Outcomes with Endovascular Treatment of Patients with M2 Segment MCA Occlusion in the Late Time Window.

BACKGROUND AND PURPOSE: Randomized trials in the late window have demonstrated the efficacy and safety of endovascular thrombectomy in large-vessel occlusions. Patients with M2-segment MCA occlusions were excluded from these trials. We compared outcomes with endovascular thrombectomy in patients with M2-versus-M1 occlusions presenting 6-24 hours after symptom onset. MATERIALS AND METHODS: Analyses were on pooled data from studies enrolling patients with stroke treated with endovascular thrombectomy 6-24 hours after symptom onset. We compared 90-day functional independence (mRS ≤ 2), mortality, symptomatic intracranial hemorrhage, and successful reperfusion (expanded TICI = 2b-3) between patients with M2 and M1 occlusions. The benefit of successful reperfusion was then assessed among patients with M2 occlusion. RESULTS: Of 461 patients, 367 (79.6%) had M1 occlusions and 94 (20.4%) had M2 occlusions. Patients with M2 occlusions were older and had lower median baseline NIHSS scores. Patients with M2 occlusion were more likely to achieve 90-day functional independence than those with M1 occlusion (adjusted OR = 2.13; 95% CI, 1.25-3.65). There were no significant differences in the proportion of successful reperfusion (82.9% versus 81.1%) or mortality (11.2% versus 17.2%). Symptomatic intracranial hemorrhage risk was lower in patients with M2-versus-M1 occlusions (4.3% versus 12.2%, P = .03). Successful reperfusion was independently associated with functional independence among patients with M2 occlusions (adjusted OR = 2.84; 95% CI, 1.11-7.29). CONCLUSIONS: In the late time window, patients with M2 occlusions treated with endovascular thrombectomy achieved better clinical outcomes, similar reperfusion, and lower symptomatic intracranial hemorrhage rates compared with patients with M1 occlusion. These results support the safety and benefit of endovascular thrombectomy in patients with M2 occlusions in the late window.

Prevalence of Intracranial Atherosclerotic Disease in Patients with Low-Risk Transient or Persistent Neurologic Events.

BACKGROUND AND PURPOSE: There are limited data on the prevalence and outcome of intracranial atherosclerotic disease in patients with low-risk transient or persistent minor neurologic events. We sought to determine the prevalence and risk factors associated with intracranial atherosclerotic disease in patients with low-risk transient or persistent neurologic events. MATERIALS AND METHODS: Participants with available intracranial vascular imaging from the Diagnosis of Uncertain-Origin Benign Transient Neurologic Symptoms (DOUBT) study, a large prospective multicenter cohort study, were included in this post hoc analysis. The prevalence of intracranial atherosclerotic disease of ≥50% was determined, and the association with baseline characteristics and DWI lesions was evaluated using logistic regression. RESULTS: We included 661 patients with a median age of 62 years (interquartile range, 53-70 years), of whom 53% were women. Intracranial atherosclerotic disease was found in 81 (12.3%) patients; asymptomatic intracranial atherosclerotic disease alone, in 65 (9.8%); and symptomatic intracranial atherosclerotic disease, in 16 (2.4%). The most frequent location was in the posterior cerebral artery (29%). Age was the only factor associated with any intracranial atherosclerotic disease (adjusted OR, 1.9 for 10 years increase; 95% CI, 1.6-2.5). Multivariable logistic regression showed a strong association between intracranial atherosclerotic disease and the presence of acute infarct on MR imaging (adjusted OR, 3.47; 95% CI, 1.91-6.25). CONCLUSIONS: Intracranial atherosclerotic disease is not rare in patients with transient or persistent minor neurologic events and is independently associated with the presence of MR imaging-proved ischemia in this context. Evaluation of the intracranial arteries could be valuable in establishing the etiology of such low-risk events.

