Measurement of Friction-induced Changes in Pig Aorta Fibre Organization by Non-invasive Imaging as a Model for Detecting the Tissue Response to Endovascular Catheters

In normal aorta, elastin fibres are aligned at the surface, but become less aligned with increasing depth, showing no alignment by ~ 30 μm. Collagen fibres meanwhile appear aligned down to a depth of 35 μm. Changes in collagen and elastin fibre orientation in healthy pig aorta were detected by conventional destructive histology within 5 min of application of a sliding 10 N load, while lesser loads had less impact. Good recovery of fibre orientation was observed within 20 min. Non-invasive imaging of ex vivo aorta tissue provides a good indication of the extent of fibre re-organization following frictional stress, at loads similar to those encountered during medical interventions such as catheterization. These results indicate that tissue deformation can occur from these procedures, even in healthy tissue, and highlight the potential for the development of an in vivo probe capable of monitoring vascular changes in patients.