Abstract WMP28: Follow-up of Large Intracranial Aneurysms Indicates Growth Frequency Varies According to Location and Size
Background: Although treatment is recommended for unruptured large aneurysms (≥7mm), which have higher rupture risk, in practice some aneurysms remain under observation due to a patient’s medical history or age. Detailed data about aneurysm growth during follow-up is limited. In this study, we aim to investigate growth in large aneurysms by reviewing the unruptured aneurysms cases which were followed in our center.
Hypothesis: The growth of large unruptured aneurysms varies according to aneurysm characteristics and patient medical history.
Method: A retrospective review of patient records based on unruptured aneurysms diagnosed in our center from 2005 to 2011 was performed. Large unruptured aneurysms which had more than one CTA examination separated by at least 3 months were included. Aneurysm characteristics, patient information, and medical history were recorded. Univariate and multivariate logistic regression were used to analyze aneurysm growth.
Results: From a total of 410 unruptured aneurysms followed in our center, 50 large aneurysms (41 females, 9 males; age 67.3±12.6 years) were included: 42 aneurysms with initial size 7-12.9 mm, 7 aneurysms 13-23.9 mm, and 1 aneurysm ≥24 mm. During the average 25.6 month follow-up, 15 (30%) aneurysms enlarged and 35 (70%) were unchanged. The growth frequency of aneurysms located in ICA, MCA, ACA, BA was 40%, 22%, 20% and 17%, respectively. The growth frequency of aneurysms of sizes 7-12.9 mm, 13-23.9 mm and ≥24 mm was 23.8%, 71.4% and 0, respectively. Using univariate logistic regression analysis, duration of follow-up (P=0.023), and history of ischemic stroke (P=0.027) were associated with growth. Multivariate logistic regression showed only duration of follow-up as a risk factor for growth (OR, 1.056 per month; 95% CI 1010 to 1.104; P=0.016). Only one aneurysm (ICA) ruptured in the follow-up (70 months), resulting in a rupture rate of 6.7% (1/15) enlarged aneurysms (0/35 unchanged aneurysms).
Conclusion: A large percentage of aneurysms selected for observation grew, and growth frequency varied according to aneurysm location and size. A larger, future study may identify additional factors associated with growth, including ones specific to aneurysm characteristics like location and initial size.
- © 2012 by American Heart Association, Inc.