Management of isthmic-cervical insufficiency in pregnancy

In recent years, transvaginal ultrasound examination has been used to monitor the condition of the cervix. In this case, to assess the condition of the isthmic part of the cervix and for prognostic purposes, according to the summary literature data provided by A. D. Lipman et al. (1996), the following points should be taken into account:

• A cervical length of 3 cm is critical for the risk of miscarriage in primiparous women and in women with multiple pregnancies at less than 20 weeks and requires intensive monitoring of the woman, including her in a risk group.
• In women with multiple pregnancies up to 28 weeks, the lower limit of the norm is the length of the cervix, equal to 3.7 cm for primigravidas, 4.5 cm for multigravidas (with transvaginal scanning).
• In women who have given birth to many children, the normal length of the cervix at 13-14 weeks is 3.6-3.7 cm without statistically significant differences between healthy women and patients with isthmic-cervical insufficiency. Isthmic-cervical insufficiency is indicated by a shortening of the cervix at 17-20 weeks to 2.9 cm.
• A cervical length of 2 cm is an absolute sign of miscarriage and requires appropriate surgical correction.
• When assessing the informative value of the length of the cervix, it is necessary to take into account the method of its measurement, since the results of transabdominal ultrasound examination significantly differ from the results of transvaginal ultrasound examination and exceed them by an average of 0.5 cm.
• The width of the cervix at the level of the internal os normally gradually increases from the 10th to the 36th week from 2.58 to 4.02 cm.
• A prognostic sign of the threat of termination of pregnancy is a decrease in the ratio of the length of the cervix to its diameter at the level of the internal os to 1.16+0.04 with the norm equal to 1.53+0.03.

The low location of the placenta and the tone of the uterus significantly influence the changes in the parameters of the cervix discussed above.

It is not enough to diagnose "isthmic-cervical insufficiency" based only on ultrasound data. More accurate information can be obtained only by examining the cervix in mirrors, and by vaginal examination - identifying a soft and short cervix.

Treatment of pregnant women with isthmic-cervical insufficiency

Methods and modifications of surgical treatment of isthmic-cervical insufficiency during pregnancy can be divided into three groups:

1. mechanical narrowing of the functionally defective internal os of the cervix;
2. suturing of the external os of the cervix;
3. narrowing of the cervix by creating a muscular duplication along the lateral walls of the cervix.

The method of narrowing the cervical canal by creating a muscular duplication along its lateral walls is the most pathogenetically justified. However, it has not found wide application due to its complexity, as well as due to the fact that it is unacceptable in cases of pronounced shortening of the cervix, cicatricial changes, and old ruptures.

The method of narrowing the internal os of the cervix is used more widely in all variants of isthmic-cervical insufficiency. In addition, the methods of narrowing the internal os are more favorable, since a drainage hole remains in these operations. When suturing the external os, a closed space is formed in the uterine cavity, which is unfavorable if there is a latent infection in the uterus. Among the operations that eliminate the inferiority of the internal os of the cervix, the most widely used are modifications of the Shirodkar method: the MacDonald method, the circular suture according to the Lyubimova method, the U-shaped sutures according to the Lyubimova and Mamedalieva method. When suturing the external os of the cervix, the Czendi method is most often used, and when narrowing the cervical canal - a modification of the Teryan method.

Indications for surgical treatment of isthmic-cervical insufficiency are as follows:

• history of spontaneous miscarriages and premature births (in the second and third trimesters of pregnancy);
• progressive, according to clinical examination, insufficiency of the cervix: change in consistency, appearance of flabbiness, shortening, gradual increase in the “gaping” of the external os and the entire cervical canal and opening of the internal os.

Contraindications to surgical treatment of isthmic-cervical insufficiency are:

• diseases and pathological conditions that are a contraindication to maintaining pregnancy (severe forms of cardiovascular diseases, liver, kidneys, infectious, mental and genetic diseases);
• increased excitability of the uterus, which does not disappear under the influence of medications;
• pregnancy complicated by bleeding;
• fetal malformations, presence of a non-developing pregnancy according to objective examination data (ultrasound scanning, results of genetic testing);
• III-IV degree of purity of vaginal flora and the presence of pathogenic flora in the discharge of the cervical canal. It should be noted that cervical erosion is not a contraindication to surgical correction of isthmic-cervical insufficiency if pathogenic microflora is not released. In this case, it is advisable to use methods of narrowing the internal os of the cervix. The Czendi method is contraindicated.

