Median Infarct Volume Research Articles

Abstract W MP3: Endovascular Therapy in Large Vessel Occlusion Strokes with ASPECTS of 5-7 May Result in Reduced Infarct Volumes and Better Functional Outcomes

Introduction: Intra-arterial therapy (IAT) for large vessel occlusions strokes (LVOS) has been increasingly utilized. The benefit of endovascular reperfusion in patients with mid-range ASPECTS remains to be established. Materials and methods: Retrospective analysis of LVOS patients with ASPECTS 5-7 treated with IAT (n=86) or medical therapy alone (±IV t-PA; n=15) at two academic centers from 2009-2012. Definitions employed: Symptomatic ICH: any parenchymal hematoma; Successful reperfusion: modified TICI≥2B; Good and acceptable clinical outcomes: 90-day mRS 0-2 and 0-3, respectively. Final infarct volumes were calculated based on 24-hour post-procedure CT or MRI scans. Results: Mean age (67±14 vs. 67±19 years) and baseline NIHSS (20±5 vs. 20±6) were similar in the IAT and medical treatment groups. Successful reperfusion was achieved in 58 (67%) IAT patients. Symptomatic and asymptomatic ICH occurred in 9 (10%) and 31 (36%) IAT patients, respectively. The IAT rates of 90-day good and acceptable outcomes were 20% (17/86) and 33% (28/86), respectively. Successful reperfusion in IAT patients was associated with smaller FIV (p=0.015) and higher rates of good (p=0.02) and acceptable (p=0.03) outcomes. The median final infarct volume was significant lower with IAT vs. medical therapy (80ml [IQR, 38-122] vs. 190ml [121-267], p=0.015). There was a strong trend towards a higher hemicraniectomy requirement in medically vs. endovascularly treated patients (20% versus 6%, p=0.06) despite similar in-hospital mortality (20% versus 26.7 %, p=0.75). Conclusions: Despite a low probability of achieving functional independence, IAT in LVOS patients with ASPECTS 5-7 appears to result in smaller final infarct volumes leading to a reduction in the need for hemicraniectomy and decreasing the degree of overall disability. Therefore, it may be a reasonable option for patients and families who favor a shift from severe to moderate disability. Prospective studies utilizing shift in outcome measures are warranted to confirm these results.

Right-side propensity of cardiogenic emboli in acute ischemic stroke with atrial fibrillation

Objectives. We attempted to determine the propensity for sidedness of cardiogenic emboli associated with atrial fibrillation (AF) by comparing the sides on which microembolic signals (MES) were detected via transcranial Doppler (TCD) monitoring and the location of infarcts on magnetic resonance imaging. Design. Patients with AF on Holter monitoring and MES on TCD monitoring were selected from an ischemic stroke registry. Patients with prosthetic valves or cerebral/carotid artery stenosis were excluded. Results. By TCD monitoring of 30 patients, 78 MES were detected: 47 on the right and 31 on the left side (60.3% vs. 39.7%, p < 0.01, chi-square test). Among 21 patients who had middle or anterior cerebral artery (MCA/ACA) territory infarcts, 16 had right-side-dominant infarcts and 5 patients had left-side-dominant infarcts (76.2% vs. 23.8%, p < 0.01, chi-square test). The median infarct volume on the right side was 16.2 (3.18–75.4) ml, while that of left side was 1.2 (0.25–5.05) ml (p < 0.01, Mann–Whitney U test). Conclusion. This study demonstrated the existence of a right-side propensity of cardiogenic emboli and the larger infarct volume of right-side MCA/ACA stroke in patients with AF. These results can be attributed to anatomical differences between the innominate and the left common carotid artery.

Clinical correlates of infarct shape and volume in lacunar strokes: the Secondary Prevention of Small Subcortical Strokes trial.

