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The purpose of the study is to review the surgical technique, complication rate and obstetric outcome associated with the laparoscopic approach to the placement of the cervico-isthmic cerclage.
A prospective cohort study was conducted from 2003-2008 and compared with previously reported cases of cervico-isthmic cerclage by laparotomy and laparoscopy.
Thirty-one patients underwent cerclage placement during pregnancy and 34 patients were not pregnant at the time of the surgery. Seven cases were converted to laparotomy due to complications arising from uterine vessel bleeding or impaired surgical visibility; 2 pregnancies were lost perioperatively. No other complications occurred. The fetal salvage rate (n = 67 pregnancies) was 89% with a mean gestational age of 35.8 ± 2.9 weeks. Six pregnancies were lost in the second trimester due to the consequences of acute or subacute chorioamnionitis.
Our findings suggest that the cervico-isthmic cerclage placed laparoscopically compares favorably with the traditional laparotomy approach.
Cervical incompetence occurs in 0.5-1% of all pregnancies, has a recurrence risk of ∼30% and typically presents in the second trimester as pelvic pressure and cervical dilation in the absence of uterine activity or ruptured membranes.
The etiology of cervical incompetence can be classified as (1) a mechanical failure of the cervix to remain closed against the increasing uterine distention pressure, or (2) a functional failure due to premature cervical ripening.
introduced an alternative to the vaginal approach—the placement of a cerclage at the cervical isthmus: a noose-like suture positioned around the isthmus in the avascular space above the cardinal and uterosacral ligaments placed by laparotomy.
This technique was intended when the vaginal approach was not feasible due to altered cervical anatomy (ie, congenital anomaly, scarring due to cone biopsy, or laceration at delivery); the indication was extended by Novy
to include a failed transvaginal cerclage in a previous pregnancy. Cervico-isthmic cerclage reviews quote a successful pregnancy outcome rate from 76.5-100%; however, the morbidity associated with the surgical procedure is significant.
In an era when endoscopic surgery provides a minimally invasive alternative with documented benefit over the traditional laparotomy approach, it has been proposed that the cervico-isthmic cerclage could be completed laparoscopically.
The objective of the present study is to review the surgical technique, morbidity, and obstetric outcome associated with the laparoscopic approach to placement of the cervico-isthmic cerclage. Our findings will be compared with reports of the traditional cervico-isthmic cerclage placed by laparotomy and more recently laparoscopy.
A prospective observational cohort study was conducted from January 2003 to June 2008 at Mount Sinai Hospital (Toronto, Canada) with institutional ethics board approval (MSH REB no. 06-0149-E). The indication for cerclage placement was a presumptive diagnosis of mechanical cervical incompetence based on the Novy criteria.
Pregnant patients underwent pelvic ultrasound to confirm viability, and were offered first trimester aneuploidy screening or diagnostic chorionic villi sampling prior to cerclage placement. After surgery, pregnant patients underwent routine cervical/vaginal swabs and urine culture. All infections were treated with routine antibiotic therapy; if the test of cure indicated ongoing infection, suppressive antibiotic therapy was prescribed for the remainder of the pregnancy.
The patient was prepared in the dorsal lithotomy position with a urinary catheter in situ. If the patient was not pregnant, a transcervical uterine manipulator was used; for the pregnant patient, a sponge on ring forcep was placed into the vaginal fornix to facilitate uterine manipulation. A traditional 4 puncture operative laparoscopy set up is used. Initial abdominal entry is achieved through the closed Veress technique at the umbilicus.
For cases done during pregnancy, the gravid uterus was avoided through entry in the left upper quadrant by the closed Veress technique or through an open Hassan technique at the umbilicus. Abdominal insufflation was maintained at 12-15 mmHg using CO2.
Step 1: development of the paravesical and vesico-uterine spaces
The vesicouterine peritoneum was incised using the CO2 laser (Coherent Inc., Santa Clara, CA) or monopolar scissors across the lower uterine segment, and a combination of sharp and blunt dissection was used to reflect the bladder from the lower uterine segment and anterior cervix. Paravesical spaces were developed bilaterally through a combination of blunt and sharp dissection.
