How is a cornual (interstitial) rupture repaired?

Repair of Cornual (Interstitial) Rupture

For a ruptured cornual/interstitial pregnancy, immediate surgical excision via laparoscopic cornual resection is the definitive treatment, with laparotomy reserved for hemodynamically unstable patients. 1

Surgical Approach: The Gold Standard

The RCOG guidelines clearly state that surgical management by laparoscopic cornual resection or salpingotomy is an effective option for interstitial pregnancy 1. When rupture has occurred, conservative medical management is no longer appropriate—surgical intervention becomes mandatory to prevent life-threatening hemorrhage.

Key Surgical Techniques

Laparoscopic cornual resection is the preferred approach when the patient's hemodynamic status permits:

• Hemostasis strategies are critical given the rich vascular supply:

  • Inject highly diluted vasopressin (20 U diluted in 1000 mL normal saline; inject 150-250 mL of 0.02 U/mL solution into the uterus below the interstitial pregnancy) 1
  • Apply bulldog clamps temporarily to reduce uterine vascularization 2
  • Consider peritoneal opening with ureteral identification before proceeding 2

• Excision methods:

  • Automatic stapler technique: simultaneously excises and stitches the uterine cornua, enabling rapid laparoscopic management even in ruptured cases 3
  • Traditional cornual resection with multilayer uterine sutures 2
  • Electrocauterization, endoloop application, or encircling suture before evacuation 1

• Critical surgical principle: While cornuostomy (simple incision and evacuation) may seem more conservative, cornual resection should be preferred for ruptured cases to ensure complete removal and reduce recurrence risk 2. Inadequate repair increases the risk of uterine rupture in subsequent pregnancies 4.

Multilayer Repair is Essential

After excision, multilayer uterine sutures with anatomical restoration must be performed 2. This is not optional—failure to adequately repair the myometrial defect significantly increases the risk of catastrophic uterine rupture in future pregnancies, potentially occurring as early as 27 weeks gestation 4.

When Laparoscopy vs. Laparotomy

Laparoscopy is feasible for ruptured interstitial pregnancy IF:

• The patient is hemodynamically stable or can be rapidly stabilized
• The surgeon has appropriate laparoscopic expertise
• The procedure can be performed rapidly 3, 5

Immediate laparotomy is indicated when:

• Profound hemorrhage with hypovolemic shock
• Hemodynamic instability that cannot be quickly corrected
• Lack of laparoscopic expertise in emergency setting 6

Important Caveats

⚠️ Common pitfall: Misdiagnosing interstitial pregnancy as incomplete abortion, leading to attempted D&E, which can precipitate catastrophic rupture 6. The interstitial portion has greater capacity to expand before rupture due to surrounding myometrium, so rupture often occurs later (8-16 weeks) with more severe hemorrhage than typical tubal ectopic pregnancies.

⚠️ Future pregnancy risk: All patients must be counseled about increased risk of uterine rupture in subsequent pregnancies. Close monitoring in future pregnancies is mandatory, with consideration for delivery planning that accounts for the cornual scar 4.

⚠️ Urinary tract anomalies: When dealing with true cornual pregnancy (in a unicornuate uterus with rudimentary horn), be alert for associated urinary tract anomalies 1. The distinction matters because true cornual pregnancy requires excision of the entire rudimentary horn via laparoscopy or laparotomy 1.

Non-Surgical Options Are NOT Appropriate for Rupture

While the guidelines mention that methotrexate and expectant management can be considered for stable, unruptured interstitial pregnancies with low β-hCG levels 1, these options are completely unsuitable once rupture has occurred. Surgery is non-negotiable in the ruptured scenario.