Background Embolectomy using ‘Stent retriever Assisted Vacuum-locked Extraction’ (SAVE) is effective in intracranial large vessel occlusion. The choice which post-bifurcational trunk should be chosen for distal stent retriever placement in M1 occlusions is elusive.

Methods Retrospective analysis of prospectively collected data of a comprehensive stroke center between 2015 and 2018. One hundred and one consecutive patients with M1 occlusions were treated with SAVE. Digital subtraction angiography (DSA) series were studied to determine the anatomy of middle cerebral artery branches, the position of the stent retriever, and measurements of vessel diameters by contrast injection via microcatheter. First-pass successful reperfusion was defined as modified Thrombolysis in Cerebral Infarction (mTICI) ≥2 b, and near-complete/complete reperfusion was mTICI ≥2 c/3.

Results In 76/101 (75%) patients microcatheter-series were documented. Microcatheter was placed in the inferior trunk in 30/76 (40%) cases. First-pass near-complete/complete reperfusion was more likely achieved when the inferior trunk was chosen for stent retriever placement (mTICI ≥2 c: 22/30 (73%) vs. 22/46 (48%), p=0.034, and mTICI 3: 20/30 (67%) vs. 17/46 (37%), p=0.018). Median diameter of the inferior trunk was larger compared to superior trunk (1.4 mm (IQR 1.3–1.6) vs. 1.18 mm (IQR 0.9–1.4), p=0.011). The inferior trunk was dominant in 56/76 (74%) cases. Successful reperfusion was associated when the dominant trunk was selected (33/40 (83%) vs. 22/36 (61%), p=0.043).

Conclusion The choice of the inferior trunk for distal stent retriever placement in M1 occlusions is associated with a better reperfusion result when using SAVE.

Disclosures V. Maus: None. A. Brehm: None. S. Henkel: None. M. Psychogios: None.