Acute Intracranial Large Vessel Occlusion Research Articles

Intravenous Tirofiban Versus Alteplase Before Endovascular Treatment in Acute Ischemic Stroke: A Pooled Analysis of the DEVT and RESCUE BT Trials.

The present study aimed to evaluate the efficacy and safety of intravenous tirofiban versus alteplase before endovascular treatment (EVT) in acute ischemic stroke patients with intracranial large vessel occlusion. This was a post hoc analysis using data from 2 multicenter, randomized trials: the DEVT trial (Direct Endovascular Treatment for Large Vessel Occlusion Stroke) from May 2018 to May 2020 and the RESCUE BT trial (Intravenous Tirofiban Before Endovascular Thrombectomy for Acute Ischemic Stroke) from October 2018 to October 2021. Patients with acute intracranial large vessel occlusion within 4.5 hours from last known well were dichotomized into 2 groups: tirofiban plus EVT versus alteplase bridging with EVT. The primary outcome was functional independence (modified Rankin Scale score of 0-2) at 90 days. Safety outcomes included symptomatic intracranial hemorrhage and 3-month mortality. Multivariable logistic regression (adjusting for baseline systolic blood pressure, occlusion site, onset-to-puncture time, anesthesia, and first choice of EVT) and propensity score overlap weighting (balance in demographic covariates, stroke characteristics, and initial management between groups) were performed. One-hundred and eighteen alteplase-treated patients in the DEVT trial and 98 tirofiban-treated patients in the RESCUE BT trial were included (median age, 70 years; 115 [53.2%] men). The rate of functional independence was 60.2% in the tirofiban group compared with 46.6% in the alteplase group (adjusted odds ratio, 1.25 [95% CI, 0.60-2.63]). Compared with alteplase, tirofiban was not associated with increased risk of symptomatic intracranial hemorrhage (6.8% versus 9.2%; P=0.51) and mortality (17.8% versus 19.4%; P=0.76). The propensity score overlap weighting analyses showed consistent outcomes. Among patients with intracranial large vessel occlusion within 4.5 hours of onset, tirofiban plus EVT was comparable to alteplase bridging with EVT regarding the efficacy and safety outcomes. These findings should be interpreted as preliminary and require confirmation in a randomized trial. URL: https://www.chictr.org.cn; Unique identifiers: ChiCTR-IOR-17013568 and ChiCTR-INR-17014167.

Preprocedural D-Dimer Level as a Predictor of First-Pass Recanalization and Functional Outcome in Endovascular Treatment of Acute Ischemic Stroke.

We aimed to evaluate the association between preprocedural D-dimer levels and endovascular and clinical outcomes. We retrospectively reviewed patients with acute intracranial large-vessel occlusion who underwent mechanical thrombectomy. Plasma D-dimer levels were measured immediately before the endovascular procedure. Endovascular outcomes included successful recanalization, first-pass recanalization (first-pass effect (FPE) and modified FPE (mFPE)), thrombus fragmentation, and the number of passes of the thrombectomy device. Clinical outcomes were assessed at 3 months using the modified Rankin Scale. A total of 215 patients were included. Preprocedural D-dimer levels were lower in patients with FPE (606.0 ng/mL [interquartile range, 268.0-1062.0]) than in those without (879.0 ng/mL [437.0-2748.0]; p = 0.002). Preprocedural D-dimer level was the only factor affecting FPE (odds ratio, 0.92 [95% confidence interval, 0.85-0.98] per 500 ng/mL; p = 0.022). D-dimer levels did not differ significantly based on successful recanalization and thrombus fragmentation. The number of passes of the thrombectomy device was higher (p = 0.002 for trend) and the puncture-to-recanalization time was longer (p = 0.044 for trend) as the D-dimer levels increased. Patients with favorable outcome had significantly lower D-dimer levels (495.0 ng/mL [290.0-856.0]) than those without (1189.0 ng/mL [526.0-3208.0]; p < 0.001). Preprocedural D-dimer level was an independent factor for favorable outcome (adjusted odds ratio, 0.88 [0.81-0.97] per 500 ng/mL; p = 0.008). In conclusion, higher preprocedural D-dimer levels were significantly associated with poor endovascular and unfavorable functional outcomes.