Surgical correction of isthmic-cervical insufficiency is usually performed in the period from 13 to 27 weeks of pregnancy. The time of the operation should be determined individually depending on the time of occurrence of clinical manifestations of isthmic-cervical insufficiency. The results of microbiological studies show that with surgical correction of isthmic-cervical insufficiency later than 20 weeks, as well as with prolapse of the fetal bladder at any stage of pregnancy, opportunistic pathogens are sown in large quantities from the cervical canal significantly more often compared to those operated on at 13-17 weeks of pregnancy.

In order to prevent intrauterine infection, it is advisable to perform the operation at 13-17 weeks, when there is no significant shortening and opening of the cervix. As the pregnancy term increases, the insufficiency of the "locking" function of the isthmus leads to mechanical lowering and prolapse of the fetal bladder. This creates conditions for infection of the lower pole by its ascending route - from the lower parts of the genital tract against the background of a violation of the barrier antimicrobial function of the contents of the cervical canal. In addition, the fetal bladder, penetrating into the cervical canal, contributes to its further expansion. In this regard, surgical intervention at later stages of pregnancy with pronounced clinical manifestations of isthmic-cervical insufficiency is less effective.

The following methods of surgical correction of isthmic-cervical insufficiency are proposed:

MacDonald's circular purse-string suture method for cervical closure

Under aseptic conditions, the cervix is exposed using vaginal speculums. The anterior and posterior lips of the cervix are grasped with Muso forceps and pulled forward and downward. A purse-string suture is applied at the border of the transition of the mucous membrane of the anterior vaginal fornix to the cervix, the ends of the threads are tied in a knot in the anterior vaginal fornix. Lavsan, silk, chromium-plated catgut can be used as suture material. In order to prevent tissue cutting when tightening the purse-string suture, it is advisable to insert a Hegar dilator No. 5 into the cervical canal.

Instead of the purse-string suture according to the MacDonald method, a modification by Lysenko V.K. et al. (1973) is used. A nylon or lavsan thread is passed in the submucosal layer of the vaginal part of the cervix at the level of the fornices with a puncture in the anterior and posterior fornices. The ends of the ligatures are tied in the anterior fornix. The submucosal circular arrangement of the thread ensures uniform collection of the cervix around the entire circumference and eliminates slippage of the threads.

Circular seam according to the method of Lyubimova A.I.

The essence of this method is to narrow the isthmic part of the cervix in the area of the internal os using a copper wire thread in a polyethylene sheath, without cutting or repeatedly puncturing the cervix. Under aseptic conditions, the cervix is exposed in mirrors and grasped with Muso forceps. The copper wire in a polyethylene sheath is fixed with four lavsan or silk sutures on the anterior, posterior and lateral walls of the cervix closer to the internal os. The wire is gradually twisted with a clamp. In order not to overtighten the wire and not to cause a disruption in the nutrition of the cervical tissues, a Hegar dilator No. 5 is placed in the canal. The circular suture is placed on the surface of the mucous membrane. Its relaxation is eliminated by simply twisting the wire with a soft clamp. The circular suture is applied when the cervix is sufficiently long and there is no gross deformation.

U-shaped sutures on the cervix according to the method of Lyubimova A.I. and Mamedalieva N.M.

Under aseptic conditions, the cervix is exposed using vaginal speculums. The anterior and posterior lips of the cervix are grasped with Musot forceps and pulled forward and downward. At the border of the transition of the mucous membrane of the anterior layer of the vagina to the cervix, 0.5 cm from the midline on the right, the cervix is pierced with a needle with a lavsan thread through the entire thickness, making a puncture in the posterior fornix. Then the end of the thread is transferred to the lateral fornix on the left, the mucous membrane and part of the thickness of the cervix are pierced with a needle with a puncture in the anterior fornix at the level of the first puncture. The ends of the thread are taken with a clamp. The second lavsan thread is also passed through the entire thickness of the cervix, making a puncture 0.5 cm to the left of the midline. The end of the second lavsan thread is transferred to the lateral fornix on the right, then the mucous membrane and part of the thickness of the cervix are pierced with a puncture in the anterior fornix. The ends of the thread are tightened and tied with three knots in the anterior fornix. A tampon is inserted into the vagina for 2-3 hours.

