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CERVICAL INCOMPETENCE

Dr. Kattey k.a(mbbs, mph)

© 2009, Johns Hopkins University. All rights reserved.

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OUTLINE

Introduction

Epidemiology

Historical perspective

Relevant anatomy.

Pathogenesis.

Aetilogy/Risk Factors

Diagnosis.

Treatment & Complications of Cerclage

Conclusion.

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Definition

Cervical incompetence is the inability for the cervix to retain an intra-uterine pregnancy till term as a result of structural and functional defects of the cervix.

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Introduction

• Cervical incompetence not only poses a management dilemma to the modern day obstetrician, but is also a source of anxiety for the couples with recurrent pregnancy wastage.

• Cervical incompetence is the most important cause of recurrent spontaneous midtrimester abortion.

• It is thought to be responsible for approximately 15% of habitual immature deliveries in the 2nd trimester of pregnancy.

Introduction (Cont’d)

• In this condition, the cervix begins to dilate (and not by initiation of contractions), and there’s inability to hold the weight of the pregnancy, leading to bulging of the amniotic membranes into the vaginal canal rupture fetal loss/ preterm birth.

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Epidemiology

• It is estimated that cervical incompetence will complicate anywhere from 0.1% to 2% of all pregnancies.

• Some authors say1% of all pregnancies, and up to 8% of pregnancies with a history of recurrent 2nd trimester loss.

• Ikimalo JI, Izuchukwu KE, Inimgba N (Afr J Reprod Health; Sept 2012) found an incidence of 0.17% of ante-natal patients in UPTH, 2004-2008.

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Historical Perspective

• One of the 1st recorded references was by Cole/Culpepper, who in

1658 described that ‘the orifice of the womb is so slack that it cannot

rightly contract itself to keep in the seed’.

• Gream in 1865 noted that dilatation/division may be contributory. He

published the term cervical incompetence in the Lancet.

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• Palmer & Lacomme in1948 in the U.K described the gaping internal os.

• Lash AF and Lash SR (Am J Obstet Gynecol, 1950) described the incompetent internal os and

the surgical procedure.

• V.N Shirodkar, an Indian, in 1955, reported the 1st successful surgical procedure performed

during pregnancy for cervical incompetence.

• McDonald, an Australian, in 1957, described the much simpler purse-string cerclage technique.

• Hefner in 1961, described the Wurm’s procedure.

• Benson & Durfee in 1965 advocated for abdominal approach in pregnant women.

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AnatomyHistologically, the cervix contains fibrocollagenousstromal tissue.

Anatomically,

-Internal os: the opening of the cervix into the body of uterus.

-External os – its size and shape varies widely with age, hormonal state, and whether the woman has had a vaginal birth. In nonparous women it appears as a small, circular opening. Versus being fish mouthed (meaning wider, more slit-like and gaping) in parous women.

In pregnancy, the normal cervical length is 4 + 1cm.

Pathogenesis

•The function of the cervix during pregnancy depends on the regulations of connective tissue metabolism.

•Collagen is the principal component in the cervical matrix, others are: (proteoaminoglycans, elastin and glycoproteins, like fibronectin).

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Pathogenesis (Cont’d)

The biochemical events implicated in cervical ripening are:1. Decrease in total collagen content, 2. Increase in collagen solubility and 3. Increase in collagenolytic activity.

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Pathogenesis/ Aetiology

The cervical competence is a specific entity involving not just an abnormality or defect of cervical collagen, but is also due to either:

1. Absence of the usual cervical musculature in cases of congenital cervical incompetence, or

2. Injury or damage to the cervical musculature caused by previous trauma.

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Aetiology

- Unknown, Congenital and Acquired.- Congenital causes include:

- congenital mullerian duct abnormalities (e.g. septate uterus, bicornuate uterus)

- Connective tissue disorder (Ehlers-Danlos syndrome)- DES exposure in utero

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• Acquired causes include:Surgical trauma

Cone biopsy or loop electrosurgical excision procedures Repeated forced cervical dilatation asso. with 2nd trimester D&C Previous Manchester repair with cervical amputation.

Obstetric injuries Compression necrosis of the cervix due to prolonged 2nd stage of labor Spontaneous and iatrogenic cervical laceration (e.g. Duhrssen’s

incision) Extension of the uterine incision into the cervix during CS

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Diagnosis

• Based on history, symptoms and investigations.

