Iliac Vein Compression Syndrome (IVCS), also known as May-Thurner syndrome, was first identified in 1956 by two doctors, May and Thurner. It happens when a vein on the left side of the body, called the left common iliac vein, gets compressed by an artery from the right side, known as the right common iliac artery. Over time, this constant squeezing can cause the vein to become narrow or even blocked because of scar tissue and other changes. This can make it hard for blood to flow through the vein as it should. This explains why deep vein thrombosis (DVT), blood clots in deep veins, is five times more common in the left versus right leg.

In fact, the iliac vein may also be compressed on the right in some people. The exact number of people who have iliac vein compression isn’t known. This condition can affect both men and women. About 30% of people might have it without showing any symptoms, a situation sometimes called a “permissive lesion.” Essentially, symptoms will start if something else goes wrong, like an infection, or an injury to the leg.

Causes of leg swelling:

Swelling in the legs can happen for many reasons, and it’s important to know why it’s happening to get the right treatment. Here’s a simpler way to understand the causes:

Conditions that will cause bilateral leg swelling only:

1. Heart failure
2. Kidney failure
3. Liver failure
4. Side effects from certain medicines.

Condition that will cause either one or both legs swelling:

1. Varicose veins, which are swollen, twisted veins.
2. Blockage or clot in the deep veins of the legs (known as DVT).
3. Iliac vein compression syndrome, where a vein in the pelvis is squeezed.
4. Lymphedema, a condition where fluid builds up because the lymphatic system is blocked or damaged.

If your legs are swollen, it’s crucial to see a specialist, like a vascular surgeon, who can determine what’s causing the swelling. Dr. Tan Yih Kai is an experienced Vascular Surgeon who specializes in treating leg swelling caused by vein problems. Don’t hesitate to contact him for advice and to schedule an appointment.

Symptoms:

People with iliac vein compression may develop symptoms because of increased pressure in the veins. The symptoms include:

1. Formation of blood clots in the iliofemoral vein, which is a major vein in the leg (known as DVT, or deep vein thrombosis).
2. Swelling in the leg
3. Pain in the leg.
4. Ulcers or open sores that don’t heal easily.
5. Lipodermatosclerosis, a type of skin change where the skin becomes thickened and discoloured, often looking like it’s tightening.
6. Venous claudication, which means leg pain or discomfort, especially when walking, due to poor blood flow.

These symptoms occur because of upstream vein compression in the pelvis, which leads to higher pressure in the leg veins, making it hard for blood to flow properly.

Diagnostic Evaluation:

For diagnosing iliac vein compression, the following evaluations are commonly used:

Ultrasound: This test checks for varicose veins or venous reflux, a condition in which blood flows backwards in the veins.

CT venogram or MR venogram: These are specialized scans that help visualize compression in the iliac vein and check for the presence of tumours in the pelvic area.

Diagnostic Venogram: This is a type of X-ray used to visualize the veins. During the procedure, a special dye is injected into the veins, making them visible on X-ray images. However, it only provides 2D images and might not catch everything.

Endovascular Interventions

Endovascular interventions, which involve treating from within the blood vessels, have become the preferred method of treatment.

Using a stent to open up the veins in the pelvis and lower abdomen (specifically the iliac and caval veins) has proven to be both safe and effective. This approach is typically recommended for patients who have ongoing, noticeable symptoms from deep vein problems that haven’t improved with standard treatments.

A tool called Intravascular Ultrasound (IVUS) is commonly used during the stenting procedure to help place the stent accurately and ensure the best possible outcome.

IVUS allows the visualization of:

1. Percentage of vein stenosis
2. Real-time vessel diameter measurement
3. Length of stenosis
4. Location of side branches
5. Calcium, thrombus, and intravenous scarring

What to expect after a stent in the iliac vein?

The stent’s placement should only result in mild discomfort that subsides quickly. It’s common for some patients to feel back pain for about 1 to 2 weeks after the procedure. Typically, this discomfort can be effectively managed with over-the-counter painkillers or anti-inflammatory medications.

The outcome of iliac vein stenting

Research on iliac vein stenting has found very promising results. The success rate of the stent remaining open and effective was found to be 98.7% after 6 months, 98.3% after 1 year, and 97.9% after 2 years of follow-up.

Conclusion:

Chronic venous disease can seriously impact a person’s life. Often, iliac vein compression syndrome isn’t diagnosed as frequently as it should be. Venous stenting, a procedure with a low risk of complications, has a very low chance of causing serious problems. It’s not only a safe and effective treatment, but it also offers lasting results.