CERVICAL CERVICAL INCOMPETENCEINCOMPETENCE

Jeannet E. Canda ,RNJeannet E. Canda ,RN

Cervical incompetence(CI)Cervical incompetence(CI)

It is premature painless dilatation of endocervical canal

in pregnancy the before onset of labor

IncidenceIncidence

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

and is thought to be responsible for approximately 15% of habitual immature deliveries between 16 and 28 weeks of gestation

the etiologythe etiology

In most cases, the etiologyIn most cases, the etiology is is unknownunknown

KnownKnown causes include causes include Congenital Congenital weakness as Mullerian abnormalities weakness as Mullerian abnormalities (cervical hypoplasia, (cervical hypoplasia, in uteroin utero diethylstilbestrol [DES] exposure), diethylstilbestrol [DES] exposure), traumatictraumatic abnormalities (prior abnormalities (prior surgical or obstetric trauma), and surgical or obstetric trauma), and connective tissueconnective tissue abnormalities abnormalities (Ehlers-Danlos syndrome).(Ehlers-Danlos syndrome).

Cervical AnatomyCervical Anatomy Embryologically, the body and cervix of the uterus

are derived from fusion and recanalization of the paramesonephric (Mullerian) ducts, a process that is complete by the 5th month of pregnancy.

Histologically, the cervix consists of fibrous connective tissue, muscle, and blood vessels. Muscular connective tissue constitutes approximately 15% of the cervical stroma, but is not uniformly distributed throughout the cervix, constituting approximately 30%, 18%, and 7% of the upper, mid, and lower thirds of the cervix, respectively (2).

Conversely, the fibrous connective tissue content of the cervical stroma increases as one moves from the external os to the uterine corpus, and it this component that is believed to confer tensile strength to the cervix. Defects in tensile strength are thought to lead to premature cervical dilatation and pregnancy loss.

Despite many advances Despite many advances in modern in modern obstetrics ,there obstetrics ,there remains much remains much controversy regarding controversy regarding the diagnosis and the diagnosis and treatment of cervical treatment of cervical incompetenceincompetence

DiagnosisDiagnosisThere is There is no preciseno precise method for method for

diagnosing CIdiagnosing CIStrongest evidence for diagnosis of CI is Strongest evidence for diagnosis of CI is

lack oflack of any other causes for reccurrent any other causes for reccurrent pregnancy loss eg : chromosomal pregnancy loss eg : chromosomal abnormalities,infection,endocrine abnormalities,infection,endocrine disorders,immunologic disease)disorders,immunologic disease)

WithWith history of consistent with condition history of consistent with condition . - Or + Pre-pregnancy physical findings. - Or + Pre-pregnancy physical findingsUltrasonography isUltrasonography is useful useful as adjunct to as adjunct to

other diagnostic measures other diagnostic measures

history of consistent with history of consistent with conditioncondition

Painless premature cervical dilatation during pregnancy and before onset of labour

a sudden unexpected rupture of the membranes followed by painless expulsion of the fetus

Resulting in repeated mid trimester spontaneous miscarriage or premature delivery

Ultrasonography is Ultrasonography is usefuluseful before cerclage – length of cervical canal , width of

isthmus , funneling of upper part of cervical canal with protrusion of the membranes(when the cervical os (opening) is greater than 2.5 cm, or the length has shortened to less than 20 mm. Sometimes funneling is also seen ) )

After cerclage – determine exact site of cerclage,proximal cervical canal segment length above cerclage ,distal cervical canal segment length below cerclage,internal os diameter ,funneling if present , and protrusion of membranes)Negative U/S can not exclude CI

Positive U/S in routine screen in pregnant women without history of pregnancy loss are not necessary at risk

but close follow up is required

TreatmentTreatment

RESTRESTCERCLAGE or encerclage.CERCLAGE or encerclage.

The alternative to The alternative to cerclagecerclage

strict bed rest, sometimes in the Trendelenburg position.

However, when women with midtrimester membrane prolapse are managed expectantly, preterm prelabor rupture of membranes occur in a great majority of cases.

These women rarely maintain the pregnancy for an appreciable length of time.

There's no guaranteeThere's no guarantee

that a cerclage will prevent a that a cerclage will prevent a pregnancy loss; however, in most pregnancy loss; however, in most instances it will prolong the instances it will prolong the pregnancy, often enabling a woman pregnancy, often enabling a woman to carry to term. You may be at risk to carry to term. You may be at risk for incompetent cervix if you have for incompetent cervix if you have had a previous pregnancy loss in had a previous pregnancy loss in the second trimester, if you have the second trimester, if you have had surgery on your cervix, or if you had surgery on your cervix, or if you have had multiple pregnancy have had multiple pregnancy terminationsterminations

IndicationsIndications Suspected cervical incompetence remains

the only acceptable indication for cervical cerclage. Indications can be classified as follows:

(1) Prophylactic (elective) cervical cerclage (2) Asymptomatic women with sonographic

evidence of cervical shortening and/or funneling may also benefit from cervical cerclage (often called urgent cerclage)

