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

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

Rob Molenberg  1 , Marlien W Aalbers  1 , Auke P A Appelman  2 , Maarten Uyttenboogaart  2   3 , J Marc C van Dijk  1
Affiliations
Meta-Analysis

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

Rob Molenberg et al. Eur J Neurol. 2021 Nov.

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.

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Conflict of interest statement

None.

Figures

FIGURE 1
FIGURE 1
Example of aneurysm wall enhancement in a patient with a left middle cerebral artery aneurysm. All images are coronal projections and were made during the same scanning session. (a) Coronal maximum intensity projection of 3D time‐of‐flight MRA. High spatial resolution, fat‐saturated 3D T1 SPACE black blood MRI before (b) and after (c) administration of gadolinium, showing circumferential aneurysm wall enhancement
FIGURE 2
FIGURE 2
PRISMA flow diagram
FIGURE 3
FIGURE 3
Meta‐analysis of the association between AWE and aneurysm instability. (a) Cross‐sectional studies with aneurysm rupture as the outcome. (b) Cross‐sectional studies with aneurysm growth or symptomatic presentation as the outcome. (c) Longitudinal studies with aneurysm growth or rupture as the outcome. The size of the squares is proportional to the weight of each study, with the horizontal lines representing the 95% CI of the RR or PR estimate. The diamonds represent the pooled estimate with 95% CI. Studies are arranged based on effect size
See this image and copyright information in PMC

Comment in

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