Asherman syndrome are intrauterine adhesions leading to complete or partial obliteration of the uterine cavity. With Asherman syndrome, hypomenstrual syndrome or amenorrhea, algodismenorrhea, violation of childbearing function (miscarriage, infertility) is observed, sometimes a hematometer develops. Asherman syndrome is diagnosed by ultrasound, hysteroscopy, ultrasound-hysterosalpingoscopy, hormonal tests. Treatment consists in hysteroscopic dissection of synechiae, cyclic hormone therapy. The prognosis for subsequent childbearing is due to the severity and prevalence of intrauterine synechiae.
Intrauterine synechiae are connective tissue junctions that solder the walls of the uterus together and cause its deformation. In the presence of synechiae, the normal endometrium undergoes atrophic transformation. Intrauterine synechiae lead to a disorder of menstrual function, create mechanical obstacles to the advancement of spermatozoa, worsen the conditions for implantation of the fetal egg. This leads to the main manifestations of Asherman syndrome – hypomenorrhea, secondary amenorrhea, spontaneous abortions, infertility.
In gynecology, the development of intrauterine synechiae is associated with the effects of infectious, traumatic agents and neurovisceral factors. The most common cause of Asherman syndrome is previous mechanical injuries of the basal endometrium. Endometrial injury may occur due to surgical termination of pregnancy, the use of intrauterine contraceptives, diagnostic curettage of the uterine cavity with uterine bleeding or endometrial polyps, operations on the uterine cavity (myomectomy, metroplasty, conization of the cervix). Damage to the endometrium can be aggravated by the addition of infection during the wound phase with the development of endometritis.
The development of intrauterine fusion can be facilitated by genital tuberculosis, the diagnosis of which is confirmed by endometrial biopsy or bacteriological examination of menstrual secretions. Intrauterine instillations, radiation therapy for tumors of the uterus and ovaries also have a negative effect on the endometrium. Often, the formation of intrauterine synechiae occurs against the background of a previous frozen pregnancy, because the remnants of placental tissues stimulate the activity of fibroblasts and the early formation of collagen before the regeneration of the endometrium.
According to the type of histological structure, there are 3 groups of intrauterine synechiae. Film splices usually consist of basal endometrial cells, are easily dissected by the tip of a hysteroscope and correspond to a mild form of Asherman syndrome. With a moderate degree, intrauterine synechiae are fibrous-muscular, firmly soldered to the endometrium, bleed when dissected. The severe form of Asherman syndrome is characterized by dense, connective tissue intrauterine synechiae, which are difficult to dissect.
According to the degree of involvement of the uterine cavity and the prevalence of intrauterine synechiae, there are 3 degrees of Asherman syndrome. At grade I, less than 25% of the uterine cavity is involved in the pathological process, synechiae are thin, do not spread to the bottom of the uterus and the mouth of the tubes. In the II degree of the disease, synechiae occupy from 25% to 75% of the uterine cavity, there is no adhesion of the walls, there is partial obliteration of the bottom and mouth of the fallopian tubes. The third degree of Asherman syndrome corresponds to the involvement of almost the entire uterine cavity (>75%).
Operative gynecology uses the international European classification of the Association of Gynecologists-Endoscopists, according to which there are five degrees of intrauterine pathology. The classification is based on the data of hysteroscopy and hysterography, taking into account the condition of intrauterine synechiae, their extent, the presence of occlusion in the mouth of the tubes, the degree of damage to the endometrium.
The first degree of Asherman syndrome is characterized by the presence of thin and delicate intrauterine synechiae, which are easily destroyed upon contact, by the free mouths of the fallopian tubes. In the second degree of Asherman syndrome, a dense single spike is detected connecting isolated parts of the uterine cavity; synechiae is not destroyed by contact with the end of the hysteroscope; the mouths of the fallopian tubes are viewed. It is possible to localize synechiae in the area of the internal uterine pharynx with unchanged upper parts of the uterine cavity.
The third degree of Asherman syndrome corresponds to the presence of dense multiple synechiae connecting separate parts of the uterine cavity, and unilateral obliteration of the mouth of the fallopian tube. In the fourth degree of Asherman syndrome, dense extensive intrauterine synechiae, partial occlusion of the uterine cavity and the mouths of both tubes are detected. The fifth degree combines extensive processes of fibrosis and scarring of the endometrium with the phenomena of I or II, III or IV degree of Asherman syndrome, as well as hypomenorrhea or amenorrhea.
