title: Thromboembolic complications with Pipeline Embolization Device placement: impact of procedure time, number of stents and pre-procedure P2Y12 reaction unit (PRU) value.
abstract: BACKGROUND
  Thromboembolic events after Pipeline Embolization Device (PED) placement remain a feared complication among neuroendovascular surgeons. This study aimed to investigate potential risk factors for thromboembolic events in patients undergoing PED placement.
  
  
  METHODS
  Medical records of patients who underwent PED placement from April 2011 to August 2013 were reviewed. Variables including pre-procedure P2Y12 reaction unit (PRU) value, procedure time, number of PEDs deployed and perioperative neurovascular complications were recorded. Multivariate analysis was performed to identify risk factors for perioperative thromboembolic complications.
  
  
  RESULTS
  Seventy-four patients were identified. Six patients (8.1%) had changes in neurological status after PED placement including five (6.8%) thromboembolic complications and one (1.4%) delayed intracranial hemorrhage; 50.9% of patients had diffusion-weighted imaging (DWI) changes on post-procedural MRI. Longer procedure time (>116 min) and multiple PED placements (>1) were statistically significant risk factors for symptomatic thromboembolic events (p<0.01). A pre-procedural PRU value >208 had an OR of 11.32 (95% CI 0.06 to 212.57) for symptomatic thromboembolic complications, but the result was not statistically significant.
  
  
  CONCLUSIONS
  DWI changes on MRI occurred at a much higher rate than new neurological symptoms following PED placement. Longer procedure time and multiple PED deployment are associated with higher risks of new neurological changes due to thromboembolic events. There was a trend for an increased risk of a symptomatic thromboembolic event in patients with pre-procedural PRU values >208. Reloading (clopidogrel 600 mg) patients with preoperative PRU >208 was safe and may have a protective effect on thromboembolic events.
authors.affiliation: Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois, USA.
authors.forename: Lee A
authors.initials: LA
authors.lastname: Tan
authors.affiliation: Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois, USA.
authors.forename: Kiffon M
authors.initials: KM
authors.lastname: Keigher
authors.affiliation: Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois, USA.
authors.forename: Stephan A
authors.initials: SA
authors.lastname: Munich
authors.affiliation: Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois, USA.
authors.forename: Roham
authors.initials: R
authors.lastname: Moftakhar
authors.affiliation: Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois, USA.
authors.forename: Demetrius K
authors.initials: DK
authors.lastname: Lopes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004621:Embolization, Therapeutic / Q000009:adverse effects* / Q000295:instrumentation / Q000639:trends; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000097:blood / Q000175:diagnosis / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care / Q000379:methods* / Q000639:trends; D058925:Receptors, Purinergic P2Y12 / Q000097:blood*; D012189:Retrospective Studies; D012307:Risk Factors; D015607:Stents / Q000009:adverse effects*; D013923:Thromboembolism / Q000097:blood* / Q000175:diagnosis / Q000209:etiology*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: C548576:P2RY12 protein, human; D058925:Receptors, Purinergic P2Y12
keywords: Complication; Embolic; Flow Diverter; Platelets; Stent