What is the ICD-10 Code for May-Thurner Syndrome?

by  Aimee L. Wilcox, CPMA, CCS-P, CST, MA, MT
Sep 18th, 2022

Also known as iliac vein compression (ILVC), May-Thurner syndrome (MTS) was described by May R and Thurner J in 1957, as a serious condition of the lower extremity vascular system that puts a patient at high risk of deep venous thrombosis (DVT).

Blood travels throughout the body through a series of blood vessels with arteries carrying oxygenated blood away from the heart to all parts of the body and veins returning the oxygen-depleted blood back to the heart and lungs for re-oxygenation. The iliac artery and iliac veins are located anterior to the lower spine in the pelvic region. In some people, the iliac artery crosses over and in front of the iliac vein. Arteries are highly pressurized vessels and can put undue pressure on the iliac vein behind it, compressing the vein into the spine, resulting in iliac vein compression syndrome (IVCS) or May-Thurner Syndrome (MTS). When compressed, the iliac vein prevents adequate blood flow back to the heart and lungs, making the patient susceptible to the formation of spurs within the iliac vein and resultant deep vein thrombosis (DVT) in the iliac vein. Although ILVC or MTS is more prevalent in the left leg, it can present in the right, or bilateral, iliac veins and is more common among females than males.

This syndrome is characterized by unilateral lower extremity pain and swelling caused by venous hypertension from compression of the iliac vein into the spine by the iliac artery.

Symptoms associated with this syndrome include but are not limited to: 

• Ankle swelling
• Ulcers of the skin around the ankles
• Legs that feel very heavy and fatigued
• Leg cramps
• Claudication and leg pain
• Skin changes
• Skin discoloration (hyperpigmentation)
• Hardened areas of the skin
• Varicose veins in the pelvic area

What Causes May-Thurner Syndrome? 

While it is estimated that twice as many women are diagnosed with MTS than men, healthcare providers believe there are many more people with MTS than previously thought, because not all patients with the syndrome manifest symptoms. Additionally, a National Institutes of Health (NIH) article states, 

“The radiological studies, which specifically chose patients with left lower extremity DVT, reported MTS incidence in such patients to be between 22% to 76%.”

The risk of DVT with MTS is increased with prolonged inactivity, pregnancy, use of birth control pills, cancer, infection, dehydration, and surgery. 

How is MTS Diagnosed?

Patients presenting with symptoms may start with more conservative testing like ultrasound, CT or MRI scans, or a venogram; however, depending upon findings the patient may need to undergo additional and invasive testing that includes catheter-based venogram or an intravascular ultrasound where a catheter is inserted into the vein allowing an ultrasound of the inside of the vein to be performed for better imaging and confirmation of the severity of the syndrome. 

How is MTS Treated?

Symptomatic patients may require treatment with angioplasty for stent placement, bypass surgery, or a repositioning of the iliac artery behind the iliac vein so it does not put pressure on it. Patients who are also diagnosed with DVT may require additional treatment that includes blood thinners to prevent the formation of additional clots, medications to dissolve or bust up a current clot, or possibly a vena cava filter to prevent a blood clot from advancing into the lungs. 

What is the ICD-10-CM Code for MTS? 

Search the Alphabetic Index under the following key words: 

• Compression
• Vein
• I87.1 Compression of vein (final code)

As per the ICD-10-CM official guidelines, never code directly from the Alphabetic Index, but instead, always confirm the code in the Tabular List and be sure to look for any inclusion terms or instructional notations that may provider additional reporting guidance.

About the Author: Aimee Wilcox is a medical coding, billing, and auditing consultant, author, and educator with more than 30 years of clinical and administrative experience in healthcare, coding, billing, and auditing. Medicine, including coding and billing, is a constantly changing field full of challenges and learning and she loves both. She believes there are talented medical professionals who, with proper training and excellent information, can continue to practice the art of healing while feeling secure in their billing and reimbursement for such care.

About Aimee L. Wilcox, CPMA, CCS-P, CST, MA, MT

Aimee L. Wilcox is a medical coding, billing, and auditing consultant, author, and educator with more than 30 years of clinical and administrative experience in healthcare, coding, billing, and auditing. Medicine, including coding and billing, is a constantly changing field full of challenges and learning and she loves both. Aimee believes there are talented medical professionals who, with proper training and excellent information, can continue to practice the art of healing while feeling secure in their billing and reimbursement for such care.