Strength of Association between Infarct Volume and Clinical Outcome Depends on the Magnitude of Infarct Size: Results from the ESCAPE-NA1 Trial.

BACKGROUND AND PURPOSE: Infarct volume is an important predictor of clinical outcome in acute stroke. We hypothesized that the association of infarct volume and clinical outcome changes with the magnitude of infarct size. MATERIALS AND METHODS: Data were derived from the Safety and Efficacy of Nerinetide in Subjects Undergoing Endovascular Thrombectomy for Stroke (ESCAPE-NA1) trial, in which patients with acute stroke with large-vessel occlusion were randomized to endovascular treatment plus either nerinetide or a placebo. Infarct volume was manually segmented on 24-hour noncontrast CT or DWI. The relationship between infarct volume and good outcome, defined as mRS 0-2 at 90 days, was plotted. Patients were categorized on the basis of visual grouping at the curve shoulders of the infarct volume/outcome plot. The relationship between infarct volume and adjusted probability of good outcome was fitted with linear or polynomial functions as appropriate in each group. RESULTS: We included 1099 individuals in the study. Median infarct volume at 24 hours was 24.9 mL (interquartile range [IQR] = 6.6-92.2 mL). On the basis of the infarct volume/outcome plot, 4 infarct volume groups were defined (IQR = 0-15 mL, 15.1-70 mL, 70.1-200 mL, >200 mL). Proportions of good outcome in the 4 groups were 359/431 (83.3%), 219/337 (65.0%), 71/201 (35.3%), and 16/130 (12.3%), respectively. In small infarcts (IQR = 0-15 mL), no relationship with outcome was appreciated. In patients with intermediate infarct volume (IQR = 15-200 mL), there was progressive importance of volume as an outcome predictor. In infarcts of > 200 mL, outcomes were overall poor. CONCLUSIONS: The relationship between infarct volume and clinical outcome varies nonlinearly with the magnitude of infarct size. Infarct volume was linearly associated with decreased chances of achieving good outcome in patients with moderate-to-large infarcts, but not in those with small infarcts. In very large infarcts, a near-deterministic association with poor outcome was seen.

Infarct Growth despite Successful Endovascular Reperfusion in Acute Ischemic Stroke: A Meta-analysis.

BACKGROUND: Infarct volume inversely correlates with good recovery in stroke. The magnitude and predictors of infarct growth despite successful reperfusion via endovascular treatment are not known. PURPOSE: We aimed to summarize the extent of infarct growth in patients with acute stroke who achieved successful reperfusion (TICI 2b-3) after endovascular treatment. DATA SOURCES: We performed a systematic review and meta-analysis by searching MEDLINE and Google Scholar for articles published up to October 31, 2020. STUDY SELECTION: Studies of >10 patients reporting baseline and post-endovascular treatment infarct volumes on MR imaging were included. Only patients with TICI 2b-3 were included. We calculated infarct growth at a study level as the difference between baseline and follow-up MR imaging infarct volumes. DATA ANALYSIS: Our search yielded 345 studies, and we included 10 studies reporting on 973 patients having undergone endovascular treatment who achieved successful reperfusion. DATA SYNTHESIS: The mean baseline infarct volume was 19.5 mL, while the mean final infarct volume was 37.5 mL. A TICI 2b reperfusion grade was achieved in 24% of patients, and TICI 2c or 3 in 76%. The pooled mean infarct growth was 14.8 mL (95% CI, 7.9-21.7 mL). Meta-regression showed higher infarct growth in studies that reported higher baseline infarct volumes, higher rates of incomplete reperfusion (modified TICI 2b), and longer onset-to-reperfusion times. LIMITATIONS: Significant heterogeneity among studies was noted and might be driven by the difference in infarct growth between early- and late-treatment studies. CONCLUSIONS: These results suggest considerable infarct growth despite successful endovascular treatment reperfusion and call for a faster workflow and the need for specific therapies to limit infarct growth.

