FLAIR Vascular Hyperintensities as a Surrogate of Collaterals in Acute Stroke: DWI Matters.

BACKGROUND AND PURPOSE: FLAIR vascular hyperintensities are thought to represent leptomeningeal collaterals in acute ischemic stroke. However, whether all-FLAIR vascular hyperintensities or FLAIR vascular hyperintensities-DWI mismatch, ie, FLAIR vascular hyperintensities beyond the DWI lesion, best reflects collaterals remains debated. We aimed to compare the value of FLAIR vascular hyperintensities-DWI mismatch versus all-FLAIR vascular hyperintensities for collateral assessment using PWI-derived collateral flow maps as a reference. MATERIALS AND METHODS: We retrospectively reviewed the registries of 6 large stroke centers and included all patients with acute stroke with anterior circulation large-vessel occlusion who underwent MR imaging with PWI before thrombectomy. Collateral status was graded from 1 to 4 on PWI-derived collateral flow maps and dichotomized into good (grades 3-4) and poor (grades 1-2). The extent of all-FLAIR vascular hyperintensities and FLAIR vascular hyperintensities-DWI mismatch was assessed on the 7 cortical ASPECTS regions, ranging from 0 (absence) to 7 (extensive), and associations with good collaterals were compared using receiver operating characteristic curves. RESULTS: Of the 209 included patients, 133 (64%) and 76 (36%) had good and poor collaterals, respectively. All-FLAIR vascular hyperintensity extent was similar between collateral groups (P = .76). Conversely, FLAIR vascular hyperintensities-DWI mismatch extent was significantly higher in patients with good compared with poor collaterals (P < .001). The area under the curve was 0.80 (95% CI, 0.74-0.87) for FLAIR vascular hyperintensities-DWI mismatch and 0.52 (95% CI, 0.44-0.60) for all-FLAIR vascular hyperintensities (P < .001 for the comparison), to predict good collaterals. Variables independently associated with good collaterals were smaller DWI lesion volume (P < .001) and larger FLAIR vascular hyperintensities-DWI mismatch (P = .02). CONCLUSIONS: In acute ischemic stroke with large-vessel occlusion, the extent of FLAIR vascular hyperintensities does not reliably reflect collateral status unless one accounts for DWI.

Endovascular treatment for acute ischemic stroke at a primary stroke center: First results of the Perpignan center.

INTRODUCTION: Converting a high-volume primary stroke center (PSC) into a stroke center that can perform emergency endovascular treatment (EVT) could reduce the time to thrombectomy. We report the first results of a newly established EVT facility at the Perpignan PSC and their comparison with the targets defined by the established guidelines. PATIENTS AND METHOD: For this comprehensive observational study, data of patients with acute ischemic stroke (AIS) due to proximal large vessel occlusion (LVO) and treated by EVT at the Perpignan PSC from December 5, 2019 to September 15, 2020 were extracted from an ongoing prospective database. RESULTS: During the study period, 37 patients underwent EVT at the Perpignan PSC. The median (range) symptom-onset to recanalization time was 262min (100-485min). The median (range) intra-hospital times were: 20min (2-58min) for door-to-imaging, 57min (30-155min) for imaging-to-puncture, 55min (15-180min) for puncture-to-recanalization, and 137min (59-319min) for door-to-recanalization. At 3 months post-AIS, the favorable outcome (modified Ranking Score: 0-2) rate was 50% and the mortality rate was 19.4%. These results are comparable to those of previous clinical trials, and meet the targets defined by the current consensus statements for EVT. DISCUSSION AND CONCLUSION: Our results show the feasibility and safety of EVT in a PSC for patients with AIS due to LVO. The implementation of this strategy may be important for shortening the time to thrombectomy.

A regional strategy to decrease the time to thrombectomy in patients with low probability of treatment by thrombolysis.

BACKGROUND AND PURPOSE: The best transportation strategy for patients with suspected large vessel occlusion (LVO) is unknown. Here, we evaluated a new regional strategy of direct transportation to a Comprehensive Stroke Center (CSC) for patients with suspected LVO and low probability of receiving intravenous thrombolysis (IVT) at the nearest Primary Stroke Center (PSC). METHODS: Patients could be directly transported to the CSC (bypass group) if they met our pre-hospital bypass criteria: high LVO probability (i.e., severe hemiplegia) with low IVT probability (contraindications) and/or travel time difference between CSC and PSC<15 minutes. The other patients were transported to the PSC according to a "drip-and-ship" strategy. Treatment time metrics were compared in patients with pre-hospital bypass criteria and confirmed LVO in the bypass and drip-and-ship groups. RESULTS: In the bypass group (n=79), 54/79 (68.3%) patients met the bypass criteria and 29 (36.7%) had confirmed LVO. The positive predictive value of the hemiplegia criterion for LVO detection was 0.49. In the drip-and-ship group (n=457), 92/457 (20.1%) patients with confirmed LVO met our bypass criteria. Among the 121 patients with bypass criteria and confirmed LVO, direct routing decreased the time between symptom discovery and groin puncture by 55 minutes compared with the drip-and-ship strategy (325 vs. 229 minutes, P<0.001), without significantly increasing the time to IVT (P=0.19). CONCLUSIONS: Our regional strategy led to the correct identification of LVO and a significant decrease of the time to mechanical thrombectomy, without increasing the time to IVT, and could be easily implemented in other territories.

