Forças mecânicas e veias safenas humanas: implicação na revascularização do miocárdio

Abstract

Vascular endothelial cells are exposed to a variety of in vivo mechanical forces, specifically, shear stress for the blood flow, tensile stress from the compliance of the vessel wall and the hydrostatic pressure from containment of blood within inside the vasculature. Many authors studied hemodynamic, functional and morphological human saphenous veins alterations caused by these different forces with conflictant results. This review text was motivated with the specific aim of analyze literature data and some experimental data carried out in our laboratory. The adopted review subjects were: 1) Endothelial responses and gene regulation to shear stress; 2) Effects of the hydrostatic pressure in the endothelial cell morphology, gene expression of the endothelial cellular surface and proliferation of endothelial cells; 3) Effects of the traction on the human saphenous vein endothelium.

Regulation of Thrombomodulin Expression and Release in Human Aortic Endothelial Cells by Cyclic Strain

“…attenuation, hyper-elevation) of either of these forces can contribute to endothelial activation that may lead to vessel remodeling and vascular diseases (e.g. atherosclerosis, hypertension, stroke, vein graft thrombosis, ventilator-induced lung injury, retinopathy) [9]–[13].…”

Relative Contributions of 5-Hydroxytryptamine (5-HT) Receptor Subtypes in 5-HT-Induced Vasoconstriction of the Distended Human Saphenous Vein as a Coronary Artery Bypass Graft

“…21) This is due, in part, to the fact that distention of the SV with high intraluminal pressure induces functional and morphological alterations, which leads to early thrombosis and graft failure. 19,[21][22][23] Distention with high pressure is a routine part of surgical preparation of the SV for grafting in order to check for leaks and to increase the vascular diameter during perioperative and postoperative periods. During surgical preparation for grafting in individual hospitals, SV is distended with various degrees of pressure, which are sometimes very high.…”

“…During surgical preparation for grafting in individual hospitals, SV is distended with various degrees of pressure, which are sometimes very high. 19) Okon et al 23) reported that the distention of the SV at pressures of up to 600 mmHg attenuated the contractile ability and impaired the endothelial function of the vessels. They also reported that the distention of the SV at the pressure range 100 to 300 mmHg augmented the contractile responses to depolarization and a-adrenergic stimulation in the vessels, and that, moreover, the endothelium-dependent dilation was either unchanged or even enhanced by the distension at this pressure range.…”

“…This fact should be considered in experiments for evaluation of 5-HT receptor subtypes responsible for vascular functions because the distension may influence both contractile and dilatory responses of the SV. 19) The aim of the present study was to elucidate the relative contribution of 5-HT receptor subtypes mediating 5-HTinduced vasoconstriction of the distended human SV obtained from CABG surgery. We examined the effects of sarpogrelate and SB224289, antagonists of 5-HT 2A and 5-HT 1B receptors, respectively, on the 5-HT-induced vasoconstriction and also performed immunolabeling of the 5-HT 2A and 5-HT 1B receptors in the distended SV.…”

Compatibility of cassava starch films as nitric oxide carrier for potential medical device

“…Saphenous vein has been widely used in coronary artery bypass surgery; however, the effectiveness of this graft is limited by the patency of the vein that is much lesser than the arterial grafts, mainly due to the functional and structural characteristics of the vein that may be affected by the high pressures distensions of the arterial environment. As a consequence of this hemodynamic alteration, the vein graft suffers radial deformation resulting in failure, occluding up to 50% of the grafts within 10 years after surgery . An external, nonrestrictive polyester stent for reducing the wall thickening in porcine vein grafts has been studied .…”