Purpose: Experimental stenoses were created in canine aortae to compare the effects of stent placement and balloon angioplasty on the vasa vasorum.
Materials and methods: A balloon-expandable Palmaz stent was placed in the proximal stenosis, and angioplasty was performed in the distal stenosis in each of eight dogs. Two dogs were killed at 4, 8, 12, and 18 months, respectively. Specimens were studied by means of microangiography, histology, scanning electronic microscopy, and Spalteholz technique.
Results: At up to 12 months, there was proliferation of the vasa vasorum and a rich plexus formed in each of the animals at each treated site. More vasa vasorum were seen after stent placement than after angioplasty. The new vessels were mainly venules located in the media. At 18 months, there was regression of the venules and the vasa vasorum distribution returned to baseline.
Conclusion: The authors conclude that the effects of stents on the vasa vasorum are temporary.