Mechanical Thrombectomy in Middle Cerebral Artery M2 Occlusion: Mechanical Aspiration Thrombectomy Alone versus Combined with Stent-retriever

Introduction: While revascularization for M2 occlusions is generally recommended and considered beneficial, the optimal approach (aspiration vs stentriever/combined) is less well defined in the literature.

Methods: Controlling for inter-operator technical variability, patients who underwent thrombectomy for M2 occlusions by a single operator were stratified by first pass approach: manual aspiration thrombectomy (MAT/aspiration alone) and stentriever-mediated manual aspiration thrombectomy (SMAT/combination). Efficacy outcomes included good reperfusion (mTICI score ≥2b) and a favorable 90-day functional outcome (mRS score of ≤2). Safety outcomes included 90-day mortality and symptomatic intracranial hemorrhage.

Results: One hundred three patients were identified: 57 underwent MAT whereas 46 underwent SMAT. Good reperfusion was comparable between SMAT and MAT groups (93.5% vs. 87.7%, P=0.33). Intracranial hemorrhage complication rate was higher in SMAT compared to MAT (13% vs. 1.8%, P=0.04). Puncture-to-recanalization time was longer in SMAT (34.4 vs. 19.9 minutes, P< 0.001). In multivariable analysis, complete or good reperfusion was associated with shorter puncture-recanalization time (adjusted odds ratio [aOR], 0.85) or less total pass (aOR, 0.58), respectively. Good reperfusion with a favorable 90-day functional outcome was associated with no hyperlipidemia (aOR, 0.13). Ninety-day mortality was associated with hyperlipidemia (aOR, 7.28), higher NIHSS (aOR, 1.27) and SMAT (aOR, 5.21). In propensity-score matched analysis of 66 patients with comparable baseline and technical efficiency, the safety outcomes were not different between SMAT and MAT groups.

Conclusion : SMAT compared with MAT did not result in improved revascularization rate or functional outcome, while it was related to more hemorrhagic complication and mortality.