Endometriosis Overview and Risk Factors

Definition

• Endometriosis is the presence of endometrial tissue (glands and stroma) outside the uterus.

Risk Factors

• First-degree relatives have a 6 times higher risk of endometriosis.
• Early menstruation (before age 11) increases risk.
• Shorter menstrual cycles (less than 27 days) increase risk.
• Heavy menstrual periods (lasting over 7 days) increase risk.
• Nulliparity (never having given birth) increases risk.
• Obstruction of menstrual flow (Müllerian anomalies) increase risk.

Pathophysiology

• Under hormonal influence, endometrial tissue outside the uterus thickens, breaks down, and bleeds each month.
• Trapped blood forms cysts.
• The trapped blood irritates surrounding tissue, causing scar tissue and adhesions.
• This can lead to infertility and pain.

Pathogenesis (Theories)

• Sampson's theory (Retrograde menstruation): Menstrual blood flows backward through fallopian tubes, implanting endometrial tissue in pelvic organs. This theory only explains pelvic endometriosis.
• Meyer and Ivanoff theory (Coelomic metaplasia): Chronic irritation of pelvic peritoneum by menstrual blood causes metaplasia, explaining endometriosis in abdominal viscera, retrovaginal septum and umbilicus.
• Halban's theory (Lymphatic theory): Normal endometrium can metastasize to pelvic lymph nodes through lymphatic channels.
• Vascular theory: Endometriosis can occur in distant sites like lungs or arms.
• Direct implantation: Endometrial or decidual tissues implant in susceptible sites, such as abdominal scars from surgery.

Sites of Endometriosis

• Pelvic: Ovary, cul-de-sac, uterosacral ligaments, posterior surface of the uterus, posterior broad ligament, rectovaginal septum, tubes and round ligaments.
• Extrapelvic (less common): Lungs, thorax, urinary tract, cervix, hernial sacs, umbilicus, laparotomy/episiotomy sites, tubal stumps after sterilization, extremities.

Clinical Manifestations

• Dyspareunia (painful intercourse)
• Dysuria (painful urination)
• Chronic pelvic pain
• Dysmenorrhea (painful menstruation)
• Abnormal menstruation
• Infertility

Physical Examination

• Abdominal examination may not show abnormalities.
• A mass in the lower abdomen might be felt, potentially due to endometriosis lesions.
• Pelvic examination may detect tenderness, nodules in the pouch of Douglas, or bilateral adnexal masses.
• Bluish spots at the posterior fornix during speculum examination might suggest endometriosis.

Diagnostic Tests

• Transvaginal ultrasound (TVS)
• Laparoscopy (the gold standard for diagnosis)
• Serum CA-125 (non-specific marker, higher in severe endometriosis).

Stages of Endometriosis

• Staged using factors like location, number and size of lesions, and depth of the endometrial implants. (Minimal, Mild, Moderate, Severe)

Treatment

• Medical: NSAIDs (first-line for mild dysmenorrhea), OCT (3 months), progestins (DMPA, MPA, NETA), aromatase inhibitors.
• Surgical: Excision of endometrium, adhesions removal, restoration of pelvic anatomy, endometriosis cystectomy (if cyst >5cm), fulguration (ablation of endometriotic deposits), LUNA (laparoscopic uterosacral nerve ablation), and hysterectomy + BSO (optional).