Clinical and Procedural Outcomes with or without Balloon Guide Catheters during Endovascular Thrombectomy in Acute Ischemic Stroke: A Systematic Review and Meta-analysis with First-line Technique Subgroup Analysis.

BACKGROUND: Balloon guide catheters are increasingly used to improve clot retrieval by temporarily stopping proximal blood flow during endovascular thrombectomy. PURPOSE: Our aim was to provide a summary of the literature comparing the procedural and clinical outcomes of endovascular thrombectomy with or without balloon guide catheters, depending on the first-line technique used. DATA SOURCES: We used PubMed/MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews. STUDY SELECTION: We chose studies that compared using balloon guide catheters with not using them. DATA ANALYSIS: Random effects meta-analysis was performed to compare the procedural outcomes measured as the first-pass effect, successful reperfusion, number of passes, procedural duration, arterial puncture to reperfusion time, distal emboli, and clinical outcomes. DATA SYNTHESIS: Overall, a meta-analysis of 16 studies (5507 patients, 50.8% treated with balloon guide catheters and 49.2% without them) shows that the use of balloon guide catheters increases the odds of achieving a first-pass effect (OR = 1.92; 95% CI, 1.34-2.76; P < .001), successful reperfusion (OR = 1.85; 95% CI, 1.42-2.40; P < .001), and good functional outcome (OR =1.48; 95% CI, 1.27-1.73; P < .001). Balloon guide catheters reduce the number of passes (mean difference = -0.35; 95% CI, -0.65 to -0.04; P = .02), procedural time (mean difference = -19.73; 95% CI, -34.63 to -4.83; P = .009), incidence of distal or new territory emboli (OR = 0.5; 95% CI, 0.26-0.98; P = .04), and mortality (OR = 0.72; 95% CI, 0.62-0.85; P < .001). Similar benefits of balloon guide catheters are observed when the first-line technique was a stent retriever or contact aspiration, but not for a combined approach. LIMITATIONS: The analysis was based on nonrandomized trials with a moderate risk of bias. CONCLUSIONS: Current literature suggests improved clinical and procedural outcomes associated with the use of balloon guide catheters during endovascular thrombectomy, especially when using the first-line stent retriever.

The Risk of Stroke and TIA in Nonstenotic Carotid Plaques: A Systematic Review and Meta-Analysis.

BACKGROUND: Severe carotid stenosis carries a high risk of stroke. However, the risk of stroke with nonstenotic carotid plaques (<50%) is increasingly recognized. PURPOSE: We aimed to summarize the risk of TIA or stroke in patients with nonstenotic carotid plaques. DATA SOURCES: We performed a comprehensive systematic review and meta-analysis in patients with acute ischemic stroke in whom carotid imaging was performed using MEDLINE and the Cochrane Database, including studies published up to December 2019. STUDY SELECTION: Included studies had >10 patients with <50% carotid plaques on any imaging technique and reported the incidence or recurrence of ischemic stroke/TIA. High-risk plaque features and the risk of progression to stenosis >50% were extracted if reported. DATA SYNTHESIS: We identified 31 studies reporting on the risk of ipsilateral stroke/TIA in patients with nonstenotic carotid plaques. Twenty-five studies (n = 13,428 participants) reported on first-ever stroke/TIA and 6 studies (n = 122 participants) reported on the recurrence of stroke/TIA. DATA ANALYSIS: The incidence of first-ever ipsilateral stroke/TIA was 0.5/100 person-years. The risk of recurrent stroke/TIA was 2.6/100 person-years and increased to 4.9/100 person-years if intraplaque hemorrhage was present. The risk of progression to severe stenosis (>50%) was 2.9/100 person-years (8 studies, n = 448 participants). LIMITATIONS: Included studies showed heterogeneity in reporting stroke etiology, the extent of stroke work-up, imaging modalities, and classification systems used for characterizing carotid stenosis. CONCLUSIONS: The risk of recurrent stroke/TIA in nonstenotic carotid plaques is not negligible, especially in the presence of high-risk plaque features. Further research is needed to better define the significance of nonstenotic carotid plaques for stroke etiology.

