive variation, and average real variability.

Results:
Among 361 patients with ICH (age 72.7±12.8, male 55%, non-lobar 76%), 31 (9%) developed AKI. For all SBP measure, the 12-hour SBP reduction was associated with the increased risk of AKI in multivariable analysis (odds ratio [per10 mmHg increase] 1.30; 95% CI 1.10-1.35). There was no significant association between the SBP variability and risk of AKI. The area under the receiver operating characteristic curve of the 12-hour SBP reduction for predicting AKI was 0.75. The association between the 12-hour SBP reduction and AKI was not modified by preexisting chronic kidney disease (interaction P=0.40).

Conclusion:
Early BP reduction in the first 12 hours of admission contributed to the risk of AKI in acute ICH. This may have clinical implication to avoid excess absolute BP reduction in patients with acute ICH.
Abstract WMP103: Comparative Impact of Extent of Lobar Intracerebral Hemorrhage Removal on Outcome in the MISTIE III and STICH II Trials
Authors: Polster Sean P , Carrion-Penagos Julian , Gregson Barbara A , Cao Ying , Thompson Richard E , Stadnik Agnieszka , Money Patricia Lynn , Koskimaki Janne , Lyne Sean , Fam Maged D , Girard Romuald , Lane Karen , McBee Nichol , Ziai Wendy , Hao Yi , Dodd Robert , Carlson Andrew P , Camarata Paul J , Caron Jean-Louis , Harrigan Mark R , Dawson Jesse , Mendelow A. David , Zuccarello Mario , Hanley Daniel F , Awad Issam A ,   On behalf of the MISTIE III & STICH II investigators
Published: June 2021

Introduction:
The Minimally Invasive Surgery Plus Recombinant Tissue Plasminogen Activator for Intracerebral Hemorrhage Evacuation Phase III trial (MISTIE III) concluded that the extent of hematoma reduction confers a mortality and functional benefit. It is unclear if a minimum extent of evacuation is needed for mortality and functional outcome benefit in lobar cases with MISTIE and with open surgical interventions.

Objective:
We analyzed the effect of extent of lobar ICH evacuation on clinical outcome at 180 days after undergoing the MISTIE procedure and open craniotomy, in the context of the MISTIE III and STICH II clinical trials, respectively.

Methods:
Patients randomized to the surgical arm with lobar ICH, who underwent the procedure in the MISTIE III trial (n=84) and the STICH II trial (n=266) were analyzed, excluding cases crossing over to surgery. We assessed end of treatment ICH volume on post procedure CT scans and % hematoma evacuation, in relation to survival and likelihood of mRS 0-3. Cubic spline modeling with dichotomized outcome was used to compare the extent of hematoma evacuation on clinical outcome.

Results:
End of treatment volume of < 28 mL in lobar ICH MISTIE III patients and < 30 mL in STICH II trial patients showed a significantly increased probability of achieving an mRS of 0-3 at 180 days (p<0.03, p<0.006, respectively). This threshold was achieved in 83.1% of lobar cases undergoing MISTIE and in 92.1% of surgical cases in STICH II. Achieving survival benefit at 180 days trended towards improved probability with further hematoma volume reduction without a threshold value in MISTIE III, and was significant per mL reduction in STICH II (p<0.001). Analysis by percent of hematoma evacuation trended toward better probabilities of survival and improved functional outcome but were not significant.

Conclusion:
This analysis confirms that extent of hematoma evacuation is important in attaining the benefits of both minimally invasive and open surgical interventions in non-herniating lobar ICH patients randomized in clinical trials. Extent of ICH evacuation must be considered in the analysis of comparative effectiveness of various techniques and in the design of future trials.
Abstract WMP108: ABO Compatible Platelet Transfusion After Intracerebral Hemorrhage is Associated With Better Platelet Recovery and Outcomes Than Incompatible Transfusions
Authors: Magid-Bernstein Jessica , Beaman Charles , Yang Winni , Xu Katherine , Agarwal Sachin , Park Soojin , Claassen Jan , Connolly E. S , Hod Eldad , Roh David
Published: June 2021

Introduction:
There is conflicting evidence of the risks and benefits of platelet transfusions after intracerebral hemorrhage (ICH). Current practice does not necessitate the transfusion of ABO matched platelets despite evidence that platelet recovery is suboptimal in patients receiving ABO incompatible platelet transfusions.

Hypothesis:
We hypothesize that ICH patients receiving compatible platelet transfusions after ICH have better platelet recovery and outcomes compared to those receiving incompatible platelets.

