Endometriosis is a common condition that causes pain and infertility.  The condition is defined as the lining of the womb (endometrium) that is present outside the womb cavity.

It is difficult to be accurate on how common it is but it is probably in the order of 10 to 30% of women.  The extent of the disease does not correlate well with the severity of the symptoms that it causes. 


Unfortunately it is not clear what the cause of endometriosis is but we do know that it is associated with menstruation and it may be associated with bleeding that occurs backwards (retrograde menstruation)   i.e. goes out through the tubes and into the abdominal cavity.  However, endometriosis can also be found in the lungs so this would not explain distant spread. 


The most common sites of endometriosis are on the ligaments behind the uterus (uterosacral ligaments) and the area in the abdominal cavity that is behind the uterus.  It is also seen on the ovaries and rarely in the bowel and the bladder. (Pouch of Douglas)

In appearance endometriosis looks like blue/black ink spots (Figure 1). With more severe disease these areas may be larger and have scarring around them.  The scarring may also lead to adhesions which may bind the bowel to the area of endometriosis. (Figure 2)

Symptoms of endometriosis

As mentioned above the degree of endometriosis may not correlate with the severity of the disease so some women who have severe endometriosis may not have any symptoms.  The commonest symptoms from endometriosis are painful periods, painful intercourse, intermittent or continuous pelvic pain, and infertility. 

If a woman with endometriosis is examined abdominally there may be nothing to feel or there maybe a cyst that has formed from the endometriosis which can be felt.  On pelvic examination she may have tender areas at the top of the vagina or behind the cervix and if severe disease is present the womb may be tender and fixed (non mobile), and one may be able to feel the nodules on the ligaments behind the womb.

Investigations

An ultrasound scan of the pelvis may reveal an endometrioma (endometriosis chocolate cyst) but will not detect the small nodules.  These nodules are diagnosed by laparoscopy which is where a telescope is inserted into the abdomen usually through an incision just below the belly button. 

Treatment

Treatment can either be medical or surgical.  What normally happens is that if endometriosis is there when the laparoscopy is performed then it is treated surgically at the time.  Some women may be given medical therapy to suppress further disease for some months postoperatively while others may take nothing and see whether the surgical treatment has been enough.  Surgical treatment involves diathermying, lasering or excision of the areas of endometriosis.  If scar tissue is present this may also be excised and if adhesions are there they may be divided.

Medical treatment is aimed at inhibiting ovulation and menstruation usually for 6 to 9 months.  Historically 9 months was chosen because it was noticed that women who had endometriosis improved after a term pregnancy.  The medical options for treatment are Danazol, the combined oral contraceptive pill, high dose progestogens, or GnRH analogues. 

The combined oral contraceptive is probably the easiest and it is given continuously rather than having a break of a week each month.  The commonest side effect of this if continued for many months is breakthrough bleeding.

Progestogens – these can be given orally or by a 3 monthly injection.

GnRH analogues – these drugs put women into a temporary menopause so the side effects are menopausal.  If they are given for longer than 3 to 6 months then there may be significant bone loss so ‘add back therapy’ needs to be given so that the bones are protected, and the hot flushes are eliminated. 

For women who have completed their family and are plagued by significant pain they may resort to having removal of the womb, ovaries and fallopian tubes.  If they then go on to hormone replacement therapy they will need oestrogen and progestogen continuously, rather than oestrogen alone which will stimulate any endometriosis if any deposits have been left.  .  

Endometriosis and fertility If the endometriosis has caused scarring so that the tubes may be blocked or the ovaries may be hidden then this will obviously effect fertility.  However, it appears the presence of isolated spots of endometriosis are associated with infertility and this is an area of a vast amount of research.

Endometriomas (endometriosis cysts)

Endometriomas are endometriosis cysts and are usually found in the ovary.  It is caused by ovarian endometriosis and when bleeding occurs it becomes encapsulated in a cyst and the cyst increases in size.  Each month the endometriosis bleeds, increasing the size of the cyst and when opened these cysts contain ‘chocolate coloured fluid. (Figure 3)  With the advances in pelvic ultrasound scanning these can be detected on a scan even when they are very small.

Medical treatment will not decrease the size of an endometrioma and if they are causing symptoms then they are usually dealt with laparoscopically which involves removing the cyst.  One of the methods to do this is to puncture the cyst and suck out the thick blood chocolate fluid inside it (Figure 3) and then dissect out the cyst capsule.  This can be done through the incision below the umbilicus and 2 small ports on either side of the lower part of the abdomen.

Ovarian cysts

Functional cysts of the ovaries are common and they usually cause no symptoms.  A lot of cysts of the ovary will spontaneously resolve.  With the advances in ultrasound scanning very small cysts can now be picked up which are of no significance.

If an ovarian cyst is found and it is less than 5cm and appears quite simple (that is just filled with fluid) then is can just be monitored.  There is a blood test that can be done which will give an indication of whether the cyst is benign or cancerous. 

If the cysts persist and are causing symptoms then they can be removed laparoscopically and sent off to the laboratory to be examined. 

Click here for more information on Gynaecology consultants at London Bridge Hospital