Influence of operator experience on the technical and clinical results of Woven EndoBridge endovascular treatment for intracranial aneurysms.

BACKGROUND & PURPOSE: The safety and efficacy of the Woven EndoBridge (WEB) device has been proven in recent multicenter trials. This study investigated whether operator experience influences WEB treatment-related outcomes. MATERIAL AND METHODS: This was a retrospective analysis of a prospectively collected multicenter database. The data of all patients who underwent WEB treatment for an intracranial aneurysm from March 2014 to June 2020 in two high-volume centers were pooled. Operator experience was indexed by the number of WEB treatments performed previously. The primary endpoint was the overall complication rate. Secondary endpoints were long-term adequate (Raymond-Roy classification of 1-2.) angiographic occlusion, WEB-related complications, number of WEB not deployed, procedure duration, and radiation exposure (air kerma). RESULTS: Among 237 patients (mean age 59.4 +/- 11.5 years) treated with WEB (median aneurysm diameter, 5.8 mm; interquartile range 4.5-7 mm), WEB-related complications occurred in 28 patients (11.8%) and adequate long-term occlusion was achieved for 154 aneurysms (86%). The median number of WEB treatment performed previously per operator was 20 (IQR, 9-41). The overall complication rate, WEB-related complication rate and aneurysm occlusion rate were not significantly correlated with WEB operator experience. There were also no significant correlations between the WEB operator experience and the number of WEB not deployed, procedure duration or radiation exposure. CONCLUSION: There was no significant association between the number of WEB treatments previously performed per operator and any technical or clinical results after intracranial aneurysm treatment with WEB. These results imply a relatively short learning curve for this device in high-volume neurovascular centers.

Prevalence of carotid web in a French cohort of cryptogenic stroke.

BACKGROUND AND PURPOSE: Carotid webs (CaW) may be an under-recognized cause of anterior circulation cryptogenic ischemic stroke (ACIS). Prevalence is still unknown in European patients with ACIS. OBJECTIVE: To evaluate the prevalence of CaW in ACIS and describe patients with CaW phenotype in a cohort of patients from a French stroke center. METHODS: We conducted a retrospective monocentric cohort study from 01/01/2015 to 31/12/2019 (Montpellier University Hospital, France), in consecutive anterior ischemic stroke (AIS) patients ≤65 years old from a prospective stroke database. Using ASCOD phenotyping, ACIS patients were selected and cervical CTA were reviewed to find CaW. RESULTS: Among 1053 consecutive AIS patients, 266 ACIS patients with CTA were included. Among patients included (mean age 50, women 58%), CaW was in the ipsilateral carotid (iCaW) in 21 patients: 7.9% (95%CI [4.6-11.1]), (mean age 51, 11 women, 16 Caucasian). iCaW were uncovered during study review of CTA in 6/21 (29%) patients. Comparison between patients with iCaW and those without iCaW showed no differences except that of a higher rate of intracranial large vessel occlusion (LVO) (62.4 vs 37.6%; p = 0.03). Patients with iCaW under conservative medical therapy had an annualized stroke recurrence rate (SRR) of 11.4% (95%CI [8.4-15.1]. CONCLUSIONS: iCaW was identified as a source of stroke in about 8% of a French population ≤65 years with ACIS. iCaW was associated with a higher rate of LVO and a high SRR under conservative medical therapy.

Flow-Diversion Treatment for Unruptured ICA Bifurcation Aneurysms with Unfavorable Morphology for Coiling.

BACKGROUND AND PURPOSE: Few reports described flow diversion for ICA bifurcation aneurysms. Our aim was to provide further insight into flow diversion for ICA bifurcation aneurysms difficult to treat with other strategies. MATERIALS AND METHODS: Consecutive patients receiving flow diverters for unruptured ICA bifurcation aneurysms were collected. Aneurysm occlusion (O'Kelly-Marotta grading scale) and clinical outcomes were evaluated. RESULTS: Twenty saccular ICA bifurcation aneurysms were treated with the Pipeline Embolization Device deployed from the M1 to the ICA, covering the aneurysm and the A1 segment. All patients presented with an angiographic visualized contralateral flow from the anterior communicating artery. Mean aneurysm size was 6.5 (SD, 3.2) mm (range, 4.5-20 mm). All lesions had an unfavorable dome-to-neck ratio (mean/median, 1.6/1.6; range, 0.8-2.8; interquartile range = 0.5) or aspect ratio for coiling (mean/median = 1.5/1.55; range, 0.8-2.5; interquartile range = 0.6). One was a very large aneurysm (20 mm). Nineteen medium-sized lesions were completely occluded during the angiographic follow-up (13 months). No cases of aneurysm rupture or retreatment were reported. No adverse events were described. Aneurysm occlusion was associated with the asymptomatic flow modification of the covered A1 that was occluded and contralaterally filled among 10 patients (50%), narrowed among 9 patients (45%), and unchanged in 1 subject (5%). There was no difference in the mean initial diameter of the occluded (2.1 [SD 0.4] mm; range, 1.6-3 mm) and narrowed (2 [SD, 0.2] mm; range, 1.7-2.6 mm) A1 segments. CONCLUSIONS: Medium-sized unruptured ICA bifurcation aneurysms with unfavorable morphology for coiling can be treated with M1 ICA flow diversion. Aneurysm occlusion is associated with flow modifications of the covered A1 that seems safe in the presence of a favorable collateral anatomy through the anterior communicating artery complex.

