[Mechanical and functional predictive factors for restenosis and arterial remodeling after experimental angioplasty]

Arterial remodelling plays an important part in post-angioplasty restenosis but the physiopathology of this process is not fully understood. Abundant collagen synthesis and endothelial dysfunction have been demonstrated after angioplasty, but their role in restenosis and remodelling has not been studied. The aim of this study was therefore to assess endothelial function and collagen with respect to the severity of restenosis and the type of arterial remodelling. Atherosclerosis was induced by an association of endothelial abrasion and a high cholesterol diet in the femoral arteries of 22 white New Zealand rabbits. Four weeks later, angioplasty was performed. The acetylcholine endothelium-dependant vasomotricity (expressed as % inhibition of contraction to phenylephrine), collagen and morphology were assessed 28 days after angioplasty. The change in acetylcholine endothelium-dependant vasomotricity was greater in severe restenosis (r = 0.61, p = 0.02). Endothelium-dependant relaxation was not significantly altered when remodelling was expansive and very abnormal when it was constrictive (35.5 +/- 13.0 vs 3.7 +/- 7.9%; p = 0.04). Restenosis was associated with an increase in collagen (r = 0.69, p = 0.004). The density of collagen was significantly higher in constrictive remodelling than in expansive remodelling (34.5 +/- 4.5 vs 18.2 +/- 4.7%; p = 0.03). Endothelial dysfunction and collagen accumulation are correlated with the severity of restenosis and with constrictive remodelling after angioplasty in an experimental model.