Frequency and predictors of poststroke epilepsy after mechanical thrombectomy for large vessel occlusion stroke: results from a multicenter cohort study

BackgroundPoststroke epilepsy (PSE) represents an important complication of stroke. Data regarding the frequency and predictors of PSE in patients with large-vessel occlusion stroke receiving mechanical thrombectomy (MT) are scarce. Furthermore, information on acute and preexisting lesion characteristics on brain MRI has not yet been systematically considered in risk prediction of PSE. This study thus aims to assess PSE risk after acute ischemic stroke treated with MT, based on clinical and MRI features.MethodsIn this multicenter study from two tertiary stroke centers, we included consecutive acute ischemic stroke patients who had received MT for acute intracranial large vessel occlusion (LVO) between 2011 and 2017, in whom post-interventional brain MRI and long term-follow-up data were available. Infarct size, affected cerebrovascular territory, hemorrhagic complications and chronic cerebrovascular disease features were assessed on MRI (blinded to clinical information). The primary outcome was the occurrence of PSE (> 7 days after stroke onset) assessed by systematic follow-up via phone interview or electronic records.ResultsOur final study cohort comprised 348 thrombectomy patients (median age: 67 years, 45% women) with a median long-term follow-up of 78 months (range 0–125). 32 patients (9%) developed PSE after a median of 477 days (range 9–2577 days). In univariable analyses, larger postinterventional infarct size, infarct location in the parietal, frontal or temporal lobes and cerebral microbleeds were associated with PSE. Multivariable Cox regression analysis confirmed larger infarct size (HR 3.49; 95% CI 1.67–7.30) and presence of cerebral microbleeds (HR 2.56; 95% CI 1.18–5.56) as independent predictors of PSE.ConclusionIn our study, patients with large vessel occlusion stroke receiving MT had a 9% prevalence of PSE over a median follow-up period of 6.5 years. Besides larger infarct size, presence of cerebral microbleeds on brain MRI predicted PSE occurrence.

Endovascular therapy for acute intracranial large vessel occlusion due to atherothrombosis: Multicenter historical registry

BackgroundAtherothrombotic stroke-related large vessel occlusion (AT-LVO) is caused by two etiologies, the intracranial artery occlusion due to in situ occlusion (intracranial group) or due to embolism from cervical carotid occlusion...

Mechanical Thrombectomy for Pediatric Large Vessel Occlusions : ASystematic Review and Meta-analysis.

Acute intracranial large vessel occlusion (LVO) is an important cause of morbidity and mortality among children; however, unlike in adults, no clinical trial has investigated the benefit of mechanical thrombectomy (MT) in pediatric LVO. Thus, MT remains an off-label procedure for pediatric stroke. To investigate the efficacy and safety of MT in pediatric LVO. Asystematic literature search was conducted in Ovid MEDLINE, Ovid Embase, Scopus, Web of Science, and Cochrane Central Register of Clinical Trials databases. Studies reporting safety and efficacy outcomes for endovascular treatment of pediatric LVO were included. Data regarding recanalization, functional outcome, symptomatic intracranial hemorrhage (sICH), and mortality were extracted from the included studies. Functional outcome was assessed with the modified Rankin scale (mRS). Afixed or random-effects model was used to calculate pooled event rates and 95% confidence intervals (CI). In this study 11 studies comprising 215 patients were included. The successful recanalization rate was 90.3% (95% CI = 85.77-95.11%), and complete recanalization was achieved in 52.7% (95% CI = 45.09-61.62%) of the cases. The favorable (mRS = 0-2) and excellent (mRS = 0-1) outcome rates were 83.3% (95% CI = 73.54-94.50%) and 59.5% (95% CI = 44.24-80.06%), respectively. The overall sICH prevalence was 0.59% (95% CI = 0-3.30%) and mortality rate was 3.2% (95% CI = 0.55-7.38%). In our meta-analysis, MT demonstrated apromising safety and efficacy profile for pediatric patients, with consistently high efficacy outcomes and low complication rates. Our results support the utilization of MT in pediatric LVOs; however, prospective studies are still needed to further establish the role of pediatric MT as afirst-line treatment strategy.

Clinical outcomes of rescue stenting for failed endovascular thrombectomy: a multicenter prospective registry

BackgroundMechanical thrombectomy (MT) is a primary endovascular modality for acute intracranial large vessel occlusion. However, further treatment, such as rescue stenting, is occasionally necessary for refractory cases. We aimed to...

