title: Predictors of thrombotic complications and mass effect exacerbation after pipeline embolization: The significance of adenosine diphosphate inhibition, fluoroscopy time, and aneurysm size.
abstract: BACKGROUND
  The mechanisms leading to delayed rupture, distal emboli and intraparenchymal hemorrhage in relation to pipeline embolization device (PED) placement remain debatable and poorly understood. The aim of this study was to identify clinical and procedural predictors of these perioperative complications.
  
  
  METHODS
  We conducted a retrospective review of consecutive patients who underwent PED placement. We utilized a non-commercial platelet aggregation method measuring adenosine diphosphate (ADP)% inhibition for evaluation of clopidogrel response. To our knowledge, this is the first study to test ADP in neurovascular procedures. Multivariable regression analysis was used to identify the strongest predictor of three separate outcomes: (1) thrombotic complications, (2) hemorrhagic complications, and (3) aneurysm mass effect exacerbation
  
  
  RESULTS
  Permanent complication-related morbidity and mortality at 3 months was 6% (3/48). No specific predictors of hemorrhagic complications were identified. In the univariate analysis, the strongest predictors of thrombotic complications were: ADP% inhibition<49 (p=0.01), aneurysm size (p=0.04) and fluoroscopy time (p=0.002). In the final multivariate analysis, among all baseline variables, fluoroscopy time exceeding 52 min was the only factor associated with thrombotic complications (p=0.007). Aneurysm size≥18 mm was the single predictor of mass effect exacerbation (p=0.039).
  
  
  CONCLUSIONS
  Procedural complexity, reflected by fluoroscopy time, is the strongest predictor of thrombotic complications in this study. ADP% inhibition is a reliable method of testing clopidogrel response in neurovascular procedures and values of <50% may predict thrombotic complications. Interval mass effect exacerbation after PED placement may be anticipated in large aneurysms exceeding 18 mm.
authors.affiliation: UCLA, Los Angeles, CA, USA rraychev@mednet.ucla.edu.
authors.forename: Radoslav
authors.initials: R
authors.lastname: Raychev
authors.affiliation: UCLA, Los Angeles, CA, USA.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tateshima
authors.affiliation: UCLA, Los Angeles, CA, USA.
authors.forename: Fernando
authors.initials: F
authors.lastname: Vinuela
authors.affiliation: UCLA, Los Angeles, CA, USA.
authors.forename: Jim
authors.initials: J
authors.lastname: Sayre
authors.affiliation: UCLA, Los Angeles, CA, USA.
authors.forename: Reza
authors.initials: R
authors.lastname: Jahan
authors.affiliation: UCLA, Los Angeles, CA, USA.
authors.forename: Nestor
authors.initials: N
authors.lastname: Gonzalez
authors.affiliation: UCLA, Los Angeles, CA, USA.
authors.forename: Viktor
authors.initials: V
authors.lastname: Szeder
authors.affiliation: UCLA, Los Angeles, CA, USA.
authors.forename: Gary
authors.initials: G
authors.lastname: Duckwiler
mesh_terms: D000244:Adenosine Diphosphate / Q000097:blood*; D000783:Aneurysm / Q000150:complications / Q000175:diagnosis* / Q000628:therapy*; D015415:Biomarkers / Q000097:blood; D004621:Embolization, Therapeutic / Q000009:adverse effects* / Q000295:instrumentation*; D019544:Equipment Failure Analysis; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D020767:Intracranial Thrombosis / Q000000981:diagnostic imaging / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D011379:Prognosis; D011474:Prosthesis Design; D012189:Retrospective Studies; D012720:Severity of Illness Index; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D000244:Adenosine Diphosphate
keywords: Aneurysm; complications; embolization; flow diversion; intracranial hemorrhage; mass effect; pipeline