Authors:

Niharika Narra

Date Created:

Not specified

Course Title:

Professor:

Not specified

About Paper:

Aortic dissections (ADs) and abdominal aortic aneurysms (AAAs) are common aortic pathologies. AD is characterized as a tear in the intima, forming a false lumen. AAA is the localized-dilation and weakening of the aortic wall, resulting in complex flow patterns. While distinct, both frequently develop thrombus within the lumen (AAA) or within the wall (AD). Due to the hemodynamic differences, we hypothesize that thrombus structure and composition will vary between these two conditions. To examine this, we utilized murine models: 1) topical elastase-?-Aminopropionitrile for AAA and 2) angiotensin II-infused apolipoprotein E-deficient mice for AD. Using serial ultrasound measurements, we detected vessel expansion and monitored 1) diameter changes and 2) thrombus deposition. Using histology, we quantified the degree and composition of intramural (IMT) and intraluminal thrombus (ILT) in ADs and AAAs respectively. Color segmentation of Movat's pentachrome slides revealed a significantly higher percent area of fibrin (p<0.001) in ILT, while red blood cells (RBCs) were significantly higher (p<0.001) in IMT. Histology and scanning electron microscopy images showed fibrin layers in the ILT structure, while the IMT formed a compact network of fibrin and RBCs. Higher amount of fibrin appears to correlate with a greater degree of organization in the ILT, which may be caused by the active blood flow in AAAs. This pattern is mostly absent in the low wall shear stress environment of the false lumen of ADs. These findings are an initial effort to correlate thrombi formation with vessel growth rate and rupture risk to improve patient outcomes. Keywords: Aortic Aneurysm; Aortic Dissection; Thrombus; Scanning Electron Microscopy; Histology

Source:

Purdue University / 2024

Topics:

No topics listed

Co-authors:

Niharika Narra