(3) Emergency (salvage) cervical cerclage Cerclage should be delayed until after 14

weeks so that early miscarriage caused by other factors is possible. There is no consensus about how late in pregnancy

1-1- Prophylactic (elective) cervical Prophylactic (elective) cervical cerclagecerclage

Decision to perform cerclage must be made individually for each patient

There's no guarantee that a cerclage will prevent a pregnancy loss; however, in most instances it will prolong the pregnancy, often enabling a woman to carry to term

Once CI has been strongly suggested by combination of history(asymptomatic women with a history of prior pregnancy loss and/or preterm delivery due to cervical incompetence)clinical and U/S suggested findings

Prophylactic cervical cerclage may be placed because the probability of recurrence in a subsequent pregnancy is 15-30%

It may be placed prior to pregnancy, but is more commonly placed between 10 -16 weeks’ gestation.

The stitch is usually removed around 37 weeks and labour ensues fairly rapidly if the diagnosis was correct. Abdominal cerclage requires an elective caesarean section and the stitch is usually left in-situ for future pregnancies.

In order to avoid In order to avoid unnecessary elective unnecessary elective

cerclagecerclage

there is a growing tendency to there is a growing tendency to delay it until evidence of delay it until evidence of cervical changes at ultrasound cervical changes at ultrasound scan appears---- scan appears---- urgent cervical urgent cervical cerclagecerclage..

2 - urgent cervical 2 - urgent cervical cerclagecerclage although the data in this regard is

controversial. There are several retrospective studies suggesting that cervical cerclage in asymptomatic women with short cervical length and/or funneling on endovaginal ultrasound may improve perinatal outcome These studies reported an overall reduction in the incidence of preterm delivery in women identified as having a short cervix by transvaginal sonography before 24 weeks’ gestation and subsequently treated with cerclage to approximately 10% of controls. However, more recent studies suggest that cerclage does not prevent preterm delivery in women at high-risk for preterm birth on the basis of cervical shortening Moreover, one study showed a higher rate of preterm PROM in women who received a cerclage as compared with those without cerclage Further studies are awaited to clarify this issue.

3-3- Emergency (salvage) cervical Emergency (salvage) cervical cerclagecerclage 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.

it is a surgical procedure without proven benefit and with well-defined operative risks. As such, until adequate clinical trials are available demonstrating a clear benefit, emergency cerclage should be used judiciously and only after extensive and comprehensive patient counseling.

achieved fetal survival of 80% with cerclage at a

cervical dilatation of less than 5 cm, and 24% when cervical dilatation was 5 cm or more

Emergency cervical Emergency cervical cerclagecerclage

ContraindicationsContraindications: : 1.1.Uterine contractions. Uterine contractions. 2.2.Uterine bleeding Uterine bleeding 3.3.Chorioamnionitis Chorioamnionitis 4.4.Premature rupture of membranes Premature rupture of membranes

5.5.Fetal anomaly incompatible with Fetal anomaly incompatible with lifelife

Preoperative evaluationPreoperative 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 recommanded

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

For at least a week before and after surgery , there should be no sexual intercourse

More advanced the pregnancy, the more likely surgical intervention will stimulate preterm labor or membrane rupture

Choice of cervical Choice of cervical cerclagecerclage the decision of which technique to use can be left to the decision of which technique to use can be left to

the discretion of the operator.Under certain the discretion of the operator.Under certain circumstances, circumstances,

however, one or other technique may be preferable however, one or other technique may be preferable The most commonly employed techniques are The most commonly employed techniques are performedperformed vaginallyvaginally Shirodkar(itself and modified) and McDonald cerclage ( cerclage ( burried and burried and unburriedunburried )and a )and a transabdominaltransabdominal cervicoisthmiccervicoisthmic approach or Uterosacral cardinal ligament cerclageapproach or Uterosacral cardinal ligament cerclage is is sometimes used For example, if the cervix is very sometimes used For example, if the cervix is very short or lacerated, a Shirodkar cerclage may be short or lacerated, a Shirodkar cerclage may be technically easier to place The transabdominal technically easier to place The transabdominal route is beneficial in treating patients with cervices route is beneficial in treating patients with cervices that are either extremely short, congenitally that are either extremely short, congenitally deformed, deeply lacerated, or markedly scarred deformed, deeply lacerated, or markedly scarred because of previously failed transvaginal cerclage because of previously failed transvaginal cerclage procedures In cases where there has been procedures In cases where there has been extensive cervical trauma or an anatomical defect, extensive cervical trauma or an anatomical defect, this stitch can be used. It is permanent and requires this stitch can be used. It is permanent and requires a cesarean delivery--- a cesarean delivery--- The Lash cerclage. The Lash cerclage.

