Endometriosis is a relatively common disease in the reproductive age women (3-10%) and even more common in the infertility population (20-40%). Endometriosis is defined as the presence of endometrial cells outside of the uterus that can result in pain and infertility.
There are numerous theories to explain how the disease develops. The most accepted one is the drainage of the menstrual debris, cells and blood back into the abdomen and pelvis through the fallopian tubes. Whereas the drainage occurs in most women during their menses, only some women develop the disease. It is difficult to identify those at risk. Genetics play a role in the development of endometriosis, because first degree relatives of affected women are at 6-7 times greater risk of developing endometriosis compared to the general population.
It has been proposed that endometriosis is closely related to a dysfunction in the immune system. Impaired immune response in some women may result in ineffective removal of the endometrial cells from the pelvic area that may result in endometriosis. A number of substances are involves in the pathophysiology of the disease including cytokines, interleukins, TNF and natural killer cells. Exact mechanism of endometriosis pathology is still yet to be determined.
Endometriosis can cause pain by involving the nerves in the pelvic area, causing irregular bleeding into the tissue they are attached to, or by releasing inflammatory substances into the peritoneal-pelvic cavity. Pain can be associated with menses or intercourse. Alternatively, pain can be intermittent or continues depending on the extent and the location of the disease.
Endometriosis can cause infertility by distorting tubal and ovarian anatomy that may result in the prevention of egg capture by the fallopian tubes. It may interfere with early egg and embryo development as well as affect implantation by changing the endometrial receptivity.
Clinical diagnosis of endometriosis is based on the presence of pelvic pain that can present as excessive menstrual pain, pain during intercourse and pain that’s radiating which is dull and sometimes deep and aching. It may radiate to the thighs and legs or present with rectal pressure. Rarely it brings nausea and vomiting as well. Although severity of the disease is thought to correlate with symptoms to a certain degree, patients with advanced disease may not have any symptoms at all, while those with mild disease may have excruciating pain.
Physical examination may reveal certain findings that may suggest the presence of the disease, but generally endometriosis is not reliable and diagnostic. In most cases, the diagnosis of endometriosis is made by exclusion of other causes of pelvic pain. Surgical diagnosis is the gold standard which can include simply the observation of the lesions that are typical for endometriosis or pathological diagnosis from the lesions that can be biopsied or removed during surgery.
A blood test called CA-125 can be elevated in some endometriosis patients, but is not a good test for screening or diagnosis of the disease. It is a cell surface antigen that can be measured in blood and is most useful in patients with certain types of ovarian cancer who are being followed up after treatment. Its use in endometriosis is very limited and routine testing is not recommended.
Pelvic ultrasound or MRI (Magnetic Resonance Imaging) can identify advanced disease involving the ovaries that had resulted in the development of specific type of endometriosis cysts called endometriomas. However, in the absence of ovarian cysts neither one is useful for diagnosis.
Endometriosis is classified into four stages (I-IV) based on the severity of the lesions and adhesions (scarring), which can only be determined by surgery, mainly laparoscopy. Stage I-II are defined as minimal-mild endometriosis and stages III-IV are moderate-severe.
Once the diagnosis of endometriosis is established either clinically or surgically, the treatment options depend on the desire to become pregnant or not. If pregnancy is not planned and the main complaint is pain, medical treatment is typically used as the first line management.
Medical treatment of endometriosis has concentrated on lowering estrogen levels in the body to suppress the growth of old and prevent the development of new lesions. Some of these options are drugs called Danazol, progesterone, birth control pills (BCP) and GnRH agonists (i.e. Lupron type drugs). These drugs are equally effective; no one treatment is the best, as they all have benefits and side effects.
Interestingly, one form of treatment can prove effective when another approach has failed to relieve pain symptoms: BCP. The most commonly used medication is BCP because it is well tolerated and also provides adequate contraception and other non-contraceptive benefits. There is no significant benefit whether medical treatment improves the potential of fertility when it’s discontinued and pregnancy is attempted. In some cases of severe endometriosis, prolonged Lupron treatment may be considered to be beneficial.
Surgical treatment of endometriosis can be the first option in cases of severe pain that is not responsive to medical treatment, presence of endometriosis in the ovaries as cysts (endometriomas), presence of tubal blockage and adhesions with distortion of pelvic anatomy and when symptoms are present in adjacent organs from endometriosis. Surgical treatment also becomes diagnostic in cases in which the diagnosis is made clinically based on symptoms.
Endometriotic lesions can be surgically removed completely or ablated (coagulated, destructed) depending on the location, depth of invasion and severity. Adhesions (scarring) can also be treated during surgery (mostly laparoscopy) and tubal and ovarian anatomy can be restored back to normal. Endometriomas (endometriosis cysts) can also be removed completely with the surgical treatment.
Surgical treatment of endometriosis has been shown to improve both pain symptoms and fertility potential. Patients can achieve a spontaneous pregnancy within the first year after surgical treatment. Those who are not pregnant may need IVF treatment to achieve pregnancy.
In patients who have advanced endometriosis, completed childbearing and not been responsive to medical management, removal of the uterus, both ovaries and the fallopian tubes is the definitive treatment and effective in controlling pain more than 90% of the time.
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