Futile complete recanalization: patients characteristics and its time course.

As the goal of mechanical thrombectomy is shifting toward mTICI-3 rather than mTICI-2b, we sought to clarify the limitation of the effect of mTICI-3. A post-hoc analysis of a registry of large-vessel occlusion stroke from 46 centers was conducted. Among 2,420 registered patients, 725 patients with anterior circulation occlusion who achieved successful reperfusion were analyzed. We compared outcomes between patients with mTICI-3 and mTICI-2b, and investigated how the effect of mTICI-3 changed according to baseline characteristics and time course. The proportion of patients with favorable outcomes (mRS 0-2 at day 90) was higher among patients with mTICI-3 compared to those with mTICI-2b (adjusted OR, 2.10; 95% CI, 1.49-2.97). There was no heterogeneity in the effect of mTICI-3 with respect to age, neurological deficit, alteplase use, occluded vessels, or infarct size. mTICI-3 was associated with favorable outcomes when the puncture-to-reperfusion time was <80 minutes (adjusted OR, 2.28; 95% CI, 1.52-3.41), but not when the puncture-to-reperfusion time was ≥80 minutes. A significant heterogeneity was found in the effect of mTICI-3 reperfusion across the puncture-to-reperfusion time subgroups (P for interaction = 0.025). Until when operators should continue the procedure after mTICI-2b has been achieved, needs to be studied.