Diagnosis and monitoring of abdominal aortic aneurysm: current status and future prospects

Abstract

Abdominal aortic aneurysm (AAA) remains an important cause of morbidity and mortality in elderly men, and prevalence is predicted to increase in parallel with a global aging population. AAA is commonly asymptomatic, and in the absence of routine screening, diagnosis is usually incidental when imaging to assess unrelated medical complaints. In the absence of approved diagnostic and prognostic markers, AAAs are monitored conservatively via medical imaging until aortic diameter approaches 50-55 mm and surgical repair is performed. There is currently significant interest in identifying molecular markers of diagnostic and prognostic value for AAA. Here we outline the current guidelines for AAA management and discuss modern scientific techniques currently employed to identify improved diagnostic and prognostic markers.

Figure 1

A) Axial computed tomography image of abdominal aortic aneurysm displaying large quantity of posterior-eccentric thrombus. B) Axial computed tomography image of abdominal aortic aneurysm a moderate quantity of posterior-eccentric thrombus. C) Axial computed tomography image of an abdominal aortic aneurysm with moderate quantity of concentric thrombus and two large calcium deposits at 12 and 5 o’clock. ILT = intraluminal thrombus; L = lumen; AV = abdominal vertebra; Ca = calcium deposit.

Figure 2

Magnified (× 40) view of a Haematoxylin and eosin stained human AAA biopsy recovered during the course of surgical repair. Note that the tunica media (TM) is thinned and disorganised, (separated from the tunica adventitia (TA) during the course of histological preparation). Examination of the TA reveals the presence of invading inflammatory cells (IC), evidence of neo-vascularisation (NV), and the formation of vascular associated lymphoid tissue (VALT) follicles. The tunica intima has thinned and eroded. Microscope image kindly provided by Drs Alexandra Trollope and Corey Moran, Vascular Biology Unit, James Cook University, Australia.

Figure 3

A lateral 3D reconstruction of a mildly tortuous AAA post-treatment. In angulated aortas axial diameters tend to over-estimate the true orthogonal diameters.