Difference of Thrombus Location between Initial Noninvasive Vascular Image and First DSA Findings in Mechanical Thrombectomy for Intracranial Large Vessel Occlusion: Post Hoc Analysis of the SKIP Study.

In patients who undergo mechanical thrombectomy for intracranial large vessel occlusion, the occluded site is sometimes distal to the site shown in the initial vascular imaging. We investigated the factors related to the change in the occluded site between the sequential imagings. The 203 patients in the SKIP study were reviewed retrospectively. Magnetic resonance angiography (MRA) or computed tomography angiography (CTA) was used to assess the occluded site. The occluded site shown in the cerebral angiography appeared to be distal to the occluded site shown in the initial vascular imaging in 55 patients (group A). The location of the occluded site in the remaining 148 patients did not change between the sequential imagings (group B). MRA was used more often than CTA in group A (54 MRA, 1 CTA; P <0.01). Patients with middle cerebral artery (M1) occlusion were more likely to show change of the occluded site than patients with internal carotid artery (ICA) occlusion (M1: 38%, ICA: 9%; P <0.01). The number of patients who received intravenous recombinant tissue plasminogen activator did not differ between the two groups (group A: 54%, group B: 49%; P = 0.5). In patients with acute intracranial large vessel occlusion who require mechanical thrombectomy, physicians should be aware that the location of the thrombus may be distal to the occluded site shown in the initial vascular imaging, particularly in patients with M1 occlusion shown by MRA.

Open Microvascular Thrombectomy for Acute Intracranial Large Vessel Occlusion: Microsurgery in the Endovascular Thrombectomy Era

Open microsurgical thrombectomy for acute intracranial large vessel occlusion (LVO) has been the subject of dozens of case reports and series. However, no clear indications exist to define its role in the management of acute ischemic stroke. Our aim was to review all the available data on open microsurgical thrombectomy, for both spontaneous as well as iatrogenic intracranial vessel occlusion, in terms of indication and results. Of the 390 articles screened, 33 were included after full text screening. A total of 232 patients were reported, of whom 208 received microsurgical thrombectomy and 24 received bypass for large vessel occlusion. Patients were divided into a historic cohort (before 2002) and a recent cohort (articles published after 2002). Patients from the historic cohort were younger: median age, 55 years (interquartile range, 34-57 years) versus 69 years (interquartile range, 63-75 years) in the recent cohort (P < 0.01). The procedure was successful more often in the recent cohort (65% of patients in the historic cohort vs. 98% of patients in the recent cohort) and more patients experienced neurologic improvement (56% of patients in the historic cohort vs. 69% in the recent cohort). In the era of endovascular thrombectomy, open microsurgical techniques might still play a role in highly selected patients. The reported patients show that microsurgical thrombectomy seems efficient and effective in improving patient outcome. Ideally, a multidisciplinary approach with vascular neurosurgeons trained and skilled in microvascular techniques is recommended.

A Pre-Intervention 4-Item Scale for Predicting Poor Outcome Despite Successful Recanalization in Basilar Artery Occlusion.

Poor outcome despite successful recanalization is a relatively common occurrence after endovascular therapy (EVT) in acute intracranial large vessel occlusion. We aimed to develop a simple pre-intervention scale with readily available indicators for predicting the 90-day poor outcome in acute basilar artery occlusion (BAO) patients with successful recanalization after EVT. A prospectively registered consecutive cohort of acute BAO patients treated with EVT in a tertiary stroke center during a 6-year period was reviewed. Poor outcome despite successful recanalization was defined as a 90-day mRS of > 3 despite a post-intervention mTICI of ≥ 2b. A logistic regression analysis was employed to develop the predictive scale. The performance of the scale was estimated by ROC curve and Hosmer-Lemeshow test. Poor outcome was observed in 48 of 109 patients included in this study. The proposed scale consisted of four selected pre-intervention predictors, including the NIHSS score, Pons-Midbrain Index (PMI), bilateral thalamic infarction, and Basilar Artery on Computed Tomography Angiography (BATMAN) collateral score. The 4-item scale revealed good discrimination with an area under curve of 0.83 (95% CI = 0.75-0.90) and acceptable calibration assessed by Hosmer-Lemeshow test (P = 0.48). The optimal cutoff value of the scale (range 0-5 points) was ≥ 3 points with 77% sensitivity, 80% specificity, and 79% accuracy. As a pre-intervention predictive model, the 4-item scale has promising predictive value for poor outcome despite successful recanalization in BAO patients treated with EVT. Nevertheless, external validation with blinded outcome is still needed to confirm its performance before clinical application.

