Asherman syndrome/Intra uterine adhesions
What is Asherman’s Syndrome?
Asherman Syndrome, or intrauterine adhesions/scarring or synechiae, is an acquired uterine condition, characterized by the formation of adhesions (scar tissue) inside the uterus and/or the cervix. In many cases the front and back walls of the uterus stick to one another. In other cases, adhesions only occur in a small portion of the uterus. The extent of the adhesions defines whether the case is mild, moderate, or severe. The adhesions can be thin or thick, spotty in location, or confluent. They are usually not vascular, which is an important attribute that helps in treatment. Click here for more on Asherman’s Syndrome grades.
Most patients with Asherman’s Syndrome have scanty or absent periods (amenorrhea) but some have normal periods. Some patients have no periods but feel pain at the time that their period would normally arrive each month. This pain may indicate that menstruation is occurring but the blood cannot exit the uterus because the cervix is blocked by adhesions. Recurrent miscarriage and infertility could also be symptoms .
Asherman’s syndrome occurs when trauma to the endometrial lining triggers the normal wound-healing process, which causes the damaged areas to fuse together. Most commonly, intrauterine adhesions occur after a dilation and curettage (D&C) that was performed because of a missed or incomplete miscarriage, retained placenta with or without hemorrhage after a delivery, or elective abortion. Pregnancy-related D&Cs have been shown to account for 90% of Asherman’s Syndrome cases. Sometimes adhesions also occur following other pelvic surgeries such as Cesarean section, surgery to remove fibroids or polyps, or in the developing world, as a result of infections such as genital tuberculosis and schistosomiasis.
There is a 25% risk of developing Asherman’s Syndrome from a D&C that is performed 2 to 4 weeks after delivery. Dilation and Curettages may also lead to Asherman’s Syndrome in 30.9% of procedures for missed miscarriages and 6.4% of procedures for incomplete miscarriages. The risk of Asherman’s Syndrome increases with the number of D&Cs performed; after a single termination the risk is 16%, however, after 3 or more D&Cs, the risk increases to 32%. Each case of Asherman Syndrome is different, and the cause must be determined on a case-by-case basis. In some cases, Asherman Syndrome may have been caused by an “overly aggressive” D&C. However, this is not often considered to be the case. The placenta may have attached very deeply in the endometrium or fibrotic activity of retained products of conception could have occurred, both of which make it difficult to remove retained tissue.
There is a variant of Asherman’s Syndrome called “Unstuck Asherman’s or endometrial sclerosis that is more difficult to treat. In this condition, which may coexist with the presence of adhesions, the uterine walls are not stuck together. Instead, the endometrium has been denuded. Although curettage can cause this condition, it is more likely after uterine surgery, such as myomectomy. In these cases the endometrium, or at least its basal layer, has been removed or destroyed.
Asherman Syndrome is thought to be under-diagnosed because it is usually undetectable by routine diagnostic procedures such as an ultrasound scan. The condition is estimated to affect 1.5% of women undergoing a hysterosalpingogram (HSG), between 5 and 39% of women with recurrent miscarriage, and up to 40% of patients who have undergone D&C for retained products of conception following childbirth or incomplete abortion
Direct visualization of the uterus via Hysteroscopy is the most reliable method for diagnosis. Other methods are sonohysterography (SHG) and hysterosalpingogram (HSG).
Ideally, prevention is the best solution. It was suggested as early as in 1993 that the incidence of intrauterine adhesions (IUA) might be lower following medical evacuation (eg., misprostol) of the uterus, thus avoiding any intrauterine instrumentation. So far, one study supports this proposal, showing that women who were treated for missed miscarriage with misoprostol did not develop IUA, while 7.7% of those undergoing D&C did. The advantage of misoprostol is that is can be used for evacuation not only following miscarriage, but also for retained placenta or hemorrhaging following birth. Alternatively, D&C could be performed under ultrasound guidance rather than blindly. This would ensure that the surgeon stops scraping the lining when all retained tissue has been removed, thereby avoiding injury. Early monitoring during pregnancy to identify miscarriage can prevent the development of, or as the case may be, the reoccurrence of Asherman Syndrome as adhesions are more likely to occur after a D&C the longer the period after fetal death . Therefore, immediate evacuation following fetal death may prevent IUA. There is no evidence to suggest that suction D&C is less likely to result in adhesions than sharp D&C. Cases of Asherman’s Syndrome have been reported even following manual vacuum aspiration, and the rate of Asherman’s Syndrome has not dropped since the introduction of suction D&C.
Asherman Syndrome must be treated by a very experienced surgeon via hysteroscopy (sometimes assisted by laparoscopy) Those few surgeons experienced enough in treating severe Asherman’s Syndrome recommend the avoidance of energy sources inside the uterus (this means removing scars with scissors rather than with energy-generating instruments such as resectoscopes or lasers, although not all surgeons agree with this). Adhesions have a tendency to reform, especially in more severe cases. There are different methods to prevent re-scarring after surgery for Asherman´s Syndrome. Many surgeons prescribe estrogen supplementation to stimulate uterine healing and place a splint or balloon to prevent apposition of the walls during the immediate post-operative healing phase. Other surgeons recommend weekly in-office hysteroscopy after the main surgery to cut away any newly formed adhesions. As of yet, studies have not confirmed the method of treatment that is most likely to have a successful outcome, which would be one where the uterus/cervix remains scar-free and fertility is restored.
Non Reproductive Consequences of Asherman’s Syndrome
The reproductive consequences of Asherman Syndrome, including infertility, recurrent miscarriage, intrauterine growth restriction, placenta accreta and others, are well known. However, for all women with intrauterine scarring and amenorrhea, including those who may have completed childbearing, there are other concerns. Although the lack of menstrual periods could be secondary to hormonal abnormalities, it is more likely caused by either complete destruction of the uterine lining or by obstruction of the cervix or lower portion of the uterus; thus, menses are either retained in the uterus (leading to pelvic pain and a condition called hematometra) or flow into the abdominal cavity leading to endometriosis. Women with Asherman Syndrome may develop uterine cancer, either before or after menopause. This risk is NOT increased and may be lower than in the general population. However, the usual warning sign of uterine cancer is excessive uterine bleeding: those with obstructed menstrual flow cannot have that symptom even if they harbor a uterine growth. Therefore, pelvic ultrasound should be a routine part of their annual gynecologic visit.