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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

Multicentric Experience in Distal-to-Proximal Revascularization of Tandem Occlusion Stroke Related to Internal Carotid Artery Dissection

BACKGROUND AND PURPOSE

Internal carotid dissection is a frequent cause of ischemic stroke in young adults. It may cause tandem occlusions in which cervical carotid obstruction is associated with intracranial proximal vessel occlusion. To date, no consensus has emerged concerning endovascular treatment strategy. Our aim was to evaluate our endovascular "distal-to-proximal" strategy in the treatment of this stroke subtype in the first large multicentric cohort.

MATERIALS AND METHODS

Prospectively managed stroke data bases from 2 separate centers were retrospectively studied between 2009 and 2014 for records of tandem occlusions related to internal carotid dissection. Atheromatous tandem occlusions were excluded. The first step in the revascularization procedure was intracranial thrombectomy. Then, cervical carotid stent placement was performed depending on the functionality of the circle of Willis and the persistence of residual cervical ICA occlusion, severe stenosis, or thrombus apposition. Efficiency, complications, and radiologic and clinical outcomes were recorded.

RESULTS

Thirty-four patients presenting with tandem occlusion stroke secondary to internal carotid dissection were treated during the study period. The mean age was 52.5 years, the mean initial NIHSS score was 17.29 ± 6.23, and the mean delay between onset and groin puncture was 3.58 ± 1.1 hours. Recanalization TICI 2b/3 was obtained in 21 cases (62%). Fifteen patients underwent cervical carotid stent placement. There was no recurrence of ipsilateral stroke in the nonstented subgroup. Twenty-one patients (67.65%) had a favorable clinical outcome after 3 months.

CONCLUSIONS

Endovascular treatment of internal carotid dissection-related tandem occlusion stroke using the distal-to-proximal recanalization strategy appears to be feasible, with low complication rates and considerable rates of successful recanalization.

Endovascular Treatment of Very Large and Giant Intracranial Aneurysms: Comparison between Reconstructive and Deconstructive Techniques-A Meta-Analysis

BACKGROUND

The safety and efficacy of reconstructive and deconstructive endovascular treatments of very large/giant intracranial aneurysms are not completely clear.

PURPOSE

Our aim was to compare treatment-related outcomes between these 2 techniques.

DATA SOURCES

A systematic search of 3 data bases was performed for studies published from 1990 to 2017.

STUDY SELECTION

We selected series of reconstructive and deconstructive treatments with >10 patients.

DATA ANALYSIS

Random-effects meta-analysis was used to analyze occlusion rates, complications, and neurologic outcomes.

DATA SYNTHESIS

Thirty-nine studies evaluating 894 very large/giant aneurysms were included. Long-term occlusion of unruptured aneurysms was 71% and 93% after reconstructive and deconstructive treatments, respectively (P = .003). Among unruptured aneurysms, complications were lower after parent artery occlusion (16% versus 30%, P = .05), whereas among ruptured lesions, complications were lower after reconstructive techniques (34% versus 38%). Parent artery occlusion in the posterior circulation had higher complications compared with in the anterior circulation (36% versus 15%, P = .001). Overall, coiling yielded lower complication and occlusion rates compared with flow diverters and stent-assisted coiling. Complication rates of flow diversion were lower in the anterior circulation (17% versus 41%, P < .01). Among unruptured lesions, early aneurysm rupture (within 30 days) was slightly higher after reconstructive treatment (5% versus 0%, P = .08) and after flow diversion alone compared with flow diversion plus coiling (7% versus 0%).

LIMITATIONS

Limitations were selection and publication biases.

CONCLUSIONS

Parent artery occlusion allowed high rates of occlusion with an acceptable rate of complications for unruptured, anterior circulation aneurysms. Coiling should be preferred for posterior circulation and ruptured lesions, whereas flow diversion is relatively safe and effective for unruptured anterior circulation aneurysms.

Treatment of Distal Anterior Cerebral Artery Aneurysms with Flow-Diverter Stents: A Single-Center Experience

BACKGROUND AND PURPOSE

Flow diversion for aneurysms beyond the circle of Willis is still debated. Our aim was to evaluate the safety and efficacy of flow diversion treatment of distal anterior cerebral artery aneurysms.

MATERIALS AND METHODS

Consecutive patients with distal anterior cerebral artery aneurysms treated from January 2014 to October 2017 were evaluated retrospectively with prospectively maintained data. Treatment was performed only for unruptured or recanalized aneurysms after coiling. Technical feasibility, procedural complications, aneurysm occlusion (O'Kelly-Marotta grading scale), and clinical outcome were evaluated.

RESULTS

Fifteen patients were included in the study, with 17 distal anterior cerebral artery saccular aneurysms treated with flow-diverter stents. Mean aneurysm size was 4.25 ± 3.9 mm; range, 2-9 mm. Flow diversion was used as retreatment among 6 previously coiled aneurysms (5 ruptured and coiled in the acute phase, and 1 unruptured and recanalized). Stent deployment was technically successful in all cases. During the perioperative period, 1 patient experienced a transient minor stroke (6%), whereas 2 patients reported acute in-stent thrombosis with disabling ischemic complications (13%). Fourteen patients and 16 aneurysms were available during a mean radiologic follow-up of 12 months (range, 3-24 months). Overall, 12 (75%) aneurysms were completely occluded (O'Kelly-Marotta grading scale score D), 1 aneurysm (6%) showed near-complete occlusion (O'Kelly-Marotta grading scale score C), and 3 aneurysms (19%) were incompletely occluded (O'Kelly-Marotta grading scale, score B). All 6 aneurysms previously coiled were completely occluded after flow diversion, whereas 70% of aneurysms treated with flow diverters alone showed complete/near-complete occlusion (O'Kelly-Marotta grading scale C-D). There were no cases of aneurysm rupture, in-stent occlusion, or retreatment during long-term follow-up.

CONCLUSIONS

Treatment of distal anterior cerebral artery aneurysms with flow-diverter stents is feasible and effective, with high rates of aneurysm occlusion. Flow diversion plus coiling, in the retreatment of lesions previously coiled, allowed higher rates of occlusion compared with flow diverters alone. However, the risk of ischemic complications is not negligible, and flow-diversion treatment should be evaluated only for aneurysms not amenable to simple coil embolization.

Anterior Circulation Acute Ischemic Stroke Associated with Atherosclerotic Lesions of the Cervical ICA: A Nosologic Entity Apart

BACKGROUND AND PURPOSE

Mechanical thrombectomy for patients with acute ischemic stroke with tandem occlusions has been shown to present varying reperfusion successes and clinical outcomes. However, the heterogeneity of tandem occlusion etiology has been strongly neglected in previous studies. We retrospectively investigated patients with acute ischemic stroke atherothrombotic tandem occlusion.

MATERIALS AND METHODS

All consecutive patients with acute ischemic stroke with atherothrombotic tandem occlusions treated with mechanical thrombectomy in our center between September 2009 and April 2015 were analyzed. They were compared with patients with acute ischemic stroke with dissection-related tandem occlusion and isolated intracranial occlusion treated during the same period. Comparative univariate and multivariate analyses were conducted, including demographic data, safety, and rates of successful recanalization and good clinical outcome.

RESULTS

Despite comparable baseline severity of neurologic deficits and infarct core extension, patients with atherothrombotic tandem occlusions were older (P < .001), were more frequently smokers (P < .001), and had globally more cardiovascular risk factors (P < .001) than the other 2 groups of patients. The patients with atherothrombotic tandem occlusions had significantly longer procedural times (P < .001), lower recanalization rates (P = .004), and higher global burden of procedural complications (P < .001). In this group, procedural complications (OR = 0.15, P = .02) and the TICI 2b/3 reperfusion scores (OR = 17.76, P = .002) were independently predictive factors of favorable clinical outcome.

CONCLUSIONS

Our study suggests that atherothrombotic tandem occlusions represent a peculiar and different nosologic entity compared with dissection-related tandem occlusions. This challenging cause of acute ischemic stroke should be differentiated from other etiologies in patient management in future prospective studies.

Treatment of Middle Cerebral Artery Aneurysms with Flow-Diverter Stents: A Systematic Review and Meta-Analysis

BACKGROUND

The safety and efficacy of flow-diversion treatment of MCA aneurysms have not been well-established.

