Influence of gender on intraluminal thrombus of abdominal aortic aneurysms

Background: The mechanisms of formation of intraluminal thrombus (ILT) of a bdominal aortic aneurysms (AAA) remain unknown. The aim of this study was t o investigate the pathogenesis of AAA by analysis of ILT. Methods: We retrospectively analyzed the size of ILT in 98 consecutive pati ents with AAA undergoing abdominal computed tomography (CT) examination. Th e volume of ILT was estimated by the area ratio of ILT in CT images. Import ant baseline variables related to small ILT were determined using logistic- regression analysis. Results: There were two apparent peaks in the distribution of ILT ratio. Th irteen of 98 patients had negligible ILT with ratio less than or equal to0. 1. Female gender was the only patient characteristic independently signific antly correlated with small ILT (odds ratio 5.214, P = 0.0096). Conclusion: Our findings provide important evidence that AAA is formed by a t least two different pathogenic processes. It is likely that this differen ce in mechanisms may be caused partly by sex hormones. (C) 2001 Excerpta Me dica, Inc. All rights reserved.