title: Thrombus branching and vessel curvature are important determinants of middle cerebral artery trunk recanalization with Merci thrombectomy devices.
abstract: OBJECTIVE
  Determinants of successful recanalization likely differ for Merci thrombectomy and intra-arterial pharmacological fibrinolysis interventions. Although the amount of thrombotic material to be digested is an important consideration for chemical lysis, mechanical debulking may be more greatly influenced by other target lesion characteristics.
  
  
  METHODS
  In consecutive patients with acute ischemic stroke treated with Merci thrombectomy for middle cerebral artery M1 occlusions, we analyzed the influence on recanalization success and clinical outcome of target thrombus size (length) and shape (curvature and branching) on pretreatment T2* gradient echo MRI.
  
  
  RESULTS
  Among 65 patients, pretreatment MRI showed susceptibility vessel signs in 45 (69%). Thrombus length averaged 13.03 mm (range, 5.56-34.91) and irregular shape (curvature or branching) was present in 17 of 45 (38%). Presence and length of susceptibility vessel signs did not predict recanalization or good clinical outcome. Substantial recanalization (Thrombolysis In Cerebral Infarction 2b or 3) and good clinical outcome (modified Rankin Scale score ≤2) were more frequent with regular than irregular susceptibility vessel signs shape (57% versus 18%, P=0.013; 39% versus 6%, P=0.017). On multiple regression analysis, the only independent predictor of substantial recanalization was irregular susceptibility vessel signs (OR, 0.16; 95% CI, 0.04-0.69; P=0.014); and leading predictors of good clinical outcome were baseline National Institutes of Health Stroke Scale (OR, 1.20; 95% CI, 1.03-1.40; P= 0.019) and irregular susceptibility vessel signs (OR, 9.36; 95% CI, 0.98-89.4; P=0.052).
  
  
  CONCLUSIONS
  Extension of thrombus into middle cerebral artery division branches and curving shape of the middle cerebral artery stem, but not thrombus length, decrease technical and clinical success of Merci thrombectomy in M1 occlusions.
authors.affiliation: Department of Neurology, Henan Provincial People's Hospital, Zhengzhou, China.
authors.forename: Liangfu
authors.initials: L
authors.lastname: Zhu
authors.forename: David S
authors.initials: DS
authors.lastname: Liebeskind
authors.forename: Reza
authors.initials: R
authors.lastname: Jahan
authors.forename: Sidney
authors.initials: S
authors.lastname: Starkman
authors.forename: Noriko
authors.initials: N
authors.lastname: Salamon
authors.forename: Gary
authors.initials: G
authors.lastname: Duckwiler
authors.forename: Fernando
authors.initials: F
authors.lastname: Vinuela
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tateshima
authors.forename: Nestor
authors.initials: N
authors.lastname: Gonzalez
authors.forename: Pablo
authors.initials: P
authors.lastname: Villablanca
authors.forename: Latisha K
authors.initials: LK
authors.lastname: Ali
authors.forename: Doojin
authors.initials: D
authors.lastname: Kim
authors.forename: Bruce
authors.initials: B
authors.lastname: Ovbiagele
authors.forename: Michael
authors.initials: M
authors.lastname: Froehler
authors.forename: Matthew
authors.initials: M
authors.lastname: Tenser
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Saver
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual; D004198:Disease Susceptibility; D057510:Endovascular Procedures / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000473:pathology*; D011446:Prospective Studies; D012044:Regression Analysis; D017131:Thrombectomy / Q000295:instrumentation* / Q000379:methods; D013927:Thrombosis / Q000473:pathology*; D016896:Treatment Outcome