PURPOSE

Our aim was to evaluate angiographic and clinical outcomes after flow diversions for MCA aneurysms.

DATA SOURCES

A systematic search of PubMed, MEDLINE, and Embase was performed for studies published from 2008 to May 2017.

STUDY SELECTION

According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we selected studies with >5 patients describing angiographic and clinical outcomes after flow-diversion treatment of MCA aneurysms.

DATA ANALYSIS

Random-effects meta-analysis was used to pool the following outcomes: aneurysm occlusion rate, procedure-related complications, rupture rate of treated aneurysms, and occlusion of the jailed branches.

DATA SYNTHESIS

Twelve studies evaluating 244 MCA aneurysms were included in this meta-analysis. Complete/near-complete occlusion was obtained in 78.7% (95% CI, 67.8%-89.7%) of aneurysms. The rupture rate of treated aneurysms during follow-up was 0.4% per aneurysm-year. The rate of treatment-related complications was 20.7% (95% CI, 14%-27.5%), and approximately 10% of complications were permanent. The mortality rate was close to 2%. Nearly 10% (95% CI, 4.7%-15.5%) of jailed arteries were occluded during follow-up, whereas 26% (95% CI, 14.4%-37.6%) had slow flow. Rates of symptoms related to occlusion and slow flow were close to 5%.

LIMITATIONS

Small and retrospective series could affect the strength of the reported results.

CONCLUSIONS

Given the not negligible rate of treatment-related complications, flow diversion for MCA aneurysms should be considered an alternative treatment when traditional treatment methods are not feasible. However, when performed in this select treatment group, high rates of aneurysm occlusion and protection against re-rupture can be achieved.

MRI quantitative T2* mapping on thrombus to predict recanalization after endovascular treatment for acute anterior ischemic stroke

BACKGROUND

In anterior acute ischemic stroke (AAIS) treated with endovascular treatment (EVT), the susceptibility vessel sign (SVS+ or SVS-) is related to recanalization results (TICI 2b/3) and clinical outcome. However, a binary qualitative assessment of thrombus using SVS does not reflect its complex composition. Our aim was to assess whether a quantitative MRI marker, Thrombus-T2* relaxation time, may be assessable in clinical routine and may to predict early successful recanalization after EVT, defined as a TICI 2b/3 recanalization obtained in 2 attempts or less.

MATERIAL AND METHODS

Thrombus-T2* relaxation time was prospectively obtained from consecutive AAIS patients treated by EVT (concomitant aspiration and stent retriever). Quantitative values were compared between early recanalization and late or unsuccessful recanalization.

RESULTS

Thirty patients with AAIS were included and Thrombus-T2* relaxation time was obtained in all patients. Earlier TICI 2b/3 recanalization were obtained in 22 patients (73%) and was significantly associated with SVS+ (1/8 vs. 16/22, P=0.01) and a shorter Thombus-T2* relaxation time (mean SD, range: 257, 18-50ms vs. 45 9, 35-60ms, P<0.001).

CONCLUSION

A new quantitative MRI biomarker, the Thrombus-T2* relaxation time is assessable in clinical routine. In a preliminary study of 30 patients, a shorter Thombus-T2* relaxation time is related to earlier recanalization after EVT using combination of stent retriever and aspiration.

Endovascular Management of Tandem Occlusion Stroke Related to Internal Carotid Artery Dissection Using a Distal to Proximal Approach: Insight from the RECOST Study

BACKGROUND AND PURPOSE

Internal carotid artery dissection is a common cause of stroke in young adults. It may be responsible for tandem occlusion defined by a cervical steno-occlusive carotid wall hematoma associated with an intracranial large-vessel stroke. Intravenous thrombolysis is associated with a poor clinical outcome in these cases, and endovascular treatment has not been specifically evaluated to date. Our aim was to evaluate endovascular treatment technical and clinical efficiency in this specific occlusion topography, in comparison with treatment of isolated anterior circulation stroke.

