{
  "abstract": "Background and Purpose Mechanical thrombectomy outcomes are known to vary by occlusion site, yet current practice treats each vessel segment as a homogeneous category. Within the internal carotid artery (ICA) alone, thrombus may lodge anywhere from the cervical segment to the carotid terminus, a span exceeding 100 mm, but whether precise thrombus position within the ICA independently influences outcomes has not been investigated. We tested the hypothesis that distance from the thrombus to the ICA terminus predicts stroke severity, reperfusion success, and functional recovery after mechanical thrombectomy.Methods We conducted a single-center retrospective cohort study of 247 consecutive patients undergoing mechanical thrombectomy for anterior circulation large-vessel occlusion (ICA, N=69; M1, N=178). Distance from the proximal thrombus face to the ICA terminus was measured on pre-procedural CT angiography and analyzed per 5 mm increment. The primary analysis adjusted for 13 pre-treatment confounders. Because thrombus position determines the extent of vascular territory at risk, baseline NIHSS was treated as a downstream mediator rather than a confounder, supported by formal causal mediation analysis. M1 occlusions served as a pre-specified negative control.Results Within ICA occlusions, each 5 mm closer to the terminus was associated with significantly lower odds of achieving successful reperfusion (TICI grade OR=0.92, 95% CI 0.87–0.97, p=0.002), an effect that survived FDR correction and was 97% direct on mediation analysis. Terminus distance also independently predicted baseline NIHSS (r=−0.28, p=0.021), confirming that thrombus position reflects territory at risk. Functional outcomes showed consistent trends toward worse recovery at more distal positions, strengthening after adjustment for stroke severity. No distance effects were observed in M1 occlusions, confirming ICA-specificity.Conclusions Not all ICA occlusions are equal. Thrombus position within the ICA independently predicts reperfusion quality through a direct anatomic pathway and carries additional prognostic information for stroke severity. Pre-procedural assessment of terminus distance may help neurointerventionalists anticipate procedural difficulty and tailor thrombectomy strategy.Disclosures I. Bediako: None. J.N. Keller: None. C. Sollenberger: None. A.Q. Wu: None. E. Ozcan: None. Z. Hoglund: None. K. Scott: None. J. Catapano: None. J. Burkhardt: None. S. Kandregula: None. R. Rahmani: None. V. Srinivasan: None.Abstract E-347 Figure 1Abstract E-347 Table 1Effect of thrombus distance from ICA terminus on procedural and clinical outcomeOutcomeEffectP-valueFDR-PTICI Score (Ordinal)OR = 0.92 (0.87, 0.97)0.0020.037Successful Reperfusion (TICI ≥ 2b)OR = 0.94 (0.85, 1.02)0.1160.333First-Pass EffectOR = 0.96 (0.90, 1.02)0.1710.333Procedure Duration (min)Ratio = 1.01 (1.00, 1.03)0.0920.333mRS Change Pre-stroke to 90-dayOR = 1.04 (0.99, 1.10)0.1180.33390-Day mRS (Ordinal)OR = 1.04 (0.98, 1.10)0.1880.333Discharge mRS (Ordinal)OR = 1.05 (1.00, 1.11)0.0620.333Good Functional Outcome (mRS ≤ 2)OR = 0.96 (0.89, 1.02)0.1960.333Hospital MortalityOR = 1.05 (0.98, 1.14)0.1760.333Device EscalationOR = 1.00 (0.92, 1.09)0.9390.947",
  "authors": [
    {
      "affiliations": [
        "Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA"
      ],
      "name": "I Bediako"
    },
    {
      "affiliations": [
        "Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA"
      ],
      "name": "JN Keller"
    },
    {
      "affiliations": [
        "Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA"
      ],
      "name": "C Sollenberger"
    },
    {
      "affiliations": [
        "Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA"
      ],
      "name": "AQ Wu"
    },
    {
      "affiliations": [
        "Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA"
      ],
      "name": "E Ozcan"
    },
    {
      "affiliations": [
        "Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA"
      ],
      "name": "Z Hoglund"
    },
    {
      "affiliations": [
        "University of Rochester, Rochester, NY"
      ],
      "name": "A Anandarajah"
    },
    {
      "affiliations": [
        "Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA"
      ],
      "name": "K Scott"
    },
    {
      "affiliations": [
        "Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA"
      ],
      "name": "J Catapano"
    },
    {
      "affiliations": [
        "Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA"
      ],
      "name": "J Burkhardt"
    },
    {
      "affiliations": [
        "Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA"
      ],
      "name": "S Kandregula"
    },
    {
      "affiliations": [
        "Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA"
      ],
      "name": "R Rahmani"
    },
    {
      "affiliations": [
        "Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA"
      ],
      "name": "V Srinivasan"
    }
  ],
  "title": "E-347 Thrombus position within the internal carotid artery independently predicts stroke severity and reperfusion outcomes after mechanical thrombectomy",
  "uid": "edf50ff4-1715-52b9-aa38-8d9957dcfcf0"
}