Infarct size and location are thought to correlate with different mechanisms of lacunar infarcts. We examined the relationship between the size and shape of lacunar infarcts and vascular risk factors and outcomes. We studied 1679 participants in the Secondary Prevention of Small Subcortical Stroke trial with a lacunar infarct visualized on diffusion-weighted imaging. Infarct volume was measured planimetrically, and shape was classified based on visual analysis after 3-dimensional reconstruction of axial MRI slices. Infarct shape was ovoid/spheroid in 63%, slab in 12%, stick in 7%, and multicomponent in 17%. Median infarct volume was smallest in ovoid/spheroid relative to other shapes: 0.46, 0.65, 0.54, and 0.90 mL, respectively (P<0.001). Distributions of vascular risk factors were similar across the 4 groups except that patients in the ovoid/spheroid and stick groups were more often diabetic and those with multicomponent had significantly higher blood pressure at study entry. Intracranial stenosis did not differ among groups (P=0.2). Infarct volume was not associated with vascular risk factors. Increased volume was associated with worse functional status at baseline and 3 months. Overall, 162 recurrent strokes occurred during an average of 3.4 years of follow-up with no difference in recurrent ischemic stroke rate by shape or volume. In patients with recent lacunar stroke, vascular risk factor profile was similar among the different infarct shapes and sizes. Infarct size correlated with worse short-term functional outcome. Neither shape nor volume was predictive of stroke recurrence. http://www.clinicaltrials.gov. Unique identifier: NCT00059306.

Impact of overweight on myocardial infarct size in patients undergoing primary percutaneous coronary intervention: A magnetic resonance imaging study

ObjectiveAlthough obesity is a risk factor for cardiovascular disease and mortality, several studies have reported that patients with obesity who have suffered acute myocardial infarction or have undergone percutaneous coronary intervention (PCI) have better clinical outcomes than their normal weight counterparts. We evaluated the impact of overweight on myocardial infarct size in patients undergoing primary PCI for ST-segment elevation myocardial infarction (STEMI). MethodsWe performed contrast-enhanced magnetic resonance imaging on 193 patients undergoing primary PCI for STEMI. Infarct size was measured with delayed-enhancement imaging and the area at risk was quantified on T2-weighted images. ResultsBaseline characteristics and angiographic findings were not significantly different between the normal weight group (body mass index [BMI] < 25 kg/m2, n = 110) and the overweight group (BMI ≥ 25 kg/m2, n = 83). The median percent infarct volume and area at risk were significantly smaller in the overweight group than the normal weight group (17.9% [9.0–24.9%] vs. 20.8% [11.4–33.1%], p = 0.04 and 29.4% [20.5–37.6%] vs. 36.0% [25.7–49.6%], p < 0.01, respectively). However, the myocardial salvage index was not different between the 2 groups (overweight group vs. normal weight group, 43.2% vs. 39.2%, p = 0.69). BMI ≥ 25 kg/m2 was an independent predictor of smaller infarct size in multivariate analysis (Odds ratio 0.51, 95% Confidence interval 0.27–0.97, p = 0.039). ConclusionOverweight (BMI ≥ 25 kg/m2) is independently associated with smaller infarct size in patients undergoing primary PCI for STEMI.

Sickle cell anemia: Intracranial stenosis and silent cerebral infarcts in children with low risk of stroke

Purpose:Children with sickle cell anemia (SCA), who have mean blood flow velocities <170cm/s in the terminal internal carotid (tICA) or middle cerebral (MCA) arteries on transcranial Doppler ultrasonography (TCD), are considered to be at low risk of stroke. The prevalence of intracranial stenosis, which raises the risk of stroke, is not known in these children. Here, we estimated the prevalence of stenosis and explored its association with silent cerebral infarcts determined based on Magnetic Resonance (MR) scans. Patients/methodsWe studied prospectively a cohort of 67 children with SCA without prior clinically overt stroke or TIA (median age 8.8 years; range limits 2.3–13.1 years; 33 females) and with TCD mean velocity <170cm/s. They underwent MR imaging of the brain and MR angiography of intracranial arteries. ResultsIn 7 children (10.5%, 95% CI: 4.9–20.3%) we found 10 stenoses, including 4 with isolated left tICA stenosis and 3 with multiple stenoses. We found silent infarcts in 26 children (37.7%, 95% CI: 27.2–49.5%). The median number of infarcts in an affected child was 2 (range limits: 1–9), median volume of infarcts was 171mm3 (range limits: 7–1060mm3), and median infarct volume in relation to total brain volume was 0.020% (range limits: 0.001–0.101%). The number and volume of infarcts were significantly higher in children with arterial stenosis (both p=0.023). ConclusionsThe prevalence of intracranial arterial stenosis in children with SCA classified as at low risk of stroke by TCD mean velocity <170cm/s is high. Children with stenosis are at higher risk of brain parenchymal injury as they have more silent cerebral infarcts.