Emergency Intracranial Stenting in Acute Stroke: Predictors for Poor Outcome and for Complications.

BackgroundStent‐retriever thrombectomy is the first‐line therapy in acute stroke with intracranial large vessel occlusion. In case of failure of stent‐retriever thrombectomy, rescue stent angioplasty might be the only treatment option to achieve permanent recanalization. This study aims at identifying predictors for poor outcome and complications in a large, multicenter cohort receiving rescue stent angioplasty.Methods and ResultsWe performed a retrospective analysis of patients with large vessel occlusion who were treated with rescue stent angioplasty after stent‐retriever thrombectomy between 2012 and 2018 in 7 neurovascular centers. We defined 2 binary outcomes: (1) functional clinical outcome (good modified Rankin Scale, 0–2; and poor modified Rankin Scale, 4–6) and (2) early symptomatic intracerebral hemorrhage. Impacts of clinical, radiological, and interventional parameters on outcomewere assessed in uni‐ and multivariable logistic regression models. Two hundred ten patients were included with target vessels located within the anterior circulation (136 of 210; 64.8%) and posterior circulation (74 of 210; 35.2%). Symptomatic intracerebral hemorrhage occured in 22 patients, 86.4% (19 of 22) after anterior and 13.6% (3 of 22) after posterior circulation large vessel occlusion. Good functional outcome was observed in 44.8% (73 of 163). A higher National Institutes of Health Stroke Scale on admission (adjusted odds ratio, 1.10; P=0.002), a higher premorbid modified Rankin Scale (adjusted odds ratio, 2.02; P=0.049), and a modified Thrombolysis in Cerebral Infarction score of 0 to 2a after stenting (adjusted odds ratio, 23.24; P<0.001) were independent predictors of poor functional outcome.ConclusionsUse of rescue stent angioplasty can be considered for acute intracranial large vessel occlusion in cases after unsuccessful stent‐retriever thrombectomy. Likelihood of symptomatic intracerebral hemorrhage is higher in anterior circulation stroke.

Risk of secondary embolism events during mechanical thrombectomy for acute ischemic stroke: A single-center study based on histological analysis

ObjectiveSecondary embolism (SE) is a common adverse event during mechanical thrombectomy (MT) for acute intracranial large vessel occlusion, which could lead to incomplete revascularization and increased maneuvers. However, the mechanisms behind SE are still unclear. In this study, we aimed to investigate the risk factors of SE, with a focus on clot composition. Patients and MethodsConsecutive patients with retrieved clots were reviewed. Histologic examination for thrombus included Hematoxylin and eosin, Martius Scarlet Blue, immunohistochemistry for von Willebrand factor (VWF). Patients included were assigned to SE or no SE group. The differences in histological composition and clinical characteristics were compared, and logistic regression was conducted for predictors of SE. ResultsFifty-four patients were included, of which 19 were identified as having an SE. For patients with SE, there was more history of stroke or transient cerebral ischemia (TIA) (57.9 % vs. 28.6 %, p = 0.035), more occlusion located in terminal internal carotid artery (ICA) (63.2 % vs. 25.7 %, p = 0.007), relatively more contact aspiration used as frontline strategy (68.4 % vs. 45.7 %, p = 0.110), and less eTICI2c-3 recanalization achieved (52.6 % vs. 91.4 %, p = 0.003). As for histologic composition, the clots in SE group showed a higher proportion of erythrocyte fractions (42.9 % vs. 26.8 %, p = 0.045), while the other components were comparable with the non-SE group. Multivariate analysis suggested that a history of stroke or TIA (OR 6.45, 95 %CI 1.41–29.44, p = 0.016) and ICA occlusion (OR 8.05, 95 %CI 1.80–36.10, p = 0.006) could independently predict SE. ConclusionHistory of TIA or stroke and occlusion in the terminal ICA were found to be independent predictors for SE. Thrombus with a higher erythrocyte fractions might be more fragile. Further studies are needed.