Methods:
We conducted single-center, prospective cohort study of consecutive ICH patients admitted to a tertiary-referral academic medical center between 2009 and 2016. Spontaneous ICH patients who received 1 platelet transfusion within 24 hours after presentation were analyzed. Subjects were excluded if they had more than 1 platelet transfusion or non-medication related coagulopathy. Linear regression was used to evaluate the association of incompatible platelet transfusions with absolute count increment ([ACI], a continuous measure of platelet change after transfusion), adjusting for time between CBCs. Additional logistic regression analysis was performed to explore associations of ABO incompatible platelet transfusions with clinical outcomes: discharge mortality, poor modified Rankin Scale (mRS 4-6) at discharge and 3 months, after adjusting for ICH score, sex, and race.

Results:
Of the 135 patients studied, 62% received ABO compatible platelets and 38% incompatible platelet transfusions after ICH. Patients who received incompatible platelets had lower ACI than those who received compatible platelets (median -1 vs 15; standardized Beta=0.181, p=0.042). There was an association between incompatible transfusions and increased odds of discharge mortality (adjusted OR 4.208 [95%CI 1.478-11.985]; p=0.007).

Conclusions:
The majority of patients received ABO incompatible platelet transfusions, and these patients had worse platelet count recovery, higher mortality, and worse neurologic outcomes at discharge compared to those that received ABO compatible transfusions. Our findings warrant investigation into the impact of ABO compatibility in platelet transfusions and clinical outcomes after ICH.
Abstract WMP110: Presence, Volume, and Location of New Ischemic Injury on MRI in Stroke Patients Who Undergo PFO Closure Compared to Patients Treated Medically: An Analysis of the REDUCE Trial
Authors: Messe Steven R , Erus Guray , Bilello Michel , Davatzikos Christos , Andersen Grethe , Iversen Helle , Roine Risto O , Sjostrand Christina , Herrmann Howard C , Rhodes John F , Sondergaard Lars , Kasner Scott E
Published: June 2021

Background:
Randomized PFO closure trials have used open-label endpoint ascertainment, which may increase the risk of bias and undermine confidence in the conclusions. The Gore REDUCE Trial prospectively performed baseline and follow-up MRIs for all subjects, thereby providing an objective measure of the effectiveness of closure.

Methods:
The presence, location, and volume of new infarct, defined as an acute DWI lesion at time of recurrent clinical stroke or new lesion (>3mm) on T2/FLAIR from baseline to follow up MRI at 2 years, was evaluated using a semi-automated methodology blinded to treatment assignment, comparing patients randomized to undergo closure to those assigned medical therapy.

Results:
There were no differences in total new infarct volume, new large infarct (>3cm diameter), or new infarct location, comparing patients who underwent closure to those treated with medication (Table). New clinical stroke or clinically silent MRI infarct occurred in 18/383 (4.7%) patients who underwent closure and 19/177 (10.7%) of medically treated patients, RR 0.44, 95% CI 0.24-0.82, p=0.008. Recurrent clinical ischemic stroke occurred in 5/383 (1.3%) vs 12/177 (6.8%), RR 0.19, 95% CI 0.07-0.54, p=0.005, and silent brain infarction in 13/383 (3.3%) vs 7/177 (4.0%), RR 0.86, 95% CI 0.34-2.11, p=0.74.

Conclusions:
New MRI infarcts were generally small and the volumes and distribution of injury were similar between patients randomized to closure and those assigned to aspirin alone. The finding that silent infarcts were not smaller in volume than clinical ischemic strokes and that only clinical strokes were reduced by closure suggests that there may be ascertainment bias in clinical outcomes during open label studies. Nevertheless, as MRI is an objective outcome assessed blinded to randomization assignment, the REDUCE trial provides the highest level of evidence that PFO closure prevents recurrent ischemic brain injury, reducing new infarcts by more than half.
Abstract WMP115: Hemorrhagic and Ischemic Stroke in Patients on Oral Anticoagulants for Nonvalvular Atrial Fibrillation With and Without Antiplatelet Therapy
Authors: Morimoto Takeshi , Kinjo Norito , Sakakibara Fumihiro , Uchida Kazutaka , Ueda Shinichiro
Published: June 2021

Introduction:
Antiplatelet (APT) therapy is challenging in patients on oral anticoagulants (OACs) for nonvalvular atrial fibrillation (NVAF) who have coronary artery diseases (CAD). Analyzing large scale registry of consecutive patients with NVAF should provide further guide for the safety and efficacy of combination therapy.

Methods:
We conducted historical multicenter registry at 71 centers in Japan between March 2017 and March 2018. The eligibility criteria were patients on OACs for NVAF on February 2013. There were no exclusion criteria and consecutive patients who met the eligibility criteria were registered. All patients were followed until March 2017. Co-primary endpoints were ischemic strokes including transient ischemic attack and hemorrhagic stroke including subarachnoid hemorrhage. The secondary endpoints were all-cause mortality, ischemic events (acute coronary syndrome, ischemic strokes, or systemic embolism), and major bleedings defined by ISTH and TIMI criteria. We estimated HRs of OACs and APT combination relative to OACs alone by Cox proportional hazard model adjusting for clinically relevant confounders.

