Peripheral Artery Disease I: Introduction

Peripheral artery disease, or PAD, is an atherosclerotic disease that leads to progressive narrowing of the arteries in the upper and lower extremities. It commonly affects the abdominal aorta, iliac, and femoral arteries.

The primary cause of PAD is atherosclerosis. However, it can also result from vascular inflammation, radiation exposure, diabetes, smoking, obesity, hypertension, and hypercholesterolemia.

These factors contribute to endothelial dysfunction, increasing the endothelium's permeability and allowing low-density lipoprotein, or LDL, to penetrate the intima.

Once inside, LDL oxidizes into inflammatory oxidized LDL, attracting macrophages. These macrophages engulf oxidized LDL, forming foam cells.

These cells accumulate to form fatty streaks, which are early signs of atherosclerosis.

As foam cells accumulate and inflammation persists, atherosclerotic plaque develops, comprising cholesterol, foam cells, calcium, and a fibrous cap.

Over time, unstable plaques with thin caps and large necrotic cores may rupture, exposing thrombogenic material, triggering clot formation, and potentially causing acute limb ischemia.