Endovascular Treatment Decisions in Patients with M2 Segment MCA Occlusions.

BACKGROUND AND PURPOSE: Endovascular therapy in acute ischemic stroke is rapidly evolving. We explored physicians' treatment attitudes and practice in patients with acute ischemic stroke due to M2 occlusion, given the absence of Level-1 guidelines. MATERIALS AND METHODS: We conducted an international multidisciplinary survey among physicians involved in acute stroke care. Respondents were presented with 10 of 22 case scenarios (4 with proximal M2 occlusions and 1 with a small-branch M2 occlusion) and asked about their treatment approach under A) current local resources, and B) assumed ideal conditions (no monetary or infrastructural restraints). Overall treatment decisions were evaluated; subgroup analyses by physician and patient baseline characteristics were performed. RESULTS: A total of 607 physicians participated. Most of the respondents decided in favor of endovascular therapy in M2 occlusions, both under current local resources and assumed ideal conditions (65.4% versus 69.6%; P = .017). Under current local resources, older patient age (P < .001), longer time since symptom onset (P < .001), high center endovascular therapy volume (P < .001), high personal endovascular therapy volume (P = .005), and neurosurgeons (P < .001) were more likely to favor endovascular therapy. European respondents were less likely to favor endovascular therapy (P = .001). Under assumed ideal conditions, older patient age (P < .001), longer time since symptom onset (P < .001), high center endovascular therapy volume (P = .041), high personal endovascular therapy volume (P = .002), and Asian respondents were more likely to favor endovascular therapy (P = .037). Respondents with more experience (P = .048) and high annual stroke thrombolysis treatment volume (P = .001) were less likely to favor endovascular therapy. CONCLUSIONS: Patients with M2 occlusions are considered appropriate candidates for endovascular therapy by most respondents in this survey, especially by those performing endovascular therapy more often and those practicing in high-volume centers.

How Do Physicians Approach Intravenous Alteplase Treatment in Patients with Acute Ischemic Stroke Who Are Eligible for Intravenous Alteplase and Endovascular Therapy? Insights from UNMASK-EVT.

BACKGROUND AND PURPOSE: With increasing use of endovascular therapy, physicians' attitudes toward intravenous alteplase in endovascular therapy-eligible patients may be changing. We explored current intravenous alteplase treatment practices of physicians in endovascular therapy- and alteplase-eligible patients with acute stroke using prespecified case scenarios and compared how their current local treatment practices differ compared with an assumed ideal environment. MATERIALS AND METHODS: In an international multidisciplinary survey, 607 physicians involved in acute stroke care were randomly assigned 10 of 22 case scenarios, among them 14 with guideline-based alteplase recommendations (9 with level 1A and 5 with level 2B recommendation) and were asked how they would treat the patient: A) under their current local resources, and B) under assumed ideal conditions. Answer options were the following: 1) anticoagulation/antiplatelet therapy, 2) endovascular therapy, 3) endovascular therapy plus intravenous alteplase, and 4) intravenous alteplase. Decision rates were calculated, and multivariable regression analysis was performed to determine variables associated with the decision to abandon intravenous alteplase. RESULTS: In cases with guideline recommendations for alteplase, physicians favored alteplase in 82.0% under current local resources and in 79.3% under assumed ideal conditions (P < .001). Under assumed ideal conditions, interventional neuroradiologists would refrain from intravenous alteplase most often (6.28%, OR = 2.40; 95% CI, 1.01-5.71). When physicians' current and ideal decisions differed, most would like to add endovascular therapy to intravenous alteplase in an ideal setting (196/3861 responses, 5.1%). CONCLUSIONS: In patients eligible for endovascular therapy and intravenous alteplase, we observed a slightly lower decision rate in favor of intravenous alteplase under assumed ideal conditions compared with the decision rate under current local resources.

