May-Thurner Syndrome (MTS), also known as iliac vein compression or Cockettes syndrome, is a condition wherein the right iliac artery, or the big pelvic artery, squeezes the left iliac vein, commonly known as the big left pelvic vein. MTS is not hereditary, but rather a completely anatomical condition.
MTS usually causes pain, soreness, and deep vein thrombosis (DVT) on the left leg, which is a blood clot that forms in the veins of the leg. The iliac is located near the ilium, or the large upper part of the hipbone.
How it Came About
The syndrome was first described by James Playfair McMurrich, a professor of Anatomy at the University of Michigan, in the early 20th century. It was initially called “Isolated left lower extremity swelling secondary to left iliac vein compression” up until 1956, when Dr. R. May and Dr. J. Turner described it anatomically, and clinically defined as such by Dr. Cockett and Dr. Thomas in 1965.
In modern times, the definition of MTS has been expanded from a simple mechanical condition of the veins to a broader disease profile known as Non-thrombotic Iliac Vein Lesions, or NIVL. NIVL can involve both right and left iliac veins (MTS only affects the left iliac vein), as well as other vein segments.
While some people think that May-Thurner Syndrome is hereditary, extensive studies have shown that it is, in fact, a mechanical problem that occurs randomly. Other factors, like excessive weight gain, age, or trauma, can worsen the symptoms of MTS, but rarely have they been cited as the primary cause.
Signs and Risks of MTS
MTS can manifest itself as pain, especially when the left leg is unsupported, such as when it is hanging from the edge of furniture. It can also manifest as significant swelling of the left leg.
There are multiple reports of people developing asymptomatic MTS, where the syndrome does not present symptoms. MTS can go unnoticed until Deep Vein Thrombosis, or DVT, occurs. DVT is a blood clot in one of the veins of the leg and can partly, or totally, restrict blood flow within the vein. While DVT in itself is rarely life-threatening, if the clot manages to dislodge itself and find its way into the brain or the heart, it can be fatal.
Because MTS affects the left iliac vein, any symptoms of it will occur in the left leg only. Some common signs of MTS and DVT are:
– Pain in the left leg
– Swollen, discolored veins in the left leg
– Varicose veins on your left leg
– Unusual warmth from the affected leg
– Tenderness of the leg
– Pelvic pain
Moreover, persons with May-Thurner syndrome condition are also susceptible to chronic venous insufficiency. These are marked by leg ulcers and severe discoloration and swelling of the leg due to additional pressure within the vein.
How To Treat MTS
Because MTS is not hereditary, there are no treatments that can prevent MTS itself. However, treatment does exist to alleviate pain and prevent future clots.
There are different ways to treat May-Thurner Syndrome and each solution depends on the severity of the condition of the leg clot. For the uncomplicated situation of the blood clot, a patient can take anti-clotting medications or choose clot-dissolving thrombolytics that are non-surgical and done via a catheter.
For severe cases of May-Thurner Syndrome, angioplasty and stent infusion can be done. Angioplasty is when a doctor threads a small tube into your vein that can be inflated like a balloon, expanding the vein. Once the vein has been expanded, a stent is inserted.
A stent is a narrow, metal mesh tube that acts like a frame inside the vein. Once inserted, the stent keeps the vein open, allowing for the seamless flow of blood. Since it is non-invasive, stent insertion has become the popular choice for treating May-Thurner Syndrome.
Vascular surgeries are not frequently performed anymore, due to the variety of non-invasive procedures. However, for more serious or advanced cases of MTS, wherein large clots have formed, there are a couple of options.
Surgery can be done to move the right iliac artery behind the left iliac vein, thereby relieving pressure on the former. For large clots, a thrombectomy can be performed, wherein doctors slice into the vein and remove the clot mechanically.
Another option is a vena cava filter. With this procedure, doctors insert a filter in your vena cava, a major vein located in the belly. While this does not prevent clots themselves, it will prevent it from going to other parts of the body, should the clot be dislodged from its original place.
MTS is a mechanical, non-hereditary condition that can be asymptomatic at first, but can develop into a serious condition if left untreated. If you present any symptoms of MTS or DVT, consult with a vascular surgeon ASAP.