You’ve just been diagnosed with May Thurner Syndrome (MTS). Your research tells you that treatment often involves placement of a stent. The idea of getting a permanent piece of metal in your body that cannot be removed scares you. On social media, you have read about countless patients who have had problems with stents with only a small smattering of patients who have done well with stents. What should you do if your doctor now suggests that you get a stent? What questions should you ask?

Over the past decade, I have treated patients from all over the United States as well as 4 continents. The one thing I’ve learned from my patients is that regardless of sex, age, race, educational background, or country, everyone has similar questions. In this blog article, I will discuss the most commonly asked questions about stenting for MTS and vascular compressions in general.

As a disclaimer, the information provided is for educational purposes only. Please contact your physician with questions that pertain to your own health.

I was diagnosed with MTS after having a CT/MRI that showed 80-90% compression of my iliac vein. I was referred to a vascular specialist who recommended a stent and told me that if I don’t get one, I am at high risk for deep vein thrombosis (DVT). Do I need a stent when I have no symptoms of MTS or history of DVT?

Absolutely not! The % of compression does NOT matter! Many men and women have compression of the iliac vein ranging from 10% to 90% and they do not have symptoms. These individuals do NOT have MTS (even those with 90% compression) because in order to have a SYNDROME, you need SYMPTOMS. If you don’t have symptoms, then what you have is May Thurner PHYSIOLOGY. For more info, click here

I’m allergic to nickel. If all stents are made of nickel, what are my options?

ALL stents have some % of nickel. Just because someone has an allergic skin reaction to nickel does not mean they will have an allergic response to a stent inside the blood vessel. Due to medicolegal issues, many physicians may be reluctant to place stents in those with known nickel allergies. That being said, many physicians including myself do not typically test for nickel allergy unless someone has a known SEVERE allergic reaction to nickel. My best advice is to discuss this issue with the vascular specialist treating you. For more info, click here

My doctor told me that a stent would be placed in my left common iliac vein. Later I found out that the stent extended into my left external iliac vein which had less than 50% narrowing. Why? 

One of the most feared complications of venous stenting is stent migration in which the stent “moves” or “migrates” to the inferior vena cava (IVC) or worse, the heart. This is commonly due to undersizing of the stent in which a small stent is put into a large vein. This is why intravascular ultrasound (IVUS) is strongly recommended when placing stents as this technology allows the physician to properly measure the size of the iliac vein. In fact, an important question to ask your vascular specialist is whether IVUS will be used during your procedure. In addition to a small diameter stent being placed in a large vein, the other common cause of stent migration is using a stent that is too short in length. Stents that are too short have a much higher risk of migrating. Therefore, longer stents extending into the external iliac vein are placed to “anchor” the stent and prevent it from migrating.

“In fact, an important question to ask your vascular specialist is whether IVUS will be used during your procedure.”

Ok that makes sense, but won’t having a stent in the normal external iliac vein cause a problem?

No it won’t cause a problem. In fact, what many don’t realize is that it is very common to have a SECOND area of compression in the external iliac vein. If that area is not covered by the stent, then a patient may not get full relief of MTS or pelvic venous insufficiency (PVI) symptoms.

                                                                                                                                                                                                                           Venous compression points in the iliac veins

In the image above, MTS compression refers to the point of compression labeled “Left proximal NIVL”. All the other compression points are not referred to as MTS but rather nonthrombotic iliac vein lesions (NIVL). These other points of compression are often not found unless IVUS is used. Therefore when placing a stent in the left common iliac vein, a physician needs to ensure that both the MTS site of compression AND the “left distal NIVL” (if there is one) are covered by the stent. The “left distal NIVL” is in the left EXTERNAL iliac vein which is why the stent needs to extend into this vein.

Side view of iliac vein showing its natural curve. (Image courtesy of Prof. Dr. Thomas Scholbach)

A third reason the stent is extended into the left external iliac vein is because the pelvis and iliac veins are curved NOT straight like the pictures you may see online. Putting a straight stent such that the end of the stent lands at the bottom of the curve can lead to pelvic pain as pictured above. Putting a longer stent that goes past the curve and into the external iliac vein can prevent complications of pelvic pain from the stent.

