Laparoscopic Placement of Cervical Cerclage

Abstract

Cervical shortening is believed to be a marker for generalized intrauterine inflammation and has a strong association with spontaneous preterm birth. A variety of therapies, including vaginal and intramuscular progesterone, pessary, and cerclage, have been demonstrated to be effective in specific clinical circumstances. Cervical cerclage can be placed via transvaginal, open transabdominal, or laparoscopic transabdominal approach, preferably before pregnancy. A laparoscopic approach may be superior to the transabdominal approach in terms of surgical outcomes, cost, and postoperative morbidity.

Although Riverius first described the association between cervical dysfunction and pregnancy loss in 1658,¹ effective therapy to prevent preterm birth has only recently become available. Cervical shortening is believed to be a marker for generalized intrauterine inflammation and has a strong association with spontaneous preterm birth that is inversely related to ultrasonically measured cervical length.^2–5 As such, a variety of therapies, including vaginal^6,7 and intramuscular progesterone,⁸ pessary,⁹ and cerclage,¹⁰ have been demonstrated to be effective in specific clinical circumstances. Yet these therapies reduce the risk of reoccurrence by 30% to 50% at best, leaving a 50% to 70% chance of another spontaneous preterm delivery. There is little guidance regarding how to treat the recidivist patient who has a subsequent preterm birth. This is a particularly important consideration because each preterm delivery increases the likelihood of a subsequent preterm delivery by 50% or more.⁵ One treatment option is to repeat the initial therapy and hope for improved odds the next time around. This is a valid approach at present because there is nothing in the obstetrical literature to suggest otherwise. However, we suggest that women who have had an initial and a second preterm birth in the setting of conventional therapy might consider the placement of laparoscopic transabdominal cerclage. We acknowledge that this procedure is relatively new to the obstetrical armamentarium and, as such, its potential risks as well as benefits must be well understood. However, we believe that it remains a viable alternative to the patient at significant risk for recurrence of preterm delivery.

The idea of suturing the cervix appears an intuitive and logical approach to preterm labor prevention, yet an extended history of failed attempts to prolong gestation in women at risk suggests otherwise. Recent advances in molecular biology and immunology have led to an improved understanding of factors contributing to cervical insufficiency and caused a paradigm shift behind the pathogenesis of this unfortunate condition. Several studies implicated biochemical, immunologic, and inflammatory stimuli affecting cervical effacement and dilation.¹¹ Intrauterine, placental, and potentially systemic inflammation were linked to an increased incidence of cervical insufficiency^12,13 and preterm birth in general.^14–17 Recently, several inflammatory cytokines in both fetal and maternal circulation have been associated with premature labor causes, including some specific for cervical insufficiency.^18,19

In light of the shifting paradigm behind the pathogenesis of preterm birth, additional insight into the mechanisms of inflammation systemically and within the uterus is needed in order to develop an effective means of its prevention and control. The effectiveness of currently available approaches to management of preterm labor should also be reevaluated. Although the precise mechanism of action of progesterone in premature birth prevention is not exactly understood, it is likely due to inhibition of gap junction formation between the uterine myometrial cells resulting in smooth muscle relaxation.²⁰ Recent reports of the immunosuppressive effect of progesterone^21–23 potentially make it an even more appropriate choice for the treatment of preterm labor. At the same time, any mechanical attempts to limit cervical dilation should be considered a last resort. The logic behind this is that cervical insufficiency appears to be far downstream in the causative chain of events leading to delivery of a premature fetus; as such, attempts to reverse the outcomes at this level are much less likely to succeed.

Progesterone

Progesterone prophylaxis is currently recommended regardless of obstetric history if short cervical length has been established as an accidental finding.²⁴ Intramuscular⁸ or vaginal^25,26 administration of progesterone or 17-alpha-hydrohyprogesterone was found to significantly decrease the incidence of preterm labor in several studies. Therefore, it is safely recommended as an initial prophylaxis in women with prior history of premature birth. Progesterone regimen is usually started at 16 weeks or anytime later in pregnancy and continued until 36 weeks of gestation.