Depending on the severity of intrauterine synechiae, hypomenstrual syndrome or secondary amenorrhea may develop. With obliteration of the lower parts of the uterus with functional preservation of the endometrium in its upper parts, the formation of hematometers may be noted.
Significantly pronounced intrauterine adhesions with a lack of functioning endometrium prevent implantation of the fetal egg; obliteration of the tubes makes the fertilization process impossible. Therefore, intrauterine synechiae are often accompanied by miscarriage or infertility. In addition, even the presence of weakly expressed intrauterine synechiae often causes the ineffectiveness of in vitro fertilization.
In most women with Asherman syndrome, menstrual and reproductive dysfunction is preceded by abortions, endometrial curettage, other intrauterine manipulations, endometritis. Gynecological examination data for intrauterine synechiae are non-specific.
Ultrasound of the pelvis in Acherman syndrome is not informative enough; the echoscopic picture may be represented by irregular endometrial cones, in the case of hematometers – an anechoic formation in the uterine cavity. Hysterosalpingoscopy allows to more clearly determine the presence of intrauterine splices.
The most complete picture is presented when performing hysterosalpingography and hysteroscopy. Hysterosalpingography reveals single or multiple filling defects having a lacunoid shape and different sizes. With dense multiple intrauterine synechiae, the uterine cavity on the X-ray looks multi-chambered, with small ducts connecting individual chambers. However, hysterosalpingography is often accompanied by false positive results due to the presence of mucus, curvature, and endometrial fragments in the uterus. With endoscopic hysteroscopy, intrauterine synechiae are defined as whitish non-vascular strands of different densities and lengths connecting the walls of the uterus, obliteration or deformation of the uterine cavity is detected.
Asherman syndrome is characterized by negative hormonal tests – the absence of menstrual-like bleeding in response to the appointment of estrogens and progesterone. In some cases, in the diagnosis of intrauterine synechiae, a Pipel biopsy with a study of tissue samples helps, which eliminates the risks of additional traumatization of the endometrium. The level of gonadotropic and sex hormones is not changed, therefore amenorrhea in Asherman syndrome is characterized as normogonadotropic.
The purpose of therapeutic measures for Asherman syndrome is the minimally traumatic elimination of intrauterine adhesions, restoration of normal menstrual function and fertility. With intrauterine synechiae, the first stage shows the surgical hysteroscopy to dissect adhesions under visual control. The separation of synechiae, depending on their density, is performed by the hysteroscope body, endoscopic scissors, forceps, hysteroresectoscope, laser. To exclude perforation of the uterus, control by ultrasound or laparoscopy is used.
After the surgical stage, a patient with Asherman syndrome is prescribed cyclic hormone therapy with estrogens and progestogens, aimed at stimulating the restoration of the endometrium and its cyclic transformation. The appointment of combined oral contraception with intrauterine synechiae is excluded, since this group of drugs contributes to atrophic changes in the endometrium. With the infectious etiology of Asherman syndrome, bacteriological examination of smears and vacuum biopsy materials is performed, antibacterial therapy is performed.
Prognosis and prevention
Further prospects after transcervical dissection of intrauterine synechiae depend on the extent and prevalence of adhesions, the degree of obliteration of the uterine cavity. Women with intrauterine synechiae of tuberculous genesis have the worst prognosis for the restoration of menstruation and fertility.
After dissection of synechiae, their re-formation is not excluded in the future. After the onset of pregnancy, patients have a high probability of spontaneous termination of pregnancy, frozen pregnancy, placenta previa, premature birth, postpartum complications. If natural conception is impossible, the IVF method of ART is recommended, in which artificial fertilization of the egg is performed. Gestation of the fetus is possible with the help of surrogate motherhood.
Pregnancy management in women with Asherman syndrome requires an obstetrician-gynecologist to take into account all possible risks. The conditions for preventing the formation of intrauterine synechiae are the prevention of abortions, careful and reasonable intrauterine manipulations and operations, timely treatment of genital infections, regular visits to a gynecologist.