BACKGROUND: Incomplete reperfusion (IR) after mechanical thrombectomy (MT) can be a consequence of residual occlusion, no-reflow phenomenon, or collateral counterpressure. Data on the impact of these phenomena on clinical outcome are limited. METHODS: Patients from the ESCAPE-NA1 trial with IR (expanded Thrombolysis In Cerebral Infarction (eTICI) 2b) were compared with those with complete or near-complete reperfusion (eTICI 2c-3) on the final angiography run. Final runs were assessed for (a) an MT-accessible occlusion, or (b) a non-MT-accessible occlusion pattern. The primary clinical outcome was modified Rankin Scale (mRS) 0-2 at 90 days. Our imaging outcome was infarction in IR territory on follow-up imaging. Unadjusted and adjusted incidence rate ratios (aIRR) with 95% confidence intervals (95% CI) were obtained. RESULTS: Of 1105 patients, 443 (40.1%) with IR and 506 (46.1%) with complete or near-complete reperfusion were included. An MT-accessible occlusion was identified in 147/443 patients (33.2%) and a non-MT-accessible occlusion in 296/443 (66.8%). As compared with patients with near-complete/complete reperfusion, patients with IR had significantly lower chances of achieving mRS 0-2 at 90 days (aIRR 0.82, 95% CI 0.74 to 0.91). Rates of mRS 0-2 were lower in the MT-accessible occlusion group as compared with the non-MT-accessible occlusion pattern group (aIRR 0.71, 95% CI 0.60 to 0.83, and aIRR 0.89, 95% CI 0.81 to 0.98, respectively). More patients with MT-accessible occlusion patterns developed infarcts in the non-reperfused territory as compared with patients with non-MT occlusion patterns (68.7% vs 46.3%). CONCLUSION: IR was associated with worse clinical outcomes than near-complete/complete reperfusion. Two-thirds of our patients with IR had non-MT-accessible occlusion patterns which were associated with better clinical and imaging outcomes compared with those with MT-accessible occlusion patterns.

Clinic of Radiology and Nuclear Medicine Universitatsspital Basel Basel Switzerland

Community Health Sciences University of Calgary Cumming School of Medicine Calgary Alberta Canada

Department of Clinical Neurosciences University of Calgary Calgary Alberta Canada

Department of Internal Medicine Neurology division University of Manitoba Max Rady College of Medicine Winnipeg Manitoba Canada

Department of Medical Imaging and Faculty of Medicine Masaryk University St Anne's University Hospital Brno Brno Czechia

Department of Neurosurgery University of Saskatchewan College of Medicine Saskatoon Saskatchewan Canada

Department of Radiology and Nuclear Medicine Amsterdam UMC Location AMC Amsterdam The Netherlands

Department of Radiology University of Calgary Calgary Alberta Canada

Division of Neurology The University of British Columbia Faculty of Medicine Vancouver British Columbia Canada

Division of Neurology University of Alberta Edmonton Alberta Canada

Division of Neurology University of Ottawa Faculty of Medicine Ottawa Ontario Canada

Hotchkis Brain Institute University of Calgary Cumming School of Medicine Calgary Alberta Canada

Klinik für Neurologie und Neurologische Intensivmedizin Klinikum Altenburger Land GmbH Altenburg Germany

Klinik für Neuroradiologie Universitätsklinikum Bonn Bonn Germany

NoNO Inc Toronto Ontario Canada

University of Saskatchewan College of Medicine Saskatoon Saskatchewan Canada

References provided by Crossref.org

Natural Evolution of Incomplete Reperfusion in Patients Following Endovascular Therapy After Ischemic Stroke

Effects of reperfusion grade and reperfusion strategy on the clinical outcome: Insights from ESCAPE-NA1 trial