Fatty streak development in the vicinity of aortic coarctations in hypercholesterolemic rabbits

The influence of altered local hemodynamics on fatty streak development in rabbits fed high cholesterol diets was investigated. An aortic coarctation was created in the abdominal aorta of nine rabbits by placing a partially constricting gold or silver band (1.7 mm x 10 mm) around the aorta between the renal arteries and aortic bifurcation. Controls were 20 rabbits; seven sham operated and 13 unoperated rabbits. The abdominal aorta 1-2 cm proximal to the coarctation showed lipid deposition involving 45 +/- 8% (mean +/- SEM) of the luminal surface which was more than occurred within or distal to the obstruction (p less than 0.05) and also more than in controls (p less than 0.05). Within the coarctation, 4 +/- 2% of the luminal surface showed lipid deposition which was less than either proximally or distally (p less than 0.01) and also less than in comparable regions in controls (p less than 0.05). The aorta 1-2 cm distal to the coarctation showed lipid deposition involving 18 +/- 4% of the surface which was similar to control rabbits. Lipid deposition in corresponding regions of the control rabbits was involved in 17 +/- 4%, 19 +/- 5% and 19 +/- 4% of the luminal surface, respectively. Fatty streak development, therefore, appeared to be inhibited within the coarctation and enhanced proximal to it. The results suggest that some early step in the process of lipid accumulation may be affected by local fluid dynamics or modification of the wall of the vessel.