Robotic-assisted single-site abdominal cerclage in the bicornuate uterus patient with cervical insufficiency

Abstract

Objective: To demonstrate the surgical techniques for improving safety in robotic-assisted abdominal cerclage in patients with bicornuate uteri complicated by recurrent pregnancy loss and cervical insufficiency.

Design: Stepwise demonstration with narrated video footage.

Setting: An academic tertiary care hospital.

Patients: Our patient is a 22-year-old G2P0020 with a history of recurrent pregnancy loss. During her first pregnancy, she was asymptomatic until 19 weeks and delivered because of a preterm premature rupture of membranes. A transvaginal cerclage was performed for her second pregnancy at 14 weeks, which ended at 16 weeks because of preterm premature rupture of membranes. The final magnetic resonance imaging report noted a "bicorporeal uterus with duplication of the uterine body, resulting in two markedly divergent uterine horns that are fused at the isthmus... unlike a typical didelphic uterus, a single, non septated cervix is noted, which shows normal appearances, measuring 3.8 cm in length." Given her history of a uterine anomaly and recurrent pregnancy loss in the absence of other biochemical factors, her maternal-fetal medicine specialist referred her to us as the patient strongly desired future viable pregnancies. The patient was counseled on multiple alternatives, including different methods of performing the cerclage, and ultimately decided on the robotic-assisted (Da Vinci Xi) prophylactic abdominal cerclage.

Interventions: The bicornuate uterus is a rare class IV mullerian duct anomaly caused by the impaired fusion of the mullerian ducts in the uterus, classically appearing in imaging studies as a heart-shaped uterus. This patient demographic reports a high incidence of obstetric complications. Pregnancy in such a uterus causes complications like first- and second-trimester pregnancy loss, preterm labor, low-birthweight infants, and malpresentation at delivery.¹ Researchers have postulated that there is an abnormal ratio of muscle fibers to connective tissue in a congenitally abnormal cervix. During pregnancy, an inadequate uterine volume may lead to increased intrauterine pressure and stress on the lower uterine segment, which can lead to cervical incompetence.² To address cervical incompetence, cervical cerclages are a commonly utilized procedure, as recent studies demonstrate that the incidence of term pregnancies in the group with documented cervical incompetence treated with cerclage placement increased from 26% to 63%.³ One observational study noted improved obstetrical outcomes occurred with interval placement, a cerclage placed in between pregnancies in the nongravid uterus, compared with cerclage placement between 9 and 10 weeks gestation, with the mean gestational age for delivery at 32.9 weeks and 34.5 weeks when a cerclage was placed in gravid and nongravid women, respectively.⁴ In addition, another retrospective study was done, which demonstrated a lower incidence of neonatal death with prophylactic cerclages.⁵ Operating on a nonpregnant uterus offers several benefits, including its reduced size, fewer and smaller blood vessels, and simplified handling. Moreover, there are clearly no concerns regarding the fetus. In the decision to use a robotic-assisted platform vs. laparoscopic, a systematic review showed the rates of third-trimester delivery and live birth (LB) using laparoscopy during pregnancy were found to be 70% and 70%-100%, respectively. The same review demonstrated slightly improved outcomes via the robotic route regarding gestational age at delivery (median, 37 weeks), rates of LB (90%), and third-trimester delivery (90%).⁶ Additional factors contributing to the preference for robotics in surgical procedures include incorporating advanced tools, which can enhance the robotic system's advantages compared with traditional laparoscopy. An invaluable tool in this context is the simultaneous utilization of Firefly mode, which employs a near-infrared camera system, achieved through injecting indocyanine green dye or integrating other light sources concurrently. The intravenous administration of indocyanine green is acknowledged widely for its safety and efficacy as a contrast agent in the evaluation of microvascular circulation and organ vascularization. This property equips surgeons with heightened precision when guiding the needle, proving especially advantageous when faced with challenges in visualizing vascular anatomy. In our specific case, we harnessed the capabilities of Firefly mode in conjunction with hysteroscopic light, enabling us to vividly illustrate the contours of a bicornuate uterus from both external and internal perspectives. We demonstrate a simplified technique of the abdominal cerclage, one cerclage around the internal cervical os of the uterus, using a robotic-assisted platform in a nongravid patient. The surgery began with the eversion of the umbilicus, and a 15-mm skin incision was made in the umbilicus. A Gelpoint mini advanced access site laparoscopy device was inserted into the incision, and CO₂ was allowed to insufflate the abdominal cavity with careful attention given to intraabdominal pressure. Once the DaVinci was docked, the surgeon began the creation of a bladder flap. The bladder was carefully dissected from the lower uterine segment and both uteri using monopolar scissors. The anatomical differences of a bicornuate uterus prompted the surgeon to dissect a wider circumference for safety reasons, where a wider dissection offers a better view of the uterine vessels and ease of introducing the Mersilene tape later on. Bilateral uterine vessels were further skeletonized and exposed anteriorly using blunt dissection and monopolar scissors. After further dissection and lateralization, the final result creates a landmark medial to the right uterine vessels at the level of the internal cervical os with which the needle of the Mersilene tape will be able to pass through. The Mersilene tape was guided from anterior to posterior via a previously straightened needle. Similarly, a landmark was created on the left, and the Mersilene tape was directed from anterior to posterior. The Mersilene tape was placed circumferentially around the internal cervical os of the bicornuate uterus, medial to the uterine vessels. Both ends of the Mersilene tape were then gently pulled, ensuring that the tape was lying flat on the anterior of the internal cervical os with no bowels or uterine vessels within it. The tape was then tied posteriorly at the 6 o'clock position with appropriate tension. A 2-0 silk was then sutured to the tails of the tape using the purse-string technique to ensure that it would remain securely tied and in the correct position. Hemostasis was assured. Both a hysteroscopy and a cystoscopy were done after the completion of the cerclage to ensure that no tape or sutures were seen within the cervical canal or the uterine cavity. None were observed.

Main outcomes measures: The success criteria for the surgery were identified as the patient's ability to attain a viable pregnancy after the cerclage placement, along with achieving LB.

Results: Subsequently, a spontaneous pregnancy was achieved. An infant weighing 3 pounds and 16 ounces was delivered by cesarean section at 36 weeks because of an oligohydramnios. The infant is currently healthy at 13 pounds.

Conclusion: Robotic-assisted abdominal cerclage around the internal cervical os in a bicornuate uterus offers a possibly feasible and straightforward technique for surgeons seeking to reduce risks, although further research is needed.

Keywords: Robotic; abdominal cerclage; bicornuate uterus; incompetent cervix; uterine anomaly.