Stroke in the Middle-East and North Africa: A 2-year prospective observational study of intravenous thrombolysis treatment in the region. Results from the SITS-MENA Registry.

BACKGROUND AND METHODS: Intravenous thrombolysis for acute ischemic stroke in the Middle-East and North African (MENA) countries is still confined to the main urban and university hospitals. This was a prospective observational study to examine outcomes of intravenous thrombolysis-treated stroke patients in the MENA region compared to the non-MENA stroke cohort in the SITS International Registry. RESULTS: Of 32,160 patients with ischemic stroke registered using the SITS intravenous thrombolysis protocol between June 2014 and May 2016, 500 (1.6%) were recruited in MENA. Compared to non-MENA (all p < 0.001), median age in MENA was 55 versus 73 years, NIH Stroke Scale score 12 versus 9, onset-to-treatment time 138 versus 155 min and door-to-needle time 54 min versus 64 min. Hypertension was the most reported risk factor, but lower in MENA (51.7 vs. 69.7%). Diabetes was more frequent in MENA (28.5 vs. 20.8%) as well as smoking (20.8 vs. 15.9%). Hyperlipidemia was less observed in MENA (17.6 vs. 29.3%). Functional independence (mRS 0-2) at seven days or discharge was similar (53% vs. 52% in non-MENA), with mortality slightly lower in MENA (2.3% vs. 4.8%). SICH rates by SITS-MOST definition were low (<1.4%) in both groups. CONCLUSIONS: Intravenous thrombolysis patients in MENA were younger, had more severe strokes and more often diabetes. Although stroke severity was higher in MENA, short-term functional independency and mortality were not worse compared to non-MENA, which could partly be explained by younger age and shorter OTT in MENA. Decreasing the burden of stroke in this young population should be prioritized.

Imaging Triage of Patients with Late-Window (6-24 Hours) Acute Ischemic Stroke: A Comparative Study Using Multiphase CT Angiography versus CT Perfusion.

BACKGROUND AND PURPOSE: The role of collateral imaging in selecting patients for endovascular thrombectomy beyond 6 hours from onset has not been established. To assess the comparative utility of collateral imaging using multiphase CTA in selecting late window patients for EVT. MATERIALS AND METHODS: We used data from a prospective multicenter observational study in which all patients underwent imaging with multiphase CT angiography as well as CTP. Two blinded reviewers evaluated patients' eligibility for endovascular thrombectomy using published collateral imaging (multiphase CTA) criteria compared with CTP using the selection criteria of the Clinical Mismatch in the Triage of Wake Up and Late Presenting Strokes Undergoing Neurointervention with Trevo (DAWN) and Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3 (DEFUSE-3) trials. CTP images were processed using automated commercial software. The outcomes of patients eligible for endovascular thrombectomy according to multiphase CTA, DAWN, or DEFUSE-3 criteria were compared using multivariable logistic regression modeling. Model characteristics were compared using the C-statistic for the receiver operating characteristic curve, the Akaike information criterion, and the Bayesian information criterion. RESULTS: Eighty-six patients presented beyond 6 hours from onset/last known well (median, 9.6 hours; interquartile range, 4.1 hours). Thirty-five patients (40.7%) received endovascular thrombectomy, of whom good functional outcome (90-day mRS, 0-2) was achieved in 16/35 (47%). Collateral-based imaging paradigms significantly modified the treatment effect of endovascular thrombectomy on 90-day mRS 0-2 (P interaction = .007). The multiphase CTA-based regression model best fit the data for the 90-day outcome (C-statistic, 0.86; 95% CI, 0.77-0.94) and was associated with the least information loss (Akaike information criterion, 95.7; Bayesian information criterion, 114.9) compared with CTP-based models. CONCLUSIONS: The collateral-based imaging paradigm using multiphase CTA compares well with CTP in selecting patients for endovascular thrombectomy in the late time window.

