Luminal diameter and vasa vasorum response to stent dilation in the rabbit aorta

We examined the changes in luminal diameter and vasa vasorum after stent dilation of the aorta of nonatherosclerotic rabbits.Balloon-expandable stents were placed in the aortas of rabbits at the L3 level and were expanded. After 8 weeks, the rabbits were euthanized, perfused with barium sulfate particles, frozen, sectioned, and X-rayed.The luminal intrastent diameter (2.3 +/- 0.23 mm) was significantly different (p.05) from the expanded stent diameter but was not different from the luminal diameter above (2.3 +/- 0.53 mm) and below (1.9 +/- 0.18 mm) the stent. The number of vasa vasorum at the stent (46 +/- 7.2) was significantly increased compared with above (21 +/- 4.8, p.001) and below (14.4 +/- 4.6, p.001) the stent.After 8 weeks, luminal diameter was uniform. The increased vasa vasorum in the stented section suggested an increase in blood flow to the aortic wall, which may be important to the remodeling process.