MATERIALS AND METHODS

As part of our ongoing prospective stroke data base started in August 2009 (Prognostic Factors Related to Clinical Outcome Following Thrombectomy in Ischemic Stroke [RECOST] Study), we analyzed all carotid artery dissection tandem occlusion strokes and isolated anterior circulation occlusions. All patients were selected for endovascular treatment according to clinical-radiologic mismatch, NIHSS ≥ 7 and DWI-ASPECTS ≥5, within 6 hours after onset. For carotid artery dissection, the revascularization procedure consisted first of distal recanalization by a stent retriever in the intracranial vessel. Following assessment of the circle of Willis, internal carotid artery stent placement was only performed in case of insufficiency. Carotid artery dissection treatment efficacy, safety, and clinical outcome were compared with the results of the isolated anterior circulation occlusion cohort.

RESULTS

Two hundred fifty-eight patients with an anterior circulation stroke were analyzed, including 57 with tandem occlusions (22%); among them, 20 were carotid artery dissection-related occlusions (7.6%). The median age of patients with tandem occlusions with internal carotid dissection was 52.45 versus 66.85 years for isolated anterior circulation occlusion (P < .05); the mean initial NIHSS score was 17.53 ± 4.11 versus 17.55 ± 4.8 (P = .983). The median DWI-ASPECTS was 6.05 versus 6.64 (P = .098), and the average time from onset to puncture was 4.38 for tandem occlusions versus 4.53 hours in isolated anterior circulation occlusion (P = .704). Complication rates and symptomatic intracranial hemorrhage were comparable in both groups (5% versus 3%, P = .49). The duration of the procedure was significantly prolonged in case of tandem occlusion (80.69 versus 65.45 minutes, P = .030). Fourteen patients with carotid artery dissection (70%) had a 3-month mRS of ≤ 2, without a significant difference from patients with an isolated anterior circulation occlusion (44%, P = .2). Only 5 carotid artery dissections (25%) necessitated cervical stent placement. No early ipsilateral stroke recurrence was recorded, despite the absence of stent placement in 15 patients (75%) with carotid artery dissection.

CONCLUSIONS

Mechanical endovascular treatment of carotid artery dissection tandem occlusions is safe and effective compared with isolated anterior circulation occlusion stroke therapy. Hence, a more conservative approach with stent placement only in cases of circle of Willis insufficiency may be a reliable and safe strategy.

Favorable Bridging Therapy Based on DWI-FLAIR Mismatch in Patients with Unclear-Onset Stroke

BACKGROUND AND PURPOSE

Standard selection criteria for revascularization therapy usually exclude patients with unclear-onset stroke. Our aim was to evaluate the efficacy and safety of revascularization therapy in patients with unclear-onset stroke in the anterior circulation and to identify the predictive factors for favorable clinical outcome.

MATERIALS AND METHODS

We retrospectively analyzed 41 consecutive patients presenting with acute stroke with unknown time of onset treated by intravenous thrombolysis and/or mechanical thrombectomy. Only patients without well-developed fluid-attenuated inversion recovery changes of acute diffusion lesions on MR imaging were enrolled. Twenty-one patients were treated by intravenous thrombolysis; 19 received, simultaneously, intravenous thrombolysis and mechanical thrombectomy (as a bridging therapy); and 1 patient, endovascular therapy alone. Clinical outcome was evaluated at 90 days by using the mRS. Mortality and symptomatic intracranial hemorrhage were also reported.

RESULTS

Median patient age was 72 years (range, 17-89 years). Mean initial NIHSS score was 14.5 ± 5.7. Successful recanalization (TICI 2b-3) was assessed in 61% of patients presenting with an arterial occlusion, symptomatic intracranial hemorrhage occurred in 2 patients (4.9%), and 3 (7.3%) patients died. After 90 days, favorable outcome (mRS 0-2) was observed in 25 (61%) patients. Following multivariate analysis, initial NIHSS score (OR, 1.43; 95% CI, 1.13-1.82; P = .003) and bridging therapy (OR, 37.92; 95% CI, 2.43-591.35; P = .009) were independently associated with a favorable outcome at 3 months.

CONCLUSIONS

The study demonstrates the safety and good clinical outcome of acute recanalization therapy in patients with acute stroke in the anterior circulation and an unknown time of onset and a DWI/FLAIR mismatch on imaging. Moreover, bridging therapy versus intravenous thrombolysis alone was independently associated with favorable outcome at 3 months.