Outcome of surgical management for active mitral native valve infective endocarditis: a collective review of 57 patients

At our institutions, mitral valve vegetation with a high risk for embolism is surgically treated as soon as possible to maintain the quality of life of patients, and valve repair has been actively performed. We reviewed the surgical outcome for active mitral infective endocarditis (AMIE) following this treatment policy. Fifty-seven patients underwent surgery for native AMIE between April 1999 and December 2012 (repair 36, replacement 21). We retrospectively investigated the risk factors for in-hospital death, the prognosis of patients with cerebral infarction, and the short- and long-term outcomes of valve repair and replacement. The preoperative conditions and the intraoperative findings in the replacement group were more complicated. But, no significant differences were observed in in-hospital mortality, 4-year survival, or 4-year reoperation-free rate between the groups (repair 8, 88.2, and 92.4%; replacement 9, 90.5, and 94.7%, respectively). The incidence of postoperative cardiac-related events including heart failure, thromboembolism, and major bleeding was higher in the replacement group. Although our study failed to identify predictors of in-hospital mortality, uncontrolled and nosocomial infections were responsible for high in-hospital mortality of 17 and 33%, respectively. Nine patients with symptomatic non-hemorrhagic cerebral infarction underwent early surgery within 2 weeks of the onset of stroke (median maximum infarct diameter and volume: 18.2 mm and 0.72 cm(3), respectively). No patients had severe hemorrhagic conversion. Mitral valve repair is appropriate to prevent postoperative cardiac-related events. Reducing in-hospital mortality due to uncontrolled infection remains challenging. Early surgery may be reasonable for patients with small non-hemorrhagic infarction.

Comparison of Final Infarct Volumes in Patients Who Received Endovascular Therapy or Intravenous Thrombolysis for Acute Intracranial Large-Vessel Occlusions

Studies comparing the efficacy of intra-arterial therapy (IAT) and medical therapy in reducing final infarct volume (FIV) in intracranial large-vessel occlusions (ILVOs) are lacking. To assess whether patients with ILVOs who received IAT have smaller FIVs than patients who received either intravenous tissue plasminogen activator therapy (IVT) or no reperfusion therapy (NRT) and to determine a National Institutes of Health Stroke Scale (NIHSS) threshold score that identifies patients most likely to benefit from IAT. Retrospective cohort study of patients with ILVOs between 2009 and 2011. Two large-volume stroke centers. Adults with anterior circulation ILVOs who presented within 360 minutes from the time last seen as normal. Patients with isolated extracranial occlusions were not included. Intra-arterial therapy, IVT, or NRT. Final infarct volumes, rates of acceptable outcome defined as a modified Rankin Scale score of 0 to 3 at hospital discharge, and NIHSS threshold scores. A total of 203 consecutive patients with ILVOs were evaluated. Baseline characteristics were similar among the 3 groups. The median infarct volume was significantly smaller for the IAT group (42 cm3) than for the IVT group (109 cm3; P = .001) or the NRT group (110 cm3; P < .01). A higher magnitude of infarct volume reduction in more proximal occlusions was noted in the IAT group compared with the IVT and NRT groups combined: internal carotid artery terminus (75 vs 190 cm3; P < .001), M1 middle cerebral artery (39 vs 109 cm3; P = .004), and M2 middle cerebral artery (33 vs 59 cm3; P = .04) occlusions. Patients were stratified based on NIHSS score at presentation (8-13, 14-19, and ≥20). For patients with an NIHSS score of 14 or higher at presentation, IAT significantly reduced FIV (46 cm3 with IAT vs 149 cm3 with IVT or NRT; P < .001) compared with patients with an NIHSS score of 8 to 13 (22 cm3 with IAT vs 44 cm3 with IVT or NRT; P = .40). Patients with an NIHSS score of 14 or higher who received IAT appear to benefit most from IAT. Our data suggest a greater reduction of FIV with IAT compared with either IVT or NRT. Moreover, patients with an NIHSS score of 14 or higher may be the best candidates for endovascular reperfusion therapy.

Abstracts from the 3rd Annual Therapeutic Hypothermia and Temperature Management ConferenceMarch 4–5, 2013Miami, FL

Abstracts from the 3rd Annual Therapeutic Hypothermia and Temperature Management ConferenceMarch 4–5, 2013Miami, FL

Endovascular Reperfusion and Cooling in Cerebral Acute Ischemia (ReCCLAIM I)

BackgroundThe efficacy of hypothermia as a neuroprotectant has yet to be demonstrated in acute ischemic stroke. We conducted a phase I pilot study to assess the feasibility and safety of...

