Concentration of Lp(a) (Lipoprotein[a]) in Aneurysm Sac Is Associated With Wall Enhancement of Unruptured Intracranial Aneurysm

Abstract

Background and Purpose: Atherosclerotic remodeling of the aneurysm wall, which could be detected as aneurysm wall enhancement (AWE) by magnetic resonance–vessel wall imaging, is a part of degenerative change of unruptured intracranial aneurysms (UIAs). The purpose of this study was to determine whether the luminal concentrations of atherosclerotic proteins in the aneurysm sac were associated with increased wall enhancement of UIAs in vessel wall imaging. Methods: We performed a prospective study of subjects undergoing endovascular treatments for UIAs. All subjects underwent evaluation using 3T–magnetic resonance imaging, including pre/postcontrast vessel wall imaging of the UIAs. Blood samples were collected from the aneurysm sac and the parent artery during endovascular procedures. Presence/absence of AWE was correlated with the delta difference in concentration for each atherosclerotic protein between the lumen of UIA and in the parent artery. Results: A total of consecutive 17 patients with 19 UIAs were enrolled. The delta difference of lipoprotein(a) was significantly higher in UIAs with AWE compared with those without AWE (−6.9±16.0 versus −45.4±44.9 μg/mL, P=0.03). Conclusions: Higher luminal concentrations of lipoprotein(a) in the aneurysm sac were significantly associated with increased wall enhancement of UIAs. A larger study is needed to confirm these findings.