Vaginal Cerclage

The effectiveness of cervical cerclage in the prevention of preterm labor remains controversial and appears to depend upon the population studied.²⁷ Evidence accumulated to date supports placement of vaginal cerclage in women with prior spontaneous preterm birth, singleton gestation, and cervical length < 25 mm by transvaginal ultrasound.²⁷ Women with a history of preterm birth should be started on progesterone for prophylaxis at 16 weeks of gestation, and cervical length should be evaluated with transabdominal ultrasound and confirmed on transvaginal ultrasound between 18 and 24 weeks. In patients with the cervical length < 25 mm, placement of vaginal cerclage should be considered. ^28,29 Conflicting evidence exists regarding the efficacy of examination-indicated vaginal cerclage placement.^30–33

Pessary

Compared with cerclage, cervical pessary is a noninvasive, easy, and cost-effective method of premature labor prevention. Originally described 50 years ago, pessary did not gain much popularity in the United States. Several studies,^34–36 including one recent randomized, controlled trial,⁹ established a decreased frequency of spontaneous delivery and lack of serious complications, and emphasized simplicity, safety, and cost effectiveness of pessary placement. At the same time, no comparison to date has been made with other available approaches, such as cerclage. In light of current evidence, cervical pessary appears to be a useful adjunct to cerclage or can be used on its own in women who are not good candidates for cerclage.

Transabdominal Cerclage

Although not a first-line method in the management of preterm birth, transabdominal cerclage (Figure 1) remains a valuable approach to preterm birth prevention if all other methods fail. First described in 1965,³⁷ transabdominal cerclage is indicated in cases of congenital short or absent cervix, amputated cervix, marked cervical scarring, cervical defects, and previous failed vaginal cerclage.^38,39 The transabdominal approach has been associated with success rates of 81% to 100% (Table 1).

Figure 1.

Transabdominal cervicoisthmic cerclage placement. AB, ascending branch of uterine artery; AVCS, avascular space between ascending and descending branches of uterine artery; C, cardinal ligament; DB, descending branch of uterine artery; P, cerclage suture. Reproduced with permission from Kjøllesdal M et al.⁵⁰

TABLe 1.

Fetal Survival Rate Following Transabdominal Cerclage Placement

Study	Patients (N)	Study Design	Reported Fetal Survival Rate (%)
Novy MJ60H	30	Literature review	81
Novy MJ60	20	Prospective cohort	90
Fick AL et al61	88	Retrospective cohort	93
Lotgering FK et al62	101	Prospective cohort	93.5
Groom KM et al63	19	Retrospective cohort	100
Thuesen LL et al64	45	Prospective cohort	100

Potential advantages of transabdominal cerclage include higher placement relative to the level of the internal os, decreased incidence of slippage, and the ability to leave the stitch in place between pregnancies.⁴⁰ Despite high fetal survival rates, transabdominal cerclage needs to be considered carefully because of the potential morbid risks to the mother. It has been associated with complications estimated at 3.4%.⁴¹ During laparotomy, the stitch is placed at the cervicoisthmic junction, a highly vascularized area. Bleeding from parametrial veins with the potential need for blood transfusion has been reported as a possible complication following transabdominal cerclage placement.^37,42–44 In addition to intraoperative complications, women with transabdominal cerclage require cesarean delivery and may potentially require hysterotomy if miscarriage or fetal demise occurs.⁴⁵

Two retrospective cohort studies and one systematic review compared the outcomes following transvaginal versus transabdominal approaches with cerclage placement. In 2000, Davis and colleagues⁴⁶ compared obstetric outcomes of singleton pregnancies in women with prior failed vaginal cerclage; 40 transabdominal and 24 transvaginal cerclage pregnancies were analyzed. The two groups were similar in race and payer status. Patients in the transabdominal cerclage group were older and had more risk factors (prior failed cerclage and spontaneous abortions). The outcomes in the transabdominal cerclage group were significant for increased gestational age at delivery and reduced incidence of preterm delivery and preterm premature rupture of membranes. In a systematic review, Zaveri and associates41 compared 117 women with transabdominal cerclage and 40 women with vaginal cerclage. The transabdominal approach was associated with a lower risk of perinatal death or delivery at < 24 weeks of gestation but a higher risk of serious operative complications (3.4% vs 0%). The most recent retrospective cohort study by Witt and colleagues⁴² included 70 patients who underwent cerclage between 1983 and 2005 at the same institution. The vaginal and transabdominal groups were similar in age, history of diethylstilbestrol exposure, loop electrical excision procedure/cold knife conization, and history of cerclage placement. The transabdominal cerclage group had lower body mass index and fewer nonwhite patients. No difference was found between the two approaches in terms of obstetric outcomes (total pregnancies, miscarriages). The rate of neonatal survival was increased to the same extent following both approaches. In terms of surgical outcomes, vaginal cerclage placement was associated with shorter mean operative time and shorter postoperative hospital stay. No difference was found in estimated blood loss, intraoperative complications, or readmissions, and the incidence of these events was low in both groups.

