Abstract TP212: 2b or Not 2b? TICI 2b Reperfusion Score in Endovascular Thrombectomy for Acute Ischemic Stroke Carries a Poor Functional Outcome

Abstract

Background: Endovascular thrombectomy (EVT) for treatment of acute ischemic stroke (AIS) in the proximal cerebrovasculature has, since its inception, become part of the standard of care when addressing AIS. Overall, one in six individuals treated has improved neurologic and functional outcomes. Reperfusion following thrombectomy in the anterior cerebral circulation has long been graded by the modified Thrombolysis in Cerebral Infarction (mTICI) scale-and the score of mTICI (2b, or, “partial filling of more than 50% of the affected vascular territory” is considered the benchmark for “good” outcomes in EVT. It remains unclear whether this score at time of reperfusion reliably predicts a sustained improvement in neurologic or functional outcome. Method: This is a retrospective review of all anterior AIS patients with large vessel occlusion (LVO) at Barrow Neurological Institute between 01/01/2018 and 12/31/2022 who underwent EVT with mTICI 2b or greater. The study was approved by the local IRB. Demographic data of patients between the ages of 18 and 95 who had AIS with LVO in the anterior Circle of Willis or its supplying vessels were collected. Other variables collected and analyzed include mTICI score, and modified Rankin Score (mRS) at discharge and 90 days. The TICI grade was obtained via digital cerebral angiography post EVT. Descriptive statistics was used to examine the differences of mRS scores at 90 days. Results: Of 81 cases reviewed, 52 (65%) had a TICI 2b score and their average mRS was 3.7, 20 (25%) had a TICI 2c and their average mRS was 3.6, and 4 (5%) had a TICI 3 with mRS 3 at discharge. At 90 days, the average mRS for TICI 2b patients was 3.2, for TICI 2c patients 2.9 and for TICI 3 patients 2.3. No difference in the rate of intracerebral hemorrhage (ICH) following reperfusion between the TICI 2 and 3 groups (17%). Conclusion: Our results demonstrated that patients with a mTICI of 2b had a higher mean mRS at discharge and minimal improvement of mRS at 90 days compared against patients with a mTICI of 2c or 3 (average change in score was -0.6, -0.7 and -1.3 in the TICI 2b, 2c and 3 groups respectively). Therefore, a reperfusion score of mTICI 2b may not be sufficient to indicate a high probability of a good functional outcome. With EVT, reaching a TICI 3 should be attempted.