Abstract 161: Variations in Mechanical Thrombectomy Techniques and Impacts Based on Occlusion Location: INSPIRE‐S Global Registry Insights

Introduction/Purpose The primary mechanical thrombectomy (MT) techniques currently utilized are stent retriever (SR) only,aspiration (ASP) only, and combination therapy (CT), with the general aim of achieving first‐passrecanalization (FPR:TICI≥2c). While differences in effectiveness among these techniques are generallymodest, they may be more pronounced in specific patient subgroups, conceivably those categorized byocclusion location. Furthermore, the benefits of technique variations, like the choice between manualaspiration and aspiration pump, are unclear. Materials/Methods INSPIRE‐S is a global, prospective registry of stroke patients treated with Medtronic Neurovasculardevices, with data adjudicated by imaging core lab and safety clinical events committee. The registrygroups patients based on the initial MT technique used. Although some studies have compared theoutcomes of different techniques across various occlusion locations, clear evidence is lacking.Additionally, real‐world data on the impact of aspiration methods (manual vs. pump) is limited. Results Between May 2020 and December 2022, 802 patients from 29 sites in 13 countries were enrolled andfollowed for 90 days: 259 treated with SR, 146 with ASP, and 397 with CT. Most occlusions (76.1%)occurred in the MCA‐M1/M2 regions. Significant differences in occlusion location were observed amongtechniques. Fewer patients with MCA‐M1/M2 occlusions were treated with ASP (ASP: 65.2%, SR: 76.1%,CT: 80.1%; p<0.01), while more patients with ICA occlusions (ASP: 22.7%, vs SR: 13.8%; p=0.03 and vs CT:15.2%; p=0.05) and BA occlusions (ASP: 9.2%, vs CT: 3.9%; p=0.03, but not vs SR: 6.1%; p=0.31) weretreated with ASP. Across the three technique groups, final complete reperfusion, FPR and good clinicaloutcomes (mRS≤2 or mRS≤pre‐stroke mRS) at 90 days were similar (Final SR: 77.5%, ASP: 70.6%, CT:72.0%; FPR SR: 48.6%, ASP: 39.9%, CT: 47.5%; mRS SR: 60.5%, ASP: 52.8%, CT: 56.6%). No significantdifferences were found in all‐cause mortality (SR: 13.1%, ASP: 14.4%, CT: 14.4%; p=0.91) or symptomaticintracranial hemorrhage within 24 hours (SR: 1.5%, ASP: 1.4%, CT: 1.5%; p=1.00). Subgroup analysisrevealed that in ICA occlusions, ASP had the lowest FPR (12.5%) compared to SR (50.0%; p=0.001) and CT(40.7%; p=0.008). ASP also underperformed in ICA (12.5%) compared to BA (76.9%) and MCA‐M1 (46.9%)for FPR (p<0.001). However, ASP showed the highest FPR (numerically) in BA occlusions. The use of anaspiration pump in the ASP group was linked to better 90‐day mRS 0‐2 outcomes compared to manualaspiration (59.8% vs. 36%, p=0.008, adjusted p=0.015), with no significant differences in final completereperfusion (68.1% vs. 69.8%) or FPR (39.7% vs. 37.7%). Similar trends were observed in the CT group formRS 0‐2 (58.7% vs. 48.3%, p=0.06). Conclusions INSPIRE‐S data from a diverse, large‐scale patient population shows that reperfusion, clinical, and safetyoutcomes were similar regardless of the first‐line MT technique used. Notably, while ASP was mostfrequently employed for ICA occlusions, it was associated with the lowest FPR rates. Use of an aspirationpump improved 90‐day mRS outcomes compared to manual aspiration. These findings suggest thatfurther research is warranted to determine the optimal use of different MT techniques depending onocclusion location.