• Strongest evidence for diagnosis of CI is lack of any other causes for recurrent pregnancy loss (e.g. chromosomal abnormalities, infection, endocrine disorders, immunologic disease).

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DIAGNOSIS

HISTORY

• Classical presentation:-Recurrent mid trimester miscarriage-painless cervical dilatation-Rupture of membranes/expulsion of fetus

• Preterm delivery• Elicit other predisposing factors• Diagnosis based on history is retrospective• One classical hx may also be suggestive

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Diagnosis

• EXAMINATION• may find cervix open with bulging membrane

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Investigations (non-pregnant)

• Easy passage of a size 8 Hegar’s/Pratt’s dilator number 15-17

• Foley’s catheter traction test - size 16 F balloon filled with 1ml of water (6mm)

• Hysterosalpingography- dilated internal os > 8mm /widened isthmus( funnel/ Inverted Bishop’s cap)

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Investigations (pregnant)• Weekly or forthnightly cervical assessment- softening

effacement and dilatation.

• Serial ultrasound assessment of the lower uterine segment and cervix.

• Cervical stress test usually done at 15 –24 weeks (increasing transfundal intrauterine pressure while monitoring cervical length and the appearance of funnelling).

• This test is currently recommended for patients with suspected features of incompetent cervix, undergoing ultrasonography.

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ULTRASONOGRAPHY

• Ultrasound is the best technique to measure the cervical opening or the length of the cervix.

• It provides an objective and reproducible method of measuring the length of the cervix

• Transabdominal (requires full bladder)

• Transvaginal (more accurate)

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USS

Transvaginal ultrasound preferred to Transabdominal ultrasound

-empty bladder- Identification of anatomical landmarks of the external and internal os

TECHNICAL DIFFICULITIES1.Cervix may be falsely normal if the bladder is over distended

2.Increased intrauterine pressure may give false impression of incompetence

3.Transducer angulation and pressure- artificial distortions

4. Contraction in the lower uterine segment can give a false impression.

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Transvaginal Ultrasonography Findings• ‘funneling’ of the internal cervical os (at rest or particularly in respond to

transabdominal pressure on the uterine fundus) is the ultrasonographic appearance of cervical incompetence.

• length of the cervical canal: <2.5cm – risk

• diameter of the internal os:>15 mm in the 1st trimester and > 20mm in the 2nd trimester

• protrusion of the fetal membranes through the os

• presence of fetal parts in the cervix or vagina

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Transvaginal Sonography

• Funneling specifically refers to the separation of the internal os from the two sidewalls of the upper end of the cervical canal.

• A normal sagittal view of the cervix shows a “T” shaped endocervical canal vs. deviations such as Y, V, U.

• Y= initial effacement and subsequent V, U visualized on progressive endocervial change and cervical shortening.

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Ultrasonographic findings

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Transvaginal Sonography

• TVS in contrast to HSG, is Non-invasive Repeatable over time Can be performed during pregnancy

• Negative USS can not exclude CI

• Positive USS during routine screening in pregnant women without history of pregnancy loss do not necessarily place them at risk, but close follow up is required.

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Investigations (Cont’d)

• In some situation it may be necessary to conduct test to exclude other causes of recurrent pregnancy losses-

-Diabetes mellitus -Thyroid dysfuntion -Lupus anticoagulant -Chromosonal anomalies -Cervical infection

• The role of magnetic resonance imaging- cost prohibitive

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TREATMENT

SURGICAL /MEDICAL/CONSERVATIVE

SURGICAL-Cerclage procedures-Bridging procedure-Repair procedures-Scarification procedures

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CERVICAL CERCLAGE

• Evidence-based procedure that reduces perinatal and maternal morbidity and mortality arising from cervical incompetence.

• The success rate can be high (80-90%) when done early in pregnancy.

• Following cervical cerclage in UPTH, miscarriage rate was 9.4%; preterm delivery occurred in 21.8% while term pregnancy occurred in 68.8% of the women. (Ikimalo JI, Izuchukwu KE, Inimgba N (Afr J Reprod Health; Sept 2012)

• Usually done prior to 18 weeks, but after 13 weeks. Many say between 14-16 weeks.

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Source: BMSH Gynecology Operation Records 2012

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CERVICAL CERCLAGE

INDICATIONS FOR CERCLAGE• Suspected/confirmed cervical incompetence remains the only acceptable indication

for cervical cerclage.