LEO Baby Stent Use following Balloon-Assisted Coiling: Single- and Dual-Stent Technique--Immediate and Midterm Results of 29 Consecutive Patients

BACKGROUND AND PURPOSE

We report our preliminary results in terms of safety and efficacy in using the low-profile LEO Baby stent for the treatment of large-neck and complex intracranial aneurysms with balloon-then-stent-assisted coiling and single- or dual-stent-assisted coiling.

MATERIALS AND METHODS

Clinical and radiologic data of all consecutive patients treated at our institution from September 2012 to October 2013 for an intracranial aneurysm by using a LEO Baby stent were retrospectively analyzed. Immediate and midterm clinical and anatomic follow-up of each patient is reported.

RESULTS

Twenty-nine patients with 29 aneurysms were treated with LEO Baby stents at our institution. The mean age of patients was 48 years; 20 patients were women (71%). One patient was treated in the acute phase of a subarachnoid hemorrhage. In 8 procedures, a double-lumen-catheter balloon was used for balloon-then-stent-assisted coiling. In 3 cases, a LEO Baby stent was used in a Y-, T-, and telescopic dual-stent configuration. In 18 cases, a single LEO Baby stent was used. In 2 cases, technical failure to deploy the stent resulted in acute parent artery thrombosis. In 3 further cases, thromboembolic complications occurred intraoperatively. MR imaging and angiographic midterm follow-up showed complete aneurysm occlusion for 96% of the followed patients (27/29). Clinical outcome was favorable for all patients followed up.

CONCLUSIONS

Results obtained in our study by using the LEO Baby stent for balloon-then-stent and single- or dual-stent-assisted coiling of complex and distally located intracranial aneurysms are encouraging. Incomplete or inadequate opening of the device is a potential cause of laminar blood flow alteration and thrombus formation.

Complications and follow up of subarachnoid hemorrhages

Complications of subarachnoid hemorrhage are the major life threatening and functional components of the follow up of a ruptured aneurysm. Knowing how to identify these is a key challenge. They vary in type throughout the postoperative follow up period. The aim of this article is firstly to list the main complications of the acute phase (rebleeding, acute hydrocephalus, acute ischemic injury and non-neurological complications), the subacute phase (vasospasm) and the chronic phase of subarachnoid hemorrhages: (chronic hydrocephalus and cognitive disorders) and to describe their major clinical and radiological features. Secondly, we describe the long-term follow up strategy for patients who have suffered a subarachnoid hemorrhage and have been treated endovascularly or by surgery. This follow up involves a combination of clinical consultations, cerebral MRI and at least one review angiogram.

Patient selection for stroke endovascular therapy--DWI-ASPECTS thresholds should vary among age groups: insights from the RECOST study

BACKGROUND AND PURPOSE

The purpose of this study was to evaluate the benefits of endovascular intervention in large-vessel occlusion strokes, depending on age class.

MATERIALS AND METHODS

A clinical management protocol including intravenous treatment and mechanical thrombectomy was instigated in our center in 2009 (Prognostic Factors Related to Clinical Outcome Following Thrombectomy in Ischemic Stroke [RECOST] study). All patients with acute ischemic stroke with an anterior circulation major-vessel occlusion who presented within 6 hours were evaluated with an initial MR imaging examination and were analyzed according to age subgroups (younger than 50 years, 50-59 years, 60-69 years, 70-79 years; 80 years or older). The mRS score at 3 months was the study end point.

RESULTS

One hundred sixty-five patients were included in the analysis. The mean age was 67.4 years (range, 29-90 years). The mean baseline NIHSS score was 17.24 (range, 3-27). The mean DWI-derived ASPECTS was 6.4. Recanalization of TICI 2b/3 was achieved in 80%. At 3 months, 41.72% of patients had a good outcome, with a gradation of prognosis depending on the age subgroup and a clear cutoff at 70 years. Only 19% of patients older than 80 years had a good outcome at 3 months (mean ASPECTS = 7.4) with 28% for 70-79 years (mean ASPECTS = 6.8), but 58% for 60-69 years (mean ASPECTS = 6), 52% for 50-59 years (mean ASPECTS = 5.91), and 72% for younger than 50 years (mean ASPECTS = 6.31). In contrast, the mortality rate was 35% for 80 years and older, and 26% for 70-79 versus 5%-9% for younger than 70 years.

