{
  "abstract": "Introduction/Purpose Medium and distal vessel occlusions constitute a meaningful proportion of acute ischemic strokes, yet the optimal endovascular approach remains uncertain. Mechanical thrombectomy in smaller, tortuous arteries may be technically challenging and can increase the risk of vessel injury or distal embolization. Intra-arterial thrombolysis has emerged as a potential primary endovascular strategy; however, the existing evidence is derived largely from small studies. Moreover, outcomes are frequently confounded by concomitant or rescue mechanical thrombectomy, limiting the ability to isolate and accurately assess the safety and effectiveness of intra-arterial thrombolysis.Materials and Methods Our review was conducted in accordance with PRISMA guidelines. We searched PubMed, EMBASE, Google Scholar, and ClinicalTrials.gov from inception through January 2026 for human clinical studies evaluating intra-arterial thrombolysis (IAT) as stand-alone endovascular therapy for acute ischemic stroke due to primary medium/distal intracranial vessel occlusion, explicitly excluding cases in which mechanical thrombectomy (MT) was intended or performed. Eligible designs included randomized trials, prospective/retrospective cohorts and case series, provided an extractable IAT-alone arm/subgroup for MeVO/DiVO was included (even when other arms in the same study included MT). Occlusions were defined as: Medium vessel occlusion MeVO (M2-M3, A2, P2) and distal vessel occlusion DiVO (M4, A3-A5, P3-P4). Studies of large vessel occlusion and any study incorporating any method of MT were excluded. The objective was to characterize safety and potential efficacy of IAT. Prespecified outcomes included angiographic reperfusion (TICI/eTICI), 90-day functional outcome (mRS) and symptomatic intracranial hemorrhage (sICH).Results Six eligible studies comprising 164 patients met inclusion criteria. Angiographic reperfusion (post-IAT TICI/eTICI) was reported for 39 patients, with TICI 0-1 in 18/39 (46.2%) and TICI 2-3 in 21/39 (53.8%). Symptomatic intracranial hemorrhage (sICH) was assessable in 80 patients, with no events reported (0/80, 0%). Ninety-day functional outcome (mRS) was available for 123 patients: mRS 0-2 occurred in 103/123 (83.7%), while mRS 3-6 occurred in 20/123 (16.3%).Conclusion This review encompassed a total of 164 MeVO/DiVO cases, reperfusion rates were modest (TICI 2-3: 53.8% [21/39]), symptomatic ICH was not observed among reported cases (0% [0/80]), and 90-day functional independence was reported in 83.7% (103/123), suggesting an overall reassuring safety signal. By excluding any attempted mechanical thrombectomy, this review achieved its primary objective of characterizing safety without thrombectomy-related confounding. Given the relatively low angiographic success observed, current evidence suggests IAT may be more appropriately considered as an adjunct/rescue strategy in conjunction with mechanical thrombectomy rather than as stand-alone treatment.Disclosures I. Aboumoussa: None. C. Martin: None. M. Ahmed: None.Abstract O-015 Figure 1",
  "authors": [
    {
      "affiliations": [
        "Neurology, University of Missouri Kansas City, Kansas City, MO"
      ],
      "name": "I Aboumoussa"
    },
    {
      "affiliations": [
        "Neuroendovascular Surgery, Saint Lukes Hosptial of Kansas City, Kansas City, MO"
      ],
      "name": "C Martin"
    },
    {
      "affiliations": [
        "Neurology, University of Missouri Kansas City, Kansas City, MO"
      ],
      "name": "M Ahmed"
    }
  ],
  "title": "O-015 Intraarterial thrombolysis as primary endovascular therapy for acute ischemic stroke due to primary medium/distal vessel occlusion: a systematic review",
  "uid": "4e9161e5-16c2-5fac-a432-7838a70a3200"
}