WP3a – MR CLEAN MeVO, Multicenter Randomized Clinical TriaL of Endovascular

WP leaders

Julie Staals (MUMC+) & Adriaan van Es (LUMC)

The workpackage

Since the first MR CLEAN trial, published in 2015 by members of our consortium, and the confirmation and further development in several other trials (including MR CLEAN NOIV, MED and LATE by CONTRAST 1.0 consortium), EVT is recommended for acute ischemic stroke (AIS) caused by a large vessel occlusion of the anterior intracranial circulation, both for patients within the first 6 hours after last-seen-well and for more strictly imaging-selected patients in the 6-24h time window. It is unknown whether the well-established clinical benefit of EVT for LVOs can be extrapolated to Medium Vessel Occlusions (MeVOs). It could be that the clinical benefit of recanalization by EVT of a MeVO is smaller compared to a large vessel occlusion, due to the smaller volume of the tissue-at-risk and the higher likelihood of treatment response to intravenous thrombolysis. In addition, EVT for MeVOs might be more prone to per-procedural complications due to the more tortuous anatomy and smaller caliber of distal intra-cranial arteries. Nevertheless, in clinical practice these more distal occlusions are increasingly treated with EVT, and recently published case series point to a positive clinical effect of EVT for MeVO. We hypothesize that EVT plus best medical treatment in patients with acute ischemic stroke caused by MeVO leads to better neurological outcome compared to best medical treatment alone.


  1. To assess in an RCT the safety and efficacy of EVT in acute ischemic stroke patients with onset or last-seen-well <24h, and an intracranial medium vessel occlusion (distal M2, M3, A2, A3, P1, P2, P3-segments) confirmed by neuroimaging.
  2. To re-develop and adapt clinical (MR PREDICTS) and imaging scales (ASPECTS, eTICI, collateral score, CT perfusion thresholds) for MeVO strokes.