CONCLUSIONS

The elderly may benefit from thrombectomy when their ischemic core volume is low in comparison with younger patients who still benefit from acute recanalization despite larger infarcts. Stroke volume thresholds should, therefore, be related and adjusted to the patient's age group.

Extra-aneurysmal flow modification following pipeline embolization device implantation: focus on regional branches, perforators, and the parent vessel

BACKGROUND AND PURPOSE

Flow-diverter technology has proved to be a safe and effective treatment for intracranial aneurysm based on the concept of flow diversion allowing parent artery and collateral preservation and aneurysm healing. We investigated the patency of covered side branches and flow modification within the parent artery following placement of the Pipeline Embolization Device in the treatment of intracranial aneurysms.

MATERIALS AND METHODS

Sixty-six aneurysms in 59 patients were treated with 96 Pipeline Embolization Devices. We retrospectively reviewed imaging and clinical results during the postoperative period at 6 and 12 months to assess flow modification through the parent artery and side branches. Reperfusion syndrome was assessed by MR imaging and clinical evaluation.

RESULTS

Slow flow was observed in 13 of 68 (19.1%) side branches covered by the Pipeline Embolization Device. It was reported in all cases of anterior cerebral artery coverage, in 3/5 cases of M2-MCA coverage, and in 5/34 (14.7%) cases of ophthalmic artery coverage. One territorial infarction was observed in a case of M2-MCA coverage, without arterial occlusion. One case of deep Sylvian infarct was reported in a case of coverage of MCA perforators. Two ophthalmic arteries (5.9%) were occluded, and 11 side branches (16.2%) were narrowed at 12 months' follow-up; patients remained asymptomatic. Parent vessel flow modification was responsible for 2 cases (3.4%) of reperfusion syndrome. Overall permanent morbidity and mortality rates were 5.2% and 6.9%, respectively. We did not report any permanent deficit or death in case of slow flow observed within side branches.

CONCLUSIONS

After Pipeline Embolization Device placement, reperfusion syndrome was observed in 3.4%, and territorial infarction, in 3.4%. Delayed occlusion of ophthalmic arteries and delayed narrowing of arteries covered by the Pipeline Embolization Device were observed in 5.9% and 16.2%, respectively. No permanent morbidity or death was related to side branch coverage at midterm follow-up.

WEB intrasaccular flow disruptor-prospective, multicenter experience in 83 patients with 85 aneurysms

BACKGROUND AND PURPOSE

The safety and efficacy of WEB flow disruption have been analyzed in small, retrospective series. The object of this study was to evaluate the safety and efficacy of WEB flow disruption in a large, multicenter, prospectively collected population.

MATERIALS AND METHODS

Data from all patients treated with the WEB-DL device between June 2011 and October 2013 in 11 French neurointerventional centers were prospectively collected and retrospectively analyzed. Complications occurring during and after treatment were analyzed as well as morbidity and mortality at 1 month. Aneurysm occlusion status at the last follow-up was analyzed.

RESULTS

Eighty-three patients with 85 aneurysms were included in this series. Technical success was achieved in 77 patients with 79 aneurysms (92.9%). Periprocedural complications were observed in 9 patients (10.8%), leading to permanent neurologic deficits in 3 (3.9%). Morbidity and mortality at 1 month were 1.3% and 0.0%, respectively. Angiographic follow-up was performed for 65/79 aneurysms (82.3%) 3-24 months after treatment (mean, 5.3 months). Complete aneurysm occlusion was observed in 37/65 aneurysms (56.9%); neck remnant, in 23/65 (35.4%); and aneurysm remnant, in 5/65 (7.7%).

CONCLUSIONS

In this large prospective series of patients, WEB flow disruption was a safe and efficient technique.

Intracranial aneurysmal pulsatility as a new individual criterion for rupture risk evaluation: biomechanical and numeric approach (IRRAs Project)

BACKGROUND AND PURPOSE

The present study follows an experimental work based on the characterization of the biomechanical behavior of the aneurysmal wall and a numerical study where a significant difference in term of volume variation between ruptured and unruptured aneurysm was observed in a specific case. Our study was designed to highlight by means of numeric simulations the correlation between aneurysm sac pulsatility and the risk of rupture through the mechanical properties of the wall.

