Introduction: The natural history and indications for prophylactic treatment of UIAs remains controversial. To address this, we endeavored to identify and rate all features relevant to the assessment and management of unruptured intracranial aneurysms (UIA) by convening a panel of specialists from the diverse fields (Neurology, Clinical Epidemiology, Neurosurgery and Neuroradiology) involved in research and treatment of UIAs.
Methods: Following composition of the research group, a 5-round, survey-based Delphi consensus process was initiated to a) identify, b) rate all features, which may be relevant to assess UIAs and their treatment. Ranking scales were repeatedly used to determine statistical weight for each factor and to exclude significant discrepancies between rounds (intra rater agreement). Medians for ratings were calculated and categorized into high relevance, moderate relevance and low relevance. Inter-rater agreement (IRA) was calculated using the standardized quartile coefficients of dispersion and categorized into very high, high, low and very low IRA
Results: Thirty-nine specialists, from 12 different countries participated in the Delphi process. A total of 8 patient-related and 10 aneurysm-related features were rated as highly relevant to support either aneurysm repair or conservative management by the panel. With respect to risk of treatment, a total of 6 factors were rated highly important and important for decision making in the management of UIAs. However, our data clearly illustrated the existing heterogeneity with respect to the natural history of UIAs, especially for factors rated as highly relevant, as evident by low IRA. Interestingly, the IRAs for ratings for risk of treatment were very high or high.(see also attachment)
Conclusions: Our data underlines that the assessment of the natural history of UIAs is multifactorial and somewhat heterogeneous, even within a group of cerebrovascular specialists. This heterogeneity seems to be distinctly lower for the assessment of factors relevant for risk of treatment of an UIA.
Patient Care: Our data highlights distinct aspects of uncertainty in the natural history of UIAs. These aspects should be specifically addressed in future studies on the natural history of UIAs.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of different features of patients with UIAs for assessment of a treatment indication and 2) highlight features in the natural history of UIAs that deserve further scientific attention.