Step 2: creation of broad ligament peritoneal windows
Anteversion of the uterus revealed a transparent posterior leaf of the broad ligament, an avascular space to create a window in the broad ligament on each side of the uterus. Fluid placement in the anterior cul-de-sac facilitated identification of the avascular space. The opening was created by a “push and spread” technique through the peritoneum with a laparoscopic grasper and enlarged by stretching the opening parallel and lateral to the uterine vessels. Creating this window allowed for caudal displacement of the ureters and identified the uterine vessels at the cervico-isthmic junction.
Step 3: placement of suture material through broad ligament peritoneal window
A no. 1 Prolene (Ethicon Inc., Somerville, NJ) suture on a CT-1 needle was passed into the abdomen through a 10-12 mm port on a laparoscopic needle holder. It is critical that the needle be set to pass from the posterior aspect of the right broad ligament window through anteriorly to prepare the trailing suture length for the final step; in this step the needle and suture sit lateral to the right sided uterine vessels.
Steps 4 and 5: right and left sided placement of cerclage at the cervico-isthmic junction
The needle was introduced medial and posterior to the uterine vessels, a small purchase of cervical tissue at the level of the cervico-isthmic junction is taken, and the needle is followed through anteriorly with the distal end of the suture in the cul-de-sac behind the uterus. This step anchored the suture on the right side of the uterus. The suture material and needle was passed anteriorly across the lower segment to the left side of the uterus. In a similar fashion, the needle is placed medial to the left sided uterine vessels and a small purchase of cervical tissue at the level of the left sided cervico-isthmic junction was taken as the needle was passed through posteriorly through the broad ligament window leaving the needle in the cul-de-sac and securing the suture to the left side of the uterus (Figure, A and B).
Step 6: the cerclage knot secured
The cerclage was tied by either an extracorporeal or intracorporeal knot at the posterior aspect of the uterus. The tension of the suture can be adjusted over a transcervical 5 mm Hegar dilator in the nonpregnant patient. The suture placement should sit at the level of the internal cervical os, above the uterosacral ligaments, the knot at the posterior aspect of the uterus (Figure, C and D).
At the conclusion of the procedure, the laparoscopic ports are removed, the gas evacuated, and the abdominal wall and skin are repaired in the usual fashion. No tocolytic agents were administered during or post procedure for gravid patients. Perioperative antibiotics were administered at the discretion of the primary surgeon. Nonpregnant patients were discharged home from the postoperative recovery area; pregnant patients were admitted overnight for observation and a pelvic ultrasound to confirm fetal viability.
Sixty-five patients underwent laparoscopic cervico-isthmic cerclage during the study period; patient demographics are presented in Table 1. Thirty-one patients underwent cerclage placement in the first or second trimester (<16 weeks' gestation) and 34 patients were not pregnant at the time of the surgery. Seven cases were converted to laparotomy due to either complications arising from uterine vessel bleeding (n = 5) or impaired surgical visibility (n = 2) due to morbid obesity; 6 of these patients were pregnant. Two patients experienced a perioperative pregnancy loss; both cases had been converted to laparotomy due to bleeding requiring uterine vessel ligation and 1 of the cases was ∼16 weeks' gestation. No other immediate surgical complications related to laparoscopy occurred. All patients delivering after 24 weeks of gestation underwent cesarean section with the cerclage left intact; no operative complications of this surgery occurred. Six patients had the cerclage removed at the time of delivery and a tubal ligation performed. The cerclage was removed in 1 patient at the time of delivery at term as it was no longer intact, and 1 patient had the cerclage removed postpartum through a posterior colpotomy as it had eroded through the posterior fornix into the vagina.