CONTRA-INDICATIONS

• Uterine contractions

• Uterine bleeding

• Chorioamnionitis

• Premature rupture of membranes.

• Fetal anomaly incompatible with life.

CERVICAL CERCLAGE PROCEDURESCurrently, there are five different techniques for performing

cervical cerclage:

1. McDonald procedure.

2. Shirodkar operation.

3. Wurm procedure (Hefner cerclage).

4. Transabdominal cerclage .

5. Lash procedure .

• The two most common are the McDonald and Shirodkar.

CERVICAL CERCLAGE PROCEDURES1. McDonald procedure

Most commonly used in this centre

In Lithotomy position cervix is visualized using a Sim’s speculum

The anterior and posterior lips held with sponge holding forceps

The junction between the anterior vaginal rugose and smooth cervical mucosa is identified- internal os

Placement of the suture is done just below this point

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McDonald procedure (Cont’d)

Four bites in the substance of the cervix are taken circumferentially purse string

First bite taken just before 12 o’clock and last just after 12 0’clock

The needle removed and the knotted up to four times with the knot left 2-3 cm long

Success rates 85%-95%

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MacDonald Procedure

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Shirodkar Technique

Developed in 1955

Vaginal approach to the cervix

Involved placement of a nonabsorble suture such as fascia lata, silk, nylon or mersilene tape around the cervix at the internal os.

-The suture lies completely beneath vaginal and cervical mucosa

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Shirodkar Procedure

The junction between the anterior vaginal wall rugose with the smooth cervical mucosa is identified.

Transverse incision 2cm long is made at the junction and the bladder bluntly dissected until the uterovesical peritoneum is identified.

An atraumatic needle is passed submucosally in the cervix postero-anteriorly and knotted

The vaginal mucosa thereafter sutured anterioposteriorly

Shirodkar Procedure

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• Original idea was to leave stitch in situ and opt for caesarean section

• Modified Shirodkar: the delivery does not necessarily have to be by cesarean, nor the suture left intact.

• Success rates 80%

Shirodkar and MacDonald

• Both the McDonald and Shirodkar cervical sutures are equally effective as a vaginal

approach to cervical cerclage.

• McDonald suture is generally easier to perform with no major difference in success.

• Both initially started suturing with catgut, but Shirodkar turned to fascia lata and

McDonald turned to silk as they realized the importance of a permanent cervical

support.

• One significant difference since then has been the present day use of Mersilene tape

as the suture material.

Wurm procedure

• The Hefner cerclage, also known as the Wurm procedure, is used for later diagnosis of the incompetent cervix.

• 1st described by Rogers Wurm.

• It is usually done with a U or mattress suture, and is of benefit when there is

minimal amounts of cervix left.

• Done after dislocation of a previous cerclage, partial cervical dilatation and partial effacement

• Mattress sutures are placed at 12 & 6 o’ clock position and 3 & 9 o’clock position

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Trans abdominal cerclage

• Developed by Benson and Durfee in 1965

• Post conception/preconception

• Abdomen entered via a midline or Pfannenstiel’s incision

• Cerclage stitch inserted at the cervico isthmic level via avascular window in the board ligament

• Delivery is by abdominal route

• Method preserved for patients with extremely short cervix, previously failed vaginal cerclage

• Can be done via laparoscopy

LASH PROCEDURE

• Lash believed there is a structural defect in the anterior cervix at the time of spontanous abortion.

• performed in non-pregnant state

• wegded shaped segment of the area of defect is removed above the internal os

• remaining area is sutured with chromic catgut in two layers.

• permanent and requires CS

• success rate as reported by Lash and Lash 86%

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CERVICAL CERCLAGE (Cont’d)

• Cerclage can be

1. Prophylactic (Elective) cervical cerclage.

2. Emergency (Salvage) cervical cerclage .

Preoperative evaluation.

• Cerclage should generally be delayed until after 14weeks so that early abortions due to other factors will be completed.

• Obvious cervical infection should be treated,

cultures for gonorrhea, chlamydia, and group B streptococci are recommended

• Sonography to confirm a living fetus and to exclude major fetal anomalies

A. PROPHYLACTIC/ELECTIVE CERCLAGE • A planned cerclage placement after history, examination and

investigations have been done.

• It may be placed prior to pregnancy, but is more commonly

placed between 14 -16 weeks’ gestation.

• The stitch is usually removed around 37 weeks or at the

onset of labour.

