Successful mechanical thrombectomy in acute ischemic stroke: revascularization grade and functional independence

Most studies define the technical success of endovascular thrombectomy (EVT) as a Thrombolysis in Cerebral Infarction (TICI) revascularization grade of 2b or higher. However, growing evidence suggests that TICI 3 is the best angiographic predictor of improved functional outcomes. To assess the association between successful TICI revascularization grades and functional independence at 90 days, we performed a systematic review and network meta-analysis of thrombectomy studies that reported TICI scores and functional outcomes, measured by the modified Rankin Scale, using the semi-automated AutoLit software platform. Forty studies with 8691 patients were included in the quantitative synthesis. Across TICI, modified TICI (mTICI), and expanded TICI (eTICI), the highest rate of good functional outcomes was observed in patients with TICI 3 recanalization, followed by those with TICI 2c and TICI 2b recanalization, respectively. Rates of good functional outcomes were similar among patients with either TICI 2c or TICI 3 grades. On further sensitivity analysis of the eTICI scale, the rates of good functional outcomes were equivalent between eTICI 2b50 and eTICI 2b67 (OR 0.81, 95% CI 0.52 to 1.25). We conclude that near complete or complete revascularization (TICI 2c/3) is associated with higher rates of functional outcomes after EVT.

Predictors of parenchymal hemorrhage after endovascular treatment in acute ischemic stroke: data from ANGEL-ACT Registry

BackgroundParenchymal hemorrhage (PH) is a troublesome complication after endovascular treatment (EVT).ObjectiveTo investigate the incidence, independent predictors, and clinical impact of PH after EVT in patients with acute ischemic stroke (AIS) due to anterior circulation large vessel occlusion (LVO).MethodsSubjects were selected from the ANGEL-ACT Registry. PH was diagnosed according to the European Collaborative Acute Stroke Study classification. Logistic regression analyses were performed to determine the independent predictors of PH, as well as the association between PH and 90-day functional outcome assessed by modified Rankin Scale (mRS) score.ResultsOf the 1227 enrolled patients, 147 (12.0%) were diagnosed with PH within 12–36 hours after EVT. On multivariable analysis, low admission Alberta Stroke Program Early CT score (ASPECTS)(adjusted OR (aOR)=1.13, 95% CI 1.02 to 1.26, p=0.020), serum glucose >7 mmol/L (aOR=1.82, 95% CI 1.16 to 2.84, p=0.009), and neutrophil-to-lymphocyte ratio (NLR; aOR=1.05, 95% CI 1.02 to 1.09, p=0.005) were associated with a high risk of PH, while underlying intracranial atherosclerotic stenosis (ICAS; aOR=0.42, 95% CI 0.22 to 0.81, p=0.009) and intracranial angioplasty/stenting (aOR=0.37, 95% CI 0.15 to 0.93, p=0.035) were associated with a low risk of PH. Furthermore, patients with PH were associated with a shift towards to worse functional outcome (mRS score 4 vs 3, adjusted common OR (acOR)=2.27, 95% CI 1.53 to 3.38, p<0.001).ConclusionsIn Chinese patients with AIS caused by anterior circulation LVO, the risk of PH was positively associated with low admission ASPECTS, serum glucose >7 mmol/L, and NLR, but negatively related to underlying ICAS and intracranial angioplasty/stenting.Trial registration numberNCT03370939.

Cost-effectiveness of thrombectomy in patients with minor stroke and large vessel occlusion: effect of thrombus location on cost-effectiveness and outcomes

BackgroundTo evaluate the cost-effectiveness of endovascular thrombectomy (EVT) to treat large vessel occlusion (LVO) in patients with acute, minor stroke (National Institute of Health Stroke Scale (NIHSS) <6) and impact of occlusion site.MethodsA Markov decision-analytic model was constructed accounting for both costs and outcomes from a societal perspective. Two different management strategies were evaluated: EVT and medical management. Base case analysis was done for three different sites of occlusion: proximal M1, distal M1 and M2 occlusions. One-way, two-way and probabilistic sensitivity analyses were performed.ResultsBase-case calculation showed EVT to be the dominant strategy in 65-year-old patients with proximal M1 occlusion and NIHSS <6, with lower cost (US$37 229 per patient) and higher effectiveness (1.47 quality-adjusted life years (QALYs)), equivalent to 537 days in perfect health or 603 days in modified Rankin score (mRS) 0–2 health state. EVT is the cost-effective strategy in 92.7% of iterations for patients with proximal M1 occlusion using a willingness-to-pay threshold of US$100 000/QALY. EVT was cost-effective if it had better outcomes in 2%–3% more patients than intravenous thrombolysis (IVT) in absolute numbers (base case difference −16%). EVT was cost-effective when the proportion of M2 occlusions was less than 37.1%.ConclusionsEVT is cost-effective in patients with minor stroke and LVO in the long term (lifetime horizon), considering the poor outcomes and significant disability associated with non-reperfusion. Our study emphasizes the need for caution in interpreting previous observational studies which concluded similar results in EVT versus medical management in patients with minor stroke due to a high proportion of patients with M2 occlusions in the two strategies.

