When do you use a prophylactic cerclage?

Procedure

1.

Obtain informed consent (see sample patient consent form available atwww.expertconsult.com). The clinician should follow universal blood and body fluid precautions.

Document intrauterine viability.

The patient is brought to the operating room where either general or regional anesthetic is administered. Local anesthesia or a paracervical block should be avoided because of concern for altered uterine blood flow.

Place the patient in the dorsal lithotomy position with feet in candy cane stirrups; prepare and drape in a sterile fashion.

Drain the bladder with a red rubber catheter (a Foley catheter is not necessary).

Place a weighted Graves speculum in the posterior vagina.

Insert a Deaver or right-angle retractor in the vagina to provide adequate exposure; have an assistant hold it carefully to avoid bladder trauma.

Using a ring forceps, grasp the anterior lip of the cervix at 12 o’clock, and displace it superiorly.

Place a stitch at the 6 o’clock position in the midportion of the cervix equidistant from the ectocervix and the vaginal reflection (near the cervicovaginal junction). Place the suture through the midportion of the cervical stroma, being careful not to enter the cervical canal. Sutures that are too shallow may tear out when drawn tight. Be aware of the cervical vascularity (at 3 and 9 o’clock). Direct the needle toward the 3 o’clock position within the cervical tissue.

Proceeding in a counterclockwise manner (clockwise if left-handed), pass the suture to the 3 o’clock position. Remove it from the cervix and then immediately loop it back into the cervix. Pass the stitch to the 12 o’clock position, again, within the tissue itself. Withdraw it and then reinsert in same area. Again, pass the stitch to the 9 o’clock position, withdraw, and reinsert. Finally, pass the stitch to the starting position (6 o’clock) and withdraw the suture (seeFig. 143.1).

Cinch down the suture, similar to a pursestring. Without drawing too tightly (to avoid tissue strangulation), tie it, leaving ends long enough to grasp with ring forceps for removal. By starting at the 6 o’clock position instead of the 12 o’clock position, the patient may have decreased bladder irritation from the suture because the knot rests in the posterior vagina. However, evidence does not support the superiority of this, and starting the stitch at 12 o’clock to place the knot anteriorly may make later removal of the cerclage easier.

Some surgeons prefer to place a second cerclage lower than the first, although no improvement in outcome has been documented. Complications such as membrane rupture or bladder perforation may be more frequent.

The patient then recovers while being placed on a fetal monitor to ensure fetal well-being.

Discharge after a period of adequate observation. Antibiotics are not recommended, and tocolytic agents have no proven benefit.

Complete a postoperative note indicating the type of cerclage placed (McDonald), the suture type, the anesthesia, the location of the suture placement, and the number of knots placed. A diagram is helpful. Place a copy of the operative report in the patient’s medical record.

Cerclage

Cervical cerclage is a purse-string suture of the cervix intended to mechanically prevent cervical dilation. A number of investigators have evaluated the use of cerclage to prevent PTB in women with shortened cervical length, and they have not demonstrated a significant effect (Berghella et al, 2004; To et al, 2004). A more recent trial indicated a significant beneficial effect (adjusted odds ratio, 0.23; 95% confidence interval, 0.08 to 0.66) of cerclage in women with a history of previous SPTB and cervical length less than 15 mm (Berghella et al, 2008; Owen et al, 2009).

Cervical Cerclage

Preterm PROM complicates about one-fourth of pregnancies with a cervical cerclage and one-half of pregnancies requiring an emergent cerclage.38,186,187 Only a single randomized controlled study of cerclage removal after PROM has been performed.188 This study found no improvement in latency (56.3% versus 45.8% delivered within 1 week,P = .59) or newborn outcomes with cerclage retention after PROM. This prospective study is supported by data from retrospective cohorts. The risk for adverse perinatal outcomes does not appear to be different when PROM occurs with a cerclage or without one, provided the cerclage is removed on admission after PROM.189,190

Several small studies comparing pregnancies with preterm PROM in which the cerclage was retained or removed yielded consistent patterns.191–193 No study found cerclage retention after PROM to reduce the frequency or severity of infant morbidities after preterm PROM, and each demonstrated statistically insignificant trends toward increased maternal infectious morbidity with only brief pregnancy prolongation. One study found increased infant mortality and mortality resulting from sepsis with cerclage retention after PROM.191 Another compared different practices at two institutions and found longer latencies with cerclage retention, but this finding could reflect population or practice differences at these institutions rather than the effect of cerclage retention.192

Because cerclage retention after PROM has not been shown to improve perinatal outcomes and there are potential risks related to leaving the cerclage in situ, removal is recommended when PROM occurs, particularly if the indication for initial cerclage placement was not strong. Although deferred removal might enhance pregnancy prolongation for corticosteroid administration, the risks and benefits of this approach have not been determined.

