title: Less can be more: Targeted embolization of aneurysms associated with arteriovenous malformations unsuitable for surgical resection.
abstract: BACKGROUND
  To mitigate risks of hemorrhage, high-risk features of brain arteriovenous malformations (BAVMs) can be targeted to reduce the risk of rupture. Previous investigation has examined embolization of a pedicle supplying a high-risk feature; this study examines embolization targeted specifically at aneurysms associated with BAVMs.
  
  
  METHODS
  Patients with BAVMs treated at two high-volume neurointerventional services were retrospectively reviewed. Patients treated with intention to occlude only the associated aneurysm itself were analyzed. Demographic and lesion characteristics were identified, as were technical and clinical outcomes. Adverse events were defined as hemorrhage, new seizure, and death.
  
  
  RESULTS
  Thirty-two patients met inclusion criteria out of 1103 patients treated during the study period. Twenty-seven (84.4%) BAVMs were acutely ruptured, all with the aneurysm identified as the hemorrhage source. Twenty-four (75.0%) lesions involved eloquent territory. There were equal numbers of feeding artery and nidus aneurysms. Follow-up data were available for a total of 101.3 patient-years for a mean follow-up time of 2.9 years. One patient died; the remaining 31 patients had improved functional status at last contact. Annualized rate of hemorrhage after treatment was 1.0%; rate of adverse events after treatment was 3.0%. Excluding time after confirmed occlusion following radiosurgery, annualized rates were 1.4% and 4.8%, respectively.
  
  
  CONCLUSIONS
  In inoperable BAVMs, targeted embolization of associated aneurysms can be performed safely and effectively. This should be considered in high-risk lesions prior to radiosurgery or in cases when no other treatment options are available. Such intervention warrants further investigation.
authors.affiliation: Department of Radiology and Biomedical Imaging, Division of Neurointerventional Radiology, University of California San Francisco, USA matthew.alexander@ucsf.edu.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Alexander
authors.affiliation: Department of Radiology and Biomedical Imaging, Division of Neurointerventional Radiology, University of California San Francisco, USA.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Cooke
authors.affiliation: Department of Radiology, University of Washington, USA.
authors.forename: Danial K
authors.initials: DK
authors.lastname: Hallam
authors.affiliation: Department of Anesthesia and Perioperative Care, University of California San Francisco, USA.
authors.forename: Helen
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Radiology and Biomedical Imaging, Division of Neurointerventional Radiology, University of California San Francisco, USA.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Hetts
authors.affiliation: Department of Radiology, University of Washington, USA.
authors.forename: Basavaraj V
authors.initials: BV
authors.lastname: Ghodke
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017542:Aneurysm, Ruptured / Q000209:etiology / Q000628:therapy*; D002533:Cerebral Angiography; D002648:Child; D002675:Child, Preschool; D004121:Dimethyl Sulfoxide; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002532:Intracranial Aneurysm / Q000209:etiology / Q000628:therapy*; D002538:Intracranial Arteriovenous Malformations / Q000150:complications / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011145:Polyvinyls; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: C450660:Onyx copolymer; D011145:Polyvinyls; D004121:Dimethyl Sulfoxide
keywords: Arteriovenous malformation; aneurysm; embolization; intracranial hemorrhage