The Lash cerclageThe Lash cerclage

is the only type that is placed prior to is the only type that is placed prior to pregnancy. In cases where there has pregnancy. In cases where there has been extensive cervical trauma or an been extensive cervical trauma or an anatomical defect, this stitch can be anatomical defect, this stitch can be used. It is permanent and requires a used. It is permanent and requires a cesarean delivery. cesarean delivery.

Shirodkar techniqueShirodkar technique With the Shirodkar technique, the vaginal

mucosa membrane is elevated. A band of homologous fascia or narrow band of some material such as Mersilene is wrapped around the internal os and tied. The vaginal mucosa is then restored to its original position and sutured.

The Shirodkar can be both permanent (requiring a cesarean section) or it can be removed near term. This stitch is started at a 12 o’clock position, worked through the cervix to a 6 o’clock position, ending back in the 12 o’clock position on the other side of the cervix. It is also pulled tightly and tied to keep the cervix closed. How the stitch is tied off determines whether it will be removed or if it is permanent.

Modified ShirodkarModified Shirodkar’’s s techniquetechnique

It is done under general anaesthesia. Cervix is exposed and held with sponge holding forceps. A transverse incision is taken over anterior lip of cervix at junction of portiovaginalis and vaginal rugosity. Bladder is separated and pushed off from area of internal os. With the help of two large curved round body needles ligature of black silk is passed starting from the edge through substance of cervix and taken out posteriorly, perpendicularly. Similar procedure is repeated on other side. Knot is tied posteriorly in the midline keeping it exterior. Anterior incision is sutured by few interrupted sutures using an absorbable material.

This procedure differs from Shirodkar’s encerclage as the needle is not passed submucosally, but through substance of the cervix and no incision is taken posteriorly. The knot is kept exterior to facilitate easy removal of suture.

McDonald techniqueMcDonald technique

a simpler procedure, a non-a simpler procedure, a non-absorbable suture in placed around absorbable suture in placed around the cervix high on the cervical the cervix high on the cervical mucosa mucosa

stitch is weaved in and out of the stitch is weaved in and out of the cervix and pulled tightly and tied to cervix and pulled tightly and tied to keep the cervix closed. keep the cervix closed.

The Hefner cerclageThe Hefner cerclage

when incompetent cervix is diagnosed when incompetent cervix is diagnosed later in pregnancy. It has an added later in pregnancy. It has an added benefit when there is little cervix to benefit when there is little cervix to work with. This cerclage is removed work with. This cerclage is removed closer to term as well. closer to term as well. also know as the Wurm procedure, is also know as the Wurm procedure, is used for later diagnosis of the used for later diagnosis of the incompetent cervix. It is usually done incompetent cervix. It is usually done with a U or mattress suture, and is of with a U or mattress suture, and is of benefit when there is minimal amounts benefit when there is minimal amounts of cervix left. of cervix left.

Transabdominal cerclageTransabdominal cerclage is not frequently performed is not frequently performed is only indicated for those patients with is only indicated for those patients with

previous failed cervical cerclages, shortened or previous failed cervical cerclages, shortened or amputated cervix, and/or deep traumatized amputated cervix, and/or deep traumatized cervixcervix

The surgical techniqueThe surgical technique -- -- caudal reflection of the caudal reflection of the bladder, placement of an encircling A 5mm widebladder, placement of an encircling A 5mm wide mercilene tape medial to the uterine vessels in mercilene tape medial to the uterine vessels in an avascular space above the junction of the an avascular space above the junction of the cervix and the uterine isthmus without cervix and the uterine isthmus without dissection or tunneling among broad ligament dissection or tunneling among broad ligament vesselsvessels above the cardinal and uterosacral above the cardinal and uterosacral ligamentsligaments , and tying of the knot posteriorly. , and tying of the knot posteriorly.

This prevents erosion of the knot into the base This prevents erosion of the knot into the base of the bladder and allows for removal via of the bladder and allows for removal via posterior colpotomy in an emergency situation. posterior colpotomy in an emergency situation.

Most agree that removal of the suture should Most agree that removal of the suture should occur after the woman has completed her familyoccur after the woman has completed her family

ComplicationComplication While these procedures are life-saving, they While these procedures are life-saving, they

also have potential risks: also have potential risks: Premature rupture of membranes (1-9%) Premature rupture of membranes (1-9%) Chorioamnionitis (Infection of the amniotic Chorioamnionitis (Infection of the amniotic

sac, 1-7%) (This risk increases as the sac, 1-7%) (This risk increases as the pregnancy progresses and is at 30% for a pregnancy progresses and is at 30% for a cervix that is dilated more than 3 cms.) cervix that is dilated more than 3 cms.)

Preterm Labor Preterm Labor Cervical laceration or amputation (This can Cervical laceration or amputation (This can

be at the procedure or at the delivery, from be at the procedure or at the delivery, from scar tissue that forms on the cervix.) scar tissue that forms on the cervix.)

Bladder Injury (rare) Bladder Injury (rare) Maternal hemorrhage Maternal hemorrhage Cervical dystocia Cervical dystocia Uterine rupture Uterine rupture

Thank youMam jean