Results:
Median age was 74 (range 20-101) years of 7826 registered patients. Sustained NVAF accounted for 49% and 73% of patients had history of CAD. Cumulative incidences of ischemic stroke and hemorrhagic stroke at 4 years were 3.8% and 0.91% in No-APT group while 5.3% and 1.2% in APT group, respectively (Figure). Adjusted HRs (95%CI) of APT group for ischemic stroke and hemorrhagic stroke were 1.03 (0.76-1.40) and 1.27 (0.67-2.4), respectively. Adjusted HRs (95%CI) for all-cause mortality, ischemic events, and major bleedings were 0.98 (0.79-1.23), 0.98 (0.74-1.32), and 1.25 (1.00-1.57), respectively.

Conclusions:
Adding APT in patients on AOC for NVAF did not decrease ischemic strokes and not increase hemorrhagic strokes. Because combination therapy might increase the risk of major bleedings, OAC alone should be prioritized.
Abstract WMP118: Anticoagulation Therapy Reduces Recurrent Stroke in Embolic Stroke of Undetermined Source (ESUS) Patients With Elevated Coagulation Markers or Severe Left Atrial Enlargement
Authors: Patel Kishan S , Liu Michael , Rangaraju Srikant , Ellis Deandrea , Duncan Alexander , Hoskins Michael , Belagaje Samir , Belair Trina , Henriquez Laura , Nahab Fadi
Published: June 2021

Introduction:
Left atrial enlargement (LAE) and markers of coagulation and hemostatic activation (MOCHA) have previously been shown to identify ESUS patients who are more likely to have subsequent diagnosis of atrial fibrillation (AF), malignancy or recurrent strokes. The objective of this study was to evaluate if anticoagulation therapy reduces recurrent stroke in ESUS patients with LAE or abnormal MOCHA.

Methods:
Consecutive ESUS patients seen in the Emory Clinic from January 1, 2017, to June 30, 2019, underwent outpatient cardiac monitoring and the MOCHA profile (serum d-dimer, prothrombin fragment 1.2, thrombin-antithrombin complex and fibrin monomer) obtained ≥ 2 weeks after the index stroke. All patients were on antiplatelet therapy at the time of testing. Anticoagulation was offered to patients with an abnormal MOCHA (≥ 2 elevated markers) or severe LAE (LA volume index >40 ml/m
2
). Patients were evaluated for AF, malignancy, recurrent stroke or hemorrhage at routine clinical follow-up. We compared this patient cohort (cohort 2) to a historical cohort (cohort 1) who underwent the same protocol but remained on antiplatelet therapy during follow-up.

Results:
Baseline characteristics and endpoints are shown in the Table. Overall 46 (23%) patients in Cohort 2 initiated anticoagulation based on abnormal MOCHA or severe LAE. Cohort 2 had significantly lower rates of recurrent stroke than cohort 1 (14% vs. 3%, p=0.008) with no major hemorrhages.

Conclusion:
Anticoagulation therapy in a subgroup of ESUS patients with abnormal MOCHA or severe LAE may be associated with a reduced rate of recurrent stroke. A prospective, multicenter study is warranted to validate these results.
Abstract WMP119: Short Term Use of Direct Oral Anticoagulants is Not Associated With Decreased Bleeding in High Risk Patients Following Percutaneous Left Atrial Appendage Closure
Authors: Farhat Salman , Adedinsewo Demilade , Sennhauser Susie , Winder Jeffrey , Salwa Najiyah , Venkatachalam K.L. , Pollak Peter , Parikh Pragnesh
Published: June 2021

Introduction:
Percutaneous left atrial appendage closure is well established as an alternative to anticoagulation therapy for stroke prophylaxis among patients with non-valvular atrial fibrillation (NVAF) with relative or absolute contraindications to anticoagulation. Only the Watchman® (BSC) device has FDA approval for this indication. There are no current guidelines on the choice of short term antithrombotic therapy following placement of the Watchman® device. The landmark Watchman® clinical trials utilized warfarin and aspirin in the first 45 days to facilitate endothelialization; however these studies were started prior to direct oral anticoagulants (DOAC) becoming widely available. Our main objective was to compare bleeding outcomes with warfarin vs. DOACs following Watchman® device placement.

Methods:
We conducted a retrospective chart review of all patients who received a Watchman® device at all three Mayo Clinic sites (MN, FL, AZ) between January 2010 and December 2018 with follow up for outcomes at 45 days or 6 weeks following procedure. We conducted bivariate analysis using t-tests and chi-square tests as appropriate. A logistic regression model was constructed to evaluate the effect of anticoagulant choice on bleeding and thromboembolic outcomes. Clinically significant bleeding was defined as bleeding leading to interruption of anticoagulation regimen or requiring transfusion.