Mechanical Thrombectomy in Nighttime Hours: Is There a Difference in 90-Day Clinical Outcome for Patients with Ischemic Stroke?

BACKGROUND AND PURPOSE: Few data are available regarding the influence of the timing of ischemic stroke management, such as daytime and nighttime hours, on the delay of mechanical thrombectomy, the effectiveness of revascularization, and clinical outcomes. We aimed to investigate whether admission during nighttime hours could impact the clinical outcome (mRS at 90 days) of patients with acute ischemic stroke treated by mechanical thrombectomy. MATERIALS AND METHODS: We retrospectively analyzed 169 patients (112 treated during daytime hours and 57 treated during nighttime hours) with acute ischemic stroke in the anterior cerebral circulation. The main outcome was the rate of patients achieving functional independence at 90 days (mRS ≤2), depending on admission time. RESULTS: In patients admitted during nighttime hours, the rate of mRS ≤ 2 at 90 days was significantly higher (51% versus 35%, P = .05) compared with those admitted in daytime hours. Patients in daytime and nighttime hours were comparable regarding admission and treatment characteristics. However, patients in nighttime hours tended to have a higher median NIHSS score at admission (P = .08) and to be younger (P = .08), especially among the mothership group (P = .09). The multivariate logistic regression analysis confirmed that patients in nighttime hours had better functional outcomes at 90 days than those in daytime hours (P = .018; 95% CI, 0.064-0.770; OR = 0.221). CONCLUSIONS: In a highly organized stroke care network, mechanical thrombectomy is quite effective in the nighttime hours among acute ischemic stroke presentations. Unexpectedly, we found that those patients achieved favorable clinical outcomes more frequently than those treated during daytime hours. Larger series are needed to confirm these results.

Predictors of Favorable Outcome after Endovascular Thrombectomy in MRI: Selected Patients with Acute Basilar Artery Occlusion.

BACKGROUND AND PURPOSE: Clinical outcomes after endovascular treatment for acute basilar artery occlusions need further investigation. Our aim was to analyze predictors of a 90-day good functional outcome defined as mRS 0-2 after endovascular treatment in MR imaging-selected patients with acute basilar artery occlusions. MATERIALS AND METHODS: We analyzed consecutive MR imaging-selected patients with acute basilar artery occlusions endovascularly treated within the first 24 hours after symptom onset. Successful and complete reperfusion was defined as modified TICI scores 2b-3 and 3, respectively. Outcome at 90 days was analyzed in univariate and multivariate analysis regarding baseline patient treatment characteristics and periprocedural outcomes. RESULTS: One hundred ten patients were included. In 10 patients, endovascular treatment was aborted for failed proximal/distal access. Overall, successful reperfusion was achieved in 81.8% of cases (n = 90; 95% CI, 73.3%-88.6%). At 90 days, favorable outcome was 31.8%, with a mortality rate of 40.9%; the prevalence of symptomatic intracranial hemorrhage within 24 hours was 2.7%. The median time from symptom onset to groin puncture was 410 minutes (interquartile range, 280-540 minutes). In multivariable analysis, complete reperfusion (OR = 6.59; 95% CI, 2.17-20.03), lower pretreatment NIHSS (OR = 0.77; 95% CI, 0.64-0.94), the presence of posterior communicating artery collateral flow (OR = 2.87; 95% CI, 1.05-7.84), the absence of atrial fibrillation (OR = 0.18; 95% CI, 0.03-0.99), and intravenous thrombolysis administration (OR = 2.75; 95% CI, 1.04-7.04) were associated with 90-day favorable outcome. CONCLUSIONS: In our series of MR imaging-selected patients with acute basilar artery occlusions, complete reperfusion was the strongest predictor of a good outcome. Lower pretreatment NIHSS, the presence of posterior communicating artery collateral flow, the absence of atrial fibrillation, and intravenous thrombolysis administration were associated with favorable outcome.

Flow-Diversion Treatment for Unruptured Nonsaccular Intracranial Aneurysms of the Posterior and Distal Anterior Circulation: A Meta-Analysis.