Imaging of Patients with Suspected Large-Vessel Occlusion at Primary Stroke Centers: Available Modalities and a Suggested Approach.

The overwhelming benefit of endovascular therapy in patients with large-vessel occlusions suggests that more patients will be screened than treated. Some of those patients will be evaluated first at primary stroke centers; this type of evaluation calls for standardizing the imaging approach to minimize delays in assessing, transferring, and treating these patients. Here, we propose that CT angiography (performed at the same time as head CT) should be the minimum imaging approach for all patients with stroke with suspected large-vessel occlusion presenting to primary stroke centers. We discuss some of the implications of this approach and how to facilitate them.

Early reperfusion rates with IV tPA are determined by CTA clot characteristics.

BACKGROUND AND PURPOSE: An ability to predict early reperfusion with IV tPA in patients with acute ischemic stroke and intracranial clots can help clinicians decide if additional intra-arterial therapy is needed or not. We explored the association between novel clot characteristics on baseline CTA and early reperfusion with IV tPA in patients with acute ischemic stroke by using classification and regression tree analysis. MATERIALS AND METHODS: Data are from patients with acute ischemic stroke and proximal anterior circulation occlusions from the Calgary CTA data base (2003-2012) and the Keimyung Stroke Registry (2005-2009). Patients receiving IV tPA followed by intra-arterial therapy were included. Clot location, length, residual flow within the clot, ratio of contrast Hounsfield units pre- and postclot, and the M1 segment origin to the proximal clot interface distance were assessed on baseline CTA. Early reperfusion (TICI 2a and above) with IV tPA was assessed on the first angiogram. RESULTS: Two hundred twenty-eight patients (50.4% men; median age, 69 years; median baseline NIHSS score, 17) fulfilled the inclusion criteria. Median symptom onset to IV tPA time was 120 minutes (interquartile range = 70 minutes); median IV tPA to first angiography time was 70.5 minutes (interquartile range = 62 minutes). Patients with residual flow within the clot were 5 times more likely to reperfuse than those without it. Patients with residual flow and a shorter clot length (≤15 mm) were most likely to reperfuse (70.6%). Patients with clots in the M1 MCA without residual flow reperfused more if clots were distal and had a clot interface ratio in Hounsfield units of <2 (36.8%). Patients with proximal M1 clots without residual flow reperfused 8% of the time. Carotid-T/-L occlusions rarely reperfused (1.7%). Interrater reliability for these clot characteristics was good. CONCLUSIONS: Our study shows that clot characteristics on CTA help physicians estimate a range of early reperfusion rates with IV tPA.

Impact of age and baseline NIHSS scores on clinical outcomes in the mechanical thrombectomy using solitaire FR in acute ischemic stroke study.

BACKGROUND AND PURPOSE: Age and stroke severity are inversely correlated with the odds of favorable outcome after ischemic stroke. A previously proposed score for Stroke Prognostication Using Age and NIHSS Stroke Scale (SPAN) indicated that SPAN-100-positive patients (ie, age + NIHSS score = 100 or more) do not benefit from IV-tPA. If this finding holds true for endovascular therapy, this score can impact patient selection for such interventions. This study investigated whether a score combining age and NIHSS score can improve patients' selection for endovascular stroke therapy. MATERIALS AND METHODS: The SPAN index was calculated for patients in the prospective Solitaire FR Thrombectomy for Acute Revascularization study: an international single-arm multicenter cohort for anterior circulation stroke treatment by using the Solitaire FR. The proportion with favorable outcome (90-day mRS score ≤2) was compared between SPAN-100-positive versus-negative patients. RESULTS: Of the 202 patients enrolled, 196 had baseline NIHSS scores. Fifteen (7.7%) patients were SPAN-100-positive. There was no difference in the rate of successful reperfusion (Thrombolysis In Cerebral Infarction 2b or 3) between SPAN-100-positive versus -negative groups (93.3% versus 82.8%, respectively; P = .3). Stroke SPAN-100-positive patients had a significantly lower proportion of favorable clinical outcomes (26.7% versus 60.8% in SPAN-100-negative, P = .01). In a multivariable analysis, SPAN-100-positive status was associated with lower odds of favorable outcome (OR, 0.3; 95% CI, 0.1-0.9; P = .04). A higher baseline Alberta Stroke Program Early CT Score and a short onset to revascularization time also predicted favorable outcome in the multivariable analysis. CONCLUSIONS: A significantly lower proportion of patients with a positive SPAN-100 achieved favorable outcome in this cohort. SPAN-100 was an independent predictor of favorable outcome after adjusting for time to treatment and the extent of preintervention tissue damage according to the Alberta Stroke Program Early CT Score.