Results:
232 patients were identified (33% female), mean age in years, CHADS2VASC score and HASBLED scores were 77, 5 and 4 respectively. Overall, 39% were initiated on non-warfarin therapies and 11% had a significant bleeding episode during follow up. There was no difference in clinically significant bleeding events (11% vs. 12%; OR 0.92, 95% CI: 0.32 – 2.65) with short term DOAC use compared to warfarin. Patients who received a Watchman® due to GI bleeding were more likely to have a bleeding event in the first 6 weeks following Watchman® (OR: 4.08, 95% CI: 1.30 – 12.75).

Conclusion:
This observational study demonstrates no significant difference in bleeding episodes with DOACs compared to warfarin during the first 6 weeks following Watchman® device placement in patients at high risk for bleeding. Larger prospective studies are needed.
Abstract WMP120: Pre-stroke Statin Enhancement of Collateralization in Acute Ischemic Stroke
Authors: Ma Mengmeng , Zhu Jiaying , He Li
Published: June 2021

Background:
Recent studies suggested that prior statin therapy could lower the initial stroke severity and improve stroke functional outcome in case of stroke onset. It was speculated that pre-stroke statin may enhance collateral circulation and result in favorable functional outcome. This study aimed to investigate the association of pre-stroke statin use with leptomeningeal collaterals in acute ischemic stroke patients.

Methods:
We prospectively and consecutively enrolled 239 acute ischemic stroke patients with acute infarction due to occlusion of the middle cerebral artery within 24 hours from May 2011 to April 2017. CTA imaging was performed for all patients to detect middle cerebral artery thrombus; regional leptomeningeal collateral score (rLMCS) was used to assess the degree of collateral circulation; admission NIHSS was used to measure stroke severity; modified Rankin scale (mRS) at 90 day was used to measure outcome. Univariate and multivariate analyses were performed.

Results:
239 patients met inclusion criteria. 54 patients use statin before stroke onset. Pre-stroke statin use was independently associated with good collateral circulations (rLMCS>10) (OR, 4.786; 95% CI, 1.195 - 19.171; P = 0.027). Pre-stroke statin use was not independently associated with lower stroke severity (NIHSS≤14) (OR, 1.955; 95%CI, 0.657- 5.816; P = 0.228), but pre-stroke statin use was independently associated with good outcome (mRS≤2) (OR, 3.868; 95%CI, 1.325 - 11.289; P = 0.013).

Conclusion:
Pre-stroke statin use seems enhance collateralization and improve clinical outcomes in patients with acute stroke. However, clinical controlled studies should be used to verify this claim.
Abstract WMP13: Multiphase MRA Collateral Map: Prediction of Tissue Outcome and Penumbra in Patients With Acute Ischemic Stroke in the Anterior Circulation
Authors: KIM Hyun Jeong , Lee Taek Jun , Roh Hong Gee , Park Jeong Jin , Lee Hyung Jin , Jeon Yoo Sung , Chun Young Il , Lee Sang Bong , Jung Yu Jin , Ryu Seon Young
Published: June 2021

Background and Purpose:
We developed the MRA collateral map derived from dynamic MR angiography and grading methods with significant linear association with functional outcomes of patients with acute ischemic stroke (AIS). This study is to verify the value of the MRA collateral map for predicting tissue outcome and penumbra in patients with AIS.

Materials and Methods:
From a prospectively maintained registry, patients with AIS due to occlusion or stenosis of the unilateral ICA and/or M1 MCA within 8 hours of symptom onset were included. The collateral-perfusion grading based on the MRA collateral map was estimated using 6-scale MAC. Changes of infarct area were divided into two groups with and without infarct growth (IG
+
and IG
-
). Areas of baseline DWI lesion, Tmax > 6s, and decreased collateral-perfusion on each phases of the MRA collateral map, and infarct lesion on follow-up image were compared by visual assessment.

Results:
One hundred thirty-five patients, including 85 males (mean age, 69 years old), were included. Shorter onset-to-door times (OR=1.04, 95% CI=1.01-1.08) and successful early reperfusion (OR=0.19, 95% CI=0.05-0.66) were independently associated with IG
-
in multivariate analysis. In subgroup analysis, good collateral-perfusion status was associated with IG
-
(OR=0.30, 95% CI=0.10-0.91). In IG
+
group, the infarction grew within hypoperfused area on the phase of the MRA collateral map immediately before the phase that matches the baseline DWI lesion. There was no infarct growth beyond hypoperfused area on the capillary phase of the MRA collateral map in both IG
+
and IG
-
groups. The area of Tmax > 6s matched with the hypoperfused area on capillary phase of the MRA collateral map in 83% of patients.

