Endometriosis

Endometriosis is a condition affecting approximately 10% of women of reproductive age where small deposits of the lining of the uterus (endometrium) develop in abnormal sites possibly causing scarring, pain or infertility. Endometriosis most commonly occurs in the pelvic tissues including on or beneath the ovaries, behind the uterus adjacent to the rectum (Pouch of Douglas) over the bladder or in the abdominal wall. It sometimes occurs outside the pelvis affecting the appendix or intestines and rarely other areas. The scarring that results from endometriosis may cause organs or tissues to stick together (adhesions) thus causing pain or infertility.

Adenomyosis is a condition in which pockets of endometrial tissue are present within the muscle of the uterus. This condition may cause heavy and painful periods. Adenomyosis is difficult to diagnose. There may be a swollen and tender uterus on pelvic examination but there are no definitive tests that can be used to diagnose it. Medical treatment for the heavy and painful periods may only be partially successful. Some newer treatments, including the progesterone IUCD and progesterone implants, seem to be more successful but they have not yet been formally evaluated in the treatment of adenomyosis. The most definitive treatment may be a hysterectomy.

Traditionally gynaecologists have used electro-surgery or laser techniques to destroy endometriotic lesions that were visible on the surface. This approach has been recognised to miss endometriosis that is deep or close to vital structures. Over the last 10 years experts in the management of endometriosis have used a different surgical approach where endometriotic tissue is excised. This ensures that all the endometriosis is removed after careful dissection away from vital structures such as the bowel, bladder and ureters.

Long-term studies have shown that this type of approach is highly successful. 70-90% of women have complete or partial relief of pelvic pain symptoms. The chances of becoming pregnant after surgery increase by 40%. Approximately 33% of patients (1 in 3) may experience recurrent pain symptoms over 5 years. Of these approximately 25% have endometriosis. There is some evidence that medical treatment for 6 months after surgical excision may delay the onset of such recurrent pain symptoms.

Even when adequately treated endometriosis has a tendency to recur. However, there are various medical and surgical treatments available to manage this disease and its symptoms. Complete surgical removal of endometriosis may control this disease and its symptoms for many years providing a return to normal activity and a new life for long term sufferers.

Endometriomas are cysts within the ovary that are caused by endometriosis. The cysts are filled with old blood, which is very thick and dark in colour. This is why they are commonly known as chocolate cysts. They often involve both ovaries and are associated with widespread endometriosis in the pelvis. Although rupture of these cysts has been described, it is most uncommon. They are usually slow growing and are often present for many years before they are discovered. Surgical removal is the only effective treatment. In many cases drainage of an endometrioma may be performed when diagnosed. This is then followed by medical treatment, which may reduce the size of the cyst prior to definitive surgery.

Medical treatment alone will not improve fertility. Surgical treatment, in the form of ablation or removal of endometriosis lesions, can improve fertility. Studies have shown that surgical treatment of endometriosis improves the chances of spontaneous pregnancy by 40%. Fertility treatment such as intra-uterine insemination of sperm (IUI) and in-vitro fertilisation (IVF) can also improve the chances of pregnancy in women with endometriosis. It is also probable that IUI and IVF will be more likely to succeed if any endometriosis is treated surgically prior to performing such fertility treatment.

Endometriosis is the subject of considerable ongoing research worldwide. There is considerable work being done to identify the role of the immune system and genetics in endometriosis as well as in the development of new medical and surgical treatments. In particular there is a great deal of interest in the outcome of randomised trials comparing laparoscopic (keyhole) surgical excision of endometriosis to traditional laser or electro-surgical destruction of endometriosis.

Although the precise cause of endometriosis is still not fully explained there are a number of possible causes. The most likely explanation is that tiny fragments of endometrium pass backwards through the tubes during a period and deposit in the pelvis where they subsequently implant and grow. This is known as retrograde menstruation and the transplantation theory.

