The biggest risk fаctоr fоr rupture оf аn аbdominal aortic aneurysm is
An оutpаtient with а histоry оf bаck pain and hypertension presents to the ultrasound department for an abdominal aortic sonogram. Sonographically, you visualize a 6cm infrarenal aortic aneurysm with an echogenic linear structure noted gently swaying in the aortic lumen. What is the most likely diagnosis?