MATERIALS AND METHODS

In accordance with previous work suggesting a correlation between the risk of rupture and the material properties of cerebral aneurysms, 12 fluid-structure interaction computations were performed on 12 "patient-specific" cases, corresponding to typical shapes and locations of cerebral aneurysms. The variations of the aneurysmal volume during the cardiac cycle (ΔV) are compared by using wall material characteristics of either degraded or nondegraded tissues.

RESULTS

Aneurysms were located on 6 different arteries: middle cerebral artery (4), anterior cerebral artery (3), internal carotid artery (1), vertebral artery (1), ophthalmic artery (1), and basilar artery (1). Aneurysms presented different shapes (uniform or multilobulated) and diastolic volumes (from 18 to 392 mm3). The pulsatility (ΔV/V) was significantly larger for a soft aneurysmal material (average of 26%) than for a stiff material (average of 4%). The difference between ΔV, for each condition, was statistically significant: P=.005.

CONCLUSIONS

The difference in aneurysmal pulsatility as highlighted in this work might be a relevant patient-specific predictor of aneurysm risk of rupture.

Diffusion-weighted imaging score of the brain stem: A predictor of outcome in acute basilar artery occlusion treated with the Solitaire FR device

BACKGROUND AND PURPOSE

The prognosis for ischemic stroke due to acute basilar artery occlusion is very poor: Early recanalization remains the main factor that can improve outcomes. The baseline extent of brain stem ischemic damage can also influence outcomes. We evaluated the validity of an easy-to-use DWI score to predict clinical outcome in patients with acute basilar artery occlusion treated by mechanical thrombectomy.

MATERIALS AND METHODS

We analyzed the baseline clinical and DWI parameters of 31 patients with acute basilar artery occlusion, treated within 24 hours of symptom onset by using a Solitaire FR device. The DWI score of the brain stem was assessed with a 12-point semiquantitative score that separately considered each side of the medulla, pons, and midbrain. Clinical outcome was assessed at 180 days by using the mRS. According to receiver operating characteristic analyses, the cutoff score determined the optimal positive predictive value for outcome. The Spearman rank correlation coefficient assessed the correlation between the DWI brain stem score and baseline characteristics.

RESULTS

Successful recanalization (Thrombolysis in Cerebral Infarction 3-2b) was achieved in 23 patients (74%). A favorable outcome (mRS ≤ 2) was observed in 11 patients (35%). An optimal DWI brain stem score of <3 predicted a favorable outcome. The probability of a very poor outcome (mRS ≥ 5) if the DWI brain stem score was ≥5 reached 80% (positive predictive value) and 100% if this score was ≥6. Interobserver reliability of the DWI brain stem score was excellent, with an intraclass correlation coefficient of 0.97 (95% CI, 0.96-0.99). The DWI brain stem score was significantly associated with baseline tetraplegia (P = .001) and coma (P = .005).

CONCLUSIONS

In patients with acute basilar artery occlusion treated by mechanical thrombectomy, the baseline DWI brain lesion score seems to predict clinical outcome.

Stent retrievers in acute ischemic stroke: complications and failures during the perioperative period

BACKGROUND AND PURPOSE

Stent retriever-assisted thrombectomy promotes high recanalization rates in acute ischemic stroke. Nevertheless, complications and failures occur in more than 10% of procedures; hence, there is a need for further investigation.

MATERIALS AND METHODS

A total of 144 patients with ischemic stroke presenting with large-vessel occlusion were prospectively included. Patients were treated with stent retriever-assisted thrombectomy ± IV fibrinolysis. Baseline clinical and imaging characteristics were incorporated in univariate and multivariate analyses. Predictors of recanalization failure (TICI 0, 1, 2a), and of embolic and hemorrhagic complications were reported. The relationship between complication occurrence and periprocedural mortality rate was studied.

