Diagnosis in Canada
According to the SOGC, the gold standard for diagnosisis direct visualization at laparoscopy and histologic study. Disease severity is best described by the appear ance and location of the endometriotic lesions and any organ involve ment.
The American Society for Reproductive Medicine has developed a classification to allow staging of endometriosis at laparoscopy. This type of classification has lim ited utility for clinical management since disease stage may not correlate with the patient’s symptoms. Most communications to health care providers will include a classification of disease as minimal, mild, moderate, or severe, which is described in the ASRM classifica tion system. It is important to appreciate that the diag no sis and descrip tion of dis ease are highly subjective and will vary among prac ti tio ners. Video and image
cap tur ing sys tems allow for objec tive documentation of disease at laparoscopy.
Diagnostic laparoscopy is not required before treat ment in all patients pre sent ing with pel vic pain. Although laparoscopy is considered a minimally invasive procedure, it still carries the risks of sur gery, includ ing bowel and blad der perforation and vascular injury. The over all risk of any complication with laparoscopy, minor or major, is 8.9%.11
Drug Treatment Standards in Canada
Combned Estrogen and Progestin Therapy (Birth Control)
The use of oral contraceptives that combine estrogen and progestin is considered first-line treatment for pelvic pain associated with endometriosis. Surprisingly, although oral contraceptives have been used for years, only a few RCTs comparing their use with other methods of medical mangement have been con ducted. Recently, Harada et al.4 ran domly assigned 100 women with chronic pelvic pain secondary to endometriosis to therapy with a low-dose oral contraceptive or placebo cyclically for 4 cycles.
There was significant relief of heavy bleeding with the oral contraceptives com pared with placebo but no dif - fer ence in relief of non-menstrual pelvic pain.
Oral Progestin Therapy
Estrogen stimulates endometriotic growth. Since oral contraceptives contain both estrogen and progestin, progestins alone have been used for the management of chronic pain in patients with endometriosis.
DEPOT Progestin Therapy
DMPA, injected intra mus cu larly, is widely used world wide for birth con trol and has been stud ied for the relief of endometriosis pain. A subcutaneous formulation of DMPA (104 mg), not cur rently available in Canada, has been investigated in 2 RCTs that compared it with leuprolide acetate depot. Over the 6-month study period, and for up to 12 months there after, DMPA-SC was equivalent to leuprolide acetate in relieving pain. There was some loss of BMD but not as much as in the group receiving leuprolide ace tate with out addback.
Interuterine Progestin-Releasing System
Levonorgestrel, a potent 19-nortestosterone-derived progestin, has been shown to have potent anti-estro genic effects on the endometrium. An avail able LNG-releas ing IUS provides 20 mg/d of levonorgestrel locally in the pel vis, which results in atrophic endometrium and amenorrhea in up to 60% of patients with out inhib it ing ovulation. In recent studies of the LNG-IUS, slightly more than half of
patients with chronic pelvic pain and mild to moderate endometriosis were satisfied or very satisfied with the treatment after 6 months.
Danazol was the predominant medical treatment for endometriosis 2 decades ago. It is an oral “impeded” or weak androgen that is able to suppress gonadotropin secretion and induce amenorrhea. Although effec tive in many cases of pelvic pain related to endometriosis, danazol is associated with androgenic side effects such as weight gain, acne, hirsutism, breast atro phy, and, rarely, virilization.
For women who do not respond to CHCs or progestins or have recur rence of symp toms after ini tial improve ment GnRH ago nist treat ment with HT addback should be considered as second-line treatment. A GnRH agonist should never be used with out HT addback. Any standard HT regimen containing 1 mg of 17b-estradiol or the equivalent should be adequate.
The use of aromatase inhibitors for medical management of endometriosis is still experimental and is based on the observation that endometriotic lesions express the enzyme aromatase and are able to make their own estrogen, even in the absence of gonadotropin stimulation. Two pilot studies examined pain relief after 6 months of daily treatment with an aromatase inhibitor together with high-dose norethindrone acetate or an oral contraceptive. Both showed significant (but not complete) resolution of pelvic pain in women with endometriosis who had not responded
to first-line treatment.
Management of pain associated with endometriosis with targeted medical therapies may require at least 1 cycle to initiate pain relief. For example, GnRH agonist therapy started in the luteal phase or during menses will not prevent dysmenorrhea and may even accentuate pain because of the ini tial flare effect in the first cycle. In this situation, it is appropriate to provide analgesia in the form of NSAIDs or even opioids to make the patient more comfort able until the primary medical management becomes effective.
Surgical Treatment Standards in Canada
Endometriosis should only be surgically treated when either pain or infertility is a presenting symptom. As an incidental finding at the time of surgery, endometriosis does not require any medical or surgical treatment. Suspected ovarian
endometriomas or pelvic masses should be evaluated according to the SOGC guidelines for pelvic masses.
The surgical management of endometriosis involves careful consideration of the indications for surgery, preoperative evaluation, surgical techniques, surgeon experience, and ancillary techniques and procedures.
Surgery may be either “conservative” or “definitive.” Conservative surgical management of endometriosis has the goal of restoring normal anatomy and relieving pain. This approach is most often applied to women of reproductive age who wish to conceive in the future or to avoid induction of menopause at an early age. It may involve direct ablation, lysis, or excision of lesions, interruption of nerve path ways, removal of ovarian endometriomas, and excision of lesions
invading adjacent organs (bowel, bladder, appendix, or ureter).