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

BackgroundMechanical thrombectomy (MT) is a primary endovascular modality for acute intracranial large vessel occlusion. However, further treatment, such as rescue stenting, is occasionally necessary for refractory cases. We aimed to investigate the efficacy and safety of rescue stenting in first-line MT failure and to identify the clinical factors affecting its clinical outcome.MethodsA multicenter prospective registry was designed for this study. We enrolled consecutive patients who underwent rescue stenting for first-line MT failure. Endovascular details and outcomes, follow-up patency of the stented artery, and clinical outcomes were summarized and compared between the favorable and unfavorable outcome groups.ResultsA total of 78 patients were included. Intracranial atherosclerotic stenosis was the most common etiology for rescue stenting (97.4%). Seventy-seven patients (98.7%) were successfully recanalized by rescue stenting. A favorable outcome was observed in 66.7% of patients. Symptomatic intracranial hemorrhage and mortality were observed in 5.1% and 4.0% of patients, respectively. The stented artery was patent in 82.1% of patients on follow-up angiography. In a multivariable analysis, a patent stent on follow-up angiography was an independent factor for a favorable outcome (OR 87.6; 95% CI 4.77 to 1608.9; p=0.003). Postprocedural intravenous maintenance of glycoprotein IIb/IIIa inhibitor was significantly associated with the follow-up patency of the stented artery (OR 5.72; 95% CI 1.45 to 22.6; p=0.013).ConclusionsIn this multicenter prospective registry, rescue stenting for first-line MT failure was effective and safe. For a favorable outcome, follow-up patency of the stented artery was important, which was significantly associated with postprocedural maintenance of glycoprotein IIb/IIIa inhibitors.

Selective arterial temporary flow arrest with balloons during transvenous embolization for the treatment of brain arteriovenous malformations: a feasibility study with MRI-monitored adverse events

BackgroundThe technique of endovascular transvenous embolization for brain arteriovenous malformations (AVMs) has emerged in the last 8 years as a very promising therapeutic alternative for otherwise incurable cases. Selective temporary flow arrest during transvenous endovascular embolization (TFATVE) is a novel adaptation of our previously described transvenous approach, which employs hyper-compliant balloons intra-arterially for the selective occlusion of arterial feeders during ethylene vinyl copolymer (EVOH) injection, in order to reduce intra-nidal pressure and increase nidi occlusion rates.MethodsWe performed a feasibility study of the TFATVE technique between January 2016 and April 2020. Consecutive patients were included. All patients had at least one axial brain MRI or CT in the first 48 hours following intervention, and at least one brain MRI scan within the first postoperative month, in order to detect both silent and clinically evident adverse events. Patients’ demographics, angio-architectural characteristics, total injection and procedure times, angiographic and clinical outcomes were analyzed.Results22 patients underwent TFATVE during transvenous endovascular treatment of brain AVMs. Among them, 86.4% were high Spetzler-Martin’s grade. Good clinical outcome (modified Rankin Scale <2) was achieved in 95.5% of the cases, with 0% of procedure-related mortality and 4.5% of clinically significant, procedure-related morbidity. Total occlusion of the nidus was achieved in >90% of the cases at the end of the procedure and angiographic stability was achieved in all cases; 100% of the cases had angiographic cure at follow-up.ConclusionsTFATVE seems a safe and effective technique when conducted in carefully selected patients in highly specialized centers.

Endovascular treatment for cerebral venous thrombosis: current status, challenges, and opportunities

Cerebral venous thrombosis (CVT) mostly affects young people. So far, endovascular treatment (EVT) has not been shown to be beneficial in CVT, partially because venous EVT tools are not yet fully optimized, and therefore EVT is only used as a rescue treatment in rare cases. Identifying a subgroup of CVT patients that could benefit from EVT is challenging, given the milder course of disease compared with acute ischemic stroke, the paucity of data on prognostic factors (both in the clinical and imaging domain), and the lack of consensus on what constitutes 'technical success' in CVT EVT. In this review, we discuss the major obstacles that are encountered when trying to identify CVT patients that may benefit from EVT, and propose a roadmap that could help to overcome these challenges in the near future.