BACKGROUND: Treatment management and outcomes of unruptured nonsaccular aneurysms are different compared with their saccular counterparts. PURPOSE: Our aim was to analyze the outcomes after flow diversion among nonsaccular unruptured lesions. DATA SOURCES: A systematic search of 3 data bases (2005-2019) was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. STUDY SELECTION: We included studies reporting flow diversion for nonsaccular unruptured aneurysms of the posterior and distal anterior circulations. Anterior circulation lesions were included if located distal to the petrocavernous and supraclinoid ICA (MCA, A1, anterior communicating artery, A2). Giant dolichoectatic holobasilar lesions were excluded because of their poor treatment outcomes. DATA ANALYSIS: Aneurysm occlusion and complication rates were calculated (random effects meta-analysis). DATA SYNTHESIS: We included 15 studies (213 aneurysms). The long-term adequate occlusion rate was 85.3% (137/168; 95% CI, 78.2%-92.4%; I2 = 42.3%). Treatment-related complications were 17.4% (41/213; 95% CI, 12.45%-22.4%; I2 = 0%). Overall, 15% (37/213; 95% CI, 10%-20%; I2 = 0%) were ischemic events. Procedure-related morbidity was 8% (20/213; 95% CI, 5%-12%; I2 = 0%). Fusiform or dissecting types had comparable adequate occlusion (116/146 = 83%; 95% CI, 74%-92%; I2 = 48% versus 33/36 = 89%; 95% CI, 80%-98%; I2 = 0%; P = .31) and complication rates (35/162 = 17%; 95% CI, 10%-25%; I2 = 24% versus 11/51 = 19%; 95% CI, 10%-31%; I2 = 0%; P = .72). Aneurysm size (>10 versus ≤10 mm) was independently associated with a higher rate of complications (OR = 6.6; 95% CI, 1.3-15; P = .02). The rate of ischemic events after discontinuation of the antiplatelet therapy was 5% (5/93; 95% CI, 2%-9%; I2 = 0%). LIMITATIONS: Small and retrospective studies were available for this meta-analysis. CONCLUSIONS: Unruptured nonsaccular aneurysms located in the posterior and distal anterior circulations can be effectively treated with flow diversion. Nevertheless, treatment-related complications are not negligible, with about 15% ischemic events and 8% morbidity. Larger size (>10 mm) significantly increases the risk of procedure-related adverse events.

Effect of the phenotype of the M1-middle cerebral artery occlusion on the recanalization rates in the ASTER trial.

INTRODUCTION: An adequate recanalization grade is an independent predictor of a good clinical outcome in patients with acute ischemic stroke. It can be obtained with stent retrievers (SR) and contact aspiration (CA). The aim of this ancillary study of the ASTER trial was to investigate the effect of the regular and irregular phenotype of the M1-middle cerebral artery (M1-MCA) segment occlusion on the procedural and clinical outcomes in the ASTER trial population. METHODS: The predetermined occlusion phenotype assessment was performed by the core laboratory of the ASTER trial and patients with M1-MCA occlusion were included in this study. Clinical and procedural outcomes were analyzed according to the technique used and to the occlusion phenotype. RESULTS: 188 patients were included in the analysis (95 received SR, 93 CA as first-line treatment). The occlusion phenotypes were graded as irregular in 52.7% of cases (n=99, 95% CI 45.5% to 59.8%). In patients with an irregular occlusion phenotype, complete or adequate recanalization at the end of the first-line strategy was more often achieved with SR than CA (TICI 3: SR 44.1% vs CA 22.5%, OR 0.35, 95% CI 0.14 to 0.89, p=0.027), with a shorter procedure time, a lower number of passes (>2 passes: SR 32.2% vs CA 57.5%, OR 3.31, 95% CI 1.36 to 8.03, p=0.009), and higher rates of favorable clinical outcome (SR 55.2% vs CA 31.6%, OR 0.40, 95% CI 0.16 to 0.97, p=0.042). CONCLUSION: Irregular M1-MCA occlusion phenotypes treated with SR as first-line approach were associated with better procedural and clinical outcomes in the ASTER trial population.

Predicting Factors of Angiographic Aneurysm Occlusion after Treatment with the Woven EndoBridge Device: A Single-Center Experience with Midterm Follow-Up.

BACKGROUND AND PURPOSE: Flow disruption with the Woven EndoBridge is increasingly used for the treatment of intracranial aneurysms. We examined factors leading to aneurysm occlusion and Woven EndoBridge shape change during a midterm follow-up. MATERIALS AND METHODS: Patients with a minimum 12-month angiographic follow-up were included. Through a univariate and multivariate analysis, independent predictors of adequate occlusion (Raymond-Roy 1/Raymond-Roy 2) and Woven EndoBridge shape change (decrease of the height of the device) were assessed. RESULTS: Eighty-six patients/aneurysms were included. The aneurysm mean size was 5.5 mm (range, 3-11.5 mm). The most common locations were the MCA (43/86 = 50%), basilar tip (13/86 = 15.1%), and anterior communicating artery (12/86 = 14%). Twenty-one patients (21/86 = 24%) had acute SAH. Immediate and long-term Raymond-Roy 1/Raymond-Roy 2 occlusion rates were 49% (42/86) and 80% (68/86), respectively. Woven EndoBridge shape change was detected among 22% (19/86) of cases. At binary logistic regression, wide ostium (≥4 mm) (OR = 0.2; 95% CI, 0.01-1; P = .04) and regular aneurysm morphology (OR = 5.9; 95% CI, 1.4-24; P = .01) were independent factors of incomplete and adequate aneurysm occlusion, respectively. In addition, irregular morphology (OR = 5.4; 95%CI, 1.4-19; P = .01) and a wide ostium (OR = 9.8; 95% CI, 1.6-60; P = .03) significantly increased the probability of the Woven EndoBridge shape change. Decrease of the Woven EndoBridge height was more common among incompletely occluded aneurysms (6/12 = 50% versus 13/74 = 17.5%), but it was not an independent prognosticator of occlusion at the multivariate model. CONCLUSIONS: The likelihood of good occlusion was 5 times lower in the presence of a wide ostium, whereas aneurysms with regular morphology were 6 times more likely to be occluded. Woven EndoBridge shape modification was strongly influenced by the aneurysm shape and ostium size, and it was not independently associated with the angiographic occlusion.

