title: Endovascular thrombectomy for acute ischemic stroke in failed intravenous tissue plasminogen activator versus non-intravenous tissue plasminogen activator patients: revascularization and outcomes stratified by the site of arterial occlusions.
abstract: OBJECTIVE
  Intracranial mechanical thrombectomy is a therapeutic option for acute ischemic stroke patients failing intravenous tissue plasminogen activator (IV tPA). We compared patients treated by mechanical embolus removal in cerebral ischemia (MERCI) thrombectomy after failed IV tPA with those treated with thrombectomy alone.
  
  
  METHODS
  We pooled MERCI and Multi MERCI study patients, grouped them either as failed IV tPA or non-IV tPA, and assessed revascularization rates, procedural complications, symptomatic hemorrhage rates, clinical outcomes, and mortality. We also evaluated outcomes stratified by the occlusion site and final revascularization.
  
  
  RESULTS
  Among 305 patients, 48 failed, and 257 were ineligible for IV tPA. Nonresponders to IV tPA trended toward a higher revascularization rate (73% versus 63%) and less mortality (27.7% versus 40.1%) and had similar rates of symptomatic hemorrhage and procedural complications. Favorable 90-day outcomes were similar in failed and non-IV tPA patients (38% versus 31%), with no difference according to occlusion site. Among patients failing IV tPA, good outcomes tended to occur more frequently in revascularized patients (47.1% versus 15.4%), although this relationship was attributable solely to middle cerebral artery and not internal carotid artery occlusions, with no difference in mortality. Among IV tPA-ineligible patients, revascularization correlated with good outcome (47.4% versus 4.4%) and less mortality (28.5% versus 59.6%).
  
  
  CONCLUSIONS
  The risks of hemorrhage and procedure-related complications after mechanical thrombectomy do not differ with respect to previous IV tPA administration. Thrombectomy after IV tPA achieves similar rates of good outcomes, a tendency toward lower mortality, and similar revascularization rates when stratified by clot location. Good outcomes correlate with successful revascularization except with internal carotid artery occlusions in tPA-nonresponders.
authors.affiliation: Division of Interventional Neuroradiology, David Geffen School of Medicine at UCLA, 757 Westwood Plaza, Los Angeles, CA 90095-7437, USA.
authors.forename: Zhong-Song
authors.initials: ZS
authors.lastname: Shi
authors.forename: Yince
authors.initials: Y
authors.lastname: Loh
authors.forename: Gary
authors.initials: G
authors.lastname: Walker
authors.forename: Gary R
authors.initials: GR
authors.lastname: Duckwiler
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000401:mortality / Q000628:therapy; D002340:Carotid Artery Diseases / Q000401:mortality / Q000628:therapy; D002539:Cerebral Arterial Diseases / Q000401:mortality / Q000628:therapy; D002548:Cerebral Revascularization / Q000379:methods; D018572:Disease-Free Survival; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D006470:Hemorrhage / Q000209:etiology / Q000401:mortality / Q000628:therapy; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000401:mortality / Q000628:therapy; D015996:Survival Rate; D017131:Thrombectomy; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator