The Incidence Of Post-Treatment Cerebral Microbleeds After Combined Therapy Of Endovascular Thrombectomy And Tpa

Introduction: Cerebral microbleeds (CMBs) are considered as a risk factor for stroke. The incidence of post-tPA microbleeds have been reported in recent studies, however, it is not clear that whether hybrid procedure (the combination of tPA and endovascular thrombectomy) for ischemic stroke would increase risk of post-treatment CMBs more than treatment with tPA or endovascular thrombectomy alone. Objective of this study is to compare the incidence of post-treatment CMBs and symptomatic exraischemic hemorrhage by treatments: hybrid procedure, tPA alone, and endovascular thrombectomy alone.Hypothesis: Combined therapy of endovascular thrombectomy and tPA for ischemic stroke have higher incidence of post-treatment CMBs than tPA or endovascular thrombectomy alone.Methods: We retrospectively reviewed pre- and post-T2*-weighted MRI of ischemic stroke patients who received above treatments in our hospital during 2010 to 2014. The presence and number of CMBs were assessed according to the Brain Observer Microbleeds Scale. We compared the number of pre-treatment CMBs, incidence of newly-occurred post-treatment CMBs and symptomatic extraischemic hemorrhage within a year after treatments among hybrid procedure, tPA alone, and endovascular thrombectomy alone.Results: A total of 147 (hybrid procedure n=17, tPA alone n=90, endovascular thrombectomy alone n=40) patients’ pre- and post-treatment MRIs were reviewed. The average number of pre- treatment CMBs was 1.4±4.0 and there was no difference among treatments. The incidence of post-treatment CMBs was significantly higher in hybrid procedure (n=5, 29.4%) and tPA alone (n=18, 20.0%) than endovascular thrombectomy (n=1, 2.5%). However, there was no difference between hybrid procedure and tPA alone. Symptomatic extraischemic hemorrhage was found only one patient who received endovascular thrombectomy alone.Conclusion: The incidence of CMBs after treatments was increased in treatments using tPA. However, there was no difference in post-treatment incidence between hybrid procedure and tPA alone. This result suggests that additional thrombectomy after tPA would not increase the risk of CMBs.