Endometriosis is a condition in which endometrial tissue grows outside of the uterine cavity, most commonly in the ovaries, uterosacral ligaments or pelvic wall. It causes inflammation, which in turn can lead to fibrosis, adhesions and cyst formation. It is an important cause of infertility.
Aetiology and Epidemiology
Endometriosis has an unknown aetiology and is poorly understood. Theories of its aetiology include a genetic link or Sampson’s Theory of retrograde menstruation locally, often via the fallopian tubes, with distant spread due to blood vessel and/or lymph involvement.
Common sites for the lesions are the ovary, rectum, uterus and bladder – but it can also affect the umbilicus, abdominal scars and even the lungs. Diagnosed in 1-2% of women, but lesions are present asymptomatically in <20%. It is more common in nulliparous women.
The severity of signs and symptoms do not correspond well to the extent or severity of the disease. Endometriosis may be asymptomatic e.g. incidental finding during surgery.
- Chronic pelvis pain (non-cyclical)
- Dysmenorrhoea (painful cramps during menses)
- Menorrhagia (excessive menstrual bleeding)
- Deep Dyspareunia (painful sex)
- Dysuria (painful urination)
- Dyschezia (painful defecation)
- Acute pain (with cyst rupture)
- Rectal bleeding
- Umbilical bleeding
- Frank haematuria
- Normal examination
- Uterine tenderness
- Uterine thickening
- Retroverted uterus
- Immobile uterus
- Recto-vaginal nodule
Diagnosed via visualisation of the endometrial lesions via laparoscopy +/- biopsy.
Pelvic USS or trans-vaginal USS are important to rule out other causes, or identifying an endometrioma.
Endometriosis is often associated with chronic pelvic pain, and can be extremely unsettling for the patient during acute ‘attacks’ of the condition. Patients are often frustrated by a lack of cause or explanation, therefore it is essential to explore and satisfy the patient’s ideas, concerns and expectations prior to commencing a management plan. n women of reproductive age, endometriosis is managed conservatively.
- 50% of cases spontaneously regress or do not progress.
- Pregnancy and menopause effectively treat endometriosis by preventing menstruation.
- Appropriate analgesia – this may include tranexamic acid, mefenamic acid, or other NSAIDs if mefenamic acid is contraindicated.
- If USS is inconclusive as to the cause of this pelvic pain, a trial of a combined oral contraceptive pill or gonadotrophin-releasing hormone agonist (which simulates the menopause) may be recommended.
- If symptoms have not been resolved after 3–6 months, the RCOG recommends diagnostic laparoscopy for pelvic pain, particularly if radiological scanning is not successful in diagnosing etiology of illness.
Once the source of the pain has been located, be it an active endometrial lesion or an adhesion, then there are several surgical treatments available:
- Laser of thermal ablation
- Adhesion dissection
- Hysterectomy +/- oophorectomy (only in extreme cases after all other treatments have been attempted)
- Cysts - known as 'Chocolate cysts' when endometrial tissue grows inside the ovary.
- Frozen pelvis - pelvic organs fixed and rigid due to lots of adhesions, patient is sub fertile
- Infertility - due to the formation of adhesions following recurrent inflammation.