Clinical relevance of intracranial hemorrhage after thrombectomy versus medical management for large core infarct: a secondary analysis of the SELECT2 randomized trial.

BACKGROUND: The incidence of intracerebral hemorrhage (ICH) and its effect on the outcomes after endovascular thrombectomy (EVT) for patients with large core infarcts have not been well-characterized. METHODS: SELECT2 trial follow-up imaging was evaluated using the Heidelberg Bleeding Classification (HBC) to define hemorrhage grade. The association of ICH with clinical outcomes and treatment effect was examined. RESULTS: Of 351 included patients, 194 (55%) and 189 (54%) demonstrated intracranial and intracerebral hemorrhage, respectively, with a higher incidence in EVT (134 (75%) and 130 (73%)) versus medical management (MM) (60 (35%) and 59 (34%), both P<0.001). Hemorrhagic infarction type 1 (HBC=1a) and type 2 (HBC=1b) accounted for 93% of all hemorrhages. Parenchymal hematoma (PH) type 1 (HBC=1c) and type 2 (HBC=2) were observed in 1 (0.6%) EVT-treated and 4 (2.2%) MM patients. Symptomatic ICH (sICH) (SITS-MOST definition) was seen in 0.6% EVT patients and 1.2% MM patients. No trend for ICH with core volumes (P=0.10) or Alberta Stroke Program Early CT Score (ASPECTS) (P=0.74) was observed. Among EVT patients, the presence of any ICH did not worsen clinical outcome (modified Rankin Scale (mRS) at 90 days: 4 (3-6) vs 4 (3-6); adjusted generalized OR 1.00, 95% CI 0.68 to 1.47, P>0.99) or modify EVT treatment effect (Pinteraction=0.77). CONCLUSIONS: ICH was present in 75% of the EVT population, but PH or sICH were infrequent. The presence of any ICH did not worsen functional outcomes or modify EVT treatment effect at 90-day follow-up. The high rate of hemorrhages overall still represents an opportunity for adjunctive therapies in EVT patients with a large ischemic core.

Diffusion-weighted imaging lesions after intracranial aneurysm treatment with Pipeline Flex and Pipeline Flex with Shield technology: a retrospective cohort analysis.

BACKGROUND: The Pipeline Flex embolization device with Shield technology (PED Shield) is the first flow diverter for brain aneurysm treatment approved in the United States using surface-modified technology. The effect of PED Shield on decreasing perioperative diffusion-weighted imaging positive (DWI+) hits, as a marker for in-human decrease thrombogenicity, is unclear. OBJECTIVE: To determine if the number of periprocedural DWI+ lesions differs between patients with an aneurysm treated with PED Flex and PED Shield. METHODS: This retrospective study compares the outcomes of consecutive patients with an aneurysm treated with PED Flex and PED Shield. The primary outcome of interest was the occurrence of DWI+ lesions. We also assessed potential predictors of DWI+ lesions and compared the outcomes between on-label and off-label treatment indications. RESULTS: 89 patients were included, 48 (54%) treated with PED Flex and 41 (46%) with PED Shield. After matching, the incidence of DWI+ lesions was 61% and 62% for the PED Flex and PED Shield groups, respectively. Results were consistent across each model with no significant differences in DWI+ lesions between treatment groups, and effect sizes ranging from OR=1.08 (95% CI 0.41 to 2.89) after propensity score matching to OR=1.84 (95% CI 0.65 to 5.47) after multivariable regression. Multivariable models demonstrated reduced DWI+ lesions with balloon-assisted therapies and posterior circulation treatment, while a significant linear relationship was encountered with fluoroscopy time. CONCLUSION: There was no significant difference in the incidence of perioperative DWI+ lesions between patients with an aneurysm treated with PED Flex and PED Shield. Larger cohorts are likely needed to demonstrate differences between the devices.

Anterior circulation location-specific results for stent-assisted coiling - carotid versus distal aneurysms: 1-year outcomes from the Neuroform Atlas Stent Pivotal Trial.

