What causes the narrowing (stenosis) of a blood vessel? скачать в хорошем качестве

What causes the narrowing (stenosis) of a blood vessel?

In hemodialysis access, there is often narrowing within the blood vessels. There could be narrowing within the arteries and veins. Typically, the veins narrow because of irritation, which is a different entity than the narrowing in the cardiac vessels that you see with atherosclerosis or plaque. The narrowing within the venous system is usually intimal hyperplasia or scar tissue. It can also be extrinsic, which means that if there is swelling or a hematoma forming outside the vessel, the vessel can be narrowed as it is being crushed by the hematoma or swelling. The venous system usually carries blood back to the heart in a low flow and low-pressure system. After a fistula or a graft is created, there is often a high flow or high-pressure system that develops from the arterial flow. There are also complications from cannulation. Every other day during treatment, the dialysis access is being stuck with needles. That can cause trauma to the veins as well. In a graft where the surgeon connects the graft to the native vein, the area of suturing that the surgeon used to stitch the graft to the vein can also have scar tissue, causing narrowing.