Conclusion:
In this study, tissue fate in AIS was dependent on early reperfusion. In case of unsuccessful early reperfusion, it was associated with collateral-perfusion status. We suggest that the extent of penumbra can be estimated by the MRA collateral map.
Abstract WMP16: Radiographic Characteristics of Mild Ischemic Stroke Patients With Visible Intracranial Occlusion; Data From the INTERRSeCT Multi-Center Prospective Imaging Study
Authors: Lau Hsien Lee , Gardener Hannah , Saini Vasu A , Krementz Nastajjia , Field Thalia , Dowlatshahi Dar , Smith Eric E , Hill Michael D , Coutts Shelagh B , Demchuk Andrew M , Romano Jose G , Menon Bijoy K , Asdaghi Negar
Published: June 2021

Background:
Early neurological deterioration occurs in one third of mild ischemic strokes primarily due to the presence of a visible intracranial vessel occlusion. We studied the clinical and vascular occlusive patterns, thrombus characteristics and recanalization rates in patients with mild ischemic stroke and a visible intracranial vessel occlusion.

Methods:
We studied patients enrolled in the INTERRSeCT multi-center prospective study of acute ischemic strokes with visible intracranial occlusions. We compared the clinical, thrombus characteristics and recanalization rates between two groups, 1) mild ischemic NIHSS≤5 and 2) moderate/severe strokes NIHSS >5, with or without IV alteplase treatment. Vessel imaging with CT angiography (CTA) was initiated within 12 hrs of symptom onset followed by repeat imaging with CTA or cerebral angiogram (before endovascular therapy; EVT) within 4 +/- 2 hrs.

Results:
Among 575 patients with a visible intracranial occlusion, 12.9% had mild strokes with similar patient characteristics compared to the moderate/severe stroke group. Residual flow grades were similar between the two groups (residual flow grades I-II, 21% vs 19%). The mild stroke group had longer symptom-onset-to -CT (240 vs 167 min, p=0.02) and -CTA (246 vs 172 min, p=0.02) times, longer CT to needle time (35 vs 26 min, p<0.01), more distal occlusions (49% in M2 of the middle cerebral artery), lower clot burden scores 9 (6-9) vs 6 (4-9) (p<0.001), better collateral flow (9.1 vs 7.6, p=0.001) and no association between residual flow grade and recanalization. The mild stroke group was less likely to receive IV alteplase (62% vs 84%), but more likely to recanalize (rAOL2b and 3) with (46% vs 29%) and without (38% vs 26%) IV alteplase.

Conclusion:
Some thrombus characteristics that predict recanalization in more severe strokes do not predict recanalization in mild strokes, such as residual blood flow through intracranial occlusions, though they have similar cardiovascular risk factors. Less than half of patients with mild strokes recanalized with IV alteplase which was associated with longer decision-making times suggesting that more aggressive use of thrombolytics and/or EVT may be viable treatment options in this population.
Abstract WMP2: Pearls and Pitfalls of the Transradial Approach for Neurointerventions: Lessons Learned After 570 Cases
Authors: Sweid Ahmad , Khanna Omaditya , Das Somnath , Kim Julie , Curtis Darcy , Weinberg Joshua , Chalouhi Nohra , Al Saiegh Fadi , Mouchtouris Nikolaos , Ghosh Ritam , Tjoumakaris Stavropoula , Ghooch Michael R , Rosenwasser Robert H , Jabbour Pascal M
Published: June 2021

Background and Purpose:
Trans radial catheterization is an alternate route of access that has started to gain more widespread use for neuroendovascular procedures. There are several randomized controlled trials from cardiac field that had established its safety and efficacy. We present our institution’s experience in performing neuroendovascular interventions via a transradial approach.

Methods:
We conducted a retrospective analysis and identified 570 patients who underwent consecutive neuroendovascular interventions via radial artery access. Data collection was performed on indication for procedure, sheath size, catheter type, number of vessels selectively catheterized, fluoroscopy time, procedure duration, radiation exposure, conversion to femoral approach, access site complication, and procedure success.

Results:
Of 570 patients with an average age of 59.4 years ± 14.7, 406 (71.2%) underwent diagnostic angiograms and 164 (28.7%) underwent therapeutic procedures. The overall mean number of vessels catheterized was 2.9 ± 1.7 per procedure. The RCCA was the most frequent selectively catheterized artery; 340 (22.9%), followed by LCCA; 306 (20.6%), RICA; 250 (16.8%), LICA; 238 (16.0%), RVA; 159 (10.71%), LVA; 76 (5.1%), RECA; 61 (4.1%), and lastly the LECA selectively catheterized in 54 (3.6%). The average amount of contrast given was 83.4 cc ± 51.Successfully completed therapeutic procedures included aneurysm simple coiling (34 patients), stent assisted coiling (30 patients), flow diversion (34) patients), ICA balloon angioplasty and stenting (20 patients), Web device (8), AVM embolization (14), IAC for retinoblastoma (1 patient), and stroke thrombectomy (23 patients). The average duration was 72 mins ± 43, and average fluoroscopy time was 13.20 mins ± 11.20. Seventeen patients (3.2%) required conversion to transfemoral access. Twelve minor complications (2.3%) were reported including mild oozing after deflation of the balloon, ecchymosis, mild swelling. No major complications were encountered.

