Endometriosis

Definition | Aetiology | Pathophysiology | Risk Factors | Clinical Presentation | Investigations | Management | When to Refer | References

Definition

Endometriosis is a chronic condition where tissue similar to the lining of the uterus (endometrium) grows outside the uterine cavity, leading to inflammation, pain, and the formation of adhesions. It commonly affects the ovaries, fallopian tubes, and the tissue lining the pelvis but can also be found in other parts of the body.

Aetiology

The exact cause of endometriosis is not fully understood, but several theories have been proposed:

• Retrograde Menstruation: The most widely accepted theory, where menstrual blood flows backward through the fallopian tubes into the pelvic cavity, allowing endometrial cells to implant and grow outside the uterus.
• Immune System Dysfunction: An impaired immune system may fail to recognise and destroy endometrial tissue outside the uterus.
• Coelomic Metaplasia: The transformation of peritoneal cells into endometrial-like cells, possibly triggered by inflammation or hormonal factors.
• Genetic Factors: A genetic predisposition is suggested by the higher prevalence of endometriosis in women with a family history of the condition.

Pathophysiology

Endometriosis involves the abnormal growth of endometrial-like tissue outside the uterus, which responds to hormonal changes during the menstrual cycle:

• Inflammation: The presence of ectopic endometrial tissue triggers an inflammatory response, leading to pain and the formation of scar tissue (adhesions).
• Adhesions and Fibrosis: Chronic inflammation can lead to the formation of fibrous tissue and adhesions, which can distort pelvic anatomy and contribute to pain and infertility.
• Cyst Formation: Endometriomas, or "chocolate cysts," may form in the ovaries, filled with old blood from repeated cycles of bleeding within the cyst.
• Chronic Pain: Inflammation and adhesions can cause chronic pelvic pain, which may worsen during menstruation or sexual intercourse.

Risk Factors

Several factors increase the likelihood of developing endometriosis:

• Family History: Having a mother or sister with endometriosis increases the risk.
• Early Menarche: Starting periods at an early age increases the exposure to oestrogen and may raise the risk of endometriosis.
• Short Menstrual Cycles: Having menstrual cycles shorter than 27 days is associated with a higher risk.
• Heavy Menstrual Bleeding: Women with heavy periods are at increased risk.
• Nulliparity: Women who have never given birth are at higher risk.

Clinical Presentation

Endometriosis can present with a variety of symptoms, which can vary in severity. Common symptoms include:

• Pelvic Pain: The most common symptom, often cyclical, worsening before or during menstruation. Pain may also occur during ovulation.
• Dysmenorrhoea: Painful periods, often severe, that may interfere with daily activities.
• Dyspareunia: Pain during sexual intercourse, often described as deep and sharp.
• Infertility: Difficulty conceiving is a common complication, and endometriosis is a leading cause of female infertility.
• Dyschezia: Painful bowel movements, particularly during menstruation, due to endometriosis affecting the bowel.
• Chronic Fatigue: Many women with endometriosis experience persistent fatigue.
• Other Symptoms: Depending on the location of endometrial tissue, symptoms can include lower back pain, urinary symptoms, or rectal bleeding.

Investigations

The diagnosis of endometriosis may involve a combination of clinical assessment, imaging, and, in some cases, surgical confirmation:

• Clinical History: A detailed history of symptoms, including the nature, timing, and severity of pain, is crucial for suspicion of endometriosis.
• Pelvic Examination: May reveal tenderness, nodularity, or masses, particularly in the adnexal areas or along the uterosacral ligaments.
• Ultrasound: Transvaginal ultrasound can identify ovarian endometriomas but is less effective at detecting superficial peritoneal lesions.
• MRI Scan: Occasionally used for detailed mapping of deep infiltrating endometriosis, particularly when planning surgery.
• Laparoscopy: The gold standard for diagnosing endometriosis, allowing direct visualisation of endometrial implants, adhesions, and cysts. Biopsies can be taken to confirm the diagnosis histologically.

Management

Management of endometriosis aims to relieve symptoms, improve fertility, and prevent disease progression. Treatment options include:

Medical Management

• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Used to manage pain and inflammation.
• Hormonal Therapy:
  • Combined Oral Contraceptive Pill (COCP): Helps regulate menstrual cycles and reduce endometrial tissue growth.
  • Progesterone: Such as norethisterone or the levonorgestrel-releasing intrauterine system (LNG-IUS) to suppress menstruation and reduce symptoms.
  • Gonadotropin-Releasing Hormone (GnRH) Agonists: Used to induce a temporary menopause, reducing oestrogen levels and endometrial growth.
  • Aromatase Inhibitors: Occasionally used in cases of refractory endometriosis.

Surgical Management

• Laparoscopic Surgery: The mainstay for both diagnosis and treatment, where endometrial implants and adhesions are excised or ablated. It is particularly beneficial for those with severe pain or infertility.
• Hysterectomy: In cases of severe endometriosis not responsive to other treatments, hysterectomy (with or without removal of the ovaries) may be considered, particularly in women who do not wish to preserve fertility.

Supportive Management

• Pain Management: Regular use of pain relief, including NSAIDs and opioids if required, along with physical therapy and acupuncture in some cases.
• Fertility Treatment: For women struggling to conceive, assisted reproductive technologies (ART) such as in vitro fertilisation (IVF) may be recommended.
• Psychological Support: Due to the chronic nature of the disease, psychological support, including counselling and support groups, may be beneficial.

When to Refer

Referral to a gynaecologist is warranted in the following situations:

• Suspected or confirmed endometriosis, particularly if associated with severe symptoms or infertility.
• Lack of response to first-line medical treatments, or if the diagnosis remains uncertain.
• Consideration of surgical management, especially if symptoms are severe or fertility is a concern.
• Complex cases, such as those involving deep infiltrating endometriosis or endometriosis affecting non-pelvic organs.

References

1. NHS (2024) Endometriosis. Available at: https://www.nhs.uk/conditions/endometriosis/ (Accessed: 26 August 2024).
2. National Institute for Health and Care Excellence (2024) Endometriosis: Diagnosis and Management. Available at: https://www.nice.org.uk/guidance/ng73 (Accessed: 26 August 2024).
3. British Medical Journal (2024) Endometriosis: Clinical Review. Available at: https://www.bmj.com/content/346/bmj.f2512 (Accessed: 26 August 2024).

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