What is the purpose of this study?

In endometriosis, cells that detach from the lining of the womb find their way to the surface of the other organs in the abdomen. Here these cells will take hold, grow and die according to the menstrual cycle of the affected women. This is a debilitating condition that leads to pain, accumulation of blood in the abdomen and other complications.

Why endometriosis develops in some women but not in others is not clear. In theory during the menstrual period cells from the lining of the womb could find their way into the abdomen in all women. In theory, there are two main possibilities:

1. In affected women the cells from the lining of the womb could be more invasive enabling them to establish a "colony" in the abdomen (or, tummy area).

2. The cells of the abdominal lining (inside the tummy area) show less resistance than normal in affected individuals allowing colonies to be formed. This proposed study aims to distinguish between these two possibilities and to therefore find out why endometriosis affects some women, but not others.

How are the participants chosen?

Women are chosen to participate in this study for one of two reasons. One possibility is that they suffer from endometriosis and the clinical investigation or treatment of this condition requires inserting a small instrument into their abdomen (laparoscopy). This operation would have already been planned for the purposes of their clinical care. However, during this procedure we could collect the sample needed for conducting the research. Women who do not have any evidence of endometriosis but need the same investigation (laparoscopy) would make up the control group. They may be having a sterilisation or a laparoscopy to investigate pelvic pain. If they are found to have a normal healthy pelvis and agree to participate in the study we would take a small amount of fatty tissue and a sample of the cells from the lining of the womb to be used as “healthy control” in our research.

Do they have to take part?

No. Participation is entirely voluntary.

What will happen if a woman takes part?

If a patient agrees to take part in the research study, during her laparoscopy (insertion of a tube/ camera into your abdomen) a small part of the abdominal fat, about the size of a postage stamp, will be removed. Cells called mesothelial cells, will be extracted from this fatty sample in the laboratory.

During the laparoscopy it will also be necessary to visualise the neck of the womb (the cervix), and an instrument will be inserted into the neck of the womb to enable us to move the womb slightly to visualise the pelvic organs more easily from the camera above. At this stage of the procedure we would like to insert a fine biopsy sampler through the neck of the womb to allow us to sample the cells from the lining if the womb. It is a little like having a cervical smear taken. Both these procedures will be done whilst she is under anaesthetic. Cells, so called endometrial cells, will be isolated from this sample in the laboratory.

In the planned experiments we will compare how cells from the lining of the normal or diseased womb, the endometrial cells, and the cells lining the abdomen, the mesothelial cells, interact in patients with or without endometriosis.

What are the side effects of taking part?

Women will be asked to participate in this study because their clinical condition makes it necessary to look inside their abdomen using a “telescopic” instrument. The samples will be taken during this procedure. While they may have some complications as a result of the investigation or treatment this will be because of the already planned laparoscopic procedure itself not because they are participating in the study.

What are the possible disadvantages or risks of taking part?

Women will have all investigations or treatments carried out because of their underlying condition. They will not be required to make additional hospital visits and will not have to take any medication as a result of their participation. The only extra intervention is that a small amount of fatty tissue will be removed from the abdomen. This does not take more than a few minutes, will not add to the pain or discomfort that they will experience. It is theoretically possible that the site where the fat tissue is taken might bleed. However, the risk of this is very small compared to the risks that are associated with the investigation or treatment that you require based on your clinical need.

What are the benefits of taking part?

By taking part women will help us to establish whether the underlying problem in endometriosis is the excessive invasiveness of the cells derived from the womb or the low resistance of the cells lining the abdomen. This information is the first step that will help us design better therapies for the treatment for patients suffering from endometriosis. This, however, is a long term goal that will require the participation of hundreds of patients in the future.

What if new information becomes available?

As this is a research project new information will be gathered. This will not influence the way participants are being treated.

What happens if something goes wrong?

As mentioned before, any problems patients may experience is much more likely to be related to the treatment they already need and not to the fact that we are removing a small amount of fat tissue needed for the research. Regardless of this, if they wish to complain about any aspect of the way they may have been approached or treated during the course of this study, the normal National Health Service complaints mechanisms should be available to them.

What will happen to the results of the research study?

The results will be published in international research journals. At this point only statistical data will be presented. There will be no way that patients could be identified as an individual. Also the findings will be used in applications for further research funding.

Who is organising and funding the research?

This study is being organised by Liverpool Women’s NHS Foundation Trust. Funding is being provided by the Hewitt Centre Pilot Research Fund.

Who has reviewed the study?

This research has been reviewed and approved by an independent Research Ethics Committee.