Abstract
BACKGROUND: The benefit of endovascular thrombectomy for medium-vessel occlusion (MeVO) strokes is unclear. We used 90-day home time to explore outcomes in patients with MeVO versus large-vessel occlusions treated with endovascular thrombectomy. METHODS: Data are from the QuICR (Quality Improvement and Clinical Research) provincial stroke registry and linked administrative data to identify patients who underwent endovascular thrombectomy in our center from January 2015 to December 2020. Imaging data were scored by 2-physician consensus. We defined MeVO as occlusion beyond and including M2-middle cerebral artery, A2-anterior cerebral artery, or P2-posterior cerebral artery segments. Successful reperfusion was defined as Thrombolysis in Cerebral ischemia grades (≥2b/3). The primary outcome was patient home time (the number of nights a patient is back at their premorbid living situation without an increase in level of care within 90 days of the stroke) using random forest regression. Covariate contribution to home time was determined using partial dependence plots. RESULTS: Among 663 patients who underwent endovascular thrombectomy, 139 (20.9%) had MeVO (median age, 71 years; 50.4% women; median National Institutes of Health Stroke Scale, 16). The majority (82%) had good pial collaterals, 10.4% had a tandem extracranial carotid occlusion or stenosis, and 41.7% received intravenous thrombolysis. The most common site of occlusion was M2-middle cerebral artery (58.3%). One hundred eighteen (86.7%) patients achieved successful reperfusion (Thrombolysis in Cerebral Ischemia grades ≥2b/3). Using partial dependence plots, the mean predicted home times were similar in patients with MeVO (45.5 days) versus large-vessel occlusions (44.6 days). Factors predicting lower 90-day home time in patients with MeVOs were diabetes (-8.7 days), hypertension (-6.5 days), and atrial fibrillation (-3.5 days). There was no meaningful difference in predicted 90-day home-time by sex, baseline National Institutes of Health Stroke Scale, collateral grade, or thrombolysis. CONCLUSION: Patients with MeVO who are selected for endovascular therapy with similar demographic and clinical profiles to large-vessel occlusions can achieve similar 90-day home time outcomes to large-vessel occlusions.