Abstract for presentation at The Australian and New Zealand Association of Neurologists Annual Scientific Meeting 2007

The incidence and degree of recanalization depends on site of arterial occlusion in acute ischemic stroke

  • Deidre De Silva, Royal Melbourne Hospital, Australia
  • Mr Soren Christensen, Royal Melbourne Hospital, Australia
  • Dr Kenneth Butcher, University of Alberta, United States
  • Dr Mark Parsons, John Hunter Hospital, Australia
  • Dr Christopher Levi, John Hunter Hospital, Australia
  • Prof Christopher Bladin, Box Hill Hospital, Australia
  • Dr Alan Barber, Auckland City Hospital, New Zealand
  • Dr Andre Peeters, UCL Saint-Luc, Belgium

    • Purpose: Recanalization in acute ischemic stroke is a major factor influencing reperfusion and is associated with clinical, radiological and functional improvement. Previous non-randomized, non-blinded studies have shown that MCA occlusion has a higher recanalization incidence compared to ICA occlusion. However, there is paucity of data on the impact of arterial occlusion site on degree of recanalization. In this prospective, double-blinded study of intravenous tPA versus placebo 3-6 hours from stroke onset, we compared the incidence and degree of recanalization between sites of arterial occlusion.
    Methods: We present preliminary findings of the first 99 patients in the EPITHET study, prior to unblinding of treatment groups. Site of arterial occlusion was determined using MRA scans and recanalization between day 1 and day 3-5 was assessed using the TIMI criteria.
    Results: Of the 82 patients with an acute MRA of adequate quality to be assessed, 50 had an arterial occlusion. Of these 50 patients, 41 had a sub-acute MRA of adequate quality to be assessed, revealing that 24 had recanalization (4 with TIMI 1, 6 with TIMI 2 and 14 with TIMI 3) and 17 had no recanalization. There was a significantly higher incidence of recanalization with M1 (100%,17/17) and M2 (67%,2/3) occlusions compared to ICA (24%,5/21) occlusion (p<0.001). The degree of recanalization was greater with M1 and M2 compared to ICA occlusion (Table 1). (p<0.001) In multivariate regression analysis for recanalization using variables with significant univariate associations (site of arterial occlusion, gender, AF and past smoking history), M1 occlusion (p<0.001) and no past smoking history (p=0.015) was independently associated with recanalization.
    Conclusions: We found that MCA occlusion has a significantly higher rate and degree of recanalization compared to ICA occlusion. These findings may be explained by differences in the size and type of clots between sites of arterial occlusion.

    Site of occlusion TIMI 0 TIMI 1 TIMI 2 TIMI 3
    ICA n = 21 76% (16) 14% (3) 5% (1) 5% (1)
    M1 n = 17 0% (0) 6% (1) 23% (4) 71% (12)
    M2 n = 3 33% (1) 0% (0) 33% (1) 33% (1)
    Conference Organiser - ICMS Pty Ltd