Abstract

INTRODUCTION AND MODEL

COLLATERAL LUMINAL EXPANSION AND SHEAR

WALL REMODELING

CONCLUSIONS AND DISCUSSION

REFERENCES

Discussion
Board

Studies were performed to evaluate the role of wall shear in the luminal expansion of small resistance arteries which form collateral pathways after abrupt arterial occlusion. In ~200g Wistar rats, 3-4 sequential ileal arteries were ligated. Subsequently, blood flow and wall shear rate (WSR) in collateral arteries increased ~275 and 175%, respectively. This increase in blood flow sustained normal tissue perfusion. Maximum inner arterial diameter at the beginning of the collateral path was increased ~30 and 65% at 1 and 4 weeks. Regions of the collateral path experiencing smaller increases in flow and shear had smaller increases in diameter. Increases occurred in all wall areas while the ratio of medial thickness to luminal radius was preserved. Comparisons of nuclear numbers and density between collateral and control arteries indicated that proliferation occurred first in the intima and then the media. This proliferation was followed by cellular regression after wall shear rate had been normalized. These results support the hypotheses that luminal expansion in collaterals is correlated with WSR, and that the relationship between medial thickness and luminal diameter is maintained. However, cell density is altered during luminal expansion associated with abrupt elevation of WSR. Supported by NIH HL42898.

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Presentation Number SAunthank0779
Keywords: shear stress, hyperplasis, endothelium, remodeling, collateral