Abstract 154: Protection from Transient Focal Cerebral Ischemia by Transfusion of Polynitroxylated Pegylated Hemoglobin

Polynitroxylation of hemoglobin (Hb) confers superoxide dismutase and catalase mimetic activity and can protect neurons from native Hb and glutamate. Here, we determined if transfusion of polynitroxylated pegylated Hb (PNPH) is protective in the rat filament model of 2 h of middle cerebral artery occlusion (MCAO). Transfusion of 10 ml/kg of PNPH at 20 min of MCAO reduced the median infarct volume in cerebral cortex from 40% (37-47% interquartile range; n=10) in controls to 3% (0-7%; n=10; P&lt;0.001) with PNPH and in striatum from 78% (66-88%) to 34% (0-37%; P&lt;0.001). The therapeutic window was evaluated in a second experiment. Compared to the control median hemispheric infarct volume of 22% (13-34%; n=15), infarct volume was reduced to 7% (3-13%; n=14; P&lt;0.05) when PNPH was transfused at 4 h after MCAO (2 h of reperfusion) but not significantly when transfused at 6 h (8%; 3-35%; n=14) or at 8 h (12%; 10-25%; n=14) after MCAO. To determine whether PNPH might act by promoting vasodilation, pial arteriolar diameter in the distal MCA border region was measured in closed cranial windows during MCAO. With no transfusion, MCAO induced an initial dilation (36±5%; ±SD; n=8) that subsided by 2 h (5±11%). With PNPH transfusion at 20 min of MCAO, the initial dilation (31±8%; n=7) was better maintained at 2 h (21±11%; P&lt;0.02). To determine whether delaying PNPH transfusion until 90 min of MCAO would improve penumbral perfusion, laser-Doppler flow (LDF) was measured in the ischemic border region where the reduction in LDF was less severe than in the core. LDF significantly increased from 48±18% of the pre-ischemic baseline to 67±21% (P&lt;0.005). Thus, PNPH transfusion has a significant therapeutic window for protection from transient MCAO and may act, in part, by stabilizing vascular function and improving collateral blood flow.

Abstract 158: Magnetic Resonance Angiography Signal Intensity as a Marker of Hemodynamic Impairment in Intracranial Arterial Stenosis

Background and Purpose:— Intracranial arterial stenosis (ICAS) is the predominant cause of ischemic stroke or transient ischemic attack (TIA) in Asia. Change of signal intensities (SI) across an ICAS on magnetic resonance angiography (MRA) may reflect hemodynamic severity of such lesions. Methods:— In-patients with a symptomatic single ICAS of anterior circulation on 3D time-of-flight MRA were recruited. Baseline and 1-year follow-up data were collected. Signal intensity ratio (SIR) was calculated to represent change of SIs across an ICAS on maximum intensity projections: SIR=(mean post-stenotic SI - mean background SI)/(mean pre-stenotic SI - mean background SI). Acute infarct volume was measured on diffusion-weighted images (DWI). Relationships of SIR and baseline characteristics as well as 1-year outcomes were evaluated. Results:— Thirty-six subjects (86.1% males, mean age 55.0 years) were recruited. Overall, mean SIR was 0.84±0.23. Mean SIR of the 23 (63.9%) anatomically severe stenoses was insignificantly lower than the 13 (36.1%) moderate stenoses (0.80±0.23 versus 0.92±0.21, p=0.126). The median baseline infarct volume for the 28 (77.8%) subjects with lesions on DWI was 2.40 cm 3 (IQR 0.80 to 5.78). SIR and acute infarct volume were significantly, linearly and negatively correlated, Spearman correlation coefficient being -0.471 (p=0.011). Two patients (5.6%) had recurrent ischemic strokes at 1-year follow-up. SIR values or acute infarct volumes were unrelated to 1-year outcomes in this initial study. Conclusion:— Change of signal intensity across ICAS on MRA may reflect hemodynamic and functional severity of the lesion. Future studies are warranted to further verify the relationship between this index and prognosis of stroke patients.

