Impact of Time to Treatment on Endovascular Thrombectomy Outcomes in the Early Versus Late Treatment Time Windows.

BACKGROUND: The impact of time to treatment on outcomes of endovascular thrombectomy (EVT) especially in patients presenting after 6 hours from symptom onset is not well characterized. We studied the differences in characteristics and treatment timelines of EVT-treated patients participating in the Florida Stroke Registry and aimed to characterize the extent to which time impacts EVT outcomes in the early and late time windows. METHODS: Prospectively collected data from Get With the Guidelines-Stroke hospitals participating in the Florida Stroke Registry from January 2010 to April 2020 were reviewed. Participants were EVT patients with onset-to-puncture time (OTP) of ≤24 hours and categorized into early window treated (OTP ≤6 hours) and late window treated (OTP >6 and ≤24 hours). Association between OTP and favorable discharge outcomes (independent ambulation, discharge home and to acute rehabilitation facility) as well as symptomatic intracerebral hemorrhage and in-hospital mortality were examined using multilevel-multivariable analysis with generalized estimating equations. RESULTS: Among 8002 EVT patients (50.9% women; median age [±SD], 71.5 [±14.5] years; 61.7% White, 17.5% Black, and 21% Hispanic), 34.2% were treated in the late time window. Among all EVT patients, 32.4% were discharged home, 23.5% to rehabilitation facility, 33.7% ambulated independently at discharge, 5.1% had symptomatic intracerebral hemorrhage, and 9.2% died. As compared with the early window, treatment in the late window was associated with lower odds of independent ambulation (odds ratio [OR], 0.78 [0.67-0.90]) and discharge home (OR, 0.71 [0.63-0.80]). For every 60-minute increase in OTP, the odds of independent ambulation reduced by 8% (OR, 0.92 [0.87-0.97]; P<0.001) and 1% (OR, 0.99 [0.97-1.02]; P=0.5) and the odds of discharged home reduced by 10% (OR, 0.90 [0.87-0.93]; P<0.001) and 2% (OR, 0.98 [0.97-1.00]; P=0.11) in the early and late windows, respectively. CONCLUSIONS: In routine practice, just over one-third of EVT-treated patients independently ambulate at discharge and only half are discharged to home/rehabilitation facility. Increased time from symptom onset to treatment is significantly associated with lower chance of independent ambulation and ability to be discharged home after EVT in the early time window.

Direct Bypass Surgery for Moyamoya and Steno-occlusive Vasculopathy: Clinical Outcomes, Intraoperative Blood Flow Analysis, Long-term Follow-up, and Long-term Bypass Patency in a Single Surgeon Case Series of 162 Procedures.

BACKGROUND: Cerebral extracranial-intracranial (EC-IC) direct bypass is a commonly used procedure for the treatment of cerebral hypoperfusion secondary to chronic steno-occlusive vasculopathy. We sought to determine clinical outcomes, intraoperative blood flow analysis, long term follow up, and long term patency rates from a single surgeon's series of direct cerebral bypass for moyamoya disease, moyamoya syndrome, and steno-occlusive disease. METHODS: We reviewed clinical, demographic, operative and neuroimaging records for all patients who underwent a direct EC-IC bypass by the senior author between August 1999 and November 2020. Primary outcomes analyzed were functional long-term outcomes (by modified Rankin score [mRS]), surgical complications, and short-term and long-term bypass patency. RESULTS: A total of 162 revascularization procedures in 124 patients were performed. Mean clinical follow up time was 2 years 11 months. The combined immediate and long term postoperative stroke and/or intracerebral hemorrhage rate was 6.2%. There were 17 bypasses (10%) that were found to be occluded at long-term follow-up, all but one were asymptomatic. Long-term graft occlusion was correlated with presence of complete collateralization on preoperative angiography but not cut flow index (CFI). Overall, patients had a significant clinical improvement with a mean mRS score 1.8 preoperatively and 1.2 postoperatively. CONCLUSIONS: In our consecutive series of patients treated with direct EC-IC cerebral bypass, there was significant improvement in functional outcome as measured by the mRS. The long term patency rate was 90%. There was a statistically significant correlation between complete or incomplete angiographic collateralization patterns and long-term bypass occlusion. There was no correlation between bypass type, clinical syndrome, or CFI and long-term occlusions. The role of bypass surgery and the need for surgical expertise remain strong in the treatment of moyamoya variants and a select group of atherosclerotic steno-occlusive patients.