It is likely that the immune system plays an important role in the development of endometriosis such that some women are more susceptible to endometriosis than others. This might explain why only some women develop endometriosis although most have retrograde menstruation.

Another explanation is that small areas of the lining of the pelvis (peritoneum) change from normal to endometriosis type tissue. This process is called metaplasia and could explain how a woman whose tubes have been tied or clipped or who has had a hysterectomy can still get endometriosis.

Sometimes endometriotic tissue may implant in surgical wounds or scars such as after laparoscopy or caesarean section. This is the implantation theory.

Finally there is increasing interest in possible genetic factors involved in the development of endometriosis, as frequently there is a family history of endometriosis.

The various medical treatments include progesterones (gestrinone or MPA), GNRH analogues, danazol and the combined oral contraceptive pill. These are all hormone treatments that work by suppressing the growth of endometriosis. They have all been shown to provide effective pain relief during therapy. The main differences between them are the different side effects and costs. Medical treatment alone, however, rarely leads to a complete disappearance of the endometriosis lesions. There is a high rate of recurrence of symptoms when the medical treatment is ceased.

As many patients with endometriosis complain of heavy and painful periods it is very tempting to perform a hysterectomy to relieve their symptoms. Unfortunately endometriosis is rarely isolated to the uterus. More than half of the women who have a hysterectomy (with conservation of the ovaries) have been reported to get a recurrence of their symptoms. When the ovaries are removed as many as one in 10 women will have a return of their symptoms. Performing a hysterectomy is unlikely to resolve symptoms such as pain during sex or pain in the rectal area, which are common in severe cases of endometriosis.

With early and more effective methods of diagnosing endometriosis hysterectomy is becoming less common. Advances in laparoscopic surgery have enabled the treatment of endometriosis without hysterectomy. This has the advantage of maintaining fertility and allowing a natural menopause.

Traditionally patients with endometriosis have been advised against the use of hormone replacement therapy (HRT). There are many isolated reports associating HRT with the recurrence of endometriosis related pain and even gynaecological cancers. Recent studies have not supported these views and encourage its use in patients with known endometriosis. The theoretical disadvantages of HRT must be weighed against its advantages particularly in younger women who face a prolonged period in the menopausal state. When HRT is used it must be a combination of oestrogen and progesterone. There is no evidence that withholding HRT for a period of time after surgery protects against recurrent symptoms. Tibolone is a new HRT on the Australian market. It has a different mode of action than conventional HRT, which may be advantageous in patients with endometriosis.

Endometriosis is commonly seen lying over the bladder but involvement of the bladder itself is uncommon. When it does occur it is usually associated with wide spread pelvic endometriosis. More uncommonly it may be seen in isolation after a caesarean section. It is postulated that in these cases the endometriosis may have spread to the bladder during surgery. Women with this condition often complain of having to urinate urgently and frequency with difficulty or pain. Clinical examination followed by ultrasound and cystoscopy confirms the diagnosis. Blood in the urine is not common. Medical management will relieve symptoms but recurrence is almost inevitable when it is stopped. Surgical removal of the endometriosis from the bladder wall is the most effective treatment and this is can be easily performed during laparoscopic surgery.

Generally speaking it is more comfortable and pleasant for the woman having a gynaecological examination to avoid the time of her period. However it is not necessary to cancel an appointment if a woman discovers that it will coincide with her next period.

It is quite easy to plan another consultation for examination and /or vaginal ultrasound scan should the woman prefer not to be examined during her period. Sometimes it is helpful for the gynaecologist seeing a patient with cyclical pelvic pain symptoms attributed to endometriosis to examine her around the time of her period when her symptoms are most apparent. However this is not necessary to make a diagnosis or plan further tests or treatment.

Research into the genetics of endometriosis may lead to the development of a serum (blood) test for endometriosis rather than relying on laparoscopy alone. It is even possible that gene therapy may be a treatment option for future generations of women but this is still a long way from becoming a reality.