title: Delayed ipsilateral parenchymal hemorrhage following flow diversion for the treatment of anterior circulation aneurysms.
abstract: OBJECTIVE
  The PED is a flow-diverting stent designed for the treatment of cerebral aneurysms. We report 4 cases of delayed ipsilateral IPH following the technically successful treatment of anterior circulation aneurysms with the PED.
  
  
  METHODS
  Clinical and imaging data from all patients undergoing aneurysm treatment with the PED at 2 institutions were analyzed to assess the incidence of delayed IPH after treatment with the PED.
  
  
  RESULTS
  A total of 66 patients (47 anterior circulation) with cerebral aneurysms underwent treatment with a PED between January 2008 and November 2010. Four patients experienced delayed periprocedural IPH, all after the treatment of anterior circulation aneurysms (8.5%, 4/47). The aneurysm size ranged from 5 to 21 mm. All IPHs occurred within the cerebral hemisphere, ipsilateral to the treated aneurysm, and were anatomically remote from the treated aneurysms. All procedures were uncomplicated, and patients emerged from general anesthesia at neurologic baseline. The hemorrhages became clinically evident between 1 and 6 days after the procedure. Two patients had unfavorable outcomes (mRS scores, 4 and 6).
  
  
  CONCLUSIONS
  Delayed IPH may occur after the treatment of anterior circulation aneurysms with flow diverters. This complication does not seem to be restricted to a specific aneurysm subtype and does not seem to be related to an intraprocedural complication or solely attributable to DAT.
authors.affiliation: Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada.
authors.forename: J P
authors.initials: JP
authors.lastname: Cruz
authors.forename: M
authors.initials: M
authors.lastname: Chow
authors.forename: C
authors.initials: C
authors.lastname: O'Kelly
authors.forename: B
authors.initials: B
authors.lastname: Marotta
authors.forename: J
authors.initials: J
authors.lastname: Spears
authors.forename: W
authors.initials: W
authors.lastname: Montanera
authors.forename: D
authors.initials: D
authors.lastname: Fiorella
authors.forename: T
authors.initials: T
authors.lastname: Marotta
mesh_terms: D002543:Cerebral Hemorrhage / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D002548:Cerebral Revascularization / Q000009:adverse effects* / Q000295:instrumentation; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications* / Q000175:diagnosis / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015607:Stents / Q000009:adverse effects*; D016896:Treatment Outcome