BACKGROUND: The Neuroform Atlas Stent System is an established treatment modality for unruptured anterior and posterior circulation intracranial aneurysms. Location-specific results are needed to guide treatment decision-making. However, it is unclear whether there are differences in safety and efficacy outcomes between carotid and more distal anterior circulation aneurysms. METHODS: The ATLAS IDE trial was a prospective, multicenter, single-arm, open-label interventional study that evaluated the safety and efficacy of the Neuroform Atlas Stent System. We compared differences in efficacy and safety outcomes of proximal internal carotid artery (ICA) versus distal and bifurcation anterior circulation aneurysms. RESULTS: Of 182 cases, there were 70 aneurysms in the ICA and 112 in the distal anterior circulation (including ICA terminus/bifurcation). There were no significant differences in the primary efficacy endpoint (85.5% vs 83.9%, p=0.78) and complete aneurysm occlusion rates (88.7% vs 87.9%, p=0.78) between proximal ICA aneurysms and distal aneurysms, respectively. Complications were more often encountered in distal and bifurcation aneurysms, but the overall rate of major safety events was low and comparable between the two groups (1.4% vs 6.3%, p=0.14). Recanalization and retreatment rates were also similar between the groups. CONCLUSION: The results of this study suggest that the Neuroform Atlas Stent System is a safe and efficacious treatment modality for unruptured anterior circulation intracranial aneurysms, regardless of aneurysm location. TRIAL REGISTRATION NUMBER: NCT02340585.

Safety and Efficacy of Flow Diverters for Treatment of Unruptured Anterior Communicating Artery Aneurysms: Retrospective Multicenter Study.

BACKGROUND: The anterior communicating artery (AComm) region is the most common site of intracranial aneurysms, with increased rupture risk compared with other locations. Overall, flow diverters present as a safe and efficacious treatment for intracranial aneurysms, but there is paucity of data for their use in the treatment of unruptured AComm aneurysms. We present the largest multicentric analysis evaluating the outcomes of flow diverters in AComm aneurysm treatment. METHODS: Databases from 10 centers were retrospectively reviewed for unruptured AComm aneurysms treated with flow diverters. Demographics, clinical presentation, radiographic characteristics, procedural complications, and outcomes were assessed. RESULTS: A total of 144 patients harboring 147 AComm aneurysms were treated between January 2012 and December 2021. Seventy-four were women (51.4%) and median age was 60 (IQR 50-67) years. All were unruptured AComm aneurysms. Half of the cohort had similar anterior cerebral artery sizes (51.4%). The most common morphology was saccular (94.6%), with a branch involvement in 32.7% of cases. Median vessel diameter was 2.4 mm, and the Pipeline Flex was the most prevalent device (32.7%). Median follow-up time was 17 months, with complete occlusion in 86.4% at the last follow-up. Functional independence (modified Rankin Scale score 0-2) was reported in 95.1%. Intraprocedural complications occurred in 5.6%, and postoperative complications were noted in 9.7% of cases. Combined major complication and mortality rate was 2.1%. CONCLUSIONS: Our study suggests that flow diverters are a useful treatment for AComm aneurysms. Mid-term results indicated favorable aneurysm occlusion with a good safety profile. Additional prospective studies with longer follow-up periods and independent adjudication are warranted to better assess these results.

Rescue intracranial stenting for failed posterior circulation thrombectomy: analysis from the Stenting and Angioplasty in NeuroThrombectomy (SAINT) study.

BACKGROUNDS: Recent trials have shown improved outcomes after mechanical thrombectomy (MT) for vertebrobasilar occlusion (VBO) stroke. However, there is a paucity of data regarding safety and outcomes of rescue intracranial stenting (RS) after failed MT (FRRS+) for posterior circulation stroke. We sought to compare RS to failed reperfusion without RS (FRRS-). METHODS: This is a retrospective analysis of the Stenting and Angioplasty in NeuroThrombectomy (SAINT) study, a multicenter collaboration involving prospectively collected databases. Patients were included if they had posterior circulation stroke and failed MT. The cohort was divided into two groups: FRRS+ and FRRS- (defined as modified Thrombolysis In Cerebral Infarction (mTICI) score 0-2a). The primary outcome was a shift in the degree of disability as measured by the modified Rankin Scale (mRS) at 90 days. Secondary outcomes included mRS 0-2 and mRS 0-3 at 90 days. Safety measures included rates of symptomatic intracranial hemorrhage (sICH), procedural complications, and 90-day mortality. Sensitivity and subgroup analyses were performed to identify outcomes in a matched cohort and in those with VBO, respectively. RESULTS: A total of 152 failed thrombectomies were included in the analysis. FRRS+ (n=84) was associated with increased likelihood of lower disability (acOR 2.24, 95% CI 1.04 to 4.95, P=0.04), higher rates of mRS 0-2 (26.8% vs 12.5%, aOR 4.43, 95% CI 1.22 to 16.05, P=0.02) and mRS 0-3 (35.4% vs 18.8%, aOR 3.13, 95% CI 1.08 to 9.10, P=0.036), and lower mortality (42.7% vs 59.4%, aOR 0.40, 95% CI 0.17 to 0.97, P=0.04) at 90 days compared with FRRS- (n=68). The rates of sICH and procedural complications were comparable between the groups. Sensitivity and subgroup analyses showed similar results. CONCLUSION: In patients with posterior circulation stroke who had failed MT, RS resulted in better functional outcomes with comparable safety profile to procedure termination.

