Abstract WP16: Stentrievers Increase Recanalization Rate But Not Good Outcome After Large Vessel Stroke.

Abstract

Ischemic stroke is a common cause of death and disability in the western world. Intraveneous (iv) recombinant tissue plasminogen activator (t-PA) has proven efficacious as acute treatment. Intraarterial treatment with t-PA and/or instrumentation of the vessel with the attempt to manipulate the clot and remove it (called Intra Arterial Therapy (IAT)) is emerging as a tool for treating patients with contraindications to iv t-PA or for patients with large clot burden, where iv t-PA is often unsuccessful. IAT is also potentially hazardous and in large series, 10% of patients suffer symptomatic Intracerebral Hemorrhage (ICH). Stentreivers (a new form of removable stent) have shown promise in improving recanalization and outcome in IAT. At our institution 153 patients underwent IAT from 2004-2011. Stentreivers (ST) were used as part of the recanalization procedure in 42 patients. In the ST group, mean age was 63.7 years and mean presenting NIHSS was 16.6. In the non-ST group the same numbers were 63.3 years old and an NIHSS of 15.9. Using an unpaired t-test, there were no statistical differences in neither age nor NIHSS at presentation. Time to groin puncture was 257 minutes in the ST group and 275 minutes in the non-ST group, again no statistical difference. Recanalization (defined as TICI 2b or 3) was achieved among 35 of the 42 = 83.3% in the ST group and in 47/111 = 42.3% of the patients in the non-ST group, giving an odds ratio (OR) for recanalization using ST on 6.81 (p<0.001, Fischers exact test.) Good outcome defined as a modified Rankin Score of 0-2 90 days after the stroke was achieved among 16/42 = 38.1% in the ST group and among 47/111 = 42.3 % in the non-ST group. There was no statistical difference in these numbers. Recanalization was important for good outcome in both groups. OR for good outcome given recanalization was 5.89 in the ST group (p=0.03) and 6.97 in the non-ST group (p<0.001). Recanalization is important for good outcome, but even though recanalization was achieved much more often in the ST group, this did not translate into better outcomes. One explanation could be, that recanalization seems more obvious when using stentrivers.