Laparoscopic Cerclage

Advances in the field of minimally invasive surgery resulted in development of a new approach to cervical cerclage placement. Laparoscopic cerclage offers the benefit of reduced blood loss, reduced postoperative pain, and fewer adhesions, as well as decreased length of hospital stay and overall faster recovery time.⁴⁸ Similar to the transabdominal approach, laparoscopic cerclage can be placed during pregnancy or as an interval procedure. Success rates for laparoscopic cerclage were reported in the range of 76% to 100% (Table 2), which is comparable with fetal survival rates following transabdominal cerclage. Complications of laparoscopic cerclage are similar to those associated with transabdominal cerclage and include uterine vessel bleeding, impaired surgical visibility due to morbid obesity, perioperative pregnancy loss, infection, and thromboembolism.^46,48,49 In addition, erosion of the Mersilene™ (Ethicon, Somerville, NJ) tape suture through the lower uterine segment has been reported.⁴⁹ A propylene mesh might be an acceptable alternative to the traditional 5-mm Mersilene tape,^48,52 yet more studies are needed to estimate the effectiveness and safety of this approach. A #1 Prolene™ (Ethicon) suture is another suggested alternative to Mersilene tape, the rationale being the ease of handling and removal.^55,63 Several case reports describe cerclage placement with the help of the da Vinci (Intuitive Surgical, Sunnyvale, CA) robotic system^53–55; however, the rationale, feasibility, and outcomes of this approach need to be further investigated and supported by additional studies.

TABLe 2.

Fetal Survival Rate Following Laparoscopic Cerclage Placement

Study	Patients (N)	Study Design	Reported Fetal Survival Rate (%)
Carter JF et al58	13	Prospective cohort	76
Whittle WL et al48	65	Prospective cohort	80
Mingione MJ et al65	11	Retrospective cohort	83
Nicolet G et al56	14	Retrospective cohort	83
Cho CH et al66	20	Retrospective cohort	95
Liddell and Lo67	11	Cohort study	100

Laparoscopic Cerclage Technique

Many variations of laparoscopic technique for cerclage placement have been described^56,57; here we present an overview of the procedure as employed at Brigham and Women’s Hospital (Boston, MA).

Patient Positioning and Port Placement

The placement of cerclage via the laparoscopic approach is performed under general endotracheal anesthesia. The patient is placed in the modified dorsal lithotomy position. The patient is then prepped and draped in the usual fashion for an abdominal or vaginal procedure. A uterine manipulator is inserted in the uterus in nonpregnant patients, followed by placement of a Foley catheter in the bladder. Port placement is by surgeon preference; we prefer a 10-mm umbilical trocar with 5-mm accessory trocars in the bilateral lower quadrants and left upper quadrant.

Operative Steps

The vesicouterine peritoneum is opened using the HARMONIC ACE® (Ethicon Endo-Surgery, Cincinnati, OH) and dissected off the lower uterine segment, exposing the uterine vessels anteriorly on both sides. A 5-mm nonabsorbable Mersilene polyester suture, with adjacent straightened blunt needles to allow passage through the trocar, is introduced into the abdominal cavity. The stitch is placed by passing each needle medial to the uterine vessels from posterior to anterior, at the level of the internal cervical os bilaterally. The landmarks for this placement include the uterosacral ligaments; a distance of 1.5 cm superior and 1 cm lateral to the insertion of the uterosacral ligament on the posterior uterus is a good initial guide for needle placement. The needles are then cut off and removed, and the Mersilene suture is then tied tightly around the cervix with six knots using intracorporeal knot tying. The ends of the stitch are trimmed and a silk suture is used to secure the knot to the lower uterine segment in an effort to minimize protrusion of the knot. The vesicouterine peritoneum is then reapproximated over the laparoscopic cerclage with a running 2-0 Monocryl™ (Ethicon) suture that is tied intracorporeally. The patient is observed in the recovery room for 3 to 4 hours until she can tolerate oral pain medication, void spontaneously, and has adequate pain control. The patient may then be discharged home as tolerated.

