Artery stenosis refers to the abnormal narrowing of an artery, which develops over time and decreases the inner diameter of the vessel, known as the lumen. This narrowing restricts the flow of oxygen-rich blood to the tissues and organs supplied by the affected artery. This restriction can compromise organ health and performance.
How Arteries Become Narrowed
The most frequent cause of artery stenosis is atherosclerosis, a chronic disease involving the buildup of material known as plaque within the artery walls. Plaque is a complex deposit composed of fatty substances, cholesterol, cellular waste products, and calcium. The process begins with damage or dysfunction to the endothelium, the delicate inner lining of the artery.
Following endothelial damage, low-density lipoproteins (“bad cholesterol”) infiltrate the artery wall, sparking an inflammatory response. Immune cells, specifically monocytes, migrate into the area and transform into lipid-laden macrophages, often called foam cells. The accumulation of these foam cells creates a fatty streak, the earliest stage of plaque formation.
As the process advances, smooth muscle cells migrate to the site, producing a fibrous cap over the fatty core. This growing fibrous plaque gradually thickens the artery wall, leading to vessel narrowing. Over time, calcium deposits accumulate within the plaque, a process called calcification, which hardens the lesion and makes the artery less flexible.
Where Stenosis Occurs and What Symptoms Result
Symptoms of artery stenosis depend on which major artery system is affected, as the resulting lack of oxygen impacts the downstream organ.
Coronary Artery Stenosis
In the heart, this narrowing is known as coronary artery stenosis, which limits blood flow to the heart muscle. A common symptom is angina, a type of chest pain or discomfort that often occurs during physical exertion or stress, along with shortness of breath.
Carotid Artery Stenosis
Stenosis can occur in the carotid arteries, the large vessels in the neck that supply blood to the brain. A significant blockage here can lead to symptoms similar to a stroke or a Transient Ischemic Attack (TIA). These symptoms may include sudden weakness, numbness, or paralysis on one side of the body, difficulty speaking, or temporary loss of vision in one eye.
Peripheral Artery Disease (PAD)
When the arteries that supply the limbs, most often the legs, are narrowed, the condition is called Peripheral Artery Disease (PAD). The most characteristic symptom is claudication, which is muscle pain or cramping in the legs brought on by walking or exercise that typically subsides with rest. In more advanced cases, a person may experience pain, numbness, or aching in the feet or toes even at rest.
Clinical Detection and Management Options
Clinical detection for artery stenosis begins with non-invasive imaging tests designed to visualize the arteries and measure the degree of narrowing. A duplex ultrasound, which includes Doppler technology, is a widely preferred method as it uses sound waves to detect restricted blood flow within the vessel. For more detailed anatomical assessment, a physician may order a Computed Tomography Angiography (CTA) or Magnetic Resonance Angiography (MRA).
Lifestyle and Medical Management
Management of artery stenosis starts with foundational lifestyle changes. This includes adopting a heart-healthy diet, engaging in regular physical exercise, and achieving complete smoking cessation. These changes are designed to halt or slow the progression of the underlying atherosclerosis.
Medication therapy is a standard component of management and often includes drugs to control high blood pressure, lower cholesterol levels, and prevent the formation of blood clots.
Invasive Interventions
For more severe blockages, particularly those causing symptoms like stroke or severe pain, invasive interventions may be necessary to restore blood flow. These procedures can include angioplasty, where a balloon is used to widen the artery and a stent may be placed to keep it open. Another option is a surgical procedure like endarterectomy to physically remove the plaque.