CTA collateral status and response to recanalization in patients with acute ischemic stroke.

BACKGROUND AND PURPOSE: Collateral status at baseline is an independent determinant of clinical outcome among patients with acute ischemic stroke. We sought to identify whether the association between recanalization after intra-arterial acute stroke therapy and favorable clinical response is modified by the presence of good collateral flow assessed on baseline CTA. MATERIALS AND METHODS: Data are from the Keimyung Stroke Registry, a prospective cohort study of patients with acute ischemic stroke from Daegu, South Korea. Patients with M1 segment MCA with or without intracranial ICA occlusions on baseline CTA from May 2004 to July 2009 who also had baseline MR imaging were included. Two readers blinded to all clinical information assessed baseline and follow-up imaging. Leptomeningeal collaterals on baseline CTA were assessed by consensus by use of the regional leptomeningeal score. RESULTS: Among 84 patients (mean age, 65.2 ± 13.2 years; median NIHSS score, 14; interquartile range, 8.5), median time from stroke onset to initial MR imaging was 164 minutes. TICI 2b-3 recanalization was achieved in 38.1% of patients and mRS 0-2 at 90 days in 35.8% of patients. In a multivariable model, the interaction between collateral status and recanalization was significant. Only patients with intermediate or good collaterals who recanalized showed a statistically significant association with good clinical outcome (rate ratio = 3.8; 95% CI, 1.2-12.1). Patients with good and intermediate collaterals who did not achieve recanalization and patients with poor collaterals, even if they achieved recanalization, did not do well. CONCLUSIONS: Patients with good or intermediate collaterals on CTA benefit from intra-arterial therapy, whereas patients with poor collaterals do not benefit from treatment.

When is carotid angioplasty and stenting the cost-effective alternative for revascularization of symptomatic carotid stenosis? A Canadian health system perspective.

BACKGROUND AND PURPOSE: Carotid revascularization procedures can be complicated by stroke. Additional disability adds to the already high costs of the procedure. To weigh the cost and benefit, we estimated the cost-utility of carotid angioplasty and stenting compared with carotid endarterectomy among patients with symptomatic carotid stenosis, with special emphasis on scenario analyses that would yield carotid angioplasty and stenting as the cost-effective alternative relative to carotid endarterectomy. MATERIALS AND METHODS: A cost-utility analysis from the perspective of the health system payer was performed by using a Markov analytic model. Clinical estimates were based on a meta-analysis. The procedural costs were derived from a microcosting data base. The costs for hospitalization and rehabilitation of patients with stroke were based on a Canadian multicenter study. Utilities were based on a randomized controlled trial. RESULTS: In the base case analysis, carotid angioplasty and stenting were more expensive (incremental cost of $6107) and had a lower utility (-0.12 quality-adjusted life years) than carotid endarterectomy. The results are sensitive to changes in the risk of clinical events and the relative risk of death and stroke. Carotid angioplasty and stenting were more economically attractive among high-risk surgical patients. For carotid angioplasty and stenting to become the preferred option, their costs would need to fall from more than $7300 to $4350 or less and the risks of the periprocedural and annual minor strokes would have to be equivalent to that of carotid endarterectomy. CONCLUSIONS: In the base case analysis, carotid angioplasty and stenting were associated with higher costs and lower utility compared with carotid endarterectomy for patients with symptomatic carotid stenosis. Carotid angioplasty and stenting were cost-effective for patients with high surgical risk.

