Endometriosis Research Review: April 2014

Wednesday, May 07, 2014
Endometriosis research - photo not owned by Endometriosis UK

Matthew Rosser, a PhD researcher at the University of Manchester introduces the latest endometriosis research in our first edition of Endometriosis Research Review.

This research review will be produced quarterly and is primarily available only to members of Endometriosis UK. Following editions of this research review will not be published on the Endometriosis Uk website and will only be sent to members directly. Find out more about becoming a member of Endometriosis UK.

Introduction to the Research Reviews

You may not think it, but there is a substantial amount of research being done into endometriosis at the moment, in fact there has been an explosion in interest in endometriosis over recent years. To illustrate the point, if we were to search the largest database of scientific articles on the day I’m writing this, we would see that there have been 9,739 articles published with the keyword ‘endometriosis’ since the year 2000. That sounds like a lot, but to put that number in perspective, there has been more research published on endometriosis in the years after 2000 than there was in the preceding 45 years!

So, in order to get new information on endometriosis to the people it matters most to (i.e. you), I’ll be writing short, quarterly summaries of new scientific developments from all manner of research areas, from treatments to diagnostics and even new ideas about what causes the disease. These reviews are not for scientists or doctors though, they are for women with endometriosis who want to learn more about the disease, so I’ll be cutting through the jargon and just giving you the facts. All the information will come from trusted scientific sources and be reported without any bias or desire for sensation; it might even get you thinking differently about endometriosis. Where possible I will also provide links to the full versions of any articles I review, so you can read them yourself and see what conclusions you can draw from them.

Fertility

Fertility issues are one of the major challenges facing women with endometriosis, so we’ll begin with a study from The Seoul National University Hospital in South Korea1 investigating laparoscopic surgery and its effect on the ability to conceive naturally. Laparoscopic surgical treatment of endometriosis is considered one of the best options for women with endometriosis whose symptoms don’t respond well to medical therapy.

In order to assess any value of laparoscopic surgery on fertility this study took 43 infertile women with endometriosis and followed up their natural conception rates 12 months after they underwent surgery to remove their disease. The overall result was that 18 out of 43 women (41.9%) had conceived naturally after 12 months. Of those 18 women who conceived after a year 67% had conceived after three months and 94% had conceived after 6 months, which indicates that fertility is restored fairly quickly after successful surgery. Endometriosis though, is not a simple disease, there are many different types and stages in which the disease can present; so are all things equal between different types of endometriosis and the success of surgery? Fortunately the authors of this study addressed this question and found that success of surgery, in terms of restoring fertility, was not significantly different between women with different types and stages of endometriosis.

Although this study only used a rather small number of women, the results are nevertheless encouraging and it would be interesting to see more studies like this done with larger groups of patients and in different treatment centres (for example assessing the difference in success rate between a general hospital and a specialist endometriosis treatment centre). If you would like to read the full version of the article I’ve been referring to, you can do so here.

Additional Health Conditions

Fertility issues though, are not the only problem blighting women with endometriosis. The disease is the proverbial misery that loves company and many women with endometriosis suffer from other health conditions as well. Therefore, it is important that studies are made to assess the different health conditions women with endometriosis suffer from, as this gives us a far better idea of the wider impact on women’s lives. Along those lines then let’s examine an article from The University of Michigan Health System in the US2 which focuses on pain symptoms, mood conditions and asthma in adolescents and young women with endometriosis.

This study found records from 2001 to 2011 for 138 girls who had their endometriosis diagnosed before the age of 21 and carefully reviewed their medical records for a whole range of other conditions, including: irritable bowel syndrome, chronic headaches, chronic fatigue, asthma, anxiety, depression and many others.

The results of this analysis showed that 56% of girls with endometriosis had other pain conditions, which is a huge amount. The most common pain condition was irritable bowel syndrome (IBS), followed by chronic headaches and lower back pain. Importantly the study revealed that those girls with endometriosis and other painful conditions were significantly more likely to suffer from depression and anxiety. Although, even in girls with no other pain conditions, a third suffered from depression and anxiety as well, this highlights how endometriosis causes not only physical suffering, but mental anguish too.

Another interesting fact from this study is that 57 out of 138 girls had tried three or more different hormonal medical treatments for endometriosis. This indicates that there is substantial trial and error when it comes to managing the symptoms of endometriosis with drugs and that we are sorely lacking in effective front-line treatments for the disease.

One concluding remark made by the authors of this study also piqued my interest. It was the observation that the same painful conditions they investigated in this present study are more common in adult women with endometriosis than in younger women. To me this suggests that longer periods of time spent suffering with endometriosis has a detrimental effect on the body as a whole.

