title: Retrospective Analysis of Delayed Intraparenchymal Hemorrhage after Flow-Diverter Treatment: Presentation of a Retrospective Multicenter Trial.
abstract: OBJECTIVE
  Intracranial aneurysm treatment with flow diverters has shown satisfying results in terms of aneurysm occlusion, and while some cases of delayed intraparenchymal hemorrhage have been described, no systematic analysis of the risk factors affecting its occurrence has been conducted in a large series of patients. This retrospective analysis of delayed intraparenchymal hemorrhage after flow-diverter treatment is a multicenter, retrospective study using a large series of treated patients to analyze factors affecting the occurrence of delayed intraparenchymal hemorrhage.
  
  
  METHODS
  Patients treated with flow diverters and presenting with delayed intraparenchymal hemorrhage were included from December 2007 to December 2014 in 7 participating centers in France. Patient and aneurysm characteristics were recorded as were characteristics of bleeding (size, lateralization, and time to bleed), treatment, and clinical outcome after 1, 3, and 6 months.
  
  
  RESULTS
  Delayed intraparenchymal hemorrhage occurred in 11 patients between 1 and 21 days after the procedure. In 10 of these patients, hemorrhages were ipsilateral to the treated aneurysms. Five of the 11 underwent surgery, and 9 of the 11 had good clinical outcomes at 6 months (mRS ≤2).
  
  
  CONCLUSIONS
  The pathogenesis of delayed intraparenchymal hemorrhage occurring after flow-diverter treatment remains unclear. The multidisciplinary management of delayed intraparenchymal hemorrhage yields a relatively low morbidity-mortality rate compared with the initial clinical presentation.
authors.affiliation: From the Department of Neuroradiology (A.B., C.T., L.P.), Centres Hospitaliers Universitaires de Reims, Reims, France.
authors.forename: A
authors.identifier: http://orcid.org/0000-0002-2721-5023
authors.initials: A
authors.lastname: Benaissa
authors.affiliation: From the Department of Neuroradiology (A.B., C.T., L.P.), Centres Hospitaliers Universitaires de Reims, Reims, France.
authors.forename: C
authors.identifier: http://orcid.org/0000-0002-9360-6743
authors.initials: C
authors.lastname: Tomas
authors.affiliation: Department of Neuroradiology (F.C., N.S.), Centres Hospitaliers Universitaires of Pitié-Salpêtrière, Paris, France.
authors.forename: F
authors.identifier: http://orcid.org/0000-0002-6442-8239
authors.initials: F
authors.lastname: Clarençon
authors.affiliation: Department of Neuroradiology (F.C., N.S.), Centres Hospitaliers Universitaires of Pitié-Salpêtrière, Paris, France.
authors.forename: N
authors.identifier: http://orcid.org/0000-0002-5935-5100
authors.initials: N
authors.lastname: Sourour
authors.affiliation: Department of Neuroradiology (D.H.), Centres Hospitaliers Universitaires of Tours, Tours, France.
authors.forename: D
authors.identifier: http://orcid.org/0000-0002-4533-4296
authors.initials: D
authors.lastname: Herbreteau
authors.affiliation: Department of Neuroradiology (L.S.), Centres Hospitaliers Universitaires of Beaujon, Clichy, France.
authors.forename: L
authors.identifier: http://orcid.org/0000-0002-6748-8528
authors.initials: L
authors.lastname: Spelle
authors.affiliation: Department of Neuroradiology (S.G.), Centres Hospitaliers Universitaires of Créteil, Créteil, France.
authors.forename: S
authors.identifier: http://orcid.org/0000-0003-2053-2293
authors.initials: S
authors.lastname: Gallas
authors.affiliation: Department of Neuroradiology (A.-C.J.), Centres Hospitaliers Universitaires of Toulouse, Toulouse, France.
authors.forename: A-C
authors.identifier: http://orcid.org/0000-0003-4910-6386
authors.initials: AC
authors.lastname: Januel
authors.affiliation: Department of Neuroradiology (A.L.G.), Centres Hospitaliers Universitaires of Nantes, Nantes, France.
authors.forename: A L
authors.identifier: http://orcid.org/0000-0001-5466-5428
authors.initials: AL
authors.lastname: Gaultier
authors.affiliation: From the Department of Neuroradiology (A.B., C.T., L.P.), Centres Hospitaliers Universitaires de Reims, Reims, France lpierot@chu-reims.fr.
authors.forename: L
authors.identifier: http://orcid.org/0000-0002-2523-4909
authors.initials: L
authors.lastname: Pierot
mesh_terms: D000328:Adult; D002543:Cerebral Hemorrhage / Q000453:epidemiology* / Q000209:etiology*; D057510:Endovascular Procedures / Q000009:adverse effects* / Q000379:methods; D005260:Female; D005602:France; D006801:Humans; D002532:Intracranial Aneurysm / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors