title: Natural course of dissecting vertebrobasilar artery aneurysms without stroke.
abstract: OBJECTIVE
  The natural history and therapeutic management of dissecting vertebrobasilar aneurysms without ischemic or hemorrhagic stroke (nonstroke dissecting vertebrobasilar aneurysms) are not well-established. We conservatively followed patients with nonstroke dissecting vertebrobasilar aneurysms and evaluated the factors related to clinical and morphologic deterioration.
  
  
  METHODS
  One hundred thirteen patients were enrolled and divided by clinical presentation at diagnosis: asymptomatic (group 1, n = 52), pain only (group 2, n = 56), and mass effect (group 3, n = 5). Patients were conservatively managed without intervention and antithrombotic therapy. Clinical outcomes and morphologic changes were analyzed.
  
  
  RESULTS
  A total of 113 patients who were diagnosed with nonstroke dissecting vertebrobasilar aneurysm had a mean follow-up of 2.9 years (range, 27 days to 8 years). Throughout that period, 1 patient in group 1 (1.9%) and 1 patient in group 2 (1.8%) showed clinical deterioration due to mass effect, and 1 patient in group 3 (20%) developed ischemic stroke followed by subarachnoid hemorrhage. Most patients (97.3%) were clinically unchanged. Three patients who had clinical deterioration showed aneurysm enlargement (P < .001). Aneurysms remained morphologically unchanged in 91 patients (80.5%). Aneurysm enlargement was seen in 5 patients (4.4%); risk of enlargement was significantly associated with either maximum diameter (hazard ratio = 1.30; 95% CI, 1.11-11.52; P = .001) or aneurysm ≥10 mm (hazard ratio = 18.0; 95% CI, 1.95-167; P = .011).
  
  
  CONCLUSIONS
  The natural course of these lesions suggests that acute intervention is not always required and close follow-up without antithrombotic therapy is reasonable. Patients with symptoms due to mass effect or aneurysms of >10 mm may require treatment.
authors.affiliation: From the Department of Neurosurgery (N.K., Y.M., I.Y., T.I., M.E., H.A., K.I., H.T., I.K., K.N., K.K.).
authors.forename: N
authors.initials: N
authors.lastname: Kobayashi
authors.affiliation: From the Department of Neurosurgery (N.K., Y.M., I.Y., T.I., M.E., H.A., K.I., H.T., I.K., K.N., K.K.) ymurayama@jikei.ac.jp.
authors.forename: Y
authors.initials: Y
authors.lastname: Murayama
authors.affiliation: From the Department of Neurosurgery (N.K., Y.M., I.Y., T.I., M.E., H.A., K.I., H.T., I.K., K.N., K.K.).
authors.forename: I
authors.initials: I
authors.lastname: Yuki
authors.affiliation: From the Department of Neurosurgery (N.K., Y.M., I.Y., T.I., M.E., H.A., K.I., H.T., I.K., K.N., K.K.).
authors.forename: T
authors.initials: T
authors.lastname: Ishibashi
authors.affiliation: From the Department of Neurosurgery (N.K., Y.M., I.Y., T.I., M.E., H.A., K.I., H.T., I.K., K.N., K.K.).
authors.forename: M
authors.initials: M
authors.lastname: Ebara
authors.affiliation: From the Department of Neurosurgery (N.K., Y.M., I.Y., T.I., M.E., H.A., K.I., H.T., I.K., K.N., K.K.).
authors.forename: H
authors.initials: H
authors.lastname: Arakawa
authors.affiliation: From the Department of Neurosurgery (N.K., Y.M., I.Y., T.I., M.E., H.A., K.I., H.T., I.K., K.N., K.K.).
authors.forename: K
authors.initials: K
authors.lastname: Irie
authors.affiliation: From the Department of Neurosurgery (N.K., Y.M., I.Y., T.I., M.E., H.A., K.I., H.T., I.K., K.N., K.K.).
authors.forename: H
authors.initials: H
authors.lastname: Takao
authors.affiliation: From the Department of Neurosurgery (N.K., Y.M., I.Y., T.I., M.E., H.A., K.I., H.T., I.K., K.N., K.K.).
authors.forename: I
authors.initials: I
authors.lastname: Kajiwara
authors.affiliation: From the Department of Neurosurgery (N.K., Y.M., I.Y., T.I., M.E., H.A., K.I., H.T., I.K., K.N., K.K.).
authors.forename: K
authors.initials: K
authors.lastname: Nishimura
authors.affiliation: From the Department of Neurosurgery (N.K., Y.M., I.Y., T.I., M.E., H.A., K.I., H.T., I.K., K.N., K.K.).
authors.forename: K
authors.initials: K
authors.lastname: Karagiozov
authors.affiliation: Division of Molecular Epidemiology (M.U.), The Jikei University School of Medicine, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Urashima
mesh_terms: D000784:Aortic Dissection / Q000150:complications / Q000000981:diagnostic imaging / Q000628:therapy*; D002533:Cerebral Angiography; D018450:Disease Progression; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000000981:diagnostic imaging / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D020521:Stroke / Q000209:etiology; D016896:Treatment Outcome; D020217:Vertebral Artery Dissection / Q000150:complications / Q000000981:diagnostic imaging / Q000628:therapy*; D014715:Vertebrobasilar Insufficiency / Q000150:complications / Q000000981:diagnostic imaging / Q000628:therapy*