TABLE 1Patient demographics
Mean maternal age at cerclage, y
32.6 ± 4.6 (range, 22–42)
3.4 ± 2.3 (range, 0–14)
No. of live children/patient
0.43 (range, 0–2)
Patients with previous term pregnancy
T1 loss, % (mean no. T1 loss/patient)
38.5% (0.8 ± 1.8)
T2 loss, % (mean no. T2 loss/patient)
92.3% (1.6 ± 1.1)
Patient with prior TA
Patients with prior failed cerclage
Patients with previous cervical surgery (cone, LEEP)
Patient with DES exposure
Nulligravid/primigravid patients with insufficient cervical tissue
DES, diethylstilbestrol; LEEP, loop electrosurgical excision procedure; T1, first trimester; T2, second trimester.
Whittle. Laparoscopic cervicoisthmic cerclage. Am J Obstet Gynecol 2009.
Sixty-seven pregnancies have occurred in this study cohort and 8 patients remain nonpregnant. The overall pregnancy success rate defined as number of live births per number of pregnancies is 80.6%; details of pregnancy outcomes are presented in Table 2. Three pregnancies were aborted in the first trimester (1 patient had a termination due to fetal trisomy 21); all 3 cases were managed by dilatation and curettage through the cerclage. The mean gestational age at delivery for all remaining pregnancies was 34.4 ± 5.4 weeks (17.0–39.0 wk); 1 patient experienced an intrauterine fetal demise unrelated to the indication for the cerclage. Cerclage failure was defined as delivery prior to neonatal viability between 13 and 23 ± 6 weeks of gestation; 6 patients experienced a cerclage failure with a mean gestational age at presentation of 20.7 ± 2.9 weeks (range, 17.0–23.0 wk). Details of the clinical presentations are presented in Table 3; all failures were attributed to the clinical consequences of acute or subacute chorioamnionitis and occurred in women with a history of recurrent second trimester loss. Each patient was managed with a posterior colpotomy for cerclage removal followed by a vaginal delivery; all patients received intravenous antibiotics due to the clinical diagnosis of chorioamnionitis, and 1 patient was septic with a positive blood culture for Escherichia coli.
TABLE 2Pregnancy outcomes following laparoscopic cervico-isthmic cerclage placement
Perioperative pregnancy loss
n = 2
n = 1
n = 1
n = 1
Delivery <24 wk with NND
n = 6
Delivery >24 wk
n = 54
Mean GA if pregnancy lasted >12 wk
34.4 ± 5.4 wk (17-39 wk)
Mean GA if pregnancy lasted >24 wk
35.8 ± 2.9 wk (24.5-39 wk)
Distribution of GA at delivery
24 ± 28 wk n = 2
28 ± 32 wk n = 5
32 ± 36 wk n = 10
36 wk n = 53
NND with delivery >24 wk
n = 1
No. of NICU admissions
n = 12
No. with long-term sequelae of prematurity
n = 0
Weeks of pregnancy gained: 13.2
Mean GA at delivery in last pregnancy prior to cerclage: 19.7 ± 8.0 wk
Mean GA at first delivery postcerclage: 32.9 ± 8.8 wk
Fetal salvage rate
No. of liveborn children at last pregnancy prior to cerclage: 8/67 (11.9%)
No. of liveborn children at first pregnancy >12 wk postcerclage 53/60 (88.3%)
GA, gestational age; IUFD, intrauterine fetal demise; NICU, neonatal intensive care unit; NND, neonatal death; T1 SA, first trimester spontaneous abortion; T1 TA, first trimester therapeutic abortion.
Whittle. Laparoscopic cervico-isthmic cerclage. Am J Obstet Gynecol 2009.
The mean gestational age at delivery if the pregnancy continued past viability was 35.8 ± 2.9 weeks (range, 24.5–39.0 wk) (Table 4). The net number of weeks of pregnancy gained for those patients who had experienced a previous pregnancy loss was 13.5 weeks of gestation with a 6.5-fold increase in the number of liveborn children compared with the pregnancy immediately preceding the cerclage. Twelve babies were admitted to the neonatal intensive care unit, 1 baby died due to extreme prematurity, and no other long-term sequelae of prematurity were reported. Nine patients have had a second term (>37 weeks) pregnancy with the same cerclage in situ, and 1 patient has had 3 term pregnancies. Two patients had a twin gestation at the time of cerclage placement in the first trimester; both patients delivered healthy children after 34 weeks of gestation with no long-term complications of preterm birth.