Mechanical Thrombectomy for Patients with In-Hospital Ischemic Stroke: A Case-Control Study

Patients with in-hospital acute ischemic stroke (AIS) have, in general, worse outcomes compared to those presenting from the community, partly attributed to the numerous contraindications to intravenous thrombolysis. We aimed to identify and analyze a group of patients with in-hospital AIS who remain suitable candidates for acute endovascular therapies. A retrospective 6-year data analysis was conducted in patients evaluated through the in-hospital stroke alert protocol in a single tertiary care university hospital to identify those with in-hospital AIS due to acute intracranial large vessel occlusion (ILVO). Feasibility and safety of mechanical thrombectomy for in-hospital AIS was assessed in a case-control study comparing inpatients to those presenting from the community. From 1460 in-hospital stroke alert activations, 11% had a final diagnosis of AIS (n = 167). One hundred and two patients with in-hospital AIS had emergent intracranial vessel imaging and were included in our cohort. Acute ILVO was identified in 27 patients within this cohort. Patients were younger in the ILVO group and had more severe neurologic deficit on presentation. Compared to a matched (1:2) control group of patients presenting from the community, inpatients who underwent mechanical thrombectomy achieved equivalent technical success, safety, and clinical outcomes. The incidence of acute ILVO in patients with in-hospital AIS who underwent emergent vessel imaging is similar to the reported incidence of ILVO in patients presenting with community-onset AIS. Among patients with in-hospital AIS secondary to ILVO, mechanical thrombectomy is a feasible and safe therapy associated with favorable outcomes.

Mortality reduction after thrombectomy for acute intracranial large vessel occlusion: meta-analysis of randomized trials

BackgroundThrombectomy for patients with emergent large vessel occlusion (ELVO) is currently recognized as the standard of care for appropriately selected patients. As proven in several randomized clinical trials and meta-analyses,...

Abstract WP327: CT Angiogram Has High Yield in Code Stroke

Introduction: Although studies have examined emergent CTAs of the head and neck in patients seen by neurologists who are suspected of having a large vessel occlusion, the utility and accuracy of CTA for patients called as a ‘code stroke’ by any healthcare provider has not been evaluated. Methods: At our institution, imaging for all Code Stroke patients includes non-contrast CT of the brain as well as CTA of the neck and brain, regardless of severity. This imaging is often performed prior to detailed neurology evaluation. We queried our radiology department report database for all studies labelled ‘CTA ELVO’, an imaging order code which is specific for Code Stroke. We then cross-referenced this list with our prospectively acquired ischemic stroke registry, which consists of all patients discharged with a diagnosis of acute ischemic stroke. Results: Between January and August 2017, 1265 CTA ELVOs were performed. Average age was 66.3 years, and 52.4% were female. Of all CTA ELVOs, 144 were performed on inpatients (11.3%) and neuroradiologists read 149 studies (11.8%). Critical findings on vessel imaging were present in 165 studies (13%); of these 118 patients were ultimately diagnosed with acute ischemic stroke. Studies with critical findings involved older patients (73.7 years, p&lt;0.001) and were less likely to be performed on inpatients (29 studies, p=0.012) but were no different in number of females (55%, p=0.51) or whether read by a neuroradiologist (23 studies, p=0.36). Critical findings included acute intracranial large vessel occlusion involving the middle cerebral artery, intracranial internal carotid artery (ICA), or basilar artery (87 studies); critical cervical ICA stenosis, acute cervical ICA occlusion, or acute dissection (42 studies); M2 occlusion (32 studies); critical intracranial stenosis (7 studies) and vascular malformation such as aneurysm or arteriovenous malformation (6 studies). Conclusion: The yield of non-invasive vessel imaging in patients called as a code stroke in detecting critical findings is high, revealing abnormalities in approximately one in eight patients. Patients presenting with acute neurologic symptoms should receive vessel imaging as part of the initial workup for suspected stroke.