Clot composition and recanalization outcomes in mechanical thrombectomy.

BACKGROUND: Mechanical thrombectomy (MT) has become standard for large vessel occlusions, but rates of complete recanalization are suboptimal. Previous reports correlated radiographic signs with clot composition and a better response to specific techniques. Therefore, understanding clot composition may allow improved outcomes. METHODS: Clinical, imaging, and clot data from patients enrolled in the STRIP Registry from September 2016 to September 2020 were analyzed. Samples were fixed in 10% phosphate-buffered formalin and stained with hematoxylin-eosin and Martius Scarlett Blue. Percent composition, richness, and gross appearance were evaluated. Outcome measures included the rate of first-pass effect (FPE, modified Thrombolysis in Cerebral Infarction 2c/3) and the number of passes. RESULTS: A total of 1430 patients of mean±SD age 68.4±13.5 years (median (IQR) baseline National Institutes of Health Stroke Scale score 17.2 (10.5-23), IV-tPA use 36%, stent-retrievers (SR) 27%, contact aspiration (CA) 27%, combined SR+CA 43%) were included. The median (IQR) number of passes was 1 (1-2). FPE was achieved in 39.3% of the cases. There was no association between percent histological composition or clot richness and FPE in the overall population. However, the combined technique resulted in lower FPE rates for red blood cell (RBC)-rich (P<0.0001), platelet-rich (P=0.003), and mixed (P<0.0001) clots. Fibrin-rich and platelet-rich clots required a higher number of passes than RBC-rich and mixed clots (median 2 and 1.5 vs 1, respectively; P=0.02). CA showed a trend towards a higher number of passes with fibrin-rich clots (2 vs 1; P=0.12). By gross appearance, mixed/heterogeneous clots had lower FPE rates than red and white clots. CONCLUSIONS: Despite the lack of correlation between clot histology and FPE, our study adds to the growing evidence supporting the notion that clot composition influences recanalization treatment strategy outcomes.

General anesthesia vs procedural sedation for failed NeuroThrombectomy undergoing rescue stenting: intention to treat analysis.

BACKGROUND: There is little data available to guide optimal anesthesia management during rescue intracranial angioplasty and stenting (ICAS) for failed mechanical thrombectomy (MT). We sought to compare the procedural safety and functional outcomes of patients undergoing rescue ICAS for failed MT under general anesthesia (GA) vs non-general anesthesia (non-GA). METHODS: We searched the data from the Stenting and Angioplasty In Neuro Thrombectomy (SAINT) study. In our review we included patients if they had anterior circulation large vessel occlusion strokes due to intracranial internal carotid artery (ICA) or middle cerebral artery (MCA-M1/M2) segments, failed MT, and underwent rescue ICAS. The cohort was divided into two groups: GA and non-GA. We used propensity score matching to balance the two groups. The primary outcome was the shift in the degree of disability as measured by the modified Rankin Scale (mRS) at 90 days. Secondary outcomes included functional independence (90-day mRS0-2) and successful reperfusion defined as mTICI2B-3. Safety measures included symptomatic intracranial hemorrhage (sICH) and 90-day mortality. RESULTS: Among 253 patients who underwent rescue ICAS, 156 qualified for the matching analysis at a 1:1 ratio. Baseline demographic and clinical characteristics were balanced between both groups. Non-GA patients had comparable outcomes to GA patients both in terms of the overall degree of disability (mRS ordinal shift; adjusted common odds ratio 1.29, 95% CI [0.69 to 2.43], P=0.43) and rates of functional independence (33.3% vs 28.6%, adjusted odds ratio 1.32, 95% CI [0.51 to 3.41], P=0.56) at 90 days. Likewise, there were no significant differences in rates of successful reperfusion, sICH, procedural complications or 90-day mortality among both groups. CONCLUSIONS: Non-GA seems to be a safe and effective anesthesia strategy for patients undergoing rescue ICAS after failed MT. Larger prospective studies are warranted for more concrete evidence.

Correlation of von Willebrand factor and platelets with acute ischemic stroke etiology and revascularization outcome: an immunohistochemical study.