TABLE 4Effect of timing and indication for cerclage on pregnancy outcome
Indication for cervico-isthmic cerclage
Previous T2 loss +/− cone biopsy
31.2 +/− 7.8 w (17–38 w)
Previous failed vaginal cerclage +/− cone biopsy
34.1 +/− 5.3 w (20–38 w)
Nulliparous with prior cone biopsy
1 delivery at 34 w
3 delivery at >37 w
Timing of cerclage: mean GA at delivery for pregnancies >12 w
Overall, the timing of cerclage placement did not influence the gestational age at delivery but cerclage failure did occur more often when the cerclage was placed during that pregnancy (Table 4). The indication for cerclage did not affect the gestational age at delivery, but in the small number of patients for whom the cerclage was placed due to insufficient cervical tissue there was no cerclage failure (Table 4).
Table 5 presents the outcome of previously published retrospective cohorts of cervico-isthmic cerclage placed by both laparotomy and laparoscopy with an operative complication rates of 0-25% and fetal survival rates between 60-100%.
TABLE 5Cumulative results of cervico-isthmic cerclage placed during pregnancy by laparotomy and cervico-isthmic cerclage placed by laparoscopy in both pregnant and nonpregnant patients
Cervical incompetence, defined as pregnancy loss following painless cervical dilatation, has been traditionally treated with a cerclage placed in the vaginal portion of the cervix in the subsequent pregnancy.
This therapeutic intervention is based on the assumption that the structural integrity of the cervical tissue has insufficient strength to act as a barrier to delivery against the increasing intrauterine pressure of the growing gestational sac.
When this vaginal cerclage fails to hold the cervix closed or cannot be placed due to insufficient cervical tissue, an alternative approach is the placement of a cerclage at the cervico-isthmus of the uterus. Conventionally, this type of cerclage is placed in the first trimester of pregnancy through a laparotomy; however, with the advent of minimally invasive surgery, placement by laparoscopy has been described in case reports and series (Table 5).
The purpose of this study was to describe the surgical technique for the laparoscopic cervico-isthmic cerclage, its associated obstetric outcomes, and compare these outcomes with the traditional laparotomy approach using previously reported cohorts that describe both rates of operative complications and fetal survival.
The advantages of a minimally invasive approach are well established; we provide evidence that this approach confers similar if not a slightly improved rate of perioperative complications as the cervico-isthmic cerclage placed by laparotomy (10% vs 0-25%, respectively; Table 5). The main complication of either approach was excessive blood loss—in our series no patient required a blood transfusion. The second most common complication was the conversion to laparotomy due to surgical visibility—such a complication should be considered in the context that 58 women were spared a laparotomy by having the cerclage placed laparoscopically. Since the cerclage is placed similar to a “noose” in the area of the cervical isthmus, a potential complication is compression of the uterine vessels leading to compromised uterine blood flow and subsequent fetal demise; our perioperative losses could be attributed to uterine vessel compression but may also be in part due to specific vessel ligation to arrest excessive bleeding. The reported perioperative loss rate by us and others did not occur with any greater incidence using the laparoscopic approach and likely is a risk of this type of cerclage regardless of the surgical approach. As the uterine size increases it does become a technically more challenging procedure; although we reported only 2 cases of cerclage placement in the second trimester, 1 was complicated by conversion and fetal loss. In addition, the conversion to laparotomy did occur more frequently when the patient was pregnant. Placement of this cerclage using a vaginal approach with tissue dissection similar to that of a vaginal hysterectomy has recently been described; this technique may be advantageous for women who present in the late first or early second trimester.
A #1 Prolene suture was chosen in this study with the rationale based on ease of handling for placement and removal compared with the traditional 5 mm Mersilene tape; this rationale is similarly supported by Rust et al
in the choice of suture material for a vaginal cerclage. The successful results we present support the use of this type of suture material in regard to its integrity and strength. Concerning the technique for knot tying, since the Roeder knot strength has been determined to be equivalent to the intracorporeal knot, the posterior location of our knot placement favors the Roeder knot especially with the bulky pregnant uterus.