Abstract WP26: The Effects of Blood Pressure Variation Within 24 Hours of Intracerebral Large Vessel Occlusion Mechanical Thrombectomy and Clinical Outcomes

Introduction: Mechanical thrombectomy (MT) is now the standard of care for acute intracranial large vessel occlusion (LVO). There are currently no established guidelines for post MT blood pressure parameters in LVO patients. Our study examines the influence of blood pressure fluctuation and variation within the first 24 hours on clinical outcomes in post MT LVO patients. Methods: A hospital based stroke registry retrospectively identified 111 consecutive patients undergoing MT for LVO (2012-2015). Blood pressure recordings within the 1st 24 hours post MT were analyzed: Maximum (Max), minimum, median and standard deviation (SD) of the systolic (SBP), diastolic (DBP) and mean arterial pressures (MAP) were calculated individually and as composite aggregates. Good outcomes were defined as National Institute of Health Stroke Scale (NIHSS) improvement of &gt;=10 at discharge and or discharge NIHSS&lt;=2 Poor outcomes were defined as post-MT intracerebral hemorrhagic (ICH) and mortality. Univariate (UV). and multivariate logistic regression (MV) were used to identify effect of blood pressure variation on good and poor outcomes. IBM-SPSS version 21 was used for data analysis. Results: On UV analysis a lesser degree of 24 hour post MT SBP (median 16, IQR (Inter Quartile Range) 13, 23 mmHg, p=0.03) and DBP (Median 10, IQR 8, 12 mmHg p .04) SD were associated with good outcome. Maximum SBP was associated with higher rates of mortality (median 188, IQR 174-195 mmHg, p=0.03) and ICH (median 179, IQR 167-196 mmHg, p=0.05). There is no statistically significant association between Post MT 24 hours DBP or MAP maximum, minimum, median and SD values with associated poor outcomes. On MV, SBP variance and maximum SBP were found to be significantly associated with good outcomes (Odds Ratio (OR) 1.09, 95%CI (Confidence interval) 1 - 1.2, p=0.04) and mortality (OR 1.02, 95%CI 1 - 1.004, p=0.02) respectively. Conclusion: Importance of proper blood pressure regulation within the 1st 24 hours of an LVO MT cannot be understated. To maintain good outcomes after MT, minimizing SBP SD becomes important. With the underlying premise of post cerebral ischemia induced vasomotor dysregulation, controlling Max SBP also decreases ICH and mortality. A prospective study is warranted to reinforce our findings.

Occurrence of intracranial large vessel occlusion in consecutive, non-referred patients with acute ischemic stroke

The relative frequency of acute intracranial large vessel occlusion (LVO) in patients with acute ischemic stroke (AIS) who could be candidate for intra-arterial treatment (IAT) is not well known. In this study, we determined clinical variables associated with LVO and the proportion of patients with LVO among patients presenting with AIS within 6 h of symptom onset. Data of consecutive patients with AIS presenting at the emergency department (ED) of the Erasmus University Medical Center, in the Netherlands, was used. Referrals from other hospitals were excluded. From 2006 January 1st to 2012 April 30th, 1063 non-referred patients presented at our ED with AIS. 445 (42 %) arrived within 6 h of onset of symptoms. Computed tomography angiography was not performed or was of insufficient quality in 50 patients (11 %) and performed late (≥1 day) in 57 patients (13 %). The remaining 338 with AIS were included in the final analysis. 106 patients (31 %) had LVO, mostly in the anterior circulation (72 %). National Institutes of Health Stroke Scale score was the only variable associated with the presence of LVO (adjusted OR 1.23 per point [95 % Confidence interval: 1.17–1.29]). Of all patients with acute ischemic stroke who arrive within 6 h of symptom onset at the emergency department, almost one out of three have a intracranial large vessel occlusion and may be candidate for intra-arterial treatment.

Delayed Stenosis in the Intracranial Vessels following Endovascular Treatment for Acute Stroke

PurposeTo evaluate delayed stenosis of the vessels after endovascular thrombectomy using magnetic resonance (MR) angiography. Materials and MethodsOf 82 consecutive patients who underwent successful endovascular treatment for acute intracranial large vessel occlusion between October 2010 and October 2014 at a single institution, 57 patients for whom 3-month radiologic follow-up examinations using MR angiography were available were included in the analysis. MR angiography images were assessed to detect delayed stenosis, which was defined as a decrease in the diameter of treated vessels > 50% compared with MR angiography images obtained 24 hours after endovascular treatment. ResultsMR angiography images obtained 3 months after endovascular treatment revealed delayed stenosis of treated vessels in five (8.8%) of 57 patients. All cases of delayed stenosis were asymptomatic and occurred in the middle cerebral artery (MCA). Further serial radiologic follow-up showed gradual improvement of all delayed stenosis over 12 months. ConclusionsEndovascular treatment poses a risk of delayed stenosis of treated vessels, especially in the MCA. MR angiography is a useful modality in long-term follow-up to evaluate delayed stenosis after endovascular treatment.

