Does Small Vessel Disease Burden Impact Collateral Circulation in Ischemic Stroke Treated by Mechanical Thrombectomy?

Background and Purpose- The development of leptomeningeal collateral artery network might be adversely affected by small vessel wall alteration. We sought to determine whether small vessel disease (SVD) burden may impact collateral development in patients treated by mechanical thrombectomy for anterior circulation acute ischemic stroke. Methods- The patients admitted in our center for anterior circulation acute ischemic stroke and (1) treated by mechanical thrombectomy with or without thrombolysis and (2) who underwent a baseline magnetic resonance imaging were included in the study. The SVD burden and the pial collaterality were assessed through the cerebral SVD score (severe when ≥1) and the Higashida score (favorable when ≥ 3) on magnetic resonance imaging and digital subtraction angiography, respectively. Any association between the cerebral SVD score and the collaterality were assessed through comparative and regression analyses. Results- Between January 2013 and March 2018, 240 patients met the inclusion criteria (68.7±16.1 years old; 49.2 % female). The cerebral SVD scores were of 0 in 125 (52.1%), 1 in 74 (30.8%), 2 in 30 (12.5%), and 3 in 11 (4.6%) patients. Hundred and thirty-six patients (58.1%) presented a favorable collaterality score. The favorable collaterality subgroup presented a significantly higher proportion of female (79%), lower baseline National Institutes of Health Stroke Scale ( P<0.001), and higher Diffusion-Weighted Imaging-Alberta Stroke Program Early CT Scores ( P<0.001). The regression analyses showed no impact of the cerebral SVD score on the collaterality pattern (odds ratio, 1.11, 95% CI, 0.82-1.50; P=0.51). Conclusions- In patients with anterior circulation acute ischemic stroke, collateral flow status does not seem to be influenced by SVD burden.

Small vessel disease and clinical outcomes after endovascular treatment in acute ischemic stroke.

BACKGROUND: Pre-existing small vessel disease (SVD) has been associated with poor functional outcomes in patients with acute ischemic stroke treated with intravenous thrombolysis; however, there are scarce data in patients treated with endovascular therapy. We aimed to investigate the associations between SVD and clinical outcomes in patients treated with endovascular therapy. METHODS: We retrospectivel y evaluated patients with acute ischemic stroke in the anterior circulation receiving endovascular treatment. We assessed SVD markers with visual scales using non-contrast computed tomography. Early outcomes included intracerebral hemorrhage and 7-day/discharge stroke severity, and late outcomes included modified Rankin scale (mRS) 90 days after stroke. We used logistic and ordinal regression models adjusted for age, sex, stroke severity, and time-to-groin puncture time. RESULTS: A total of 175 patients were included in the study, mean (±SD) age 72.3 (± 12.4) years, 90 (51%) males. Among SVD features, only brain atrophy was associated with 7-day stroke severity (OR = 2.28; 95% CI = 1.11-4.68) and with worse mRS at 90 days (OR = 2.72; 95% CI = 1.25-5.91). Global SVD burden was associated with worse mRS at 90 days (OR = 1.63; 95% CI = 1.01-2.62) but not with 7-day stroke severity (OR = 1.71; 95% CI = 0.97-3.01). CONCLUSIONS: Pre-existing SVD burden, mainly driven by brain atrophy, negatively affects early and late clinical outcomes in anterior circulation ischemic stroke treated with endovascular therapy. Our results may help prognostic stratification of stroke patients treated with endovascular therapy.