Intracranial aneurysm wall enhancement as an indicator of instability: a systematic review and meta-analysis

Rob Molenberg; Marlien W Aalbers; Auke P A Appelman; Maarten Uyttenboogaart; J Marc C van Dijk

doi:10.1111/ene.15046

Intracranial aneurysm wall enhancement as an indicator of instability: a systematic review and meta-analysis

Eur J Neurol. 2021 Nov;28(11):3837-3848. doi: 10.1111/ene.15046. Epub 2021 Aug 25.

Authors

Rob Molenberg¹, Marlien W Aalbers¹, Auke P A Appelman², Maarten Uyttenboogaart^{2

3}, J Marc C van Dijk¹

Affiliations

¹ Department of Neurosurgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
² Medical Imaging Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
³ Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.

Abstract

Background and purpose: Aneurysm wall enhancement (AWE) of intracranial aneurysms on magnetic resonance imaging has been described in previous studies as a surrogate marker of instability. With this study, an updated literature overview and summary risk estimates of the association between AWE and different specific outcomes (i.e., rupture, growth or symptomatic presentation) for both cross-sectional and longitudinal studies are provided.

Methods: The PRISMA guideline was followed and a search was performed of PubMed and Embase to 1 January 2021 for studies that reported on AWE and aneurysm instability. In cross-sectional studies, AWE was compared between patients with stable and unstable aneurysms. In longitudinal studies, AWE of stable aneurysms was assessed at baseline after which patients were followed longitudinally. Risk ratios were calculated for longitudinal studies, prevalence ratios for cross-sectional studies and then the ratios were pooled in a random-effects meta-analysis. Also, the performance of AWE to differentiate between stable and unstable aneurysms was evaluated.

Results: Twelve studies were included with a total of 1761 aneurysms. In cross-sectional studies, AWE was positively associated with rupture (prevalence ratio 11.47, 95% confidence interval [CI] 4.05-32.46) and growth or symptomatic presentation (prevalence ratio 4.62, 95% CI 2.85-7.49). Longitudinal studies demonstrated a positive association between AWE and growth or rupture (risk ratio 8.00, 95% CI 2.14-29.88). Assessment of the performance of AWE showed high sensitivities, mixed specificities, low positive predictive values and high negative predictive values.

Conclusions: Although AWE is positively associated with aneurysm instability, current evidence mostly supports the use of its absence as a surrogate marker of aneurysm stability.

Keywords: aneurysm; gadolinium; inflammation; magnetic resonance angiography; risk assessment.

Publication types

Meta-Analysis
Review
Systematic Review

MeSH terms

Aneurysm, Ruptured* / diagnostic imaging
Aneurysm, Ruptured* / epidemiology
Cross-Sectional Studies
Humans
Intracranial Aneurysm* / diagnostic imaging
Intracranial Aneurysm* / epidemiology
Magnetic Resonance Imaging
Odds Ratio
Risk Factors