I have swelling in my left leg but mainly below the knee. Will a stent help this?

Swelling below the knee only and mainly involving the ankle is chronic venous insufficiency (CVI) until proven otherwise. When MTS causes swelling, it generally causes ENTIRE leg swelling not just below the knee/ankle. CVI is 10,000x more common than MTS and affects up to 90% of the population in their lifetime. It is treated with vein ablation not stenting. In my opinion, no patient should undergo stenting until they have been fully evaluated for CVI with an ultrasound done in the STANDING position. Many people have gotten stents unnecessarily because the US was done incorrectly, thereby leading to a negative test for CVI. Then a stent was placed and there was no improvement because MTS was not the problem. Now these patients are left with a stent that cannot be removed.

Why can’t balloon angioplasty alone be done to treat MTS?

MTS is due to compression of the iliac vein by the overlying iliac artery. This artery is under HIGH pressure as it’s getting blood directly from the heart. The iliac vein is under LOW pressure and is easily compressed by the high pressure artery. Inflating a balloon inside the vein will lift the artery off the vein and open up the vein as long as the balloon is there. Once the balloon is deflated, the artery will compress the vein again. The stent is needed to keep the vein open and lift the artery off of the vein.

I’m 20 yo and my doctor said that I am too young for a stent and that it’s dangerous. Is that true?

No. Physicians often do not want to put a stent in a young patient because even in the best of hands, no doctor can tell you what will happen to that stent over the next 50 yrs. No one has done this type of study and no one will as it would be too expensive a study to run for 50 yrs. The last thing a physician wants to do is make a patient worse, especially a young patient. This is why many physicians are reluctant to stent young patients. However, each patient has to be looked at as an individual and there are times, especially in cases of large DVT, when a stent must be placed. When stenting a young patient and especially a minor, it is crucial to have the patient’s family present during the consultation so that everyone is on the same page as to the pros/cons of stenting. 

My vascular specialist told me that once I am stented, I can no longer have children. Is that true?

Absolutely not!!! This is one of the common misconceptions that patients are told about venous stenting. Women can go on to have healthy, uneventful pregnancies. However, they may need to be on injectable blood thinners during pregnancy as well as be monitored by high-risk OB. While there is a risk of the stent getting compressed and blocked due to the growing fetus (especially in the 3rd trimester), this risk is low especially with the use of blood thinners. In my own opinion, the woman who has had extensive DVT due to MTS and has not been stented may have a higher risk of recurrent DVT with pregnancy than the woman who has been stented. However, this is based on my experience and I do not have data to support this. In over 10 yrs, I have never told a woman who I stented that she could not have children. Again, questions like this are best discussed with your healthcare team. Keep in mind that many ob-gyns are not familiar with MTS and that it is crucial that your vascular specialist collaborate with your ob-gyn if they are unfamiliar with MTS.

Do all vascular specialists treat venous disease and perform venous stenting?

Surprisingly the answer is no. Many vascular specialists treat ARTERIAL disease and only rarely treat venous disease. They often think that putting a stent in a vein is the same as putting a stent in the artery. This is FALSE! While the technical aspect of placing the stent does have similarities with placing stents in arteries, there is an entire set of “rules and judgement decisions” that one will not know unless they do a lot of venous work. Remember that you only have one chance to get a venous stent placed correctly so make sure you go to the most experienced physician in your community. This may be a vascular surgeon, interventional radiologist (IR), or interventional cardiologist.

I am scheduled to undergo a diagnostic venogram with IVUS. Is this painful and am I awake? What information will this provide that cannot be gotten from a CT/MRI? 

Vascular compressions and the medical conditions associated with them must never be diagnosed off of CT/MRI alone as these are static (not moving) images that do not give the full picture. For example, the iliac artery that compresses the vein in MTS is pulsating the same number of times as your heart rate. The artery may just compress the vein momentarily and that may be the time that the CT/MRI takes an image and shows a compression. A split second later there may be no compression. You wouldn’t want to be diagnosed with MTS based on a single image showing some compression, would you? 

