Pocket ObGyn – Endometriosis
See Abbreviations
Definition and Epidemiology (Obstet Gynecol 2011;118:69)
- Defined as presence of endometrial glands & stroma outside of nml location in
- Hormonally dependent ® mostly reproductive aged women (6–10 prevalence %).
- Prevalence of 38% in infertile women & 71–87% w/
- Risk factors: Early menarche (<11 yo), menstrual cycles <27 d, heavy & prolonged
- Protective factors: parity, lactation periods, regular exercise (>4 h/w).
Etiology
- Most commonly accepted theory = retrograde menstruation ® attachment of endometrial tissue on Other theories: Bld or lymph transport, stem cells from bone marrow, coelomic metaplasia.
Clinical Manifestations (Obstet Gynecol 2011;118:69)
- Often Common: Dysmenorrhea, CPP, menorrhagia, dyspareunia.
- Pelvic pain described as pain before onset of menses (2° dysmenorrhea), deep dyspareunia (worse during menses), sacral backache during
Diagnostic Workup/Studies (N Engl J Med 2010;362:2389)
- Physical exam findings: Uterosacral ligament nodularity, adnexal mass
- Laparoscopy w/ or w/o bx for histology (gold std). Path: Endometrial glands/stroma w/ varying amts of inflammation/fibrosis. Bld or hemosiderin-laden Bx not req, but definitive.
- Visual appearance: Classical lesions = black powder Nonclassical = red or white.
- No correlation b/w severity of visual dz & degree of pain or prog w/
- No serum markers or imaging studies useful in Imaging studies (MRI, USG) only useful if + pelvic/adnexal mass (chocolate cyst).
- US: Ovarian endometriomas appear as cyst w/ low-level, homogenous internal echoes from old TVUS = imaging of choice to detect deeply infiltrating endometriosis of rectum or rectovaginal septum. MRI rarely req.
Classification
- Numerous schemes ASRM classification most common.Value = uniform recording of OR findings & comparing therapeutic interventions.
- ASRM criteria: Stage I (minimal) ® Stage IV (sev). Based on extent & location of endometriosis lesions seen during operative
Treatment & Medications
- Best treated medically w/ surgical Surgical mgmt reserved for large endometriomas, palpable dz, or infertility (Fertil Steril 2008;90:S260).
Figure 5.2 Management algorithm for endometriosis
Modified from Hoffman BL, Schorge JO, Schaffer JI, et al., eds. Williams Gynecology. 2nd ed. New York, NY: McGraw-Hill; 2012.
- Medical therapy (Fertil Steril 2008;90:S260): Medical suppressive therapies are ineffective for infertility (Int J Gynaecol Obstet 2001;72:263)
NSAIDs: COX inhibs ® ¯ PG synthesis ® ¯ pain & inflammation
OCs: Can be used in cyclic or continuous fashion. Amenorrhea often result of continual therapy, which is often beneficial for pt w/ pain sx.
Progestins: Antagonize estrogenic effects on endometrium ® decidualization ®
eventual endometrial atrophy.
Medroxyprogesterone acetate 20–100 mg PO QD or 150 mg IM q3mo (depot) NETA 5 mg QD, 2.5 mg QD until amenorrhea or ® 20 mg/d max reached Mirena IUD. Unk MOA. Is efficacious, but not approved by FDA for this use.
GnRH agonists: ¯ signaling of HPA-axis ® ¯ estrogen ® amenorrhea & endome- trial atrophy. Nasal spray (nafarelin acetate) or depot formulation (leuprolide acetate) q1–3mo. S/e = menopause sx + ¯ bone density. Add-back therapy w/ progesterone or combo (estrogen/progesterone) used to ¯ s/e. Theory = amt necessary to prevent menopause sx < amt to stimulate endometriosis. Can be started immediately w/ GnRH agonist administration. Does not diminish efficacy of pain relief. Norethindrone acetate (only hormone FDA approved for add-back therapy) 5 mg PO QD w/ or w/o CEE (premarin) 0.625 mg QD ´ 12 mo.
Danazol (600–800 mg QD): Inhibit LH surge ® chronic anovulatory state. Substantial androgenic & hypoestrogenic s/e that limit clinical utility.
Aromatase inhibs: Still investigational. Not definitive therapy.
- Surgical therapy (Fertil Steril 2008;90:S260): Relief of pain after surgical rx = 50–95%. Laparoscopic rx of visible endometriosis improves All visible lesions should be treated.
Conservative Surg (diagnostic laparoscopy, lysis of adhesions, ablation/fulguration of visible implants, normalization of anatomy) = 1° approach for symptomatic or large endometriomas b/c medical therapy will not lead to complete resolution. Cyst excision in endometriomas has improved outcomes over simple cyst drainage.
LUNA: Disrupts efferent nerve fibers in the uterosacral ligaments ® ¯ uterine pain for intractable dysmenorrhea. No benefit > conservative Surg alone.
Presacral neurectomy: Interrupts symp innervation to uterus @ level of superi- or hypogastric plexus. Benefit in midline pain only. Technically challenging w/ sig- nif risk of bleeding. S/e: Constip, urinary dysfxn.
Hysterectomy (TAH/BSO): For those w/ debilitating sx, have completed child- bearing, & failed other therapies. Long-term adherence w/ HRT req to prevent risk of mortality a/w BSO prior to menopause (Obstet Gynecol 2010;116:733). Use estrogen/progesterone therapy d/t risk of unopposed estrogen more likely to cause growth of endometrial implants.
- Surg, followed by medical therapy offers longer sx relief than w/ Surg OC, progestins, GnRH analogs, & danazol have been shown to ¯ pain & time until recurrence (Fertil Steril 2008;90:S260; Hum Reprod 2011;26:3).