Summary

Cervical cerclage can be performed by multiple methodologies. Sufficient evidence exists to state that the procedure can advance gestational age and reduce mortality. The procedure should be reserved to those with a history of prior preterm birth and premature cervical shortening, those with prior preterm birth and evidence of persistent cervical pathology such as extensive cervical laceration, those with visible membranes in the midtrimester without intrauterine infection regardless of obstetric history, or women with a history of multiple losses characterized by painless cervical dilation. The McDonald cerclage is the simplest intervention to perform and as such, may enhance patient safety particularly in patients with marked cervical shortening, but such a hypothesis is not proven by randomized trials in this population. The Shirodkar cerclage has theoretic advantages for enhancing placement of the supportive suture into the stroma due to direct visualization. Surgeons should be familiar with each of these techniques in order to optimize the approach.

There continues to be a place in modern obstetrics for an abdominal approach to cerclage for cervical insufficiency. Although randomized clinical trials have not validated any of these approaches, the laparoscopic approach with less morbidity has been widely accepted when performed by an experienced laparoscopist. We speculate with continued experience and evolving technology, the RALS approach will be the procedure of choice for abdominal cerclage placement for both interval and current pregnancies at 11 to 13 weeks, with traditional laparotomy being reserved for later placements.

Cervical Incompetence and Cervical Cerclage

Cervical incompetence is defined as the inability to support a full-term pregnancy because of a functional or mechanical defect of the cervix.80 It is characterized clinically by acute painless dilation of the cervix usually in the mid-trimester, culminating in prolapse and/or PPROM with resultant preterm delivery. This occurs in 0.5% to 1.0% of all pregnancies, with a recurrence risk of 30%.2,9Functional failure of the cervix is premature cervical ripening (shortening and dilation normally occurring at the end of gestation) and most often is related to urogenital or intrauterine infection or inflammation and thus has a low risk of recurrence.Mechanical failure of the cervix, defined as a defect in the structural integrity of the cervix, may result from traumatic injury to the cervix, including cervical laceration, amputation, conization, excessive cervical dilation before diagnostic curettage, or therapeutic abortion.2 It may also be associated with DES in utero or uterine malformations. Serial cervical shortening in the second trimester and a positive response to fundal pressure may be used to unmask specific cervical mechanical incompetence during pregnancy.48,49,53

Certain nonsurgical approaches, including activity restriction, bed rest, and pelvic rest have not been proved to be effective for the treatment of cervical insufficiency.81,82 These patients may benefit from the placement of acervical cerclage, a suture used to reinforce the structural integrity of the cervical canal.

Indications for cerclage include83:

History indicated (prophylactic) cerclage: in patients with unexplained second-trimester delivery in the absence of labor or abruptio placentae. Three randomized controlled trials have reported on the efficacy of this approach; two found no significant improvement in outcomes84,85 and one found fewer preterm deliveries before 33 weeks in the cerclage group.86

Physical examination indicated (“rescue”) cerclage: in patients presenting with advanced cervical dilation in the absence of labor or abruptio placentae. Limited data from one small randomized trial and retrospective studies have suggested the possibility of benefit from cerclage placement in these women.83

Sonographic finding of a short cervix (<25 mm) before 24 weeks of gestation in patient with singleton pregnancy and prior history of PTB less than 34 weeks of gestation.

Cerclage

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Cervical cerclage limited to 2nd-trimester pregnancies almost always before viability

Indications: Prophylactic, US indicated or rescue

Placement: Vaginal or abdominal

Transvaginal cerclage suture placed as cranial as possible for longest CL, removed at 36-38 weeks

McDonald: Pursestring or cloverleaf configuration

Shirodkar technique aims for higher placement on cervix

No proven difference in efficacy

No improvement in outcome with placement of additional stitch

Transabdominal cerclage (TAC) placed around lower uterine segment; cesarean delivery required

If transvaginal cerclage not possible or prior failure

Congenital or surgical short cervix

Scarred or lacerated cervix

TAC outcomes equivalent for open and laparoscopic placement

If prior PTB at < 34 weeks + CL < 15 mm, cerclage seems to be effective for prevention of PTB

Also improved neonatal morbidity/mortality

Cerclage not effective for prevention of PTB in patients with short cervix and no prior PTB history