Conclusions:
Radial artery catheterization is a safe and effective access site to perform a wide range of diagnostic and therapeutic procedures. Complication and conversion rate are low making it a safe alternative.
Abstract WMP22: Synthetic Image Based Deep Learning of Stroke DWI Lesion Segmentation
Authors: Federau Christian , Christensen Soren , Scherrer Nino , Schulze Victor , Ospel Johanna , Maclaren Julian , Lansberg Maarten , Sebastian Kozerke
Published: June 2021

Introduction:
The application of deep learning to stroke image analysis (and medical images in general) faces two major challenges: first, it requires a large number of images to train, which is difficult to obtain. Second, the accurate outlining of infarcts is tedious, requires a high level of expertise, is subjective and error prone. The purpose of this work was to produce a large set of diffusion-weighted images (DWI) with perfectly defined realistic-appearing synthetic acute stroke lesions and to compare the segmentation performance of a deep neural network trained on these DWI scans with synthetic stroke lesions to a network trained on DWI scans of real stroke patients with stroke lesions manually outlined by neuroradiologists.

Methods:
449 DWI scans with stroke lesions (72 ± 14y) and 2027 normal DWI scans (38 ± 24y) were coregistered, resampled, cropped to 96 x 80 x 40 voxels, normalized and divided into training/testing sets (80/20%). Stroke lesions were manually segmented by 3 neuroradiologists. 2000 synthetic 3D stroke DWI were produced by fusing thresholded (min 8%) signal increase of random DWI lesions to random coregistered normal DWI (
A
). A 3D U-Net (Tensorflow, depth 3, initial 64 feature maps doubled with each downsampling, bottleneck 3; hyperparameters optimized with cross-validation) was trained separately on 3 datasets: human-labeled real stroke cases (HL); 2000 synthetic cases (S); human-labeled real stroke cases + 2000 synthetic cases (HL+S).

Results:
The model trained on the human-labeled real stroke cases + 2000 synthetic cases (average dice coefficient between 300 and 600 epochs= 0.66±0.14) significantly outperformed the model trained on the 2000 synthetic cases only (0.60±0.14) and the model trained on human-labeled real stroke cases only (0.55±0.18; p<10
-29
for all comparisons) (
B-C
).

Conclusions:
Deep learning segmentation of acute stroke lesions was significantly improved and was more stable by using synthetically generated images.
Abstract WMP25: Flow Diversion: Predictors of Occlusion Rates, Complications, and Long-Term Outcomes in a Large 598 Cohort, a Real-Life Experience
Authors: Sweid Ahmad , Starke Robert M , Herial Nabeel , Chalouhi Nohra , Das Somnath , Baldassari Michael , Alexander Tyler , Hussain Zubin , Kim Julie , Ramesh Sunidhi , Weinberg Joshua , Al Saiegh Fadi , Mouchtouris Nikolaos , Khanna Omaditya , Tjoumakaris Stavropoula , Gooch Michael R , Hasan David , Rosenwasser Robert , Jabbour Pascal M
Published: June 2021

Introduction:
Flow diversion has introduced a paradigm shift in the endovascular field by providing a more physiological approach to treat aneurysms. We aim to assess the efficacy and safety of flow diversion in treating a diverse large cohort of aneurysms with up to 5 years follow up.

Methods:
This is an analysis of a prospectively maintained database at a single-institution. Patients included in the analysis were consecutively treated patients between 2010 and 2019.