Outcomes Following Laparoscopic Cerclage Placement

In 2009, Carter and associates58 conducted a prospective cohort study of 12 women who underwent a laparoscopic cerclage placement between 2003 and 2008 and compared them with a retrospective cohort of seven women who had a transabdominal cerclage placed between 2002 and 2008. The demographic characteristics of the two groups were similar in age, race, median gravidity, parity, previous gestational losses, and prior failed transvaginal cerclage. Both laparoscopic and transabdominal approaches resulted in significantly improved fetal salvage rate (75% vs 71%, respectively), but results were not statistically different between the groups in terms of fetal survival, median gestation at delivery, median birth weight, and gestational age at loss. Cerclage placement during pregnancy or as an interval procedure also resulted in similar outcomes based on the variables described above. No surgical outcomes were reported. The authors concluded that laparoscopic cerclage placement is a safe and effective alternative to the transabdominal approach.

Another study comparing the outcomes of laparoscopic and transabdominal approaches with cerclage placement was also published in 2009 and similarly structured. Whittle and colleagues⁴⁸ prospectively followed 65 patients who underwent laparoscopic cerclage between 2003 and 2008, and compared the outcomes with the previously reported cases of transabdominal and laparoscopic cerclage in literature. The authors reported 67 pregnancies with the fetal salvage rate of 89% (vs 60% to 100% in literature) and the mean gestational age of 35.8 ± 2.9 weeks. The complication rate was 10.7 % (vs 0% to 25% in literature), including conversion of seven cases to laparotomy due to uterine vessel bleeding or impaired surgical visibility, loss of two pregnancies perioperatively, and six pregnancies in the second trimester due to acute or chronic chorioamnionitis. The authors also concluded that laparoscopic cerclage failure occurred more often when placed during pregnancy, but the timing of cerclage did not influence the gestational age at delivery.

Another retrospective case series by Auber and coworkers59 compared five laparoscopic with eight transabdominal cerclage procedures placed between 2004 and 2009. The authors reported a pregnancy rate of 85% with fetal survival rate of 100% regardless of surgical approach (laparoscopic vs transabdominal) and cerclage timing (interval vs during pregnancy). The authors reported shortened operative time and reduced hospitalization time for cerclage cases placed laparoscopically but did not provide any statistical validation of the difference. Complications were significant for two venous injuries in the transabdominal group and one case of suprapubic hematoma in the laparoscopic group.

The most comprehensive review of literature comparing laparoscopic to transabdominal approaches to cervical cerclage placement was published in 2011 by Burger and coworkers⁵⁷; 31 eligible studies were selected. A total of 135 patients in the laparoscopic group and 1116 patients in the transabdominal group were analyzed. The patients were further subdivided into the interval or placement during pregnancy subgroups. The groups had similar demographic characteristics, including age, gravidity, parity, obstetric history, indication for cerclage, and timing of cerclage. The highest fetal survival rate (94%) was reported with the interval transabdominal approach and the lowest (80.9%) with laparoscopic cerclage placed during pregnancy. Other pregnancy outcomes and rate of complications during pregnancy, including fetal loss, preterm premature rupture of membranes, and chorioamnionitis, were similar between the groups. There was a trend toward reduced operative time, incidence of severe hemorrhage, intraoperative fetal loss, and hospital stay among the patients treated via laparoscopic approach, but the difference was not statistically significant.

Conclusions

A laparoscopic approach to cervical cerclage placement is a potentially effective adjunct to the treatment of women at high risk of recurrent preterm birth. Laparoscopic and transabdominal approaches both yield similar obstetric outcomes, and laparoscopic cerclage may be a superior method in terms of surgical outcomes, as suggested by several studies. A prospective, randomized trial is needed in order to clearly establish the specific benefits to both surgical and obstetrical outcomes.

Main Points.

• Maternal and fetal inflammation may be a key factor contributing to the pathogenesis of preterm labor, including cervical insufficiency.

• Progestins, pessary, and cerclage are appropriate initial methods for the management of preterm birth.

• Cervical cerclage can be placed via transvaginal, open transabdominal, or laparoscopic transabdominal approach, preferably before pregnancy.

• A transabdominal approach is indicated in women who have failed prior conventional management of recurrent preterm birth.

• A laparoscopic approach may be superior to the transabdominal approach in terms of surgical outcomes, cost, and postoperative morbidity.

Figure 2.

Dissection of the vesicouterine space.

Figure 3.

Posterior uterine view of cerclage placement.

Figure 4.

The landmarks for cerclage placement on posterior uterus.

Figure 5.

The exit site of cerclage needle in the vesicouterine space.

Figure 6.

Intracorporeal knot tying following cerclage placement.

Figure 7.

Final knot secured with silk suture.