Interaction of cerclage and VP is unclear

Rescue cerclage may prolong pregnancy by 4-5 weeks

2x reduction in PTB prior to 34 weeks

No large randomized trials to prove benefit, therefore, must counsel patients about potential risks

Greater risk of failure when EO > 4 cm or hourglass membranes

Cerclage potentially harmful in multiple gestations

Cerclage monitoring is controversial

American College Obstetrics and Gynecology bulletin says not required

Proponents argue that it helps counsel patients regarding prognosis if signs of stitch failure

Membranes at or beyond level of suture

Slipped/torn suture (usually posterior)

In women with history-indicated cerclage, funneling is independent risk factor for PTB < 34 weeks

Odds ratio 10.6 if membranes to stitch < 15 mm at 18-24 weeks

Cerclage

Results of studies using cervical cerclage to prolong pregnancy in multiple gestations have been disappointing. Prophylactic cerclage has been studied and was found to be ineffective in both twins and triplets. Even in the presence of cervical shortening, no clear benefit of cerclage placement in patients with twins has been demonstrated. Newman and coworkers100 prospectively followed 147 twin pregnancies in women who underwent transvaginal ultrasonographic CL measurements between 18 and 26 weeks' gestation. Cerclage was offered to all 33 women with a transvaginal cervical length of 25 mm or less, and a cerclage was placed in 21 women. No differences were reported between the cerclage and no-cerclage groups with regard to length of gestation, birthweight, delivery before 34 weeks, PPROM, or VLBW. A 2005 meta-analysis of ultrasound-indicated cerclage found that in the subgroup with twins, cerclage placement was actually associated with a statistically significant increase in birth before 35 weeks (75% vs. 36%).101 Because cerclage is a surgical procedure that may be associated with adverse sequelae for both the mother and her fetuses, it is recommended that cerclage placement in multiple gestations be restricted to women with either a strongly suggestive history of cervical insufficiency or objectively documented cervical insufficiency based on physical examination. Neither prophylactic nor ultrasound-indicated cerclage are of benefit in multifetal gestations.

Cervical Cerclage

PPROM is a common complication after cervical cerclage placement, and it affects about one in four elective cerclages and half of emergent procedures.95 Retrospective studies reveal that perinatal complications are similar to PROM without a cerclage if the stitch is removed on admission.96 A single randomized controlled study of cerclage removal after PROM was discontinued when futility calculations determined that the power of the study would not be met. The investigation revealed no improvement in latency (56.3% vs. 45.8% delivered within 1 week, P = .59) and no improvement in newborn outcomes with cerclage retention. Despite being 1.7-fold more common in the study population, cerclage retention was not significantly associated with more frequent chorioamnionitis (41.7% vs. 25%, P = .25).97 Retrospective studies that compared stitch removal and retention after PPROM have been small but have yielded consistent patterns.98,99 Each has found insignificant trends toward increased maternal infections and only brief pregnancy prolongation; one study noted increased infant mortality and death due to sepsis when the cerclage was retained after PROM.98 Because no well-controlled study has found cerclage retention to improve newborn outcomes after PROM, early cerclage removal is recommended when PROM occurs. The risks and benefits of short-term cerclage retention during antenatal corticosteroid are unknown.

Cerclage and Preterm Premature Rupture of Membranes

Classic obstetric dogma has suggested immediate removal of the cervical cerclage stitch when preterm PROM occurs. Risks associated with the retained stitch include maternal infection from bacterial proliferation emanating from the foreign body and cervical lacerations consequent to progression of labor despite the retained stitch. Small retrospective studies have shown conflicting results. At present, there are not enough data in the literature to recommend removal or retention of the suture. If there is no evidence of IAI or preterm labor in very premature gestations, one could consider leaving the stitch in during corticosteroid administration while there is uterine quiescence [296–300].

Cerclage and Preterm Premature Rupture of Membranes

Classic obstetric dogma has suggested immediate removal of the cervical cerclage stitch when preterm PROM occurs. Risks associated with the retained stitch include maternal infection from bacterial proliferation emanating from the foreign body and cervical lacerations consequent to progression of labor despite the retained stitch. Small retrospective studies have shown conflicting results.

Currently, there are not enough data in the literature to recommend removal or retention of the suture. If there is no evidence of IAI or preterm labor in very premature gestations, one could consider leaving the stitch in during corticosteroid administration while there is uterine quiescence. After corticosteroids are maximized after 48 hours, then the stitch might be removed.290,291,292,293,294