BACKGROUND: Platelets and von Willebrand factor (vWF) are key components of acute ischemic stroke (AIS) emboli. We aimed to investigate the CD42b (platelets)/vWF expression, its association with stroke etiology and the impact these components may have on the clinical/procedural parameters. METHODS: CD42b/vWF immunostaining was performed on 288 emboli collected as part of the multicenter STRIP Registry. CD42b/VWF expression and distribution were evaluated. Student's t-test and χ2 test were performed as appropriate. RESULTS: The mean CD42b and VWF content in clots was 44.3% and 21.9%, respectively. There was a positive correlation between platelets and vWF (r=0.64, p<0.001**). We found a significantly higher vWF level in the other determined etiology (p=0.016*) and cryptogenic (p=0.049*) groups compared with cardioembolic etiology. No significant difference in CD42b content was found across the etiology subtypes. CD42b/vWF patterns were significantly associated with stroke etiology (p=0.006*). The peripheral pattern was predominant in atherosclerotic clots (36.4%) while the clustering (patchy) pattern was significantly associated with cardioembolic and cryptogenic origin (66.7% and 49.8%, respectively). The clots corresponding to other determined etiology showed mainly a diffuse pattern (28.1%). Two types of platelets were distinguished within the CD42b-positive clusters in all emboli: vWF-positive platelets were observed at the center, surrounded by vWF-negative platelets. Thrombolysis correlated with a high platelet content (p=0.03*). vWF-poor and peripheral CD42b/vWF pattern correlated with first pass effect (p=0.03* and p=0.04*, respectively). CONCLUSIONS: The vWF level and CD42b/vWF distribution pattern in emboli were correlated with AIS etiology and revascularization outcome. Platelet content was associated with response to thrombolysis.

Superficial Temporal Artery to the Middle Cerebral Artery Anastomotic Aneurysm Treated With an Endovascular Approach: A Case Report.

BACKGROUND AND IMPORTANCE: Anastomotic aneurysms are widely described in the cardiac literature; however, they have been less frequently reported in the neurological field. Historically, neurosurgeons have been treating anastomotic aneurysms arising from the superficial temporal artery to the middle cerebral artery (STA-MCA) bypass with open surgery. We proposed an endovascular treatment for our patient using the stent-assisted coiling technique, achieving good outcomes. CLINICAL PRESENTATION: A man in his late forties with symptomatic chronic carotid occlusion underwent direct STA-MCA bypass surgery. On follow-up images, an incidental anastomotic aneurysm was discovered. The risks and benefits of treatment or watchful waiting were addressed, and an endovascular approach was the chosen treatment technique. Such complication is widely described in the cardiac literature; however, it has scarce reports in the neurological field. Furthermore, stent-assisted coiling was performed achieving complete occlusion of the aneurysm maintaining good patency of the bypass. CONCLUSION: STA-MCA aneurysm at the site of anastomosis is a potential complication after a direct bypass. Traditional management has been reported using open surgery with clipping or wrapping of the aneurysm. However, we propose endovascular surgery as an alternative approach to such complication, achieving good clinical outcomes.

Safety and efficacy of balloon-mounted stent in the treatment of symptomatic intracranial atherosclerotic disease: a multicenter experience.

BACKGROUND: Randomized clinical trials have failed to prove that the safety and efficacy of endovascular treatment for symptomatic intracranial atherosclerotic disease (ICAD) is better than that of medical management. A recent study using a self-expandable stent showed acceptable lower rates of periprocedural complications. OBJECTIVE: To study the safety and efficacy of a balloon-mounted stent (BMS) in the treatment of symptomatic ICAD. METHODS: Prospectively maintained databases from 15 neuroendovascular centers between 2010 and 2020 were reviewed. Patients were included if they had severe symptomatic intracranial stenosis in the target artery, medical management had failed, and they underwent intracranial stenting with BMS after 24 hours of the qualifying event. The primary outcome was the occurrence of stroke and mortality within 72 hours after the procedure. Secondary outcomes were the occurrence of stroke, transient ischemic attacks (TIAs), and mortality on long-term follow-up. RESULTS: A total of 232 patients were eligible for the analysis (mean age 62.8 years, 34.1% female). The intracranial stenotic lesions were located in the anterior circulation in 135 (58.2%) cases. Recurrent stroke was the qualifying event in 165 (71.1%) while recurrent TIA was identified in 67 (28.9%) cases. The median (IQR) time from the qualifying event to stenting was 5 (2-20.75) days. Strokes were reported in 13 (5.6%) patients within 72 hours of the procedure; 9 (3.9%) ischemic and 4 (1.7%) hemorrhagic, and mortality in 2 (0.9%) cases. Among 189 patients with median follow-up time 6 (3-14.5) months, 12 (6.3%) had TIA and 7 (3.7%) had strokes. Three patients (1.6%) died from causes not related to stroke. CONCLUSION: Our study has shown that BMS may be a safe and effective treatment for medically refractory symptomatic ICAD. Additional prospective randomized clinical trials are warranted.