Antiplatelet Therapy in Patients with Aneurysmal SAH: Impact on Delayed Cerebral Ischemia and Clinical Outcome. A Meta-Analysis.

BACKGROUND AND PURPOSE: Delayed cerebral ischemia strongly impacts clinical outcome after aneurysmal SAH. The effect of antiplatelet therapy on delayed cerebral ischemia has been described with heterogeneous results. Our aim was to analyze the efficacy of antiplatelet therapy on delayed cerebral ischemia and clinical outcome in patients with SAH. DATA SOURCES: A systematic search of 3 databases was performed for studies published from 1990 to 2019. STUDY SELECTION: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included studies comparing the rates of delayed cerebral ischemia and clinical outcomes among patients with SAH with and without antiplatelet therapy. DATA ANALYSIS: Random-effects meta-analysis was used to pool the following: delayed cerebral ischemia, mortality, and good outcome rates. DATA SYNTHESIS: Including 7 studies, 1060 and 1762 patients with SAH were endovascularly or surgically treated with (cases) and without (controls) antiplatelet therapy, respectively. Overall, antiplatelet therapy did not significantly decrease delayed cerebral ischemia rates compared with the control group (219/1060 versus 485/1762, OR = 0.781; 95% CI, 0.46-1.31; P = .33). Among patients treated endovascularly, there was a trend toward lower delayed cerebral ischemia rates after antiplatelet therapy (157/778 versus 413/1410, OR = 0.552; 95% CI, 0.273-1.115; P = .06). Long-term (>2 weeks) antiplatelet therapy tended to be associated with a lower incidence of delayed cerebral ischemia (63/438 versus 96/353, OR = 0.379; 95% CI, 0.12-1.2; P = .06). The good-outcome rate was significantly higher (803/1144 versus 1175/1775, OR = 1.368; 95% CI, 1.117-1.676; P = .002) and the mortality rate was significantly lower (79/672 versus 97/571, OR = 0.656; 95% CI, 0.47-0.91; P = .01) among the antiplatelet therapy group. LIMITATIONS: Heterogeneity was high for most outcomes. CONCLUSIONS: Overall, the incidence of delayed cerebral ischemia seems not to be significantly reduced among the antiplatelet therapy group. However, delayed cerebral ischemia tended to be lower among subjects with both long-term antiplatelet therapy and endovascular treatment and antiplatelet administration. Poor outcome and mortality rates were significantly reduced among the antiplatelet therapy group.

Treatment of Wide-Neck Intracranial Aneurysms with the Woven EndoBridge Device Associated with Stenting: A Single-Center Experience.

BACKGROUND AND PURPOSE: The intrasaccular flow disruptor, the Woven EndoBridge device, is increasingly used for the treatment of wide-neck intracranial aneurysms. Due to unfavorable anatomy, additional stent placement is sometimes required to avoid Woven EndoBridge protrusion into bifurcation branches. We report our experience with the Woven EndoBridge associated with stent placement for the treatment of complex intracranial aneurysms. MATERIALS AND METHODS: Patients with aneurysms treated with the Woven EndoBridge Single-Layer plus stent placement were evaluated retrospectively with prospectively maintained data. The technical feasibility, procedural complications, aneurysm occlusion, and clinical outcome were studied. RESULTS: Seventeen patients and aneurysms treated with the Woven EndoBridge plus stent placement were included. The mean aneurysm size was 7 ± 3.1 mm. Aneurysm locations were the following: MCA (10 patients), anterior communicating artery (3 patients), basilar tip (3 patients), and posterior communicating artery (1 patient). Two lesions were ruptured and treated in the acute phase. The Woven EndoBridge and stent placement were successfully delivered in all cases. There were no permanent/major complications. Among the 2 patients with SAH, minor and completely reversible in-stent thrombosis occurred during treatment. An asymptomatic occlusion of the angular artery with a distal nonbifurcation aneurysm was discovered during the angiographic follow-up. Long-term (10.4 months) angiographic complete (Raymond-Roy I) and near-complete (Raymond-Roy II) occlusion was obtained in 11 (69%) and 2 (12.5%) aneurysms, respectively. The mean sizes of aneurysms showing Raymond-Roy I/Raymond-Roy II and Raymond-Roy III occlusion were 5.5 ± 2.1 mm and 10 ± 1 mm, respectively (P = .003). The mean fluoroscopy time was 35 ± 14 minutes. CONCLUSIONS: Aneurysm embolization with the Woven EndoBridge device associated with stent placement appears technically feasible and effective for the treatment of lesions with unfavorable anatomy. In our study, this strategy was relatively safe with a low rate of relevant procedure-related adverse events.

