title: Intraarterial infusion of papaverine in experimental cerebral vasospasm.
abstract: OBJECTIVE
  To determine the effectiveness of intraarterial infusion of papaverine hydrochloride (PPV) in an experimental model of cerebral vasospasm and to measure the mean blood flow velocity of the middle cerebral artery (MCA).
  
  
  METHODS
  Seven Japanese monkeys were divided into three groups: those studied 3 days-after surgery (the third-day group, n = 3); those studied 7 days after surgery (the seventh-day group, n = 3); and a control group (n = 1). Vasospasm was induced in the experimental groups by placing a blood clot in the subarachnoid space around the top of the internal carotid siphon. PPV (5 mg/kg) was infused (over 60 minutes) into the internal carotid artery (ICA). The vascular diameters of the ICA and MCA were measured on angiograms before and after infusion. The mean blood flow velocity in the MCA was measured on transcranial Doppler sonograms before and 24 hours after infusion. After fixation, the MCA was dissected out, stained, and examined microscopically.
  
  
  RESULTS
  After vasospasm induction, both arteries were narrowed more than 30% in the third-day group and more than 50% in the seventh-day group. After PPV infusion in both groups, vascular dilatation of about 20% was seen. The mean increase in blood flow velocity in the third-day group (30%) was smaller than in the seventh-day group (70%). The mean blood flow velocity in the MCA decreased by about 30% in both groups, but increased again after 24 hours nearly to the level before PPV infusion. The intimal layer was more corrugated in the seventh-day group, and hypertrophy in the smooth muscle layer was also seen. Clinical examination showed no neurologic deficit in the third-day group 24 hours after PPV infusion; neurologic deficits were observed in the seventh-day group.
  
  
  CONCLUSIONS
  PPV infusion may be more effective in early stages of vasospasm when vascular walls have fewer histologic changes.
authors.affiliation: Department of Radiology, Kagawa Medical University, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Fujiwara
authors.forename: Y
authors.initials: Y
authors.lastname: Honjo
authors.forename: M
authors.initials: M
authors.lastname: Ohkawa
authors.forename: M
authors.initials: M
authors.lastname: Tanabe
authors.forename: K
authors.initials: K
authors.lastname: Irie
authors.forename: S
authors.initials: S
authors.lastname: Nagao
authors.forename: H
authors.initials: H
authors.lastname: Takashima
authors.forename: K
authors.initials: K
authors.lastname: Satoh
authors.forename: K
authors.initials: K
authors.lastname: Kojima
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D002533:Cerebral Angiography; D002536:Cerebral Arteries; D002560:Cerebrovascular Circulation / Q000187:drug effects; D007261:Infusions, Intra-Arterial; D002546:Ischemic Attack, Transient / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D008251:Macaca; D008297:Male; D010208:Papaverine / Q000008:administration & dosage* / Q000627:therapeutic use; D015641:Radiography, Interventional; D017585:Ultrasonography, Doppler, Transcranial; D014665:Vasodilator Agents / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D014665:Vasodilator Agents; D010208:Papaverine