B. EMERGENCY CERCLAGE (Cont’d) Refers to placement of a cerclage in the setting of significant cervical dilatation

and/or effacement prior to 28 weeks’ gestation and in the absence of labor. Preserved for patients without classical features incompetence.

Patient experiencing features of incompetence in an index pregnancy: prolapse of membranes, cervical dilatation and effacement

Success rate lower than that of elective.

Higher incidence of infection

Prolonged hospital stay

The prognosis is influenced by the gestational age at the time when the suture is placed.

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The bulging membrane during emergency cerclage• Obstetrician may be confronted with a bulging membranes during emergency cerclage

• Management options • insertion of a foley’s catheter with 20ml balloon with the distal cut end inserted into the cervical

canal and inflated.

• pre cerclage amniocentesis to remove sufficient fluid to reduce the bulging membranes can be helpful.

• overfilling the bladder with 1,000 ml of saline may help by elevating the membranes out of the

operative field.

• use of 6-10 stay stitches attached to the edges of the cervix with the patient in deep trendelenburg position. Traction pushes back the membrane

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Preoperative Preparation

• Vigorous preparation with use of chemical antiseptics should be discouraged

• Copious irrigation of vagina under direct vision normal saline or ringer’s lactate. Povidine iodine preparation also advised.

• Microbial culture- cervical/urine culture

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Anaesthesia

• Various forms of anaesthesia had been used• Inhalational, spinal and general anaesthesia.• Different views• opponents of GA –excessive coughing • Proponents of inhalational anaesthesia

- relaxation of the uterus

Post-operatively,

• Antibiotics-cefoxitin, amoxicillin, ampicillin and clindamycin, erythromycin.

• Tocolytics -controversial except for patients with uterine irritability.

• Bed rest advised for the 1st 24 hours followed by mobilization and activity

• Discharge after a couple of days advised - studieshave found no benefit for staying more than one week.

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Removal of cerclage

• Timing: usually b/w 37-38 weeks

• Earlier removal-excessive vaginal bleeding -intrauterine fetal death-persistent uterine contraction-Rupture of fetal membranes

-chorioamnionitis

COMPLICATIONS OF CERCLAGE.

EARLY COMPLICATIONS

• Infections (Chorioamnionitis, Vulvovaginitis• Bleeding • Anaesthetic complications• Accidental rupture of fetal membranes• Premature labour• Maternal death in the presence of sepsis due to prom• Deep cervical laceration• Puerperal pyrexia• Urinary tract infection• Cervical amputation.

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COMPLICATIONS OF CERCLAGE (Cont’d)LATE COMPLICATIONS

• Fistula formation• Cervical stenosis• Scarring- cervical dystocia in labour• Precipitate labour.• Preterm deliveries

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MEDICAL MANAGEMENT

• Hodge pessaries-developed by Vitsky in 1961-properly placed pessaries can cause cervix to

point posteriorly-alleviate some of the direct pressure on the

cervix-prevent descent of the fetal head-best results obtained if inserted at 14 weeks -success rate 92%-removal not later than 38 weeks

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MEDICAL MANAGEMENT (Cont’d)

• Baylor Balloon-Proposed in 1972-Double silicon plastic cuff inserted on

cervix to act as cuff.

• Progesterone-Reduces uterine tone-Studies by Sharma showed a 92% success rate when it used alone compared to 82% with surgery and 47% -surgery alone

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Advice at discharge

• Avoid coitus• Avoid insertion of any substance into vagina• Gradually resume normal activity but avoid

strenuous activity• Report any increased vaginal discharge, vaginal or back pressure or pelvic cramps• Drainage of liquor, Vaginal bleeding.• Persistent uterine contraction.• Reduced or absent fetal movement. • Follow routine antenatal clinic attendance but may need to be examined

forthnightly to determine the integrity of the cerclage

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Conservative Management

• Suspicion of cervical incompetence without classical signs

• Admit into the ward

• Regular forth nightly ultrasound for assessment of cervical effacement and cervical length.

• Procedure discontinued in the event of evidence of CI(cervical internal os diameter on

• Uss=>15mm 1st trimester, 20mm 2nd trimester, Cervical Length<2.5cm,bulging membrane).

CONCLUSION

Recurrent miscarriages may

increase psychological strain on

couples, and may even lead to

broken marriages and

relationships. It is thus

important to pay attention to

the issue of the incompetent

cervix.

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