We conclude that the laparoscopic approach for the placement of the cervico-isthmic cerclage confers a similar rate of perioperative complications as the traditional laparotomy and is best completed nonpregnant or early in the first trimester.
In our series, the fetal survival rate was 80.6%; however, taking into account that 3 losses were in the first trimester and that 1 patient suffered an intrauterine demise not attributable to the cerclage, the true cerclage success rate should be defined by the pregnancies lost at the time of surgery (2 cases) and the number of live, take home babies (58 cases) after the first trimester is completed. By this definition, the rate of cerclage success was 89%, making the obstetric outcome after laparoscopic cervico-isthmic cerclage comparable to that of the abdominal approach and to that reported by others using a laparoscopic approach (Table 5).
Based on the failures that occurred in our series, what has become apparent is that cervical incompetence is a complex disease that cannot be treated solely with the placement of a cerclage—either vaginally or at the cervico-isthmus; multiple etiologies lead to a common final pathway of undesired cervical dilatation and effacement. Cervical incompetence should be described in 2 main categories: mechanical and functional. Mechanical incompetence implies that the cervical components do not have the strength to maintain the structure of the cervix through gestation.
Postulated risk factors include: cervical structural anomalies due to in utero diethylstilbestrol exposure, overdilatation of the cervix during pregnancy termination, cervical trauma from conization or loop electrosurgical excision procedures, congenital mullerian anomalies, obstetric trauma including cervical lacerations, prolonged second stage of labor, precipitous delivery.
Each risk factor describes a type of damage to the anatomic elements of the cervix and should be the defining indication(s) for the cervico-isthmic cerclage regardless of the surgical approach.
Given that each of the cerclage failures we reported in our series occurred in women who presented with symptoms and signs consistent with chorioamnionitis, we propose that these patients may have an underlying pathology resulting in prematurity that is not solely attributable to mechanical cervical failure. A similar proposal has been suggested by Drakely et al,
who reported a 5% dual pathology rate in women with second trimester pregnancy loss. Functional incompetence is the premature triggering of the cervical ripening process that occurs at term; postulated risk factors include subacute or acute infection of the genitourinary tract and/or uterine cavity, abnormal placental development, suspension of the antiinflammatory effects of progesterone, and preterm labor.
Each risk factor describes a proinflammatory environment that promotes cervical ripening for which a cervical cerclage will not suspend. The patients for whom the cerclage failed in this present pregnancy each presented with a clear infectious/inflammatory process and each had experienced a previous pregnancy loss with a similar presentation. Himes and Simhan
reported that chronic endometritis leading to chronic deciduitis plays a role in the etiology of preterm labor and premature ruptured membranes. Detailed examination of the past obstetric history and placental pathology(ies) is imperative to identify risk factors for pregnancy loss, in particular a history of recurrent infectious/inflammatory preterm birth, that are not related to the structural integrity of the cervix. In such cases, counseling in regard to realistic expectations of the cerclage must be undertaken and potential role for chronic antibiotic and/or progesterone therapy must be explored. However, each of the patients who failed the cervico-isthmic cerclage had a previous failed vaginal cerclage, which can cause damage to the structural integrity of the cervix, compounding the risk for pregnancy loss by superimposing risk for mechanical failure on a background of inflammatory/infectious risk factors for premature cervical ripening. As such, we recommend a comprehensive evaluation of all women prior to cervico-isthmic cerclage placement including: radiographic evaluation of the uterine cavity, thrombophilia screen, detailed evaluation of obstetric history especially placenta pathology, cervico-vaginal swabs, and endometrial biopsy if any evidence of inflammatory lesions within the previous placental pathology. Patient selection remains the greatest challenge to and predictor of cerclage success regardless of the location of its placement.
In summary, our data indicated that the cervico-isthmic cerclage placed laparoscopically compares favorably with the traditional laparotomy approach in regard to operative technique, risk of complications, and obstetric outcome; in the carefully selected patient this cerclage may provide a reasonable alternative to achieve pregnancy success.
The cervix and prematurity: aetiology, prediction and prevention.