RESULTS

Median age was 69.5 years, and median NIHSS score was 18 at presentation. Fifty patients (34.7%) received stand-alone thrombectomy, and 94 (65.3%) received combined therapy. The procedural failure rate was 13.9%. Embolic complications were recorded in 12.5% and symptomatic intracranial hemorrhage in 7.6%. The overall rate of failure, complications, and/or death was 39.6%. The perioperative mortality rate was 18.4% in the overall cohort but was higher in cases of failure (45%; P = .003), embolic complications (38.9%; P = .0176), symptomatic intracranial hemorrhages (45.5%; P = .0236), and intracranial stenosis (50%; P = .0176). Concomitant fibrinolytic therapy did not influence the rate of recanalization or embolic complication, or the intracranial hemorrhage rate. Age was the only significant predictive factor of intracranial hemorrhage (P = .043).

CONCLUSIONS

The rate of perioperative mortality was significantly increased in cases of embolic and hemorrhagic complications, as well as in cases of failure and underlying intracranial stenoses. Adjunctive fibrinolytic therapy did not improve the recanalization rate or collateral embolic complication rate. The rate of symptomatic intracranial hemorrhage was not increased in cases of combined treatment.

Safety and efficacy of neuroform for treatment of intracranial aneurysms: a prospective, consecutive, French multicentric study

BACKGROUND AND PURPOSE

Endovascular embolization of wide-neck intracranial aneurysms can be technically challenging, especially when the anatomy is complex. Stent reconstruction of the parent artery is commonly used to treat wide-neck and bifurcated aneurysms. The main objective of this study was to investigate the periprocedural and midterm morbidity and mortality results of this procedure.

MATERIALS AND METHODS

SENAT is a consecutive, prospective, multicentric study. Patients with unruptured cerebral aneurysms who underwent endovascular treatment with the Neuroform stent system were recruited and recorded. Technical outcomes and complications were also assessed. The midterm anatomic results were re-evaluated at 12-18 months.

RESULTS

A total of 113 stents were used to treat the 107 aneurysms in 107 patients. The mean width of the aneurysm sac was 6.2 mm, and the mean diameter of aneurysm neck was 4.5 mm. The complete occlusion rate postprocedure was 66.4%. The rate of progressive occlusion at 12-18 months was 14%, and the rate of recurrence was 9.7%. The rate of subsequent treatment was 4%. The thromboembolic rate in the periprocedural period was 3.7%, and the rate of delayed TE events was 3%. Overall, the mortality rate at 12-18 months was 1%, and the permanent morbidity rate was 1%.

CONCLUSIONS

Stent-assisted coiling with the Neuroform stent system provides a high level of occlusion with low rates of subsequent treatment despite a predominant population of patients with wide-neck aneurysms. Morbidity and thromboembolic rates were comparable to studies investigating stand-alone coiling.

Evaluation of an intravenous-endovascular strategy in patients with acute proximal middle cerebral artery occlusion

BACKGROUND AND PURPOSE

IVT administered in acute ischemic stroke provides low recanalization rates in proximal intracranial occlusions, with consequently poor clinical outcome. The safety and efficacy of an IES by using mechanical thrombectomy after IVT failure were assessed in acute MCA occlusions.

MATERIALS AND METHODS

Patients presenting with acute MCA occlusion within 4.5 hours with an NIHSS score between 8 and 25 and a DWI ASPECTS of >5 were eligible. From September 2009 to September 2010, mechanical thrombectomy by using the Solitaire FR device was systematically performed if no clinical improvement was observed 1 hour after the initiation of IVT (IES group). Results in terms of clinical outcome were compared with those from an IVT series from January 2007 to August 2009 (IVT group).

RESULTS

Alteplase was administered in 123 patients with proximal intracranial occlusion. Fifty-six had a confirmed MCA occlusion: 32 were included in the IVT group; and 24, in the IES group. At 24 hours, the median NIHSS improvement was 8.5 points in the IES group (25%-75% CI, 1.5-13) and 3 points in the IVT group (25%-75% CI, 1-5) (P = .001). At 3 months, 17/22 (77%) patients from the IES group and 15/30 (50%) from the IVT group had an mRS score of ≤2. After adjustment for confounding variables, IES was strongly associated with favorable clinical outcome (77% versus 50%; adjusted odds ratio = 11.9; 95% CI, 1.6-89.1; P < .02). No symptomatic intracranial hemorrhage was observed.

CONCLUSIONS

IES by using systematic mechanical thrombectomy after IVT failure safely improves the clinical outcome at 3 months and could represent an interesting alternative in the management of patients with acute MCA occlusion.