Date of Award

3-2009

Degree Name

MS in Engineering - Biomedical Engineering

Department

Biomedical and General Engineering

Advisor

Dr. Trevor Cardinal

Abstract

Functional hyperemia and arteriolar vasodilation are impaired with chronic ischemia. We sought to examine the impact of chronic ischemia on collateral artery function. For this we used two hindlimb ischemia models to dissect the impact of different repair processes on collateral function. Ligation of the femoral artery increases shear stress in the muscular branch and results in outward remodeling and arteriogenesis. In contrast, resection of the femoral artery proximal to the muscular branch induces blood flow divergence and neutral remodeling along with expectedly greater hypoxia and inflammation. On day 14 after each surgery the diameter of the muscular branch was measured using sidestream dark field (SDF) imaging before and after gracilis muscle stimulation. A slight, but not statistically significant, impairment in functional vasodilation was observed in ligated mice (69±10% average diameter increase compared to 74±7% average diameter increase). Resected mice exhibited slightly (not statistically significant) enhanced collateral artery functional vasodilation (104±16% average diameter increase) but were also refractory to the restoration of resting vascular tone following the cessation of stimulation. Outward remodeling did not significantly impair vascular function, whereas neutral remodeling and tissue hypoxia induced impaired vascular tone.

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