Treatment of Unruptured Distal Anterior Circulation Aneurysms with Flow-Diverter Stents: A Meta-Analysis.

BACKGROUND: The safety and efficacy of flow diversion among distal anterior circulation aneurysms must be proved. PURPOSE: Our aim was to analyze the outcomes after flow diversion among MCA, anterior communicating artery, and distal anterior cerebral artery aneurysms. DATA SOURCES: A systematic search of 3 databases was performed for studies published from 2005 to 2018. STUDY SELECTION: According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included studies reporting flow diversion of distal anterior circulation aneurysms. DATA ANALYSIS: Random-effects meta-analysis was used to pool aneurysm occlusion and complication rates. From the individual patient data, univariate and multivariate analyses were used to test predictors of occlusion and complications. DATA SYNTHESIS: We included 27 studies (484 aneurysms). The long-term adequate occlusion rate (O'Kelly-Marotta scale, C-D) was 82.7% (295/364; 95% CI, 77.4%-87.9%; I2 = 52%). Treatment-related complications were 12.5% (63/410; 95% CI, 9%-16%%; I2 = 18.8%), with 5.4% (29/418; 95% CI, 3.2%-7.5%; I2 = 0%) morbidity. MCA location was an independent factor associated with lower occlusion (OR = 0.5, P = .03) and higher complication rates (OR = 1.8, P = .02), compared with anterior communicating artery and distal anterior cerebral artery aneurysms. The Pipeline Embolization Device (versus other stents) gave better occlusion rates (OR = 2.6, P = .002), whereas large/giant aneurysms were associated with higher odds of complications (OR = 2.2, P = .03). The rates of occlusion and narrowing of arteries covered by flow-diverter stents were 6.3% (29/283; 95% CI, 3.5%-9.1%; I2 = 4.2%) and 23.8% (69/283; 95% CI, 15.7%-32%; I2 = 80%), respectively. Symptoms related to occlusion and narrowing of the jailed arteries were 3.5% (6/269; 95% CI, 1.1%-5%; I2 = 0%) and 3% (6/245; 95% CI, 1%-4%; I2 = 0%), respectively. LIMITATIONS: We reviewed small and retrospective series. CONCLUSIONS: Flow diversion among distal anterior circulation aneurysms is effective, leading to adequate aneurysm occlusion in 83% of cases. However, this strategy has some limitations among MCA and larger lesions, especially related to the higher rate of complications. Compared with the other devices, the Pipeline Embolization Device seems to be associated with a higher occlusion rate.

Comparison of Prasugrel and Clopidogrel Used as Antiplatelet Medication for Endovascular Treatment of Unruptured Intracranial Aneurysms: A Meta-Analysis.

BACKGROUND: Clopidogrel is routinely used to decrease ischemic complications during neurointerventional procedures. However, the efficacy may be limited by antiplatelet resistance. PURPOSE: Our aim was to analyze the efficacy of prasugrel compared with clopidogrel in the cerebrovascular field. DATA SOURCES: A systematic search of 2 large databases was performed for studies published from 2000 to 2018. STUDY SELECTION: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included studies reporting treatment-related outcomes of patients undergoing neurointerventional procedures under prasugrel, and studies comparing prasugrel and clopidogrel. DATA ANALYSIS: Random-effects meta-analysis was used to pool the overall rate of complications, ischemic and hemorrhagic events, and influence of the dose of prasugrel. DATA SYNTHESIS: In the 7 included studies, 682 and 672 unruptured intracranial aneurysms were treated under prasugrel (cases) and clopidogrel (controls), respectively. Low-dose (20 mg/5 mg; loading and maintenance doses) prasugrel compared with the standard dose of clopidogrel (300 mg/75 mg) showed a significant reduction in the complication rate (OR = 0.36; 95% CI, 0.17-74, P = .006; I2 = 0%). Overall, the ischemic complication rate was significantly higher in the clopidogrel group (40/672 = 6%; 95% CI, 3%-13%; I2 = 83% versus 16/682 = 2%; 95% CI, 1%-5%; I2 = 73%; P = .03). Low and high loading doses of prasugrel were associated with 0.6% (5/535; 95% CI, 0.1%-1.6%; I2 = 0%) and 9.3% (13/147; 95% CI, 0.2%-18%; I2 = 60%) intraperiprocedural hemorrhages, respectively (P = .001), whereas low and high maintenance doses of prasugrel were associated with 0% (0/433) and 0.9% (2/249; 95% CI, 0.3%-2%; I2 = 0%) delayed hemorrhagic events, respectively (P = .001). LIMITATIONS: Retrospective series and heterogeneous endovascular treatments were limitations. CONCLUSIONS: In our study, low-dose prasugrel compared with clopidogrel premedication was associated with an effective reduction of the ischemic events with an acceptable rate of hemorrhagic complications.

