title: Imaging Characteristics of Growing and Ruptured Vertebrobasilar Non-Saccular and Dolichoectatic Aneurysms.
abstract: OBJECTIVE
  Vertebrobasilar, nonsaccular, and dolichoectatic aneurysms generally have a poor natural history. We performed a study examining the natural history of vertebrobasilar, nonsaccular, and dolichoectatic aneurysms receiving serial imaging and studied imaging characteristics associated with growth and rupture.
  
  
  METHODS
  We included all vertebrobasilar dolichoectatic, fusiform, and transitional aneurysms with serial imaging follow-up seen at our institution over a 15-year period. Two radiologists and a neurologist evaluated aneurysms for size, type, mural T1 signal, mural thrombus, daughter sac, mass effect, and tortuosity. Primary outcomes were aneurysm growth or rupture. Univariate analysis was performed with chi-squared tests for categorical variables and Student's t test or analysis of variance for continuous variables. Multivariate logistic regression analysis was performed to identify variables independently associated with aneurysm growth or rupture.
  
  
  RESULTS
  One hundred and fifty-two patients with 542 patient-years (mean 3.6±3.5 years) of imaging follow-up were included. Aneurysms were fusiform in 45 cases (29.6%), dolichoectatic in 75 cases (49.3%), and transitional in 32 cases (21.1%). Thirty-five aneurysms (23.0%) grew (growth rate=6.5%/year). Eight aneurysms (5.3%) ruptured (rupture rate=1.5%/year). Variables associated with growth and rupture on univariate analysis were size >10 mm (57.6% versus 16.0%, P<0.0001), mural T1 signal (39.7% versus 16.3%, P=0.001), daughter sac (56.3% versus 21.3%), and mural thrombus (45.5% versus 13.4%, P<0.0001). 26.7% of fusiform aneurysms, 9.3% of dolichoectatic aneurysms, and 59.4% of transitional aneurysms grew or ruptured (P<0.0001). The only variable independently associated with rupture was transitional morphology (P=0.003).
  
  
  CONCLUSIONS
  Vertebrobasilar, nonsaccular, and dolichoectatic aneurysms are associated with a poor natural history with high growth and rupture rates. Further research is needed to determine the best treatments for this disease.
authors.affiliation: From the Department of Neurology, Mayo Clinic, Rochester, MN (D.M.N., K.D.F.); and Department of Radiology, Mayo Clinic, Rochester, MN (W.B., A.R., R.K., D.F.K.). nasr.deena@mayo.edu.
authors.forename: Deena M
authors.initials: DM
authors.lastname: Nasr
authors.affiliation: From the Department of Neurology, Mayo Clinic, Rochester, MN (D.M.N., K.D.F.); and Department of Radiology, Mayo Clinic, Rochester, MN (W.B., A.R., R.K., D.F.K.).
authors.forename: Waleed
authors.initials: W
authors.lastname: Brinjikji
authors.affiliation: From the Department of Neurology, Mayo Clinic, Rochester, MN (D.M.N., K.D.F.); and Department of Radiology, Mayo Clinic, Rochester, MN (W.B., A.R., R.K., D.F.K.).
authors.forename: Aymeric
authors.initials: A
authors.lastname: Rouchaud
authors.affiliation: From the Department of Neurology, Mayo Clinic, Rochester, MN (D.M.N., K.D.F.); and Department of Radiology, Mayo Clinic, Rochester, MN (W.B., A.R., R.K., D.F.K.).
authors.forename: Ramanathan
authors.initials: R
authors.lastname: Kadirvel
authors.affiliation: From the Department of Neurology, Mayo Clinic, Rochester, MN (D.M.N., K.D.F.); and Department of Radiology, Mayo Clinic, Rochester, MN (W.B., A.R., R.K., D.F.K.).
authors.forename: Kelly D
authors.initials: KD
authors.lastname: Flemming
authors.affiliation: From the Department of Neurology, Mayo Clinic, Rochester, MN (D.M.N., K.D.F.); and Department of Radiology, Mayo Clinic, Rochester, MN (W.B., A.R., R.K., D.F.K.).
authors.forename: David F
authors.initials: DF
authors.lastname: Kallmes
mesh_terms: D000368:Aged; D017542:Aneurysm, Ruptured / Q000000981:diagnostic imaging*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed / Q000639:trends*; D014711:Vertebral Artery / Q000000981:diagnostic imaging*
keywords: aneurysm; human; stroke; subarachnoid hemorrhage; thrombosis