A venogram is a minimally invasive procedure done through a single puncture in the groin and/or neck. The patient is placed under conscious sedation (twilight) NOT general anesthesia. It is important that the patient be able to respond to commands as there may be times when the patient will have to hold their breath. A small catheter is placed into the vein and the catheter is directed to the various parts of the body. Contrast is injected into the catheter and the vascular anatomy (veins only not arteries) of the abdomen, pelvis, and legs can be seen on the monitor. The physician can then see whether there is anything wrong with the veins. Using IVUS, the physician can see whether there is scar tissue or old clots in the veins. The diameter of the veins can be measured and more importantly, it can be determined “in real time” whether the compression of the vein is truly real or not. If it is real, IVUS can tell the physician by how much it is compressed relative to a normal sized vessel. During the procedure, the physician can also see the direction of blood flow in the veins which is important to know as blood going backwards in the ovarian veins is a sign of reflux seen in pelvic venous insufficiency (pelvic congestion syndrome). A venogram is not painful except for the mild discomfort from the local anesthetic. The procedure lasts 30-60 minutes depending on what needs to be evaluated.  The patient then goes to recovery and is able to go home 1-2 hrs later.

What kind of follow up will I receive after stenting? Does my PCP just follow my stent?

No. Whoever puts in your stent should follow you for at least a few years and in some cases life-long. There is no proper follow up time interval or mandatory imaging that experts agree on. In my practice, I see patients 1 month after stent placement with either US or CT. I then see them at 6 and 12 months post stent placement and then yearly for up to 3 yrs. When patients are doing well, it’s hard to get them to come in yearly for the rest of their life. I only get imaging when someone has a problem as their body will let them know if something is wrong. I feel that if someone is not going to act upon the imaging findings then why get imaging.

Will I need to be on blood thinners after my stent placement?

This is a common question that has no correct answer by venous experts. Generally, if someone has had DVT and their iliac vein is completely blocked and they get a stent, blood thinners are almost always given. In those who have MTS but have never had a stent, the data is less clear. There has been no study to evaluate whether blood thinners affect the patency (likelihood of stent staying open) of stents or not. However, the highest risk of getting a DVT after stent placement is within the first 3-4 weeks of stent placement. After a stent is placed, there is a lot of inflammation in the vein, and this inflammation can lead to clotting. In my practice, I put most people on an oral blood thinner and antiplatelet medication for 1 month. To learn more about the difference between blood thinners and antiplatelet medications, click here.

What is the recovery like after stent placement? Will I have a lot of pain?

If you are getting a stent for MTS and you have never had a DVT, then your pain will be less compared to someone who has a completely blocked iliac vein and needs it opened. In either case, nearly everyone will get some degree of back pain after stent placement. This back pain tends to be the most severe for the first 24-72 hrs and then will start to subside. In most cases, back pain will last 4-6 weeks and steadily improve each week. Often walking will improve the back pain so the more one walks, the better the back pain gets. Patients may be sent home with narcotics and steroids to help with the pain. It is recommended that patients not lift anything heavy over 20 lbs for 1 month so as not to pull a back muscle and make the back pain worse. As the years go on, it is not uncommon to have a sore back on occasion after strenuous exercise. This is due to the stent and is normal. Rest, a heating pad, and over the counter pain medication is all that is often needed. If one is having severe, debilitating back pain months after stent placement, this warrants a visit to your vascular specialist as this can be a sign of too large a stent that was placed (most common) or stent blockage (less common).

When a venogram is performed, do you test for other vascular compressions?

It depends on what symptoms the patient presents with. If a patient presents with lower extremity swelling of the entire leg or a history of recurrent extensive left leg DVT, MTS must be ruled out and the venogram will focus on whether there is compression of the iliac vein. On the other hand, if the patient presents without leg symptoms but has chronic pelvic pain, flank pain, pain with intercourse, increased urinary frequency and other symptoms, then this can be due to MTS, ovarian vein reflux, or Nutcracker syndrome. In these cases, all compressions would be evaluated for. This is why seeing an experienced physician who understands the pathophysiology of venous disease is important. Just having a physician who is a “technician” and can place a stent well is not the one I would want my family member to see.