Cervical Encirclage

Cervical Encirclage

Introduction

Cervical cerclage (tracheloplasty), also known as a cervical stitch, is used for the treatment of cervical incompetence, a condition where the cervix has become slightly open and there is a risk of miscarriage because it may not remain closed throughout pregnancy. Treatment for cervical incompetence by a cervical cerclage, was first described in 1950 by Dr. Lash. 

Principle

A non-absorbable encircling suture is placed around the cervix at the level of internal os. It operates by interfering with the uterine polarity, preventing the internal os and the adjacent lower segment from being taken up.

Purpose

• A woman with an incompetent cervix is 3.3 times more likely to deliver prematurely.
• a previous preterm delivery
• previous second trimester abortions
• previous trauma or surgery to the cervix
• early rupture of membranes
• abnormalities of the uterus or cervix
• exposure as a fetus to diethylstilbestrol (DES), a synthetic hormone

Indications

• Poor obstetrical history — An elective (prophylactic or history-indicated) cerclage is typically placed at the end of the first trimester (12 to 14 weeks of gestation) to prevent recurrence of early preterm delivery.
• Cervical changes on ultrasound — An urgent (ultrasound-indicated) cerclage is performed when cervical shortening is visualized on ultrasound evaluation of the cervix.
• An emergent (rescue, physical examination indicated) cerclage is placed when advanced cervical changes are noted on digital and visual examination.

Contraindications 

• fetal anomaly incompatible with life
• intrauterine infection,
• active bleeding,
• active preterm labor,
• premature rupture of membranes
• fetal demise
• presence of fetal membranes prolapsing through the external cervical os is a relative contraindication to the procedure because the risk of iatrogenic rupture of the membranes is high

Timing of Cervical Encirclage

• The best time for the cervical cerclage procedure is in the third month (12-14 weeks) of pregnancy
• or atleast 2 weeks earlier than the lowest period of previous wastage.
• emergent cerclage is necessary after changes such as opening or shortening of the cervix have already begun. If an emergent cerclage is required, future pregnancies will probably also require a cervical cerclage.

 Removal of cervical encirclage

Generally the suture is removed at the 37th week of pregnancy, but it can be removed before if membranes rupture or at initiation of labour contractions.

 

Types of Cervical Encirclage

• McDonald’s technique
• Shirodkar technique

Mc Donanld’s Circlage

•        The non absorbable suture (Merseline) material is placed as a purse string suture as high as possible at the junction of the rugose vaginal epithelium and the smooth vaginal part of the cervix below the level of the bladder.

•        The suture starts at the anterior wall of the cervix.
•        Taking successive deep bites (4-5 sites) it is carried around the lateral and posterior walls back to the anterior wall again where the two ends of the suture are tied.

Shirodkar’s cerclage

•        Step I: The patient is put under light general anaesthesia and placed in lithotomy position with good exposure of the cervix by a posterior vaginal speculum. The lips of the cervix are pulled down by sponge holding forceps.

•        Step II: A transverse incision is given anteriorly below the base of the bladder on the vaginal wall and the bladder is pushed up to expose the level of the internal os. A vertical incision is given posteriorly on the cervico- vaginal junction
•        Step III: The non absorbable suture (No. 4 braided nylon or Merseline Dacron) material is passed submucously with the help of a cervical needle so as to bring the suture ends through the posterior incision.
•        Step IV: the ends of the suture are tied up posteriorly by a reef knot. The bulging membranes if present, must be reduced beforehand into the uterine cavity. The anterior and posterior incisions are repaired by interrupted stiches using chromic catgut.

 

Other methods of cerclage

• Hefner (or Wurm) cerclage :usually reserved for later in pregnancy when there is little cervix to work with.
• Abdominal cerclage :a permanent stitch performed through an abdominal incision instead of the vagina; reserved for when a vaginal cerclage has failed or is not possible)
• Lash cerclage :a permanent stitch performed before pregnancy because of trauma to the cervix or an anatomical abnormality

Diagnosis

Diagnosis of an incompetent cervix is usually done by medical history or by examination manually during a pelvic exam or by ultrasound scan. Some symptoms of an incompetent cervix used to decide if a cerclage is necessary are:

•cervical dilation
•shortening of the cervix
•funneling of 25% or more
•Women who are more than 4 cm dilated, who have already experienced rupture of membranes, or whose fetus has died are ineligible for cerclage.

 

Patient Preparation

·        A complete medical history will be taken.

·        A cervical exam by a transvaginal ultrasound will be performed.
·        The patient is kept on NPO after midnight before the day of surgery 
·        The patient will also be instructed to avoid sexual intercourse, tampons, and douches for 24 hours before the procedure.
·        Before the procedure is performed, an intravenous (IV) catheter will be placed in order to administrate fluids and medications.
·        Take a consent after explaining to the patient that she may have to stay in the hospital for a few hours or overnight to be monitored for premature contractions or labor.
·        Immediately after the procedure she may experience light bleeding and mild cramping, which should stop after a few days. This may be followed by an increased thick vaginal discharge, which may continue for the remainder of the pregnancy. She may receive medications to prevent infection or preterm labor.

Aftercare

• After the cerclage has been placed, the patient will be observed for at least several hours (sometimes overnight) to ensure that she does not go into premature labor.
• The patient will then be allowed to return home, but will be instructed to remain in bed or avoid physical activity for two to three days.
• Isoxsuprine (Tocolytic) 10mg tablet is given thrice daily to avoid uterine irritability.
• On discharge she is adviced to avoid intercourse, to avoid rough journey and to report if there is vaginal bleeding or abdominal pain.

Report immediately if one or more of the following signs appear:

• Contractions or cramping
• Lower abdominal or back pain that comes and goes like labor pain
• Vaginal bleeding
• A fever over 100 F or 37.8 C, or chills
• Nausea and vomiting
• Foul-smelling vaginal discharge
• Your water breaking or leaking

 Risks

• risks associated with regional or general anesthesia
• premature labor
• premature rupture of membranes
• infection of the cervix
• infection of the amniotic sac (chorioamnionitis)
• cervical dystocia (inability of the cervix to dilate normally in the course of labor)
• cervical rupture (may occur if the stitch is not removed before onset of labor)
• injury to the cervix or bladder
• bleeding

Alternatives for Cervical Encirclage

• Bed rest. The idea of bed rest is to avoid putting unnecessary pressure on the cervix.
• Tocolytics. These are drugs that are designed to stop or delay labor. Ritrodrine, terbutaline, and magnesium sulfate are some common tocolytics.
• Antibiotics. Some infections are associated with a high risk of preterm labor (e.g., upper genital tract infection). Antibiotics may be successful in preventing preterm labor from occurring by treating the infection.