Effect of stroke etiology on endovascular thrombectomy with or without intravenous alteplase: a subgroup analysis of DIRECT-MT

BackgroundStroke etiology might influence the clinical outcomes in patients with large vessel occlusion receiving endovascular treatment (EVT) with or without thrombolysis.ObjectiveTo examine whether stroke etiology resulted in different efficacy and safety in patients treated with EVT-alone or EVT preceded by intravenous alteplase (combined therapy).MethodsWe assessed the efficacy and safety of treatment strategy based on prespecified stroke etiology, cardioembolism (CE), large-artery atherosclerosis (LAA), and undetermined cause (UC) for patients enrolled in the DIRECT-MT trial. The primary outcome was the modified Rankin Scale (mRS) score at 90 days. Multivariate ordinal logistic regression analysis was used to calculate the adjusted common OR for a shift of better mRS score for EVT-alone versus combined therapy. A term was entered to test for interaction.ResultsIn this study, 656 patients were grouped into three prespecified stroke etiologic subgroups. The adjusted common ORs for improvement in the 90-day ordinal mRS score with EVT-alone were 1.2 (95% CI 0.8 to 1.8) for CE, 1.6 (95% CI 0.8 to 3.3) for LAA, and 0.8 (95% CI 0.5 to 1.3) for UC. Compared with CE, EVT-alone was more likely to result in an mRS score of 0–1 (pinteraction=0.047) and extended Thrombolysis in Cerebral Infarction ≥2b (pinteraction=0.041) in the LAA group. The differences in mortality and symptomatic intracranial hemorrhage within 90 days were not significant between the subgroups (p＞0.05).ConclusionsThe results did not support the hypothesis that a specific treatment strategy based on stroke etiology should be used for patients with large vessel occlusion (NCT03469206).

Frontline thrombectomy strategy and outcome in acute basilar artery occlusion

BackgroundNovel thrombectomy strategies emanate expeditiously day-by-day counting on access system, clot retriever device, proximity to and integration with the thrombus, and microcatheter disengagement. Nonetheless, the relationship between native thrombectomy strategies and revascularization success remains to be evaluated in basilar artery occlusion (BAO).PurposeTo compare the safety and efficacy profile of key frontline thrombectomy strategies in BAO.MethodsRetrospective analyses of prospectively maintained stroke registries at two comprehensive stroke centers were performed between January 2015 and December 2019. Patients with BAO selected after MR imaging were categorized into three groups based on the frontline thrombectomy strategy (contact aspiration (CA), stent retriever (SR), or combined (SR+CA)). Patients who experienced failure of clot retrieval followed by an interchanging strategy were categorized as a fourth (switch) group. Clinicoradiological features and procedural variables were compared. The primary outcome measure was the rate of complete revascularization (modified Thrombolysis in Cerebral Infarction (mTICI) grade 2c–3). Favorable outcome was defined as a 90 day modified Rankin Scale score of 0–2.ResultsOf 1823 patients, we included 128 (33 underwent CA, 35 SR, 35 SR +CA, and 25 switch techniques). Complete revascularization was achieved in 83/140 (59%) primarily analyzed patients. SR +CA was associated with higher odds of complete revascularization (adjusted OR 3.04, 95% CI 1.077 to 8.593, p=0.04) which was an independent predictor of favorable outcome (adjusted OR 2.73. 95% CI 1.152 to 6.458, p=0.02). No significant differences were observed for symptomatic intracranial hemorrhage, functional outcome, or mortality rate.ConclusionAmong BAO patients, the combined technique effectively contributed to complete revascularization that showed a 90 day favorable outcome with an equivalent complication rate after thrombectomy.

Nickels and tines: the myth of nickel allergy in intracranial stents

BackgroundMost intracranial stents contain nickel alloy, and nickel allergy or hypersensitivity is common. Neurological injury following endovascular treatment with a nickel containing intracranial stent has been reported in patients with purported nickel allergy, but it is unclear whether these reactions represent true nickel hypersensitivity. We quantified nickel release from commonly used intracranial stents to investigate whether such stents should be avoided in patients with nickel allergy.MethodsWe examined nickel release from seven commonly used intracranial stents: Enterprise, LVIS Jr, Neuroform, Wingspan, Zilver, Pipeline Flex Embolization Device, and Surpass Evolve. We incubated each stent in human plasma-like media for 30 days. Dimethylglyoxime (DMG) spot testing was performed on each stent to detect released nickel at 0 and 30 days. Inductively coupled plasma–optical emission spectroscopy (ICP-OES) was then used to quantify the nickel concentration of the media at 30 days. Nickel currency and nickel standard for atomic absorption spectrometry were used as positive controls.ResultsDMG spot tests indicated nickel release only from nickel currency at 0 and 30 days of incubation. No nickel release was detected from any stent at 30 days using ICP-OES.ConclusionsNickel release from commonly used intracranial stents is negligible. These results suggest that previously reported hypersensitivity to these stents may be misattributed to nickel allergy, and that patients with nickel allergy may be safely treated with select nickel-containing stents.