Modification by Orekhov L.G. and Karakhanova G.V. Teryan method

Narrowing of the cervical canal by creating a muscle duplication along the lateral walls of the cervix. After appropriate treatment, the cervix is exposed in mirrors, the anterior and posterior lips are grasped with Muso forceps and the cervix is pulled forward and downward. At 3 and 9 o'clock, the mucous membrane of the vaginal portion of the cervix is dissected with a longitudinal incision to the fornices (by 2 cm) and separated to the sides by 0.5 cm. A duplication is created from the muscle tissue on both sides by applying 3-4 catgut sutures (without tissue excision). For this purpose, the needle is inserted closer to the edge of the separated mucous membrane, capturing a sufficient portion of the muscle layer to the side and deep. The needle is punctured slightly before reaching the midline. The same needle and thread are used to similarly capture muscle tissue on the other half from the midline. When tying the thread, the muscle tissues captured in the depths protrude, creating a duplication, which contributes to the narrowing of the lumen of the cervical canal. The mucous membrane is sutured with separate catgut sutures. To assess the effectiveness of the duplication, a Hegar dilator No. 5 is inserted into the cervical canal at the time of applying and tying the sutures. If the operation is successful, the walls of the cervical canal tightly cover the dilator.

Treatment of isthmic-cervical insufficiency in case of severe ruptures of the cervix on one or both sides (treatment method proposed by Sidelnikova V.M. et al., 1988).

In case of lateral (or lateral) rupture of the cervix, it is advisable to create a duplicate of the ruptured part of the cervix.

The first purse-string suture is applied using the MacDonald method, starting the purse-string just above the rupture of the cervix. Then the second suture is performed as follows: 1.5 cm below the first circular suture, through the thickness of the cervical wall from one edge of the rupture to the other, a thread is passed circularly along a spherical circle. One end of the thread is pricked inside the cervix into the posterior lip and, having grasped the lateral wall of the cervix, a puncture is made in the anterior fornix, twisting the torn anterior lip of the cervix like a snail. The second part of the thread is pierced through the lateral wall of the cervix and brought out into the anterior fornix. The threads are tied.

Along with operations aimed at eliminating the gaping of the internal os by applying a circular suture, methods of treating isthmic-cervical insufficiency by suturing the external os of the cervix can be used.

The most widely used method is that of Czendi B. (1961). The cervix is exposed in mirrors. The anterior lip of the cheek of the uterus is fixed with soft intestinal clamps and the mucous membrane is excised around the external os by a width of 0.5 cm. Then the posterior lip is fixed and the mucous membrane is excised in the area of the external os by a width of 0.5 cm. After this, the anterior and posterior lips of the cervix are sutured together with separate catgut or silk sutures. A tampon is inserted into the vagina for 2-3 hours.

The Czendi operation is ineffective in cases of cervical deformation and prolapse of the amniotic sac. This type of surgical intervention is inappropriate for cervical erosions, suspected latent infection, and abundant mucus in the cervical canal.

Method of BadenW. et al. (1960): after exposing the cervix in the mirrors, a 1-1.5 cm wide flap is excised in the area of the anterior and posterior lips. The anterior and posterior lips of the cervix are sutured in the anteroposterior direction with separate sutures. The resulting "bridge" prevents prolapse of the amniotic sac. There are openings on the sides for the outflow of the contents of the cervical canal.

Postoperative management in case of isthmic-cervical insufficiency without prolapse of the fetal bladder

In case of cervical surgery using McDonald and Lyubimova methods, U-shaped sutures on the cervix, narrowing of the canal using Orekhov and Karakhanova methods, it is allowed to get up and walk immediately after the surgery. During the first 2-3 days, antispasmodics are prescribed for prophylactic purposes: papaverine suppositories, no-shpa 0.04 g 3 times a day, magne-V6. In case of increased excitability of the uterus, it is advisable to use beta-mimetics (ginipral, salgim, partusisten or brikanil) 2.5 mg (1/2 tablet) or 1.25 mg (1/4 tablet) 4 times a day for 10-12 days. At this stage of pregnancy, the uterus does not always respond to beta-mimetics. In case of increased uterine tone in the second trimester, it is advisable to use indomethacin in tablets of 25 mg 4 times a day, or in suppositories of 100 mg once a day for 5-6 days. For preventive purposes, it is possible to recommend acupuncture, electrophoresis of magnesium with sinusoidal modulated current.