Histological evaluation of acute ischemic stroke thrombi may indicate the occurrence of vessel wall injury during mechanical thrombectomy.

BACKGROUND: Several animal studies have demonstrated that mechanical thrombectomy (MT) for acute ischemic stroke (AIS) may cause vessel wall injury (VWI). However, the histological changes in human cerebral arteries following MT are difficult to determine. OBJECTIVE: To investigate the occurrence of VWI during MT by histological and immunohistochemical evaluation of AIS clots. METHODS: As part of the multicenter STRIP registry, 277 clots from 237 patients were analyzed using Martius Scarlett Blue stain and immunohistochemistry for CD34 (endothelial cells) and smooth muscle actin (smooth muscle cells). RESULTS: MT devices used were aspiration catheters (100 cases), stentriever (101 cases), and both (36 cases). VWI was found in 33/277 clots (12%). There was no significant correlation between VWI and MT device. The degree of damage varied from grade I (mild intimal damage, 24 clots), to grade II (relevant intimal and subintimal damage, 3 clots), and III (severe injury, 6 clots). VWI clots contained significantly more erythrocytes (p=0.006*) and less platelets/other (p=0.005*) than non-VWI clots suggesting soft thrombus material.Thrombolysis correlated with a lower rate of VWI (p=0.04*). VWI cases showed a significantly higher number of passes (2 [1-4] vs 1 [1-3], p=0.028*) and poorer recanalization outcome (p=0.01*) than cases without VWI. CONCLUSIONS: Histological markers of VWI were present in 12% of AIS thrombi, suggesting that VWI might be related to MT. VWI was associated with soft thrombus consistency, higher number of passes and poorer revascularization outcome. There was no significant correlation between VWI and MT device.

Hypoperfusion intensity ratio for refinement of elderly patient selection for endovascular thrombectomy.

BACKGROUND: Patients ≥80-year-old presenting with large-vessel occlusion treated with endovascular thrombectomy (EVT) have worst outcomes than younger individuals. Improved patient selection in this age range is warranted. We investigated the hypoperfusion-intensity-ratio (HIR) and its associations with baseline parameters and clinical outcomes in a cohort ≥80-year-old to assess whether it could an option in improving their selection for EVT. METHODS: We performed retrospective analysis of consecutive patients treated with EVT at our center between 2015 and 2019. Inclusion criteria were age ≥80-year-old, any baseline modified Rankin Scale (mRS), and anterior circulation occlusion. Demographic information, baseline characteristics, clinical data, and radiological imaging parameters were collected. HIR was dichotomized into favorable and unfavorable based on median value of the cohort. Good outcome was defined as mRS ≤2 at 90-days. RESULTS: We included 82 patients. HIR was significantly correlated with baseline ischemic core volume, NIHSS, and time-of-onset to groin puncture. Good outcome was achieved in 18.3% and mortality occurred in 34.1%. In patients with baseline mRS ≤2, the rate of good outcome was significantly higher in favorable vs unfavorable HIR (52.6% vs 20%, P=0.02). In shift-analysis, unfavorable HIR was significantly associated with downshift to mRS ≥3 (P=0.02). Regression analysis found lower baseline mRS (P=0.009), higher ASPECTS (P=0.02), complete recanalization (P=0.04), and lower HIR (P=0.02) to be associated with increased rate of good outcome. Hierarchical regression showed HIR to independently predict good outcome. CONCLUSIONS: In our cohort, HIR was correlated with baseline parameters and predicted clinical outcomes. Future studies should investigate perfusion parameters such as HIR to improve the selection of elderly patients for EVT.

Walrus large bore guide catheter impact on recanalization first pass effect and outcomes: the WICkED study.

