Combining
experimental and theoretical techniques to
quantify vascular compensation
[summary]
PIs: J.
Arciero (Department of Mathematical Sciences, IUPUI) , J. Unthank
(Department of Surgery, IUSM)
Peripheral arterial disease (PAD) affects nearly 8 million
Americans and is characterized by occluded systemic arteries (often due
to atherosclerosis) and reduced blood supply to tissue. The human
vasculature is capable of compensating for an occlusion by triggering
the dilation of collateral arteries, which are arteries that bypass the
blockage to allow blood to reach the necessary tissue regions. In some
cases, the vasculature compensation is successful, but other cases
result in significant morbidity and mortality. It is presently unknown
why certain cases of PAD are restored to normal circulatory health
while others progress to limb loss. There is currently no consistent
method for assessing microvascular compensation. Counting the number of
arterioles or capillaries in calf muscle and the number of vessel
branches in the thigh are different methods that have been used
previously to evaluate changes in vascular compensation following
arterial occlusion in the leg. However, it is not understood how
changes in each of these segments correlate to tissue perfusion and
translate to changes in vascular resistance. The lack of consistent
methods for assessing vascular compensation leads to uncertainty in the
conclusions stated in many pre-clinical PAD studies. The experimental
and theoretical approaches proposed here will advance the field of
vascular biology by obtaining accurate vessel length and diameter data
throughout an entire network using a novel experimental technique and
implementing this data in a theoretical model that can predict whether
increases in vessel diameters or vessel numbers are most significant in
restoring normal perfusion in PAD.
