Abstract Body:
Introduction: Medium-vessel occlusions (MeVO) account for 25–40% of acute ischemic stroke. Several randomized clinical trials (RCTs) are evaluating the efficacy and safety of first-line stent-retriever (SR) MeVO thrombectomy compared to medical therapy. Although aspiration thrombectomy (AT) has been previously established as non-inferior to SR thrombectomy for LVO, AT efficacy is dependent on inner diameter relative to luminal/clot cross-sectional area, and navigation of large catheters to MeVO is more challenging and potentially higher risk due to: tortuosity, smaller vessel caliber, arborization, and device limitations (e.g. ledge effect). The Tenzing^® 5 (Route 92 Medical, San Mateo, CA) and FreeClimb^TM 54 catheter is a novel delivery-aspiration catheter combination designed to facilitate MeVO AT. Aim of study: We report our clinical experience using the Tenzing-assisted delivery of aspiration (TADA) technique with FreeClimb 54 for first-line AT of MeVO. Methods: We retrospectively reviewed consecutive patients who underwent MeVO first-line AT using TADA with FreeClimb 54 at 8 institutions. Results: A total of ninety-four MeVO (65 primary and 29 secondary) were treated in 92 patients: median age 71 (IQR 58-81) years; 49/92 (53%) female. FreeClimb 54 was successfully delivered using TADA to all 94/94 MeVO: 63 M2, 12 M3, 6 A2, 4 A3, 2 P1, 7 P2. Median target vessel diameter on DSA was 1.7 (IQR 1.4-1.8) mm. A leading microwire was used to advance Tenzing in 84%. A SR was used for additional thrombectomy passes in 6/94 (6%). For primary MeVO, final eTICI 2B-3 reperfusion was achieved in 63/65 (97%), after a median of 1(IQR 1-2) pass, with modified first pass effect (mFPE) eTICI 2B/2C/3 in 57/65 (88%), and FPE (2C/3) in 43/65 (66%). Median time from groin puncture to reperfusion for 65 primary MeVO cases was 26 (23-38) minutes. Tenzing 5/FreeClimb 54-related complications occurred in 2/94 (2%): one perforation with transient asymptomatic SAH, and one ENT. Median NIHSS improvement from initial presentation to discharge was 6 (IQR 3-11). Symptomatic ICH occurred in 3/92 patients (3%). Eight patients (9%) died during hospitalization. Conclusions: MeVO first-line AT using the TADA technique with Tenzing 5/FreeClimb 54 was highly effective in achieving recanalization, including high FPE for primary MeVO, with a low complication rate. Findings should be compared to the efficacy and safety of forthcoming MeVO thrombectomy RCT, which primarily utilized SR.