Comparison of Pipeline Embolization Device Sizing Based on Conventional 2D Measurements and Virtual Simulation Using the Sim&Size Software: An Agreement Study.

BACKGROUND AND PURPOSE: The Sim&Size software simulates case-specific intraluminal Pipeline Embolization Device behavior, wall apposition, and device length in real-time on the basis of rotational angiography DICOM data. The purpose of this multicenter study was to evaluate whether preimplantation device simulation with the Sim&Size software results in selection of different device dimensions than manual sizing. MATERIALS AND METHODS: In a multicenter cohort of 74 patients undergoing aneurysm treatment with the Pipeline Embolization Device, we compared apparent optimal device dimensions determined by neurointerventionalists with considerable Pipeline Embolization Device experience based on manual 2D measurements taken from rotational angiography with computed optimal dimensions determined by Sim&Size experts blinded to the neurointerventionalists' decision. Agreement between manually determined and computed optimal dimensions was evaluated with the Cohen κ. The significance of the difference was analyzed with the Wilcoxon signed rank test. RESULTS: The agreement index between manual selection and computed optimal dimensions was low (κ for diameter = 0.219; κ for length = 0.149, P < .01). Computed optimal device lengths were significantly shorter (median, 14 versus 16 mm, T = 402, r = -0.28, P < .01). No significant difference was observed for device diameters. CONCLUSIONS: Low agreement between manually determined and computed optimal device dimensions is not proof, per se, that virtual simulation performs better than manual selection. Nevertheless, it ultimately reflects the potential for optimization of the device-sizing process, and use of the Sim&Size software reduces, in particular, device length. Nevertheless, further evaluation is required to clarify the impact of device-dimension modifications on outcome.

Flow-Diversion Effect of LEO Stents: Aneurysm Occlusion and Flow Remodeling of Covered Side Branches and Perforators.

BACKGROUND AND PURPOSE: Flow diversion with intermediate-porosity stents (braided stents) has been recently reported for distally located small aneurysms. The aim of this study was to evaluate the flow-diversion effect of LEO stents on covered vessels and for aneurysms treated with sole stent-placement therapy. MATERIALS AND METHODS: We retrospectively evaluated the following outcomes: 1) remodeling of covered side branches and perforators (extra-aneurysmal flow remodeling), and 2) the occlusion rate of aneurysms treated with sole stent-placement therapy (intra-aneurysmal flow remodeling). RESULTS: Seventy-six patients with 98 covered vessels were studied. Overall, 89 covered arteries (91%) were normal, 7 showed narrowing (7%), and 2 (2%) were occluded (1 posterior communicating artery and 1 MCA) without related complications (mean DSA follow-up, 14 months). Univariate and multivariate analyses highlighted smoking (P = .03) and the length of follow-up (P = .002) as factors associated with arterial remodeling. Of the 17 Sylvian (lenticulostriate arteries) and 7 basilar perforators, 1 (4%) group of Sylvian perforators covered with double stents had asymptomatic remodeling. Ten aneurysms (mean size, 3.5 mm) were treated with LEO stents as stent monotherapy (5 recanalized after coiling and 5 directly treated with the LEO). Complete occlusion (Raymond-Roy I) was achieved in 70% of aneurysms (mean follow-up, 14 months). The Raymond-Roy I occlusion rate among recanalized aneurysms and those directly treated with LEO stents was 80% and 60%, respectively (P = .9). CONCLUSIONS: The rate of flow remodeling on the covered arteries and perforators was 9% and 4%, respectively, and was clinically irrelevant in all cases. Complete occlusion of aneurysms treated with sole stent-placement therapy was 70%. These data stress the flow-diversion properties of LEO stents.

Treatment of Intracranial Aneurysms with Self-Expandable Braided Stents: A Systematic Review and Meta-Analysis.

BACKGROUND: The safety and efficacy of treatment with self-expandable braided stents (LEO and LVIS) required further investigation. PURPOSE: Our aim was to analyze the outcomes after treatment with braided stents. DATA SOURCES: A systematic search of 3 databases was performed for studies published from 2006 to 2017. STUDY SELECTION: According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included studies reporting patients treated with LEO or LVIS stents. DATA ANALYSIS: Random-effects meta-analysis was used to pool the following: aneurysm occlusion rate, complications, and neurologic outcomes. DATA SYNTHESIS: Thirty-five studies evaluating 1426 patients treated with braided stents were included in this meta-analysis. Successful stent delivery and complete aneurysm occlusion were 97% (1041/1095; 95% CI, 95%-98%) (I2 = 44%) and 88.3% (1097/1256; 95% CI, 85%-91%) (I2 = 72%), respectively. Overall, treatment-related complications were 7.4% (107/1317; 95% CI, 5%-9%) (I2 = 44%). Ischemic/thromboembolic events (48/1324 = 2.4%; 95% CI, 1.5%-3.4%) (I2 = 27%) and in-stent thrombosis (35/1324 = 1.5%; 95% CI, 0.6%-1.7%) (I2 = 0%) were the most common complications. Treatment-related morbidity was 1.5% (30/1324; 95% CI, 0.9%-2%) and was comparable between the LEO and LVIS groups. Complication rates between the anterior (29/322 = 8.8%; 95% CI, 3.4%-12%) (I2 = 41%) versus posterior circulation (10/84 = 10.5%; 95% CI, 4%-16%) (I2 = 0%) and distal (30/303 = 8%; 95% CI, 4.5%-12%) (I2 = 48%) versus proximal aneurysms (14/153 = 9%; 95% CI, 3%-13%) (I2 = 46%) were comparable (P > .05). LIMITATIONS: Limitations were selection and publication biases. CONCLUSIONS: In this analysis, treatment with the LEO and LVIS stents was relatively safe and effective. The most common complications were periprocedural thromboembolisms and in-stent thrombosis. The rate of complications was comparable among anterior and posterior circulation aneurysms, as well as for proximal and distally located lesions.