BACKGROUND: The use of a balloon-guide catheter (BGC) in acute stroke treatment has been widely adopted after demonstrating optimized procedure metrics and outcomes. Initial technical constraints of previous devices included catheter stiffness and smaller inner diameters. We aim to evaluate the performance and safety of the Walrus BGC, a variable stiffness catheter with a large bore 0.087 inch inner diameter (ID), via the the WICkED study (Walrus Large Bore guide Catheter Impact on reCanalization first pass Effect anD outcomes). METHODS: This is a retrospective, site adjudicated, multicenter study on consecutive patients with large vessel occlusion treated with the Walrus BGC. Baseline characteristics, procedural outcomes and functional outcomes were analyzed. RESULTS: A total of 338 patients met the inclusion criteria. The Walrus was successfully tracked into distal vasculature and allowed therapeutic device delivery in all but 3 cases (0.9%). Large aspiration catheters ≥0.070 inch ID were used in 71.9% of cases. Stent retriever thrombectomy was used as the first-line modality in 59.2% and thromboaspiration in 40.8% of cases. The successful recanalization rate (modified treatment in cerebral ischemia (mTICI) 2b/3) was 94.4%, with 64.8% of the patients achieving mTICI 2b/3 after the first pass. The Walrus-related adverse event rate was 0.6%, corresponding to two vessel dissections. Functional independence was 50% (126/252) and mortality 25% (63/252). Unfavorable outcomes were more likely in older patients, who had unsuccessful reperfusion, longer procedure times, and a higher mean number of passes. CONCLUSION: In acute ischemic stroke patients presenting with large vessel occlusion, the Walrus BGC demonstrated excellent navigability and safety profile, allowed the accommodation of leading large bore aspiration catheters, and demonstrated high vessel recanalization rates.

Pivotal trial of the Neuroform Atlas stent for treatment of posterior circulation aneurysms: one-year outcomes.

BACKGROUND: Stent-assisted coiling of wide-necked intracranial aneurysms (IAs) using the Neuroform Atlas Stent System (Atlas) has shown promising results. OBJECTIVE: To present the primary efficacy and safety results of the ATLAS Investigational Device Exemption (IDE) trial in a cohort of patients with posterior circulation IAs. METHODS: The ATLAS trial is a prospective, multicenter, single-arm, open-label study of unruptured, wide-necked, IAs treated with the Atlas stent and adjunctive coiling. This study reports the results of patients with posterior circulation IAs. The primary efficacy endpoint was complete aneurysm occlusion (Raymond-Roy (RR) class I) on 12-month angiography, in the absence of re-treatment or parent artery stenosis >50%. The primary safety endpoint was any major ipsilateral stroke or neurological death within 12 months. Adjudication of the primary endpoints was performed by an imaging core laboratory and a Clinical Events Committee. RESULTS: The ATLAS trial enrolled and treated 116 patients at 25 medical centers with unruptured, wide-necked, posterior circulation IAs (mean age 60.2±10.5 years, 81.0% (94/116) female). Stents were placed in all patients with 100% technical success rate. A total of 95/116 (81.9%) patients had complete angiographic follow-up at 12 months, of whom 81 (85.3%) had complete aneurysm occlusion (RR class I). The primary effectiveness outcome was achieved in 76.7% (95% CI 67.0% to 86.5%) of patients. Overall, major ipsilateral stroke and secondary persistent neurological deficit occurred in 4.3% (5/116) and 1.7% (2/116) of patients, respectively. CONCLUSIONS: In the ATLAS IDE posterior circulation cohort, the Neuroform Atlas Stent System with adjunctive coiling demonstrated high rates of technical and safety performance. Trial registration number https://clinicaltrials.gov/ct2/show/NCT02340585.

Quantification of clot spatial heterogeneity and its impact on thrombectomy.

BACKGROUND: Compositional and structural features of retrieved clots by thrombectomy can provide insight into improving the endovascular treatment of ischemic stroke. Currently, histological analysis is limited to quantification of compositions and qualitative description of the clot structure. We hypothesized that heterogeneous clots would be prone to poorer recanalization rates and performed a quantitative analysis to test this hypothesis. METHODS: We collected and did histology on clots retrieved by mechanical thrombectomy from 157 stroke cases (107 achieved first-pass effect (FPE) and 50 did not). Using an in-house algorithm, the scanned images were divided into grids (with sizes of 0.2, 0.3, 0.4, 0.5, and 0.6 mm) and the extent of non-uniformity of RBC distribution was computed using the proposed spatial heterogeneity index (SHI). Finally, we validated the clinical significance of clot heterogeneity using the Mann-Whitney test and an artificial neural network (ANN) model. RESULTS: For cases with FPE, SHI values were smaller (0.033 vs 0.039 for grid size of 0.4 mm, P=0.028) compared with those without. In comparison, the clot composition was not statistically different between those two groups. From the ANN model, clot heterogeneity was the most important factor, followed by fibrin content, thrombectomy techniques, red blood cell content, clot area, platelet content, etiology, and admission of intravenous tissue plasminogen activator (IV-tPA). No statistical difference of clot heterogeneity was found for different etiologies, thrombectomy techniques, and IV-tPA administration. CONCLUSIONS: Clot heterogeneity can affect the clot response to thrombectomy devices and is associated with lower FPE. SHI can be a useful metric to quantify clot heterogeneity.

