Impact of recanalisation by mechanical thrombectomy in mild acute ischemic stroke with large anterior vessel occlusion

Abstract

Background: The net clinical benefit of mechanical thrombectomy (MT) in patients presenting acute anterior circulation ischemic stroke with large-vessel occlusion (AIS-LVO) and mild neurological deficit is uncertain.

Aims: To investigate efficacy and safety of MT in patients with acute AIS-LVO and mild neurological deficit by evaluating i) the influence of recanalisation on three-month outcome and ii) mortality, symptomatic intracerebral hemorrhage (sICH) and procedural complications.

Methods: We included consecutive patients with acute AIS-LVO and National Institute of Stroke Scale (NIHSS) score<8, treated by MT at Lille University Hospital. Recanalisation was graded according to modified thrombolysis in cerebral infarction (mTICI) score, mTICI 2b/2c/3 being considered successful. We recorded procedural complications and classified intra-cerebral hemorrhages (ICH) and sICH according with European Cooperative Acute Stroke Study (ECASS) and ECASS2 criteria. Three-month outcome was evaluated by modified Rankin scale (mRS). Excellent and favourable outcomes were respectively defined as mRS 0-1 and 0-2 (or similar to pre-stroke).

Results: We included 95 patients. At three months, 56 patients (59. 0%) achieved an excellent outcome and 69 (72, 6%) a favourable outcome, both being more frequent in patients with successful recanalisation than in patients without (excellent outcome 71, 1% versus 10, 5%, P<0.001 and favourable outcome 82.9% versus 31.6%, P<0.001). The difference remained unchanged after adjustment for age and pre-MT infarct volume. Similar results were observed in patients with pre-MT NIHSS ≤5. Death occurred in five patients (5.3%), procedural complications in 12 (12.6%), any ICH in 38 (40.0%), including 3 (3.2%) sICH.

Conclusions: Achieving successful recanalisation appears beneficial and safe in acute AIS-LVO patients with NIHSS<8 before MT.