Asymptomatic Extracranial Carotid Atherosclerotic Disease - Detailed View

Introduction:

The asymptomatic extracranial carotid atherosclerotic disease condition is a blockage in a major artery outside the skull that can be a leading cause of heart or brain stroke and other diseases related to blood vessels. As this disease does not show any previous history of stroke, it is given the prefix asymptomatic. It is a common disease around the world, affecting a major population of the elderly. Risk factors like high blood pressure, diabetes, age, and smoking show the main possibility of the occurrence of the disease, and the treatment is also based on these factors.

What Is Extracranial Carotid Atherosclerotic Disease?

The extracranial carotid artery is the major blood vessel outside the skull supplying the head, neck, and face. Any fat deposits or other material on the inner walls of this major blood vessel are called extracranial carotid atherosclerotic disease.

It is of two types -

• Symptomatic extracranial carotid atherosclerotic disease.

• Asymptomatic extracranial atherosclerotic disease.

What Is Asymptomatic Extracranial Carotid Atherosclerotic Disease?

Asymptomatic extracranial atherosclerotic disease (ECAD) is a disease with a blocked extracranial carotid artery without any symptoms. When an individual without any medical history of strokes or other neurological conditions (disorders of the brain and nerves), including the carotid artery, experiences blockage of blood vessels, the person is said to be suffering from asymptomatic extracranial carotid atherosclerotic disease. The condition poses a risk factor for future stroke.

How Does Asymptomatic Extracranial Carotid Atherosclerotic Disease Cause Stroke?

Asymptomatic extracranial carotid atherosclerotic disease is a known risk factor for heart or brain stroke.

There are several ways in which extracranial atherosclerotic disease can cause stroke:

• Cholesterol embolism (blockage) is a condition in which cholesterol crystals, debris (cholesterol,fibrins), etc., block the flow from the aorta to the major branches.

• Obstruction of the blood vessel due to a blood clot from one artery to another.

• Weakening of the aorta's (blood vessel) wall.

• Reduced flow to the cerebrum (part of the brain) due to blockage.

What Are the Risk Factors of Asymptomatic Extracranial Carotid Atherosclerotic Disease?

As there are no symptoms to evaluate and diagnose the conditions, the presence of risk factors is considered. Patients with two or more risk factors are more prone to suffering from extracranial carotid atherosclerotic disease.

• Older age.

• Smoking.

• Hypertension (high blood pressure).

• High cholesterol (fat) levels.

• Diabetes (increase in sugar levels).

• Heart diseases.

What Are the Diagnostic Methods for Asymptomatic Extracranial Carotid Atherosclerotic Disease?

Usually, the risks from diagnosis methods outweigh the benefits after diagnosis. Hence in most asymptomatic cases, diagnostic procedures are avoided. A few proposed diagnostic methods are as follows:

• Carotid Duplex Ultrasonography - This imaging technique can be used in symptomatic and asymptomatic extracranial atherosclerotic disease with risk factors. This visualizes the presence of ulcerations, intraplaque bleeding, and high lipid content. This method cannot be carried out as a routine screening procedure for patients with risk factors.

• Magnetic Resonance Imaging - High-resolution magnetic resonance imaging depicts features like thinning of the wall of the blood vessel, carotid plaque (clumps of cholesterol, fibers, calcium) bleeding that can make the plaque rupture to the further transport of the ruptured parts to blood vessels causing the blocks.

• Transcranial Doppler Ultrasound is a diagnostic method that uses sound waves to detect abnormalities in the blood vessels. These sound waves, called embolic signals, are present in patients with blood vessel blockage.

• Computed Tomography (CT) - High-resolution CT imaging is performed to depict the carotid plaque components and the block's location in the blood vessel.

• MRI (Magnetic Resonance Imaging) - It visualizes the most promising results of the condition, even in the smallest blood vessels.

What Is the Management of Asymptomatic Extracranial Carotid Atherosclerotic Disease That Causes a Stroke?

The management of the asymptomatic extracranial carotid atherosclerotic disease can be done in two ways

1. Medical management.

2. Surgical management.

Medical Management:

• Statins - These are the drugs used to lower cholesterol levels. They are dose-dependent and are used according to the prescribed dosage to avail their protective effect.

• Antiplatelet Medication - This medication is used to prevent blood clots. Low-dose aspirin reduces risks for stroke and other cardiovascular events and is used as prescribed by the physician.

• Management of Risk Factors (Hypertension and Diabetes) - The goal of maintaining blood pressure below 140/90 mmHg (millimeter of mercury) for non-diabetic patients and below 140/85 mmHg for diabetic patients.

• Lifestyle Modifications Intervention - Lifestyle modifications involve modifications in diet, daily routine, and changes in habits.

1. Avoiding processed food and food with high cholesterol content.

2. Daily routine should include proper exercises to maintain an ideal weight and decrease the chances of obesity.

3. Habits like smoking and consuming alcohol should be avoided.

Surgical Management:

Surgical management has shown many benefits over medical management. The choice of Intervention is dependent on three factors:

1. The degree of stenosis (blockage).

2. The possible risk of stroke during the surgery.

3. The risk to the patient's life.

Depending on the above factors, healthcare professionals decide if the patient is favorable to undergo surgery. Various surgical management procedures are:

• Carotid Endarterectomy - It is a procedure in which the deposits in the blood vessels are removed. It is performed in patients with 60% to 99% stenosis (blockage) and an increased risk of stroke or death during the surgery.

• Carotid Artery Angioplasty and Stenting - In this procedure, a small tube is inserted into the blood vessel, which pushes the deposits toward the wall of the blood vessel. It breaks it, and the block is removed. Further, re-narrowing blood vessels is done by placing a stent (a tiny tube-like structure placed into the blood vessel to prevent its collapse).

• Transcarotid Artery Revascularization - A tube is connected to the carotid artery and an advanced machine that reverses blood flow. The freely present deposits are collected and removed, and the filtered blood is returned through the vein.

Conclusion:

Though asymptomatic extracranial carotid atherosclerotic disease does not show any symptoms, It is a life-threatening condition. This disease poses risks throughout the diagnostic procedures and even in the treatment process. The risk factors should be monitored and managed to avoid the possible occurrence and severity of the disease.