In the first 2-3 days after the operation, the cervix is examined using a mirror, the vagina and cervix are treated with a 3% hydrogen peroxide solution, a 1:5000 furacilin solution, boroglycerin or cigerol (5-6 ml), miramistin, and plivosept.

Antibacterial therapy is prescribed for extensive erosion and the appearance of a band shift in the blood formula, taking into account the sensitivity of the microflora to antibiotics. It is necessary to take into account the possibility of an adverse effect of drugs on the fetus. In this situation, the drugs of choice are semi-synthetic penicillins, which are most widely used in obstetric practice. However, cephalosporins and gentamicin, vilprafen can also be used. Most often, patients are given ampicillin at a dose of 2.0 g per day for 5-7 days. At the same time, nystatin is prescribed at 500,000 IU 4 times a day. In an uncomplicated postoperative period, the pregnant woman can be discharged for outpatient observation 5-7 days after the operation. In outpatient settings, the cervix is examined every 2 weeks. Lavsan sutures are removed at 37-38 weeks of pregnancy. After removing the stitches, a dense fibrous ring is identified on the cervix.

In the case of surgery using the Czendi method or its modification, the pregnant woman is allowed to get up on the 2nd-3rd day after the surgery. The vagina and cervix are treated with a 3% hydrogen peroxide solution, furacilin solution (1:5000), boroglycerin or cigerol, dioxidine, miramistin, plivosept daily for the first 4-5 days, then every other day or depending on the condition of the cervix. Catgut sutures are rejected after 9 days. Silk and lavsan sutures are removed on the 9th day. A scar is determined in the area of the external os with an effective operation.

Antibacterial drugs and beta-mimetics are prescribed depending on the clinical situation, as in the case of surgery with suturing of the internal os of the cervix.

Postoperative management of isthmic-cervical insufficiency with prolapse of the fetal bladder

In case of prolapse of the fetal bladder, the method of choice for surgical correction of isthmic-cervical insufficiency is the method of applying U-shaped sutures. The surgical technique is the same as described above, but the fetal bladder is filled with a wet tampon. Lavsan sutures are carefully applied and, pulling them up, the tampon is carefully removed. After the surgery, bed rest is prescribed for at least 10 days. To reduce the pressure of the presenting part and the fetal bladder on the lower segment of the uterus, the foot end of the bed is raised by 25-30 cm.

Since prolapse of the fetal bladder creates favorable conditions for infection of its lower pole, all pregnant women undergo antibacterial therapy. The antibiotic is selected taking into account the sensitivity of the isolated bacteria to it. During microbiological examination at the time of prolapse of the fetal bladder, associations of 2-3 types of microorganisms are most often detected: Escherichia and enterococcus, mycoplasma and streptococcus group A or B, mycoplasma, Klebsiella and enterococcus.

The most commonly prescribed antibacterial agent is ampicillin at a dose of 2.0 g per day for 5-7 days. It is possible to use third-generation cephalosporins, vilprafen. At the same time, prevention of viral infection activation is carried out: immunoglobulin, viferon, imunofan. The arsenal of antibacterial agents during pregnancy is limited due to the adverse effect of some of them on the fetus. It should be noted that antibacterial therapy often gives a short-term effect. Repeated studies often show a change in some opportunistic bacterial species. Apparently, in conditions of long-term hospitalization against the background of a reduced immunological status, conditions are created that are favorable for the selection of hospital strains of microorganisms. Elimination of some types of microorganisms with the help of drugs creates conditions for the colonization of the biotope not by the usual opportunistic flora, but by hospital strains of opportunistic microorganisms resistant to the drugs used. Simultaneously with antimicrobial agents, immunoglobulin should be used at a dose of 25.0 ml intravenously by drip No. 3 every other day. With a decrease in the IgA level, allergic reactions to immunoglobulin may occur. To reduce allergic reactions, immunoglobulins can be used, such as Octagam at a dose of 2.5 g 2 times with an interval of 2 days. To prevent complications, abundant fluids are prescribed (tea, juices, mineral drinks). Before the introduction of immunoglobulin, it is advisable to administer antihistamines. To normalize immunity, it is advisable to use Immunofan at 1.0 ml intramuscularly once a day for 10 days.