Mechanical thrombectomy with the Solitaire stent: is there a learning curve in achieving rapid recanalization times?

METHODS: In acute ischemic stroke, good outcome following successful recanalization is time dependent. In patients undergoing endovascular therapy at our institution, recanalization times with the Solitaire stent were retrospectively evaluated to assess for the presence of a learning curve in achieving rapid recanalization. METHODS: We reviewed patients who presented to our stroke center and achieved successful recanalization with the Solitaire stent exclusively. Time intervals were calculated (CT to angiography arrival, angiography arrival to groin puncture, groin puncture to first deployment, and deployment to recanalization) from time stamped images and angiography records. Patients were divided into three sequential groups, with overall CT to recanalization time and subdivided time intervals compared. RESULTS: 83 patients were treated with the Solitaire stent from May 2009 to February 2012. Recanalization (Thrombolyis in Cerebral Infarction score 2A) occurred in 75 (90.4%) patients. CT to recanalization demonstrated significant improvement over time, which was greatest between the first 25 and the most recent 25 cases (161-94 min; p<0.01). The maximal contribution to this was from improvements in first stent deployment to recanalization time (p=0.001 between the first and third groups), with modest contributions from moving patients from CT to the angiography suite faster (p=0.02 between the first and third groups) and from groin puncture to first stent deployment (p=0.02 between the first and third groups). CONCLUSIONS: There is a learning curve involved in the efficient use of the Solitaire stent in endovascular acute stroke therapy. Along with improvements in patient transfer to angiography and improved efficiency with intracranial access, mastering this device contributed significantly towards reducing recanalization times.

A meta-analysis of observational intra-arterial stroke therapy studies using the Merci device, Penumbra system, and retrievable stents.

BACKGROUND AND PURPOSE: The time from arterial puncture to successful recanalization is an important milestone toward timely recanalization. With the significant improvement in recanalization rates by using thrombectomy devices, procedural time to recanalization is becoming a determinant factor in choosing among available devices. We aimed to assess the impact of time to recanalization on the outcome of intra-arterial stroke therapies. MATERIALS AND METHODS: We conducted a meta-analysis of studies reporting procedural times in patients with stroke treated with the MD, PS, and RS. RESULTS: We identified 16 eligible studies: 4 on the MD (n = 357), 8 on the PS (n = 455), and 4 on RS (n = 113). Merci device studies described total procedural duration, while PS and RS studies described puncture-to-recanalization times. With a random-effects model, mean procedural duration for the MD was 120 minutes (95% CI, 105.7-134.2 minutes). Mean puncture to recanalization time for the PS was 64.6 minutes (95% CI, 44.4-84.8 minutes) and 54.7 minutes for RS (95% CI, 47.3-62.2 minutes). Successful recanalization was achieved in 211 of 357 patients (59.1%) in the MD studies (95% CI, 49.3-77.7), 394 of 455 (86.6%) in the PS studies (95% CI, 84.1-93.8), and 105 of 113 (92.9%) in the RS studies (95% CI, 90.9-99.9). Functional independence (mRS ≤2) was achieved in 31.5% of patients in the MD studies, 36.6% in the PS studies, and 46.9% in the RS studies. CONCLUSIONS: The use of the PS and RS was associated with comparable procedural time to recanalization. Available data did not allow this parameter to be determined for trials using the MD. Retrievable stents achieved the highest rate of successful recanalization and functional outcome and the lowest mortality.