An atrial septal aneurysm (ASA) is not a true aneurysm
. Rather, it is an enlarged, bulging and often mobile septum (the membrane separating the right and left upper chambers of the heart).
In a small number of cases with a true aneurysm
, the bacteria arrived through blood circulation, stranded, and caused infection of the aneurysm wall (6).
Once a collateral circulation through the smaller branches occurs, high blood flow rate continuously increases the shear stress on the arterial intimal layer, changes the medial layer responsible for the integrity and elasticity of vessels, weakens and dilates the arterial wall, which ultimately leads to the formation of a true aneurysm
A true aneurysm
is a permanent, localized dilation of all three layers of a blood vessel, by more than 50% of the usual diameter for the viewed segment .
Bjorck, "True aneurysm
in autologous hemodialysis fistulae: Definitions, classification and indications for treatment," Journal of Vascular Access, vol.
First, a multimodality imaging approach may be helpful for a correct differentiation of a submitral LV pseudoaneurysm from the rare idiopathic submitral aneurysm (mostly seen in black Africans) or postischemic true aneurysm
. Second, a fistulized periannular abscess, although unfrequent, may be a possible cause of submitral LV pseudoaneurysm even in asymptomatic patients with negative inflammatory biomarkers and blood cultures.
Kim et al., "True Aneurysm
rupture of omental artery leading to hemoperitoneum and shock in a CAPD patient," Nephrology Dialysis Transplantation, vol.
The boundaries of a false aneurysm are constituted by thrombus, as opposed to the three arterial layers as in a true aneurysm
. Although Doppler ultrasound can aid in the assessment, uterine artery angiography is necessary to make the diagnosis and provides the subsequent means for embolisation.
This patient's vascular defect appeared to be a pseudoaneurysm rather than a true aneurysm
because the integrity of the underlying vessel was intact with the exception of a narrow communication between the vessel lumen and surrounding soft tissue containing the lesion.
A true aneurysm
is an outpouching of the vessel wall, usually due to weakening of the wall.
In true aneurysm
all three layers of the vessel wall i.e.
* Depending on the type: true aneurysm
, pseudoaneurysm, dissecting aneurysm;