title: Prophylactic intra-arterial injection of vasodilator for asymptomatic vasospasm converts the patient to symptomatic vasospasm due to severe microcirculatory imbalance.
abstract: OBJECTIVE
  The strategy to treat asymptomatic angiographic vasospasm following subarachnoid hemorrhage (SAH) is controversial. In this study we review our consecutive vasospasm series and discuss an adequate treatment strategy for asymptomatic vasospasm.
  
  
  METHODS
  From January 2007 to December 2012 we treated 281 aneurysmal SAH cases, with postoperative angiography performed 9 ± 2 days after the onset of SAH. Four asymptomatic cases received intra-arterial (IA) injection of vasodilator due to angiographic vasospasm. All cases improved vasospasm immediately following intervention. But all cases turned symptomatic within 48 hours. We retrospectively analyzed the time-density angiography curve and calculated the time to peak (TTP), mean transit time (MTT), and relative blood flow (rBF). Relative blood flow was calculated as follows. The integration of the value of the time-density curve for the artery was divided by the same value for the internal carotid artery multiplied by the MTT.
  
  
  RESULTS
  The decrease in TTP and MTT for the etiologic artery was similar to that of the nonetiologic artery. But the improvement in rBF for the etiologic artery and nonetiologic artery was 10% and 17%, respectively. Blood supply to the spastic artery decreased due to iatrogenic steal.
  
  
  CONCLUSIONS
  Prophylactic IA injection of vasodilator in cases of asymptomatic vasospasm can produce symptomatic vasospasm.
authors.affiliation: Department of Neurosurgery, Hirosaki University School of Medicine, 5-Zaihuchou, Hirosaki, Aomori Prefecture 036-8562, Japan.
authors.forename: Norihito
authors.identifier: 0000-0003-3003-9160
authors.initials: N
authors.lastname: Shimamura
authors.affiliation: Department of Neurosurgery, Hirosaki University School of Medicine, 5-Zaihuchou, Hirosaki, Aomori Prefecture 036-8562, Japan.
authors.forename: Masato
authors.identifier: 0000-0001-6490-527X
authors.initials: M
authors.lastname: Naraoka
authors.affiliation: Department of Neurosurgery, Hirosaki University School of Medicine, 5-Zaihuchou, Hirosaki, Aomori Prefecture 036-8562, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Matsuda
authors.affiliation: Department of Neurosurgery, Hirosaki University School of Medicine, 5-Zaihuchou, Hirosaki, Aomori Prefecture 036-8562, Japan.
authors.forename: Kiyohide
authors.initials: K
authors.lastname: Kakuta
authors.affiliation: Department of Neurosurgery, Hirosaki University School of Medicine, 5-Zaihuchou, Hirosaki, Aomori Prefecture 036-8562, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ohkuma
mesh_terms: D000368:Aged; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D007269:Injections, Intra-Arterial; D008875:Middle Aged; D012189:Retrospective Studies; D013345:Subarachnoid Hemorrhage / Q000503:physiopathology*; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D020301:Vasospasm, Intracranial / Q000000981:diagnostic imaging / Q000503:physiopathology*
chemical_list: D014665:Vasodilator Agents