Abstract WP187: Correlation between Infarct Shape and Volume and Ischemic Risk Factors and Recurrent Ischemic Rates in Small Subcortical Stroke; Data from the SPS3 Randomized Controlled Trial

Background: Most of lacunar infarcts (LI) are due to penetrating small vessel disease, although other mechanisms can be responsible for LI. We sought to determine the relationship between the size and shape of LI and underlying risk factors and recurrent ischemic stroke rates. Methods: 872 images from the 3020 patients enrolled in the Secondary Prevention of Small Subcortical Strokes (SPS3) trial were included in this analysis. SPS3 is a multi-center randomized trial of MRI proven lacunar stroke patients. Participants with confirmation of their index event by DWI were reviewed. Infarct volume was measured planimetrically, and shape was classified as ovoid/spheroid, slab, stick, or multi-component based on visual analysis after 3D reconstruction of axial MRI slices using OsiriX software. Results: Infarct shape was ovoid/spheroid in 67%, slab in 10%, stick in 6%, and multi-component in 17% of patients. Median infarct volumes differed by shape with the smallest LI volumes observed in ovoid/spheroid: 0.52, 0.76, 0.62, and 0.93 respectively, p &lt; 0.001. Patients with ovoid/spheroid LI were of similar age (means 61 vs. 62 yr, p = 0.4), sex (57 vs 60%, p=0.5), and hypertension status (81% vs. 80%, p = 0.7), but more likely to be diabetic (43% vs. 32%, p = 0.003) and have IHD (17% vs. 10%, p =0.02) vs. those with other shapes combined. Prevalence of relevant intracranial large vessel occlusion on vascular imaging was 7% in the ovoid/spheroid S3 group and 9% in others (p = 0.5). The 6-year re-current stroke rate was 16.1% with 91 strokes occurring. There was no difference in reinfarction rate based on shape or volume. Conclusion: Lacunar strokes comprise a heterogeneous group of cerebral infarction likely secondary to variable etiologies. In this preliminary analysis infarct shape was correlated with risk factors but not with stroke infarct. Final analysis will be presented and likely the ongoing SPS3 data analyses will elucidate these differences.

Close Correlation between Quantitative and Qualitative Assessments of White Matter Lesions

Background: White matter lesions (WML) increase with age and are associated with stroke, cognitive decline and dementia. They can be visually rated or computationally assessed. Methods: We compared WML Fazekas visual rating scores and volumes, determined using a validated multispectral image-fusion technique, in Magnetic Resonance Imaging from 672 participants of the Lothian Birth Cohort 1936 and sought explanations for subjects in whom the correlation (Spearman’s ρ) between the total Fazekas score (summed deep and periventricular ratings, 0–6) and WML volume did not concur (z-score difference >1). Infarcts were identified separately. Results: The median WML Fazekas score was 2 [inter-quartile range (IQR): 2], median WML volume 7.7 ml (IQR: 13.6 ml) and median infarct volume (n = 95) 0.98 ml. Score and volume were highly correlated (Spearman’s ρ = 0.78, p < 0.001). Infarcts did not alter the correlation. Minor discordance occurred in 94/672 (14%) subjects, most with total Fazekas score of 1 (n = 20, WML volume = 4.5–14.8 ml) or 2 (n = 50, WML volume = 0.1–34.4 ml). The main reasons were: subtle WML identified visually but omitted from the volume; prominent ventricular caps but thin body lining giving a periventricular score of 1/2 but large WML volume, and small deep focal lesions which increase the score disproportionally when beginning to coalesce with little change in WML volume. Conclusions: WML rating scores and volumes provide near-equivalent estimates of WML burden, therefore either can be used depending on research circumstances. Even closer agreement could result from improved computational detection of subtle WML and modified visual ratings to differentiate prominent ventricular caps from thin periventricular linings, and small non-coalescent from early coalescent deep WML.

O-020 A comparison of infarct volumes in patients with large vessel occlusions based on treatment modality: a retrospective analysis

IntroductionIntra-arterial (IA) therapy for large vessel occlusions (LVO) results in higher recanalization rates compared to intravenous (IV) thrombolysis. Recanalization after LVO is also a predictor of better clinical outcome. Whether...

O-003 Temporal distribution of stroke volumes and clinical-diffusion mismatch in patients with proximal arterial occlusions

Background and PurposePrevious studies have demonstrated that the benefit of reperfusion therapy declines over time. The Clinical-Diffusion Mismatch (CDM) model has been suggested as surrogate for salvable tissue in acute...

P-029 Outcomes in patients with ASPECTS of 5–7 undergoing endovascular reperfusion therapy for acute ischemic stroke

IntroductionIntra-arterial (IA) therapy for large vessel occlusions (LVO) has been increasingly utilized to treat patients with acute stroke with high NIHSS. The size of pre-treatment infarct core has been linked...

The Relationship between Acute Stress Hyperglycemia and Infarct Volume in Ischemic Stroke (P07.032)

Objective: To investigate the relationship between acute infarct volume on diffusion-weighted imaging (DWI) and acute stress hyperglycemia (ASH) in a prospectively collected dataset. Background The published evidence on the relationship between ischemic lesion volume and ASH is conflicting. While some studies report higher infarct volumes in patients with ASH, others refute this by claiming that small infarcts such as lacunar infarcts are also associated with ASH. Small sample size, failure to use a consistent definition for ASH, inability to account for differences in timing of infarct volume and glucose measurements, and differences in infarct size determination contribute to the controversy. We sought to investigate the relationship between acute infarct volume and ASH in a prospectively collected dataset within the context of the Heart-Brain Interactions Study (HBS). Design/Methods: HBS is an ongoing study aiming to identify the neuroanatomic correlates of stroke-related cardiac injury and acute stress response. We performed blood glucose measurement within 36 hours and DWI within 72 hours of symptom onset in consecutive patients enrolled to the HBS. ASH was defined as elevated blood glucose (>144 mg/dl) in the absence of elevated Hemoglobin A1c ( Results: We identified 98 consecutive patients with ASH and 217 controls out of 1240. The median infarct volume was higher in patients than controls (11 cc vs. 4 cc, p Conclusions: The study shows that infarct volume is an independent predictor of ASH. The probability of ASH increases by increasing infarct volume. Disclosure: Dr. Helenius has nothing to disclose. Dr. Avery has nothing to disclose. Dr. Polnar has nothing to disclose. Dr. Caceres has nothing to disclose. Dr. Siket has nothing to disclose. Dr. AY has nothing to disclose.

Abstract 3851: Temporal Distribution of Stroke Volumes and Clinical-Diffusion Mismatch in Patients with Proximal Arterial Occlusions

Background and Purpose: Previous studies have demonstrated that the benefit of reperfusion therapy declines over time. The Clinical-Diffusion Mismatch (CDM) model has been suggested as surrogate for salvable tissue in acute ischemic stroke (AIS) patients. We sought to describe the temporal behavior profile of infarct volumes and CDM in patients suffering AIS due to proximal arterial occlusion (PAO). Methods: We performed a retrospective analysis of consecutive AIS patients admitted to two large academic institutions fulfilling the following criteria: (1) Baseline NIHSS ≥8; (2) PAO defined as MCA-M1, intracranial ICA, or tandem cervical + ICA/MCA-M1 occlusion on admission CTA/MRA; and (3) MRI-DWI performed ≤8 hours from time of stroke onset/last seen well (TSO). CDM was defined as baseline NIHSS ≥8 and DWI volume ≤25cc (as proposed by Davalos et al). Linear regression analysis was performed to define the changes on DWI lesion volume on presentation over time. The observed TSO to MRI were broken down into quartiles to look for any differences in the distribution of the baseline variables over time. Results: A total of 132 consecutive patients were identified (mean age, 66±16.8 years; 57% females; mean baseline NIHSS 17.5±5.3; occlusion site: MCA-M1, 64%; intracranial-ICA, 29%; tandem, 5%, mean TSO to DWI, 269.5±105.48 minutes). The mean DWI stroke volume on presentation was 46.7±54.8 cc (range, 0.19-436.1) and 63 (46.7%) patients had CDM. There was no significant changes in age, gender, baseline NIHSS, or occlusion site amongst the different time quartiles. Median infarct volume (cc) increased (quartile #1=8.5; #2=30.1; #3=38.5; #4=29.4) and the chances of having a CDM decreased (p&lt;0.0001) across the different time quartiles. However, there was an overall poor correlation between DWI lesion volume on presentation and TSO to MRI (R-square=0.031, Figure ) and a significant proportion of the patients still had a CDM at later time epochs (#1=91.1%[20/22]; #2=47.8%[11/23]; #3=34.4%[21/61]; #4=42.3%[11/26]). Conclusions: Although infarct volume increases and the amount of penumbral tissue decreases over time, many patients with PAO will still have salvable penumbra at the later time epochs. This reflects individual differences in anatomic and physiological characteristics including the strength of collateral flow and highlights that selected patients may benefit from reperfusion therapy even at the later time windows. Figure : Relationship between Baseline DWI Volume (cc) and Time (minutes). Line is best fitted linear regression model.