Results:
A total of 598 aneurysms were treated during a period extending from 2010-2019 (84.28% females, mean age 55.5 years, av. size 8.49mm). Adequate aneurysm occlusion rates were 63%(376), 73%(436), and 79%(472) at 6 ,12 and 24-month follow-up, respectively. The complete occlusion rate was 75% at a mean duration of 9 months. Of all patients, 8%(48) required retreatment. On multivariate analysis decreasing PED length (0.35,p=0.01), decreasing PED width (0.63,p=0.01), decreasing dome size (0.46,p=0.01), decreased neck width (0.46,p=0.01), absence of wall irregularity (0.60,p=0.01), lack of branching vessel (0.57,p=0.01), and previous treatment (0.56,p=0.05) were independent predictors of aneurysm occlusion.Morbidity rate occurred at a rate of 5.8% and morality at a rate of 2.2%. Ischemic stroke occurred at a rate of 3%. Delayed aneurysmal rupture and distal intraparenchymal hemorrhage occurred at a rate of 3.7%. On multivariate analysis; predictors of stroke were aneurysm size > 15mm. Predictors of DAR/DIPH were increasing aneurysm size, an increasing number of PED used, subjects presenting with a symptomatic aneurysm. Predictors of in-stent stenosis was balloon angioplasty. While increasing age and previous treatment were negatively associated with in-stent stenosis. Predictors of Morbidity were posterior circulation aneurysms, symptomatic presentation, increasing aneurysm size, and hypertension. While, predictors of unfavorable outcome were age > 75, acute SAH, increasing aneurysm size, and posterior circulation aneurysms.

Conclusion:
At a high-volume center with experienced operators, treatment with PED was associated with durable aneurysm occlusion and low risk of complications. The results support the increasing use of flow diverters.
Abstract WMP26: Aneurysm Location and Its Relationship With Thrombotic and Hemorrhagic Complications During Flow Diversion Procedures: A Meta-Analysis
Authors: Ajadi Ebunoluwa , Nisiewicz Michael , Kabir Shaowli , Fraser Justin
Published: June 2021

Background and Purpose:
Flow diversion with the Pipeline Embolization Device (PED; Medtronic, Minneapolis, MN) has become increasingly utilized in the treatment of otherwise difficult to manage wide-necked aneurysms. Variations in the propensity for hemorrhagic and thrombotic complications during these procedures has been attributed to differences in location as defined be an anterior circulation versus a posterior circulation location. This meta-analysis was conducted to assess and fully characterize the relationship between these aneurysm locations and thrombotic and hemorrhagic events.

Materials and Methods:
The currently available literature (2013 - 2018) was surveyed with PubMed and Google Scholar searches. Included studies were those for which aneurysm locations were accurately reported and for which intra and perioperative adverse events were noted. The data was subject to statistical analysis to assess the relationship between an anterior or posterior circulation location and thrombotic or hemorrhagic events. The collected data was subsequently statistically analyzed to assess for publication bias.

Results:
The searches yielded 49 studies, of which 34 met the inclusion criteria for this meta-analysis. The current meta-analysis assessed 4060 anterior circulation pipeline procedures for hemorrhagic complications, and 3100 for thrombotic complications. This study also assessed 608 posterior circulation pipeline procedures for hemorrhagic events, and 582 for thrombotic events. An anterior circulation location was associated with a 3% absolute risk of hemorrhagic events (CI: 0.02 - 0.04), and a 4% absolute risk of thrombotic events (CI: 0.04 - 0.05). A posterior circulation location was associated with a 6% absolute risk of hemorrhagic complications (CI: 0.04 - 0.08) and showed a greater 13% absolute risk of thrombotic events (CI: 0.10 - 0.16).

Conclusions:
A posterior circulation aneurysm location is associated with a higher propensity for both thrombotic and hemorrhagic events compared to an anterior circulation location. Thrombotic complications are almost twice as likely compared to hemorrhagic complications in the posterior location.
Abstract WMP33: Neutrophils Infiltrating Through Vasa Vasorum Facilitate Rupture of Intracranial Aneurysms
Authors: Aoki Tomohiro , Kushamae Mika , Miyata Haruka , Mizutani Tohru , Nozaki Kazuhiko
Published: June 2021

Introduction:
Subarachnoid hemorrhage due to rupture of intracranial aneurysms (IAs) has quite a poor outcome once after the onset despite an intensive medical care. An appropriate treatment intervention of IAs to prevent rupture is thus mandatory for social health. To achieve this goal, a novel therapeutic modality should be developed based on accurate understanding of the underlying pathogenesis. Although the crucial contribution of macrophage-mediated chronic inflammatory responses in the initiation and progression of IAs has been clarified, much still remains to be elucidated, e.g. what factor triggers rupture of IAs.

Methods:
10-week-old female Sprague-Dawley rats weresubjected to the combined ligation of carotid arteries and systemic hypertension to induce IAs. In this model, two different type of IAs can be induced in a same animal, spontaneously ruptured ones and ones which never rupture. Using this model, we compared ruptured IAs and unruptured ones to clarify histological features related with rupture of the lesions. Gene expression profile data was obtained by RNA-sequencing analyses of induced IAs to identify molecular cascades functioning in the process of rupture. We also examined effect of neutrophils on the rupture, subcutaneous injection of G-CSF was done.

Results:
We found the significant increase of vasa vasorum at the adventitia of ruptured IA walls compared with that in unruptured ones. Through the RNA-sequencing analysis, we identified cascades related with neutrophils as over-represented ones in ruptured lesions. The increase of neutrophils in number by G-CSF treatment then significantly facilitated rupture of IAs and inflammatory responses in situ.