Rupture limit evaluation of human cerebral aneurysms wall: Experimental study.

BACKGROUND AND PURPOSE: Rupture risk of intracranial aneurysms is a major issue for public healthcare. A way to obtain an individual rupture risk assessment is a main objective of many research teams in the world. For many years, we have investigated the relationship between the mechanical properties of aneurysm wall tissues and the rupture risk. In this work, we try to go further and investigate rupture limit values. METHODS: Following surgical clipping, a specific conservation protocol was applied to aneurysmal tissues in order to preserve their mechanical properties. Thirty-nine intracranial aneurysms (27 females, 12 males) were tested using a uniaxial tensile test machine under physiological conditions, temperature, and saline isotonic solution. These represented 24 unruptured and 15 ruptured aneurysms. Stress/strain curves were then obtained for each sample, and a fitting algorithm was applied following a Yeoh hyperelastic model with 2 parameters. Moreover, uniaxial tensile tests were conducted until rupture of samples to obtain values of stress and strain rupture limit. RESULTS: The significant parameter a C2 of the hyperelastic Yeoh model, allowed us to classify samples' rigidity following the terminology we adopted in previous papers (Costalat et al., 2011; Sanchez et al., 2013): Soft, Stiff and Intermediate. Moreover, strain/stress rupture limit values were gathered and analyzed thanks to the tissue rigidity, the status of the aneurysm (initially ruptured or unruptured) and the gender of the patient. CONCLUSION: Strain rupture limit was found quite stable around 20% and seems not to be correlated with the status of the aneurysm (initially ruptured or unruptured), neither with the gender of the patient. However, stretch and stress rupture limit seems not to be independent on the rigidity. The study confirms that ruptured aneurysms mainly present a soft tissue and unruptured aneurysms present a stiff material.

Acutely Ruptured Intracranial Aneurysms Treated with Flow-Diverter Stents: A Systematic Review and Meta-Analysis.

BACKGROUND: The implantation of flow-diverter stents for the treatment of ruptured intracranial aneurysms required further investigation. PURPOSE: Our aim was to analyze the outcomes after flow diversion of ruptured intracranial aneurysms. DATA SOURCES: A systematic search of 3 databases was performed for studies published from 2006 to 2018. STUDY SELECTION: According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included studies (from 2010 to 2018) reporting acutely ruptured intracranial aneurysms treated with flow diversion. DATA ANALYSIS: Random-effects meta-analysis was used to pool the following: aneurysm occlusion rate, complications, rebleeding, and factors influencing the studied outcomes. DATA SYNTHESIS: We included 20 studies evaluating 223 patients with acutely ruptured intracranial aneurysms treated with flow-diverter stents. Immediate angiographic occlusion was obtained in 32% (29/86; 95% CI, 15.4%-48%; I2 = 79.6%) of aneurysms, whereas long-term complete/near-complete aneurysm occlusion was 88.9% (162/189; 95% CI, 84%-93.5%; I2 = 20.9%) (mean radiologic follow-up of 9.6 months). The treatment-related complication rate was 17.8% (42/223; 95% CI, 11%-24%; I2 = 52.6%). Complications were higher in the posterior circulation (16/72 = 27%; 95% CI, 14%-40%; I2 = 66% versus 18/149 = 11.7%; 95% CI, 7%-16%; I2 = 0%) (P = .004) and after treatment with multiple stents (14/52 = 26%; 95% CI, 14%-45%; I2 = 59%) compared with a single stent (20/141 = 10%; 95% CI, 5%-15%; I2 = 0%) (P = .004). Aneurysm rebleeding after treatment was 4% (5/223; 95% CI, 1.8%-7%; I2 = 0%) and was higher in the first 72 hours. LIMITATIONS: Small and retrospective series. CONCLUSIONS: Flow-diversion treatment of ruptured intracranial aneurysms yields a high rate of long-term angiographic occlusion with a relatively low rate of aneurysm rebleeding. However, treatment is associated with a complication rate of 18%. When coiling or microsurgical clipping are not feasible strategies, anterior circulation ruptured aneurysms can be effectively treated with a flow-diversion technique, minimizing the number of stents deployed. Given the 27% rate of complications, flow diversion for ruptured posterior circulation aneurysms should be considered only in selected cases not amenable to other treatments.