Impact of calcification and intraluminal thrombus on the computed wall stresses of abdominal aortic aneurysm

Abstract

The presence of calcification increases AAA peak wall stress, suggesting that calcification decrease the biomechanical stability of AAA. In contrast, intraluminal thrombus reduces the maximum stress in AAA. Calcification and intraluminal thrombus should both be considered in the evaluation of wall stress for risk assessment of AAA rupture.

Association Between Aneurysm Shoulder Stress and Abdominal Aortic Aneurysm Expansion

“…It may well result from the formation of ILT at the previous "shoulder area," which tends to reduce the stress in the AAA. 10 Although no concomitant increase from baseline for the overall stress, overall maximum diameter stress, and overall shoulder stress was observed, a positive correlation between the expansion rate and the shoulder stress was identified. Further analysis of the 2 groups revealed that this relationship exists for rapidly expanding aneurysms only and not for slowly expanding aneurysms.…”

“…9,10 A patientspecific study previously demonstrated that maximum wall stress was 12% more specific and 13% more sensitive in predicting AAA rupture than maximum diameter alone. 11 In other patient-specific studies, peak stress was found to be significantly higher in ruptured AAAs than nonruptured AAAs.…”

Biomechanical factors in Finite Element Analysis of abdominal aortic aneurysms

“…Although, there is a lack of agreement on how calcifications actually affect it. Since the discussed constituent is stiffer than the rest of the wall, it presents possible stress concentration which is consistent with higher rupture probability [32,33]. On the other hand, calcifications cause local wall thickening [11] and demonstrate significant loadbearing effects, which results in lowering the wall stress [34].…”

Predicting Aortic Aneurysm Expansion by PET

“…If the disease continues unchecked, the aneurysm wall becomes thinner and progressively less cellular. Finally, there is often substantial adherent luminal thrombus, variously described as either protective (13)(14)(15) or destabilizing (16) to the aneurysm.…”