Although balloon angioplasty (percutaneous transluminal angioplasty, PTA) is a well-accepted method to reduce arterial stenosis, an important disadvantage of the method is the restenosis that develops in 30% to 50% of the patients.1 Although it has been accepted that intimal hyperplasia causes the restenosis,2 it recently became clear that restenosis after PTA is caused mainly by shrinkage of the vessel wall ("constrictive vascular remodeling").
Vascular remodeling has been observed in physiological conditions in response to changes in shear stress (SS), where it is aimed at restoring the original values of SS.3 Although it has been postulated that this mechanism is of importance in vascular remodeling after PTA, experimental data underlying this theory are currently lacking.1 This is of importance, because it has been shown that the endothelium plays an essential role in vascular remodeling.4 Immediately after PTA, the endothelium is disrupted and the regenerated endothelial layer is dysfunctional.5 Furthermore, because the vascular tissue is damaged after PTA, factors not involved in vascular remodeling during more physiological conditions might become of importance. Hence, the first question addressed in the present study was whether vascular remodeling after PTA is controlled by SS and if so, to which reference value the SS values will be restored during the remodeling process. To that end, we developed a method based on a combination of intravascular ultrasound (IVUS) and computational fluid dynamics that enables us to calculate regional SS over time.
The vessel wall responds to increments in blood pressure, at an unchanged flow, by increasing vessel wall thickness.6 The wall stresses (WS) calculated before and after these pressure elevations appear to be similar, implying that WS is normalized during these conditions. PTA increases local WS, and the constrictive vascular remodeling may be a consequence of WS normalization. Therefore, the second aim of the present study was to evaluate the existence of a WS feedback loop in constrictive vascular remodeling after PTA.
WS is wall stress, which can be determined using the LaPlace formula.
SS is shear stress.
The conclusion of the article was that both wall stress and shear stress control vascular remodeling after angioplasty.
I am not sure how to apply this but we do not want negative vascular remodeling reducing the size of our veins after angioplasty.