title: Multidisciplinary consensus on assessment of unruptured intracranial aneurysms: proposal of an international research group.
abstract: OBJECTIVE
  To address the increasing need to counsel patients about treatment indications for unruptured intracranial aneurysms (UIA), we endeavored to develop a consensus on assessment of UIAs among a group of specialists from diverse fields involved in research and treatment of UIAs.
  
  
  METHODS
  After composition of the research group, a Delphi consensus was initiated to identify and rate all features, which may be relevant to assess UIAs and their treatment by using ranking scales and analysis of inter-rater agreement (IRA) for each factor. IRA was categorized as very high, high, moderate, or low.
  
  
  RESULTS
  Ultimately, 39 specialists from 4 specialties agreed (high or very high IRAs) on the following key factors for or against UIA treatment decisions: (1) patient age, life expectancy, and comorbid diseases; (2) previous subarachnoid hemorrhage from a different aneurysm, family history for UIA or subarachnoid hemorrhage, nicotine use; (3) UIA size, location, and lobulation; (4) UIA growth or de novo formation on serial imaging; (5) clinical symptoms (cranial nerve deficit, mass effect, and thromboembolic events from UIAs); and (6) risk factors for UIA treatment (patient age and life expectancy, UIA size, and estimated risk of treatment). However, IRAs for features rated with low relevance were also generally low, which underlined the existing controversy about the natural history of UIAs.
  
  
  CONCLUSIONS
  Our results highlight that neurovascular specialists currently consider many features as important when evaluating UIAs but also highlight that the appreciation of natural history of UIAs remains uncertain, even within a group of highly informed individuals.
authors.affiliation: From the Department of Neurosurgery (N.E., K.B., D. Hänggi, H.-J.S.), Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; Department of Neurosurgery, Emory Stroke Center, Emory University School of Medicine, Atlanta, GA (D.L.B.); Department of Neurosurgery, The Mount Sinai Health System, New York, NY (J.B.); Departments of Neurology (R.D.B.) and Neurologic Surgery (G.L.), Mayo Clinic, Rochester, MN; Department of Neurological Surgery, Columbia University, New York, NY (E.S.C.); Mallinckrodt Institute of Radiology, Washington University School of Medicine/ Barnes Jewish Hospital, St Louis, MO (C.P.D.); Departments of Neurosurgery (D. Hasan) and Epidemiology (J.C.T.), University of Iowa, Iowa City; Department of Clinical Neurosciences, University of Helsinki, Helsinki, Finland (S.J.); Department of Neurosurgery, Tokyo Women's Medical University Medical Center East, Tokyo, Japan (H.K.); Neurosurgery Unit, Department of Clinical Neurosciences, Cambridge University Hospitals Trust, University of Cambridge, Cambridge, UK (P.J.K.); Sir Charles Gairdner Hospital, Western Australia (N.K.); Neurosurgery/ NeuroCenter, Kuopio University Hospital, University of Eastern Finland, Finland (T.K.); Department of Neurological Surgery, University of California, San Francisco (M.T.L.); Brain and Spine Center, Lankenau Medical Center, Wynnewood, PA (P.L.); Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ (C.G.M.); Department of Neurosurgery, Auckland City Hospital, Auckland, New Zealand (E.M.); Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN (J.M.); Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK (A.M.); Division of Neurosurgery, Macquarie University, Sydney, Australia (M.K.M.); Department of Neurosurgery, National Defense Medical College, Tokyo, Japan (K.M.); Department of Neurological Surgery, Nippon Medical School, Tokyo, Japan (A.M.);
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mesh_terms: D000328:Adult; D003697:Delphi Technique; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000628:therapy
keywords: Delphi technique; cerebral aneurysm; consensus; incidental aneurysm; natural history; therapeutics