Endometriosis is a condition characterised by the presence of endometrial tissue, which is normally found lining the womb, at sites outside the womb. It is most commonly found in the pelvis but it has also been found at remote sites such as the lung and nose. The prevalence (number of women with the condition at anyone one time) of the condition is not completely clear but best estimates range from 2-10% of females of reproductive age. It affects all races although is possibly more common in Caucasian and East Asian women than African races although this may be due to differing access to diagnosis. There is a genetic tendency in that the conditions can cluster in families, however most sufferers do not have a family history of note.
The cause of the condition is also not clear. The original theory was that is was due to menstrual fluid spilling from the fallopian tubes during a period and the tissue ‘taking hold’. This however cannot be the whole answer as menstrual fluid is found in most women’s pelvises during a period but less than 10% actually develop the disease. In addition this theory would not explain how endometriosis can be found in the lungs. Disorder of the immune system probably plays a part and studies have shown the immune system in ladies with and without endometriosis to be different. A further theory involves ability of cells within the body to change from one cell type to another (metaplasia). In this situation a cell, anywhere in the body, may change into an endometrial cell and develop into endometriosis although the trigger for this has yet to be proven. The probable answer is that there are several factors that can lead to endometriosis and combinations of factors increase the chance of developing the disease.
Symptoms usually consist of pain and / or sub-fertility. Pain can occur with periods, intercourse and sometimes on passing stool or urine. It may also be a more constant pain throughout the menstrual cycle. The effect of endometriosis on quality of life is enormous with studies showing effect on quality of life equal to or worse than that of patients with some cancers. The main technique for diagnosis is a laparoscopy, which involves a small camera being passed though the umbilicus (belly button) under anaesthetic to allow direct inspection of the organs of the pelvis. Because of this, and often a lack of awareness, there is frequently a delay in diagnosis with the average delay from first presentation to diagnosis being 3-11 years.
Treatments of the condition broadly speaking are broken down into medical treatments (drugs) and surgical treatments.
The aim of medical treatments is to improve symptoms by suppressing the endometriosis. Drugs used include the combined oral contraceptive pill, progestogens (eg norethisterone, provera), depo provera injection, danazol (rarely) and gonadotrophin releasing anologues (eg Zoladex, Prosap). Around 80-90% of patients will have improvement of their pain symptoms and all have similar efficacy. Relapse rates on stopping however are high with up to 50% relapsing at one year and 33-74% relapse rate at 3-5 years. This is due to the fact that these treatments suppress disease rather than irradicate it. Side effects are relatively frequent and vary from treatment to treatment. None of these treatments are suitable for patients trying to conceive as they are relatively contraceptive.
Surgical treatment is either conservative, aiming to treat the disease and leave the gynaecological organs (or as much of the gynaecological organs as possible) or radical, with hysterectomy and removal of the ovaries. This classification however is often confusing as most endometriosis experts will perform ‘radical’ excision of endometriosis whereby all the disease is excised with electrosurgery rather than simply being superficially burnt with diathermy. At present, less than 20% of UK consultant gynaecologists perform excisional laparoscopic surgery for endometriosis. An example of this sort of surgery can be found on the channnel 4 Embarrassing Bodies website, which follows one of my patients with this condition. Conservative treatment is usually carried out by keyhole surgery and most often as a day case procedure, however this does depend on the severity of the disease. Severe disease involving the bowel will usually require the gynaecologist to operate with a colorectal surgeon who specialises in keyhole surgery. Similarly, if the disease affects the ureters (tubes conecting the kidney to the bladder) or deeply invades the bladder the gynaecologist will operate with a urologist who specializes in keyhole surgery. Such surgery is extremely complex and should only be undertaken in recognised specialist centres with the training, expertise and numbers to undertake such procedures. These centres are accredited by the British Society of Gynaecological Endoscopy (BGSE) and Mr Carpenter leads the Dorset Endometriosis Centre, one of only 41 accredited centres in the England in 2016.
Overall symptomatic improvement following excisional / laser surgery occurs in 62-80%. Further laser surgery in those who relapsed or did not achieve significant benefit the first time, gives similar results with nearly two thirds having symptomatic improvement.
In patients with sub- fertility and endometriosis laparoscopic surgery has been shown to increase fertility. A large study comparing laparoscopic treatment with no treatment showed those treated had nearly a doubling (90%) of their chances of falling pregnant. Based on this the National Institute of Clinical Excellence (NICE) in the UK advise that all women with sub-fertility and endometriosis should be offered laparoscopic treatment.
In summary endometriosis is a relatively common condition whose exact cause is unclear. Drug treatment for pain symptoms is effective but symptoms usually recur on stopping. Surgical treatment is effective for pain and sub-fertility with the aim of long term cure of the condition.
An excellent video explanation of endometriosis can be found at the following website vimeo.com/20910143