Endometriosis explained:  The 3 types, diagnosis, and impact on fertility

Understanding endometriosis and its implications

Dr. Geoff Zeni joins us on EP03 of My Fertility Podcast. He is a minimally invasive gynaecologic surgeon currently practicing at Markham Stouffville Hospital with a particular interest in fertility sparing surgery. He currently does really complex gynaecologic surgeries involving endometriosis, fibroids and Mullerian anomalies. He also has a particular interest in advanced gynaecologic ultrasound, including endometriosis mapping, fibroid mapping and the evaluation of Mullerian anomalies. Outside of this, he also has an interest in surgical education and the advancement of fertility-specific endometriosis research. We thank Dr. Zeni for the work he does for the endometriosis community.

In this article, we will cover: 

  1. What is endometriosis?
  2. The 3 types of pelvic endometriosis 
  3. Making the diagnosis
  4. Endometriosis and fertility

What is endometriosis?

Endometriosis is a medical condition that affects approximately 10% of people who are born with a uterus. It is a chronic inflammatory condition that can have a wide range of clinical presentations. Some patients will present with horrible pain, while some patients will present with no symptoms whatsoever, regardless of the severity of the disease that they have. 

At its most basic form, endometriosis is when certain cells are located outside of the uterus. The cells are similar to the endometrium, which is the lining of the uterus, which one sheds every month through a period, or menstruation. These cells are very similar but not identical to the endometrium.

Most commonly, cells will be seen in the pelvis, although there are case reports of these cells being located in many other places including the brain, lungs, chest cavity, diaphragm, and even recently identified in the spleen, to name a few areas.

The clinical presentation depends on where the cells are located, so it can be quite varied. Let’s talk about pelvic endometriosis, which is by far the most common.

The 3 types of pelvic endometriosis

Pelvic endometriosis has three main forms.

Superficial endometriosis

The most common form of endometriosis is called superficial endometriosis. Imagine the entire inside of the abdomen is wrapped in peritoneum, which is a fancy word for a cellophane wrap for the inside of the abdomen. It’s a very thin layer that wraps itself over all of the different organs as well as the walls of the abdomen. A lot of the time we see these superficial deposits of endometriosis on these surfaces. That includes surfaces overlying the bladder, the rectum, as well as the sidewalls, the fallopian tubes, and the different ligaments that we see inside the pelvis.
These lesions are specific because they’re very thin. The lesions don’t invade into any of the tissues; instead they sit on top of the peritoneum.

Deeply invasive endometriosis AKA deep endometriosis

The second type of endometriosis is called deeply invasive endometriosis or deep endometriosis. Essentially these are the same cells, but they present differently and they form nodules that actually invade deeply into some of the structures, most commonly in the pelvis.

We see this a lot of the time in the ligaments that support the back of the cervix called the uterosacral ligaments, and they can be located in other places as well.

Ovarian endometriosis

The third type of endometriosis is called ovarian endometriosis, which is sometimes also called an endometrioma. They are also sometimes called chocolate cysts because they are filled with old blood that, over time, gets partially digested and looks like molten chocolate when we (surgeons) open the cysts inside the OR. 
These endometriomas or cysts can be small or big. Most commonly those cysts are attached to an area of deep endometriosis. This is a new finding that we’re recognizing more and more. Dr. Zeni believes that the endometriosis within the ovary is likely born from the deep endometriosis nodule and gets enveloped by the ovary. As it bleeds with every cycle, you end up with larger and larger cysts.

Diagnosing endometriosis

As with any medical diagnosis, we begin with a medical history, including your symptoms, fertility, pain, and then move on to a physical examination. We also have a discussion about what the patient’s goals are. 

Sometimes we can feel nodules behind the cervix on examination. In this case, we move to investigations with ultrasound or MRI and then potentially diagnosis through laparoscopy, or surgery. 

Now, in reality, that’s not usually how this works. Patients often get referred to an endometriosis specialist when there’s already a sign of superficial endometriosis. This means that a lot of the legwork has already begun. Sometimes the patient has already had surgery with a diagnosis, either a visual diagnosis or a pathologic diagnosis. However, that diagnosis doesn’t necessarily tell us how complex the disease is. 

Endometriosis diagnosis via ultrasound

Most commonly, a patient may have a diagnosis of endometriosis based on an ultrasound finding of endometriomas. Endometriomas can be visualized on an ultrasound because they have a very stereotypical appearance.  Patients can also have a diagnosis from a previous surgery where it was seen in the pelvis, or they have a presumed diagnosis based on clinical features. 

If we have tunnel vision and only treat the endometriosis, we’re not actually treating the patient, right?

Patients aren’t their disease, but they are (kind of) everything that’s causing their pain. Therefore it becomes essential to treat:

– how the muscles are interacting with pain, 

-how the nerves are interacting with pain,

-as well as the root cause, which, a lot of the time, is endometriosis

Here in Markham at CARE Imaging, we can perform advanced gynaecological ultrasounds, which can map someone’s endometriosis. At this time in Ontario, there are only two groups that are performing these ultrasounds that can map the actual location and size of lesions of deep endometriosis. One of the sites is at CARE Imaging where Dr. Zeni himself performs the examinations along with specially trained sonographers.

With this type of ultrasound, we can very accurately say that, yes, this is deep endometriosis – this is where it is – this is how big that nodule is – And these are all these things that are stuck to it or not stuck to it, which is crucual information with regards to surgery and fertility. 