Adolescent Presentation and Earlier Diagnosis via MRI

From all the accumulating evidence it is becoming apparent that endometriosis is a disease that presents its symptoms in adolescence. Several studies have shown that, in young women with chronic pelvic pain, between 25% and 73% have underlying endometriosis3-5 (the large variation in percentages is due to the different way each study was conducted). This further highlights the need for better awareness of endometriosis, so hopefully it can be diagnosed earlier and the impact of the disease can be lessened.

Speaking of earlier diagnosis it seems fitting then to end this review with a look at some research into a different way of diagnosing endometriosis. Laparoscopy will, for the foreseeable future, be the gold standard for diagnosis, but as it is a surgical procedure with the inherent risks, expense and waiting lists associated with surgery, it would be good to have a way to identify women with endometriosis before any surgical intervention is taken.

There are several methods available at the moment to look inside the human body without operating on it, like X-ray machines for example, but one of the more advanced techniques is magnetic resonance imaging or MRI. You may have heard of MRI before, you may have even had one. The MRI machine itself looks like a giant ring donut with a narrow bed in the middle which you lie on and get put into the ring. It applies a very strong magnetic field and radio waves to your body which, unlike x-rays, are very good at imaging the soft parts inside you, so it seems only logical to try and use this technique to look for endometriosis.

A research team from Homboldt Hospital, Germany6 took up this challenge and investigated whether MRI can be used to accurately find different types of endometriosis in the body. To do this they took 152 women who were already suspected of having endometriosis, then gave them an MRI to try and identify any disease, then each woman had a full investigative laparoscopy. After laparoscopies were performed, the results were compared to those of the MRI to see how accurate it was. Below is a table of the results.

Location of Endometriosis Accuracy of MRI (%)
Bladder 92.8
Pouch of Douglas 86.8
Vagina 81.6
Ovaries  80.3
Rectosigmoid colon 78.9
Uterosacral ligaments  73.7
Peritoneum 70.4

Overall we can see that MRI performs quite well, particularly in identifying endometriosis of the bladder and pouch of Douglas (which is the gap just behind the womb). The technique also fairs reasonably well at identifying endometriosis of the vagina, ovaries and colon. Unfortunately it doesn’t do so well at identifying endometriosis of the utero-sacral ligaments (the ligaments that hold the womb in place) or the peritoneum (the lining of the space where female reproductive organs sit). This is a shame in some sense because the peritoneum is the most common place for endometriosis to be found.

A factor that might affect the diagnostic accuracy of MRI is the many different appearances of peritoneal endometriosis. Sometimes the disease can look very large and obvious and sometimes it can be very subtle and small (but still very painful). There may however be ways to increase the accuracy of MRI; special chemicals can be injected into the body which enhance the image produced, which may allow for better visualisation of endometriosis.

Also some types of endometriosis can alter the structure of the pelvic organs, which in turn can be picked up by MRI, giving away the location of the disease. For example, some cases of deep pelvic endometriosis can lead to ‘cul-de-sac obliteration’. This isn’t, as the name suggests, destroying a road with only one inlet/outlet, but rather a closing of the pouch of Douglas, which can be easily detected by MRI. In the future then we may see modifications of this technique that allow a quicker identification of women with endometriosis and offer a heads-up to surgeons so they know where to look for the disease.

References

Lee HJ, Lee JE, Ku SY, Kim SH, Kim JG, Moon SY, et al. Natural conception rate following laparoscopic surgery in infertile women with endometriosis. Clinical and Experimental Reproductive Medicine 2013 Mar;40(1):29-32.

Smorgick N, Marsh CA, As-Sanie S, Smith YR, Quint EH. Prevalence of pain syndromes, mood conditions, and asthma in adolescents and young women with endometriosis. Journal of Pediatric & Adolescent Gynecology 2013 Jun;26(3):171-5.

Goldstein DP, De Cholnoky C, Emans SJ. Adolescent endometriosis. Journal of Adolescent Health 1980 Sep;1(1):37-41.

Laufer MR, Goitein L, Bush M, Cramer DW, Emans SJ. Prevalence of endometriosis in adolescent girls with chronic pelvic pain not responding to conventional therapy. Journal of Pediatric & Adolescent Gynecology 1997 Nov;10(4):199-202.

Reese KA, Reddy S, Rock JA. Endometriosis in an adolescent population: the Emory experience. Journal of Pediatric & Adolescent Gynecology 1996 Aug;9(3):125-8.

Krüger K1, Behrendt K, Niedobitek-Kreuter G, Koltermann K, Ebert AD. Location-dependent value of pelvic MRI in the preoperative diagnosis of endometriosis. European Journal of Obstetrics & Gynecology and Reproductive Biology 2013 Jul;169(1):93-8.