Accuracy of transcranial Doppler in detecting intracranial stenosis in patients with sickle cell anemia when compared to magnetic resonance angiography.

BACKGROUND: Stroke, the most devastating consequence of sickle cell anemia (SCA), is associated with endothelial damage and intracranial artery stenosis. We aimed to assess transcranial Doppler (TCD) ultrasound accuracy in detecting intracranial stenosis when compared to magnetic resonance angiography (MRA). METHODS: Children with SCA and at least one TCD and MRA within 1 month were identified from a retrospectively collected database. Sensitivity and specificity were obtained to assess the overall accuracy of TCD mean flow velocity (mFV) ≥200 cm/s in detecting vessel stenosis of ≥50%. Multivariate analysis identified independent factors associated with MRA stenosis. RESULTS: Among 157 patients in the database, 64 had a TCD and MRA within 1 month (age 11.8 ± 5.3 years, 56% female, 20% with cerebral infarcts on MRI, 8 or 13% had mFV ≥200 cm/s and 20% or 21%, had intracranial stenosis ≥50% on MRA). TCD mFV ≥200 cm/s had a high specificity (95%) but low sensitivity (29%) to detecting intracranial stenosis. As a continuous variable, TCD mFV of 137.5 cm/s had maximal specificity (77%) and sensitivity (72%). After adjustment for age, hemoglobin level, transfusion status, hydroxyurea treatment, and vessel, for every increase in cm/sec on TCD, there was a 2% increase in the odds of ≥50% stenosis on MRA (p < 0.001). CONCLUSION: Our study reports TCD mFV is a positive predictor of MRA stenosis in SCA, independent of patient characteristics, including hemoglobin. A mFV ≥200 cm/s is highly specific but less sensitive in detecting stenosis ≥50%. Lower mFV cut points may be needed for the early detection of intracranial stenosis.

Endovascular Therapy in Mild Ischemic Strokes Presenting Under 6 hours: An International Survey.

BACKGROUND: Endovascular therapy (EVT) for patients with mild ischemic stroke (NIHSS ≤5) and visible intracranial occlusion remains controversial, including within 6 hours of symptom onset. We conducted a survey to evaluate global practice patterns of EVT in this population. METHODS: Vascular stroke clinicians and neurointerventionalists were invited to participate through professional stroke listservs. The survey consisted of six clinical vignettes of mild stroke patients with intracranial occlusion. Cases varied by NIHSS, neurological symptoms and occlusion site. All had the same risk factors, time from symptom onset (5h) and unremarkable head CT. Advanced imaging data was available upon request. We explored independent case and responder specific factors associated with advanced imaging request and EVT decision. RESULTS: A total of 482/492 responders had analyzable data ([median age 44 (IQR 11.25)], 22.7% women, 77% attending, 22% interventionalist). Participants were from USA (45%), Europe (32%), Australia (12%), Canada (6%), and Latin America (5%). EVT was offered in 48% (84% M1, 29% M2 and 19% A2) and decision was made without advanced imaging in 66% of cases. In multivariable analysis, proximal occlusion (M1 vs. M2 or A2, p<0.001), higher NIHSS (p<0.001) and fellow level training (vs. attending; p=0.001) were positive predictors of EVT. Distal occlusions (M2 and A2) and higher age of responders were independently associated with increased advanced imaging requests. Compared to US and Australian responders, Canadians were less likely to offer EVT, while those in Europe and Latin America were more likely (p<0.05). CONCLUSIONS: Treatment patterns of EVT in mild stroke vary globally. Our data suggest wide equipoise exists in current treatment of this important subset of mild stroke.