Influence of topography on endothelialization of stents: Clues for new designs

To evaluate the influence of stent design on endothelialization of the sten ted surface, we placed trapezoidal objects of variable thickness on a confl uent culture of endothelial cells and subjected the assembly to flow and sh ear conditions similar to those found in arteries. After 24 h, we measured and analyzed the area on top of the objects covered by cells and the maximu m migration distance from the borders. In addition, we evaluated areas devo id of cells surrounding the objects, which developed after exposure of the assembly to flow. The cell-covered area and migration distance significantl y decreased on objects 75 mu m thick, and it was nonexistent on objects 250 mu m thick. Areas devoid of cells or gaps were largest adjacent to the dow nflow side of the object, disposed transversely to flow. Cell gaps were sma llest along the side aligned with flow. In conclusion, endothelial cell cov erage may be impaired by stent wall thickness larger than 75 mu m. It is li kely that this impairment is related to flow disturbances impairing cell at tachment.