Neuroform Atlas Stent for Treatment of Middle Cerebral Artery Aneurysms: 1-Year Outcomes From Neuroform Atlas Stent Pivotal Trial.

BACKGROUND: Heterogeneous effect of endovascular aneurysm therapy has been observed across different anatomic locations. There is a paucity of data for stent-assisted coiling of middle cerebral artery (MCA) aneurysms. OBJECTIVE: To present the results of the MCA aneurysm group from the Neuroform Atlas (Stryker Neurovascular) investigational device exemption (IDE) trial. METHODS: The Atlas IDE trial is a prospective, multicenter, single-arm, open-label study of wide-neck aneurysms (neck ≥ 4 mm or dome-to-neck ratio < 2) in the anterior circulation treated with the Neuroform Atlas Stent and approved coils. Follow-up was obtained immediately postprocedure and 2, 6, and 12 mo postoperatively. We herein describe safety and efficacy outcomes, and functional independence of the subjects with aneurysms from all segments of MCA. RESULTS: A total of 35 patients were included (27 MCA bifurcation, 5 M1, 3 M2). The mean aneurysm size was 6.0 ± 1.8 mm, and the mean neck was 4.4 ± 1.2 mm. Technical procedural success was achieved in all patients. A total of 26 patients had follow-up digital subtraction angiography available at 12 mo, with 80.8% (21/26) having complete aneurysm occlusion. Twelve-month safety data were collected for 91.4% (32/35), 8.5% (3/35) had primary safety endpoint, all 3 major ischemic strokes. Mortality occurred in 2 patients beyond 30 d unrelated to procedure (1 gallbladder cancer and 1 fentanyl intoxication). At 1 yr, modified Rankin Score was 0 to 2 in 84.4% (27/32), 3 in 9.4%, and 3 patients were missing. Approximately 5.7% (2/35) of patients were retreated at 12 mo. CONCLUSION: Stent-assisted coiling with the Neuroform Atlas Stent is a viable alternative to clipping for selected MCA aneurysms. Complete aneurysm occlusion rates have improved compared to historical data. Proper case selection can lead to acceptable endovascular results.

Association between clot composition and stroke origin in mechanical thrombectomy patients: analysis of the Stroke Thromboembolism Registry of Imaging and Pathology.

BACKGROUND: We retrospectively evaluated the composition of retrieved clots from ischemic stroke patients to study the association between histological composition and stroke etiology METHODS: Consecutive patients enrolled in the Stroke Thromboembolism Registry of Imaging and Pathology (STRIP) were included in this study. All patients underwent mechanical thrombectomy and retrieved clots were sent to a central core lab for processing. Histological analysis was performed using martius scarlet blue (MSB) staining, and quantification for red blood cells (RBCs), white blood cells (WBCs), fibrin and platelets was performed using Orbit Image Software. A Wilcoxon test was used for continuous variables and χ2 test for categorical variables. RESULTS: 1350 patients were included in this study. The overall rate of Thrombolysis In Cerebral Infarction (TICI) 2c/3 was 68%. 501 patients received tissue plasminogen activator (tPA) (37%). 267 patients (20%) had a large artery atherosclerosis (LAA) source, 662 (49%) a cardioembolic (CE) source, 301 (22%) were cryptogenic, and the remainder had other identifiable sources including hypercoagulable state or dissection. LAA thrombi had a higher mean RBC density (46±23% vs 42±22%, p=0.01) and a lower platelet density (24±18% vs 27±18%, p=0.03) than CE thrombi. Clots from dissection patients had the highest mean RBC density (50±24%) while clots from patients with a hypercoagulable state had the lowest mean RBC density (26±21%). CONCLUSIONS: Our study found statistically significant but clinically insignificant differences between clots of CE and LAA etiologies. Future studies should emphasize molecular, proteomic and immunohistochemical characteristics to determine links between clot composition and etiology.

Woven EndoBridge device for ruptured aneurysms: perioperative results of a US multicenter experience.

