Diagnostics and indications for correction
The main method for identifying the pathology is transvaginal sonography (TVS). Normally, the physician evaluates the state of the external and internal os, as well as the total length of the canal. With the development of ICI, the internal os acquires a V-shape (its depth and width are measured), and the closed part of the canal shortens.
Indications for intervention:
- Shortening of the cervix confirmed by TVS data.
- burdened obstetric history (premature birth or late spontaneous miscarriages).
- Presence of cicatricial deformity of the cervical tissues.
- Psycho-adaptive disorders in the pregnant woman (pronounced fear of recurrent pregnancy loss).
Contraindications to ICI treatment
Surgical and conservative correction is not performed if continuation of pregnancy is impossible or dangerous. Such situations include:
- Severe maternal obstetric or extragenital pathologies.
- Uncorrectable congenital fetal malformations.
- Bleeding at the time of diagnosis (e.g., due to placenta previa or retrochorionic hematoma).
- Acute infectious and inflammatory processes in the lesser pelvis (vulvovaginitis with grade III–IV cleanliness, chorioamnionitis).
- Clinical presentation of threatened miscarriage (increased myometrial tone).
Transvaginal cerclage
The surgery is performed under intravenous or spinal anesthesia. Mandatory conditions for the vaginal approach are an intact amniotic sac and the absence of its pronounced prolapse.
Main techniques:
- MacDonald method. A circular purse-string suture is applied using a strong Mersilene tape. The needle is passed deep into the tissues at the border of the transition of the anterior fornix mucosa onto the cervix. The knot is tied in the anterior fornix, leaving the ends of the sutures long for easy removal prior to delivery.
- Lyubimova–Mamedalieva method. Used in cases of amniotic sac prolapse. The cervix is fixed with bullet forceps, and the sac is gently pushed back past the internal os using a moist swab. Then, a double figure-of-eight (U-shaped) suture is applied, the swab is carefully removed, the threads are tightened, and they are tied in the anterior fornix.
Transabdominal cerclage
This approach (most often laparoscopic) is indicated for patients after cervical excision or conization, when the tissues of the vaginal portion are insufficient for classical suturing. The surgery is performed before conception or at the end of the 1st trimester (12–14 weeks).
Technique: after separating the bladder, the Mersilene tape is passed circularly through a window in the broad ligaments of the uterus strictly at the level of the internal os. The knot is formed anteriorly or posteriorly to the uterus. It is important to pass the ligature through the avascular space: inferior to the uterine artery (a. uterina), medial to the cardinal ligament (lig. cardinale), and superior to the uterosacral ligament (lig. sacrouterinum).
Delivery after such surgery is performed exclusively via planned Cesarean section (or emergency if membranes rupture and labor begins). If the woman plans further pregnancies, the tape is not removed.
Conservative therapy and potential complications
Non-surgical correction consists of the placement of obstetric pessaries. They are inserted into the vaginal fornices or placed directly onto the cervix, closing it, changing the tilt angle, and redistributing the pressure of the fetal presenting part. There are complex-shaped pessaries made of rigid materials and perforated cup-shaped silicone models (Arabin type), whose holes are necessary for the outflow of secretions.
Complications of surgical correction:
- Premature rupture of membranes (PROM).
- Bleeding and fistula formation.
- Tissue necrosis or cutting through by sutures.
- Circular avulsion of the cervix (if sutures are not removed at the onset of labor).
Briefly: answers to topical questions
What methods of transvaginal cerclage are used in obstetrics besides the MacDonald and Lyubimova–Mamedalieva methods?
In addition to the MacDonald and Lyubimova–Mamedalieva methods, Shirodkar's method is used for the surgical correction of isthmic-cervical insufficiency.
- Shirodkar method — placement of a submucosal ("high cervical") suture with dissection of the bladder.
Currently, this method is of mostly historical significance. In modern clinical practice, it is used extremely rarely due to the high invasiveness of the procedure.
At what cervical length in millimeters, according to transvaginal sonography, is ICI diagnosed?
Isthmic-cervical insufficiency is diagnosed when the cervix is shortened to 25 mm or less. The diagnosis is established asymptomatically based on ultrasound cervicometry data at a gestational age of less than 37 weeks. An additional or alternative criterion is the dilation of the cervical canal throughout its length by 10 mm or more. With progressive shortening of the cervix to 15 mm or less (in the absence of contraindications), placement of an obstetric supportive pessary or cerclage is indicated.
What tocolytic drugs are used to relieve increased myometrial tone in threatened abortion against the background of ICI?
To achieve a tocolytic effect after suturing for ICI, indomethacin is used; however, the threat of termination of pregnancy itself (increased uterine tone) is a contraindication to surgical correction of ICI. In general, in case of threatened miscarriage to reduce myometrial tone, the following groups of tocolytics are used:
- β2-adrenomimetics — hexoprenaline, fenoterol, salbutamol, terbutaline, ritodrine.
- Progestogens — hydroxyprogesterone caproate.
- Oxytocin receptor antagonists — atosiban.
- Myotropic antispasmodics — magnesium sulfate.
- CNS depressants — diazepam, enflurane.
To memorize the topography in transabdominal cerclage: the suture passes in the "safe window" — strictly below the uterine artery, but above the uterosacral ligament, bypassing the cardinal ligament laterally.
Class and exam questions
Is vaginal delivery possible after transabdominal cerclage?
No, the presence of uterine sutures after the transabdominal approach is an absolute indication for a planned Cesarean section.
What to do with the Mersilene tape after a Cesarean section if the patient wants more children?
In transabdominal cerclage, the Mersilene tape is not removed; it remains in place to carry subsequent pregnancies.
How to technically place a suture if the amniotic sac has already descended into the vagina?
In such cases, the Lyubimova–Mamedalieva method is used: the amniotic sac is gently pushed back past the internal os with a moist swab, after which a double U-shaped suture is applied.
What else to study on this topic
- Technique of safe bladder separation in laparoscopic cerclage.
- Biomechanism of action of various models of obstetric pessaries (Arabin type and others).
- Management tactics for patients with premature rupture of membranes against the background of placed sutures.
- Assessment of the degree of vaginal discharge cleanliness and sanitation prior to surgical correction.
- Differential diagnosis of the causes of cervical shortening according to transvaginal sonography.
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