Ravinder-Jeet Singh, MBBS, DM
Kaesmacher J, Chaloulos-Iakovidis P, Panos L, Mordasini P, Michel P, Hajdu SD, et al. Mechanical Thrombectomy in Ischemic Stroke Patients With Alberta Stroke Program Early Computed Tomography Score 0-5. Stroke. 2019;50:880-888.
Early and successful reperfusion leads to favourable outcome among patients with stroke having intracranial large artery occlusion. However, restoring blood flow to an infarcted tissue has a potential to induce reperfusion injury-related complications manifesting by development of malignant edema, intracerebral hemorrhage (ICH) or both. The risk is greater among those with larger pre-treatment infarct size, which is frequently defined using low ASPECTS scores (<6) or large cores (for example, >70-100 ml) on blood-flow imaging (CT/MR perfusion). Due to safety concerns, these patients were excluded from recent endovascular thrombectomy (EVT) trials. Contrary to general perception, recent literature demonstrates good safety of EVT in these patients and work by Kaesmacher et al1 is further addition to EVT safety and efficacy data in this group.
From a multicenter registry (BEYOND-SWIFT; N=2046), authors identified 237 patients who had ASPECTS 0-5 and underwent EVT. Overall, nearly equal proportion of patients had favorable outcome (mRS 0-3) and death (40.1% and 40.9%, respectively). Obviously, these patients had lower rates of favorable outcome than the group with ASPECTS 6-10 (40.1 vs 61.2%; P<0.001) and also had higher mortality (40.9 vs 21.2%; P<0.001), however, authors demonstrated no safety concerns of EVT with respect to rates of symptomatic ICH (7.2% vs 6.0%; P=0.466). The effect on all outcomes was clearly influenced by achievement of the successful reperfusion (TICI 2b/3), presence of which resulted in higher rates of favorable outcome, lower mortality and lower symptomatic ICH rates. On further inspection of the data, functional benefits were predominantly observed in ASPECTS 5 patients, nonetheless, mortality benefits were still observed in those with further lower ASPECTS scores (4 or even 0-3 group) when successful reperfusion was achieved. Patients with ASPECTS 0-5 had longer procedure duration (groin puncture to reperfusion), lower successful reperfusion rates and higher frequency of procedural complications during EVT than ASPECTS 6-10 patients. Larger clot burden and higher cervical artery dissection rates leading to procedural challenges might be few of the explanations for this observation.