Cervical Cerclage

Cervical Cerclage: Basics - Stitching Up a Weak Link

• Definition: Surgical procedure involving placing a stitch (suture) around the cervix to keep it closed.
• Goal: Prevent premature cervical dilation and preterm birth in women with cervical insufficiency (incompetence).
• Mechanism: Provides mechanical support to a weakened cervix.
• **Indications (General):
  • History-indicated: Previous preterm birth < 34 weeks due to cervical factors.
  • Ultrasound-indicated: Short cervical length (CL) < 25 mm before 24 weeks gestation.
  • Exam-indicated (rescue): Painless cervical dilation in 2nd trimester.

⭐ McDonald cerclage is the most commonly performed procedure and is technically simpler than Shirodkar.

• Timing: Ideally placed between 12-14 weeks gestation for history-indicated; can be up to 24 weeks for ultrasound/exam-indicated.
• Contraindications: Active labor, chorioamnionitis, fetal anomaly incompatible with life, vaginal bleeding, PPROM.
• 📌 McDonald = Most common, More superficial stitch around cervix.

Cerclage Indications & Timing - The When and Why

• Goal: Prevent PTB due to cervical insufficiency.
• Types: See flowchart (Prophylactic, Therapeutic, Rescue).
• Contraindications: Active labor, infection (chorioamnionitis), PPROM, fetal demise/major anomaly, significant bleeding.

⭐ For singleton pregnancy with prior spontaneous PTB <34 wks, offer cerclage if TVS shows CL <25 mm before 24 wks.

Cerclage Types & Techniques - Suture Strategies

• Vaginal Cerclage Types:
  • McDonald Cerclage:
    • Technique: Simple purse-string suture (e.g., Mersilene tape, Prolene #1) at the cervicovaginal junction.
    • Timing: Insert 12-14 weeks; Remove 36-37 weeks or at onset of labor.
    • Pros: Simpler, less dissection. Cons: Higher risk of suture slippage/displacement.
  • Shirodkar Cerclage (Modified):
    • Technique: Submucosal dissection (anterior & posterior) to place suture (e.g., Mersilene tape) as high as possible, near internal os.
    • Timing: Insert 12-14 weeks; Remove 36-37 weeks or suture may be left if Cesarean delivery planned.
    • Pros: Stronger, lower displacement risk. Cons: More complex, ↑ risk of cervical trauma, bladder/rectum injury.
• Abdominal Cerclage (Transabdominal Cervicoisthmic Cerclage - TAC):
  • Indications: Prior failed vaginal cerclages, congenitally short cervix, amputated cervix (e.g., post-trachelectomy), severe scarring.
  • Technique: Suture (e.g., Mersilene tape) placed at the cervicoisthmic junction via laparotomy or laparoscopy.
  • Timing: Ideally pre-conceptional or in early pregnancy (~10-12 weeks).
  • Delivery: Requires Cesarean section.

⭐ The Shirodkar technique aims to place the suture as close as possible to the level of the internal os for better anatomical support and efficacy, especially in cases with a significantly shortened or effaced cervix.

Cerclage Complications & Care - Post-Stitch Pointers

• Complications:
  • Immediate: Bleeding, Anesthetic risks, Premature Rupture of Membranes (PROM), Chorioamnionitis, Cervical trauma/laceration.
  • Delayed: Suture displacement/migration, Cervical stenosis/dystocia, Preterm Labor (PTL), PPROM, Infection, Uterine rupture (rare, if in situ during active labor).
• Post-Operative Care:
  • Monitoring: Uterine activity, Fetal Heart Rate (FHR), vaginal bleeding, signs of infection (fever, foul discharge).
  • Tocolysis: Prophylactic use not routine; consider for persistent uterine contractions.
  • Antibiotics: Perioperative course common; regimen varies.
  • Discharge: 24-48h post-op if stable.
• Follow-up & Advice:
  • Activity: Pelvic rest (coitus avoidance), modified physical activity.
  • Patient Education: Counsel on recognizing PTL, PPROM, infection symptoms.
• Suture Removal:
  • Elective: 36-37 weeks gestation.
  • Emergency: For active PTL, PPROM, chorioamnionitis.
  • ⭐ > Cerclage in situ during labor significantly ↑ risk of cervical laceration or uterine rupture.

High‑Yield Points - ⚡ Biggest Takeaways

• Indications include history-indicated (≥1 late miscarriage/PTB), ultrasound-indicated (short cervix <25mm before 24wks with prior PTB), and exam-indicated/rescue (painless mid-trimester dilation).
• Common techniques are McDonald (simple purse-string, most common) and Shirodkar (requires bladder dissection, more complex).
• Elective placement is typically at 12-14 weeks; removal at 36-37 weeks or with onset of labor/PPROM.
• Rescue cerclage is placed for cervical dilation/effacement in mid-trimester; success rates are variable.
• Absolute contraindications include active labor, chorioamnionitis, PPROM, lethal fetal anomaly, and significant vaginal bleeding.
• Key risks involve PPROM, chorioamnionitis, cervical laceration/trauma, and suture migration/displacement.
• Transabdominal cerclage may be considered after failed transvaginal cerclage or with very short/absent cervix.