In addition to antibacterial therapy, daily vaginal sanitation, treatment of the cervix with a 3% hydrogen peroxide solution, a 1:5000 furacilin solution, and dioxidine are prescribed. To treat the cervix, you can use syntomycin emulsion, cigerol, boroglycerin, and after 5-6 days - rosehip oil, sea buckthorn, miramistin, and plivosept. To prevent uterine contractions, beta-mimetics are prescribed - ginipral, salgim, partusisten, or brikanil at a dose of 0.5 ml in 400 ml of isotonic sodium chloride solution intravenously by drip, and then switch to a tablet preparation of 5 mg 4 times a day, gradually reducing the dose to 5 mg per day. Treatment is carried out for 10-12 days, while isoptin is prescribed at 0.04 g 3-4 times a day. At the end of tocolytic therapy or if it is necessary to reduce the dose and duration of beta-mimetics, magnesium electrophoresis and antispasmodic treatment are performed. If the uterine tone increases, it is advisable to perform treatment with indomethacin in tablets or suppositories. Patients with this pathology should be hospitalized for 1-1.5 months, depending on the course of pregnancy and possible complications. In the future, outpatient monitoring of the course of pregnancy is carried out: every 2 weeks, the cervix is examined in speculums. The stitches are removed at 37-38 weeks of pregnancy.

The most frequent complication after surgical correction of isthmic-cervical insufficiency using lavsan, silk, and nylon sutures is cutting of the cervical tissue by the thread. This may occur, firstly, if contractile activity of the uterus occurs and the sutures are not removed; secondly, if the operation is technically performed incorrectly and the cervix is overstretched with sutures; thirdly, if the cervical tissue is affected by an inflammatory process.

In these cases, when applying circular sutures according to MacDonald or Lyubimova, bedsores may form, and later fistulas, transverse or circular tears of the cervix. When U-shaped sutures cut through, the cervix ruptures mainly on the posterior lip, where the sutures intersect. In case of cutting through, the sutures should be removed. Treatment of the wound on the cervix is carried out by washing the wound with dioxidine using tampons with cigerol, syntomycin emulsion, rosehip oil, sea buckthorn.

If pathogenic microflora is present in the cervical canal contents cultures, antibiotics are prescribed taking into account the sensitivity of the isolated microorganisms to them. Later, when the cervical wound heals, the operation can be repeated. If repeated surgical correction is impossible, conservative therapy is indicated, which consists of long-term bed rest in a bed with the foot end elevated and the prescription of medications aimed at relieving uterine excitability. The foot end of the bed cannot be raised in case of infection or colpitis.

Non-surgical correction methods

In recent years, non-surgical methods of correction have been described. Various pessaries are used for this purpose. The Golgi ring can be used.

Non-surgical methods have a number of advantages: they are bloodless, extremely simple and applicable in outpatient settings. The vagina and pessary ring should be treated with furacilin and boroglycerin every 2-3 weeks to prevent infection. These methods can be used in functional cervical insufficiency, if only softening and shortening of the cervix is observed, but the cervical canal is closed, if cervical insufficiency is suspected to prevent cervical dilation.

In cases of severe cervical insufficiency, these methods are not very effective. However, a ring pessary and Golgi ring can be used after cervical suturing to reduce pressure on the cervix and prevent more severe consequences of cervical insufficiency (fistulas, cervical ruptures).

Due to the fact that it is often difficult to draw a line between functional and organic isthmic-cervical insufficiency, and also due to the fact that this pathology occurs in patients with hyperandrogenism, in which the level of progesterone is high, we do not use large doses of progesterone to treat isthmic-cervical insufficiency; in addition, it is necessary to take into account the possibility of an adverse virilizing effect on the fetus of large doses of progesterone.

Thus, timely diagnosis of isthmic-cervical insufficiency and rational etiotropic therapy using medicinal and non-medicinal means aimed at relieving the symptoms of threatened miscarriage contribute to prolongation of pregnancy and favorable perinatal outcomes.