On the other hand, if nothing appears on ultrasound, we can very confidently say that deep endometriosis is not present. 

This information is important for the consent process prior to surgery and the decision-making process with regards to fertility and fertility treatments either in conjunction with surgery or without surgery.

Surgery is not necessary for all patients, as we also have medical treatments. Treatment for endometriosis must always be tailored for the patient. Identifying superficial endometriosis lesions with ultrasound  is an up-and-coming area. We’re getting really good at identifying superficial endometriosis when there’s something that we call free fluid inside the pelvis, which is something that is naturally there. It’s not an abnormal thing, but it happens somewhat depending on where people are in their cycle. Usually there’s a little bit of fluid that we can find in the area behind the uterus, which is the most common place for us to find superficial endometriosis and we can actually see these lesions. 

Now, without that fluid present, we don’t have that window to be able to see the lesions. We don’t have the contrast to be able to see these lesions because they’re so small and they get lost where different organs are rubbing up against each other and they get lost in that interface.

The free fluid is really necessary for that diagnosis. And if we see those lesions on ultrasound, we can confidently say that they are present. However, if we don’t see them and there’s no free fluid or if there is limited free fluid in the pelvis, we cannot rule out the presence of superficial endometriosis.

There is a good portion of our population that has superficial endometriosis without deep endometriosis. It’s important to remember that – it’s not just about treating the deep endometriosis lesions that are so readily visible, but rather also the superficial lesions. Superficial lesions cannot be mapped in the same way as the deep lesions, because even if there’s free fluid, we may not have enough free fluid in the pelvis to see all of the lesions. This is very important in order to accurately give a patient a picture of what their endometriosis looks like.

Endometriosis diagnosis via surgery

When we look at the gold standard of diagnosis via surgery there are two issues:

  1.  The diagnostic laparoscopy comes with significant surgical risk: anesthetic risk, as well as the surgical risk – even entry for a laparoscopy has risk in terms of damaging organs
  2. A lot of the time the information we get from a diagnostic laparoscopy, especially if people have really complex disease, is not as good as the information we get from the ultrasound. Because deep endometriosis is hidden underneath a uterus that’s really stuck, we don’t know if there’s a lesion of deep endometriosis hiding in the wall of the rectum, which we can so easily see now with ultrasound. 

Using a3D transvaginal probe with extremely high frequency it is possible to actually look at the two layers of muscle of the rectum and determine how deep a lesion in the rectum goes. Is the lesion only in that outer layer of the muscle? Is it four centimeters long? Does it go all the way through both layers into the lumen (which is where the poop is inside the rectum) – knowing this is going to have a big impact in terms of what decisions are made for surgery, how to consent people and what to talk about in terms of really tailoring the consent process. Having all of this information, makes it possible to speak about the risks beforehand and a patient can then make a really good informed decision. 

Doctors can also arrange for a patient to see a colorectal surgeon beforehand who can participate in the surgery in a planned way, which is greatly beneficial for the patient, the hospital, and doctor themself because it allows us all to work really closely in a multidisciplinary team –  with the fertility group, but also with colorectal surgeons and the urologists at the hospital.

Again, it is crucial to have as much information as possible before surgery, so the patient knows exactly what to expect.

Endometriosis and fertility

It is important to actually look at the exact extent of endometriosis in the pelvis.Many of these lesions, especially the deep lesions, cause scarring and adhesions inside the pelvis. So things get stuck together. This becomes problematic when the adhesions involve the fallopian tubes because the fallopian tubes can be blocked and then you can get a buildup of fluid inside the tubes and the tubes essentially don’t work. THis is called a hydrosalpinx or hematosalpinx (depending on what is inside the tube). In this case, the tube that’s full of fluid or full of blood can actually prevent pregnancy either through IVF or through natural means, even if the other tube is open. If we do an embryo transfer where we are essentially by passing the tubes, the fluid from the stretched tube actually washes back into the uterus and has toxic effects on the embryo and can theoretically wash the embryo out. So it decreases implantation rates by half!

In summary, there are many different ways that endometriosis presents, both in terms of how it looks and how it affects fertility, but also – a big difference in terms of how it presents with regards to pain. 

Dr. Zeni states: pain is the most common reason he sees patients for endometriosis and fertility is the second most common. 

People can have really complex pelvic disease and no pain at all. A person can have a really minimal amount of superficial endometriosis and high degrees of pain and then everywhere in between. Therefore, the amount of endometriosis does not correlate to the (amount of) symptoms a patient has. And this is really important to note. 

It is also important to note that looking at your stage does not identify whether or not you are more affected by endometriosis than another person.

A few words from Dr. Zeni

In general, society needs to reevaluate how it approaches fertility and pelvic pain. And we need to have a lot more grace when we talk with people and when we empathize with people. It makes a huge difference in people’s lives when they’re, first of all, taken seriously and secondly, when they are listened to.

Fertility is really difficult. We know there’s so much good evidence in terms of the toll fertility takes on people’s mental health over a long period of time.

And pelvic pain is the same. When you put both those things together in the same patient, it’s horrible. These people suffer and it really hurts when I hear these stories of people who have not been taken seriously their entire lives. 
And since I’ve gone into this field, I think this is a population that has been so marginalized for such a long period of time that it’s really important that people take them seriously. And the team at Markham Fertility do such an amazing service. And I want to thank you for what you do for your patients because I think that you treat them with the empathy and the care that these women and these families deserve.

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