E-003 delayed reocclusion of recanalized intracranial arteries after mechanical thrombectomy in acute stroke patients

Purpose Occlusions of major intracranial vessels are presented with acute infarcts, which can lead to serious morbidity and mortality. Mechanical thrombectomy is an effective revascularization therapy for acute intracranial large vessel occlusion. Results of mechanical thrombectomy are varied according to the studies. Complications including dissection, hemorrhage, reocclusion are also varied. We reviewed the patients of reoccluded intracranial arteries which had initially recanalized by mechanical thrombectomy. Methods We reviewed 180 patients who have undergone Mechanical thrombectomy with Solitaire FR stent from March 2011 to January 2015. We achieved revasculisation (TICI 2,3) in 163 (91%) among 180 patients. But, we experienced delayed reocclusion of recanalized arteries after mechanical thrombectomy in 3 of 163 patients. Results Three patients were found with reocclusion of initially recanalized intracranial arteries with mechanical thrombectomy. Two of whom had occlusion of MCA, and one had occlusion of petrous ICA. We suspect the reasons of reocclusion were the dissection of occluded vessels in one patient and the thrombosis of remained thrombus (TICI2a, 2b) in 2 patients. Initial NIHSS (National Institute of Health Stroke Scale) score were 21, 5 and 15, respectively and NIHSS score at discharge were 17, 4 and 15, respectively. For all 3 patients, TICI grade were 2b, 2b and 2a after the first mechanical thrombectomy. Follow-up Angiogram showed complete reocclusion with TICI grade 0. And Final TICI grade were 2a, 2b and 2b, respectively. All three patients had concomitant PTA with balloon catheter. Conclusions We reviewed these patients and found that delayed reocclusion of recanalized vessels were noted within 24 h after first mechanical thrombectomy. The factors contributed to these results are assumed as TICI grade before and after the first mechanical thrombectomy. But, further evaluation of factors such as NIHSS score, underlying disease, laboratory findings and follow-up angiogram are needed. Also, procedural complications as vasospasm, dissection and hemorrhage should be investigated. Disclosures K. Jang: None. S. Park: None. D. Jang: None. B. Moon: None. Y. Han: None. Y. Park: None.

Long-term Magnetic Resonance Angiography Follow-up for Recanalized Vessels after Mechanical Thrombectomy

Mechanical thrombectomy is an effective revascularization therapy for acute intracranial large vessel occlusion. We retrospectively evaluated magnetic resonance angiography (MRA) follow-up data to assess the long-term patency of recanalized vessels after mechanical thrombectomy. We retrospectively reviewed medical records of consecutive patients who had undergone mechanical thrombectomy for intravenous tissue plasminogen activator-failed/ineligible acute intracranial major vessel occlusion between October 2010 and April 2013 at our institution. MRA follow-up was performed at baseline and at 24 ± 6 hours and 3 months after mechanical thrombectomy. Forty-nine patients underwent mechanical thrombectomy for acute intracranial major vessel occlusion. Mean age was 69.7 ± 11.5 years, and baseline median National Institute of Health Stroke Scale score was 15 (range, 8-24). Occlusion was found in the internal carotid artery in 18 patients (36.7%), middle cerebral artery in 26 patients (53%), and vertebral-basilar arteries in 5 patients (10.2%). Successful recanalization, as defined by a thrombolysis in cerebral infarction flow grade of 2b or 3, was achieved in 40 patients (81.6%). MRA follow-up at 24 hours after the treatment revealed that reocclusion of recanalized vessels was observed in 3 of 38 patients (7.9%). Long-term MRA follow-up showed that 2 of 27 patients (8.3%) developed diffuse severe stenosis of treated vessels. Both the patients had undergone treatment for middle cerebral artery occlusion with the Merci retriever and had been administered only anticoagulants, but not any antiplatelets. Reocclusion or late stenosis of successfully recanalized vessels was observed in 16.2% of patients. Long-term MRA follow-up of recanalized vessels will be useful, in particular, for the patient with middle cerebral artery occlusion who undergoes mechanical thrombectomy.