Abstract 3745: General Versus Local Anesthesia In Endovascular Therapy For Acute Ischemic Stroke (ais) In Anterior Vessel Occlusions. A Case-control Study

Background and purpose Recent evidence supports the shift from general (GA) to local (LA) anesthesia in endovascular acute stroke therapy. However, the optimal modality of anesthesia during this type of procedure has not been established in controlled studies. We compared safety and efficacy on clinical and imaging outcomes between these two sedation modalities in a case-control study. Methods Retrospective observational case-control study of patients with AIS and anterior arterial occlusions treated with endovascular therapy (EVT) according to similar protocols (direct IA, bridging IV t-PA/IA and failed or contraindicated IV t-PA) in two tertiary academic stroke centers that used two different sedation modalities as standard of care, the first under GA and the second under LA. From 298 patients consecutively registered between 2008 and 2011, a total of 206 were classified in two groups (GA, n=103; LA, n=103) matched by age and baseline NIHSS, blind to outcome variables. Outcome variables were ischemic lesion volume and symptomatic ICH at 24-36h, functional dependence (Rankin &gt;3) and mortality at 3 months. Logistic regression and interaction analyses were used to evaluate the effect of GA/LA on outcome variables. Results GA and LA groups were comparable regarding TOAST classification, occlusion site (for GA/LA n= 24/27 ICA or TICA; 51/50 MCA-1; 12/10 MCA-2; 16/16 tandem ICA-MCA), prior IV t-PA use (n= 54/61) and preprocedure TICI score. However, the time from onset to groin puncture (TOGP) was longer in GA patients (median hours, 5.0/3.6) who were more frequently treated following MRI mismatch criteria (n= 55/7). At 24-36 hours, median infarct volume was 25/56 cc (p=0.02) and sICH was found in 10/7 patients (p=NS). Ninety-four patients in each group had completed the 3 months follow-up. Functional dependence was found in 58/55 patients and mortality in 23/33 (p=NS). The adjusted OR of GA for poor functional outcome was 1.83 (95%CI, 0.84-3.97). There was a GA*TOGP interaction on poor outcome: in the TOGP &lt;5 hours group (n=125) the OR of GA was 2.57 (1.02-6.47) whereas it was 0.18 (0.02-1.67) in the TOGP &gt;5 h group (n=57). Conclusions This case-control study shows that endovascular acute stroke therapy under GA results in comparable clinical and radiographic outcomes than under LA. However, GA seems to be associated with poor outcome in patients treated in less than 5 hours.

Dodecafluoropentane Emulsion Decreases Infarct Volume in a Rabbit Ischemic Stroke Model

Purpose To assess the efficacy of dodecafluoropentane emulsion (DDFPe), a nanodroplet emulsion with significant oxygen transport potential, in decreasing infarct volume in an insoluble-emboli rabbit stroke model. Materials And Methods New Zealand White rabbits (N = 64; weight, 5.1 ± 0.50 kg) underwent angiography and received embolic spheres in occluded internal carotid artery branches. Rabbits were randomly assigned to groups in 4-hour and 7-hour studies. Four-hour groups included control (n = 7, embolized without treatment) and DDFPe treatment 30 minutes before stroke (n = 7), at stroke onset (n = 8), and 30 minutes (n = 5), 1 hour (n = 7), 2 hours (n = 5), or 3 hours after stroke (n = 6). Seven-hour groups included control (n = 6) and DDFPe at 1 hour (n = 8) and 6 hours after stroke (n = 5). DDFPe dose was a 2% weight/volume intravenous injection (0.6 mL/kg) repeated every 90 minutes as time allowed. After euthanasia, infarct volume was determined by vital stains on brain sections. Results At 4 hours, median infarct volume decreased for all DDFPe treatment times (pretreatment, 0.30% [ P = .004]; onset, 0.20% [ P = .004]; 30 min, 0.35% [ P = .009]; 1 h, 0.30% [ P = .01]; 2 h, 0.40% [ P = .009]; and 3 h, 0.25% [ P = .003]) compared with controls (3.20%). At 7 hours, median infarct volume decreased with treatment at 1 hour (0.25%; P = .007) but not at 6 hours (1.4%; P = .49) compared with controls (2.2%). Conclusions Intravenous DDFPe in an animal model decreases infarct volumes and protects brain tissue from ischemia, justifying further investigation.