BACKGROUND: The Woven EndoBridge (WEB) device is approved in the USA for treatment of unruptured wide-neck bifurcation aneurysms. However, the safety and effectiveness of the WEB device in the treatment of ruptured intracranial aneurysms is not clear. We aim to evaluate the perioperative safety and effectiveness of the WEB device in patients with ruptured intracranial aneurysms. METHODS: This retrospective study, conducted at eight centers in the USA, included patients with ruptured intracranial aneurysms treated with the WEB device in the setting of subarachnoid hemorrhage (SAH). Safety outcomes included intraoperative complications such as vessel perforation, thromboembolic events, and postoperative hemorrhagic or thromboembolic complications based on radiologic imaging. The primary effectiveness outcome was adequate (complete and neck remnant) aneurysm occlusion, according to the Raymond-Roy classification. RESULTS: A total of 91 patients with 94 ruptured intracranial aneurysms were included (mean age 57.7±15.2 years; 68.1% women; 82.9% wide-necked). Aneurysms were located in the anterior communicating artery (42/94, 44.6%), middle cerebral artery (16/94, 17%), and basilar artery (15/94, 16%). Adequate occlusion was achieved in 48.8% (41/84) and 80.0% (40/50) at discharge and last follow-up (mean of 3.4 months), respectively. At discharge, procedural-related morbidity was 3.3% (3/91) and there was no procedure-related mortality. No re-rupture or delayed aneurysm rupture was observed. CONCLUSIONS: This study demonstrates the perioperative safety and effectiveness of the WEB device for the treatment of patients with ruptured intracranial aneurysms in the setting of SAH, with low periprocedural morbidity and mortality. Long-term follow-up is warranted.

The use of cangrelor in neurovascular interventions: a multicenter experience.

PURPOSE: Thromboembolic events represent the most common procedure-related complication associated with neurointerventions. Cangrelor is a potent, intravenous (IV), P2Y12-receptor antagonist with a rapid onset and offset presented as an alternative antiplatelet agent. We aim to evaluate the safety and effectiveness of IV cangrelor in neurovascular intervention. METHODS: This is a retrospective analysis of data from four cerebrovascular interventional centers. We identified patients who underwent acute neurovascular intervention and received cangrelor as part of their optimum care. Patients were divided into 2 groups: ischemic and aneurysm. Periprocedural thromboembolic events, hemorrhagic complications, and outcomes were analyzed. RESULTS: Sixty-six patients were included, 42 allocated into the ischemic group (IG), and 24 into aneurysm group (AG). The IG periprocedural symptomatic complication rate was 9.5%, represented by 3 postoperative intracranial hemorrhages and 1 retroperitoneal hematoma. At discharge, 47.6% had a favorable outcome and the mortality rate was 2.4%, related to clinical deterioration of a large infarct. In the AG, 4.2% had a periprocedural complication during or after cangrelor infusion, represented by an intracranial hemorrhage in an initially ruptured aneurysm. Favorable clinical outcome was seen in 56.2% and 87.7% of ruptured and unruptured aneurysms, respectively, upon discharge. CONCLUSIONS: Cangrelor may be a feasible alternative for patients requiring immediate intervention with the use of endoluminal devices. It allows the possibility for a secure transition to long-term ticagrelor and progression to surgery in the setting of unexpected complications.

A systematic review of non-trunk basilar perforator aneurysms: is it worth chasing the small fish?

BACKGROUND AND PURPOSE: Non-trunk basilar artery perforator aneurysms (BAPAs) are rare intracranial vascular pathologies that have long been underdiagnosed, under-reported, and under-analyzed. We performed a systematic review of the efficacy and safety endpoints between conservative and active treatment approaches for non-trunk BAPAs. METHODS: Major databases were analyzed for relevant publications between 1995 and 2019. Studies comparing the outcomes between conservative and active treatment approaches such as coiling, stenting, clipping, liquid embolization, and flow diversion were included. Mortality rate, rate of permanent neurological deficit as determined by the modified Rankin Score (mRS), rate of second treatment occurrence, and perioperative complication rate were also assessed. RESULTS: A total of 24 studies, including 54 patients with 56 non-trunk BAPAs, were included. The mean maximum aneurysm diameter was 2.70 mm (range 1-10). A diagnosis was achieved with the initial DSA in 50.0% (27/54) of the patients. A conservative approach was used in 16 patients while active treatment was used in the other 38. Thirteen of 15 (86.7%) patients in the conservative group and 27/34 (79.4%) in the active treatment group had an mRS score 0-2. A non-significant higher odds of a positive outcome was observed in the conservative group (OR 1.51, 95% CI 0.50 to 4.54). The event-related mortality rate was 3.55% (3/54) with one procedure-related death in the active treatment group. CONCLUSIONS: In patients with non-trunk BAPAs unamenable to active treatment, conservative approaches may result in acceptable functional outcomes and low morbidity. Small sample sizes and under-reporting of outcomes warrant further study.