Conclusions:
These results combined together propose that rupture of lesions requires structural changes of arterial walls, vasa vasorum formation, and infiltration of neutrophils across there beyond the well-known involvement of macrophage-mediated chronic inflammation in the process of initiation, making rupture being qualitatively different process. The present study also highlights the potential of vasa vasorum formation or neutrophils as a target for drug therapy to prevent subarachnoid hemorrhage.
Abstract WMP34: Multimodal Evaluation of Unruptured Intracranial Aneurysm Wall
Authors: Hashimoto Yukishige , Furukawa Kazuhiro , Shimonaga Koji , Takahashi Hiroki , Ono Chiaki , Kaneko Mayumi , Mizoue Tatsuya , Ishida Fujimaro , Suzuki Hidenori , Matsushige Toshinori
Published: June 2021

Background and Purpose:
Recent studies have suggested that MR-vessel wall imaging (VWI) or computational fluid dynamics (CFD) could evaluate aneurysm wall features in unruptured intracranial aneurysms (UIAs). The combination of these modalities might be comprehensive and help better understanding of the pathophysiology of aneurysm wall. This study was performed to disclose the relationship between VWI and hemodynamic characteristics evaluated by CFD.

Methods:
From April 2017 through May 2019, a total of 36 microsurgically-treated UIAs preoperatively underwent VWI and CFD were reviewed. Three-dimensional T1-weighted fast spin-echo sequences were obtained before and after injection of contrast medium, and aneurysm wall enhancement (AWE) was evaluated. CFD was carried out using patient specific geometry models from three-dimensional CT angiography. Morphological variables, intraoperative inspection and hemodynamic parameters were statistically analyzed between enhanced and nonenhanced wall of UIAs. Fourteen UIAs were available for histopathological examination.

Results:
In morphological variables, maximum diameter and irregularity were associated with AWE (p=0.02, respectively). AWE lesions corresponded to intraoperatively inspected atherosclerotic lesions of UIAs (sensitivity, 0.90; specificity, 0.79). Among hemodynamic parameters, oscillatory velocity index that suggests the directional changes of the flow velocity was significantly higher in UIAs with AWE (p=0.02). Histopathologic studies revealed that wall thickening accompanied by atherosclerosis, neovascularization, and macrophage infiltration corresponded to AWE lesions, while UIAs without AWE demonstrated various histopathological findings such as myointimal hyperplasia or thinning wall with loss of mural cells and wall degeneration.

Conclusions:
Pathophysiology of AWE could be explained as atherosclerotic changes with inflammation presumably associated with aberrant flow conditions in irregular UIAs. VWI and CFD are complementarily valuable imaging techniques to understand an aneurysm wall pathophysiology.
Abstract WMP37: Burden of Neurological Complications Among Patients With Moyamoya Disease (MMD) Treated With Revascularization
Authors: Patel Smit D , Otite Fadar O , Lima Jussie , Rane Schweta , Desai Rupak , Kureshi Inam
Published: June 2021

Introduction:
Moyamoya disease is a chronic steno-occlusive vasculopathy involving the circle of Willis and typically presents with ischemic or hemorrhagic stroke. Prior studies suggest that either direct or indirect extracranial-intracranial bypass (EC-IC) is an effective treatment for MMD. However, the burden of post-discharge neurological complications after the procedure is unknown. Our study aims to identify the 90 readmission rate (90-DRR) and neurological complications upon readmission in revascularization and untreated MMD patients.

Method:
We analyzed the data from the Nationwide Readmission Database (NRD) from 2010-2015. MMD was ascertained by ICD-9 discharge code 437.5 and revascularization (EC-IC) using 39.28. SAS 9.4 was used for data analysis with categorical and continuous variables tested using the Rao Scott Chi-square test and Student’s t-test respectively.

Result:
Among total 4,902 MMD index events, 1,840 had a revascularization procedure and 3,062 did not. The 90-DRR for the treatment group was 14.72% (readmitted N=271/Index cases N=1,840) vs. 34.75% (readmitted N=1,064/Index cases N=3,062) for the non-revascularization group (P <0.0001). Baseline characteristics of MMD with revascularization were mean age (Mean±SE) 41±0.6 vs. 40±0.5 (P=0.20), Charlson comorbidity index (CCI) 1.6±0.04 vs. 1.8±0.05 (P=0.0004), female: male 3:1. Cause-specific readmission rate in both groups was reported as per table.

Conclusion:
Our analysis shows that patients treated with revascularization had significantly fewer 90-day readmissions when compared to untreated patients. MMD and ischemic stroke were the top reasons for readmission within the 90 days of discharge for both groups. A seizure was reported higher in the treatment group.