Preoperative diagnosis and successful laparoscopic management of intramural pregnancy: case report

We would like to report a case of intramural pregnancy, diagnosed preoperatively. Laparoscopic unilateral uterine arterial occlusion was performed and the lesion was excised successfully without any complications.

A 34-year-old woman, gravida 2, para 1, presented to our gynecological clinic with lower abdominal pain and amenorrhoea for 57 days. She had a laparoscopic surgery performed due to endometriosis one year before. Diagnosed as “intrauterine pregnancy” at a local hospital, she underwent induced abortion, which failed. Gynecological examination revealed a slightly enlarged uterine body. The serum β-hCG concentration was 15000 m IU/ml. Transvaginal ultrasound scan revealed a less uniform myometrium echo and a heterogeneous echogenic area stretching to the serosa layer in the posterior uterine wall, measuring 3.7 cm × 3.3 cm. Doppler flow revealed high blood flow (Fig. 1A ). Pelvic MRI showed an irregular-shaped signal within the myometrium in the left wall of the uterus. Around the lesion there were multiple tortuous low signal flow-void vascular shadows. Hysteroscopy revealed an empty uterine cavity and thickened endometrium where a blue pigmented cyst could be seen (Fig. 1B). A diagnosis of suspected intramural pregnancy was made. Laparoscopy was therefore performed under general anesthesia. A bulging mass with an extremely thin serosa was seen arising from the left side of the posterior wall of the uterus (Fig. 1C).

The operation procedure was as follows: (1) the left uterine artery was separated from the anterior peritoneal layer of the left broad ligament and the main trunk was blocked using bipolar coagulation (Fig. 1D) in order to lessen the blood flow around the lesion; (2) 1 ml of vasopressin was then injected into the myometrium around the lesion; (3) a wedge-shaped incision was made over the bulging part of the posterior wall, and then dark reddish necrotic tissue suggestive of products of conception was carefully explored, confirming that it was connected neither with the uterine cavity nor with either of the fallopian tubes; (4) the lesion was removed and the defect was then repaired. The total operative time was 60 min, and the blood loss was 80 ml. Histopathology revealed villous and trophoblast cells in blood clots and the smooth muscle. Serum concentration of β-hCG was 643.45 mIU/ml on the 7th postoperative day and returned to normal on the 15th. Regular menstruation was achieved 7 weeks afterwards. No subsequent hemodynamic instability or hemorrhage was detected during the 3-months’ follow-up, and ultrasonography at the end of the follow-up showed no change in the appearance of the uterus.

Intramural pregnancy is a rare form of ectopic pregnancy – a pregnancy implant within the myometrium, separate from the endometrial cavity and Fallopian tubes []. The exact cause is unclear. Possible risk factors include prior uterine trauma, adenomyosis, pelvic surgery, and in vitro fertilization []. As for this case, the previous history of surgery for endometriosis and the hysteroscopic findings indicated that the cause might be adenomyosis. In the past, the diagnosis could not be made until the time of surgery for uterine rupture []. In the present case, however, early detection was possible by liberal use of ultrasonography, MRI and hysteroscopy. A prompt and accurate diagnosis is crucial, avoiding complications such as uterine rupture, which is extremely dangerous and might require hysterectomy, resulting in subsequent loss of fertility []. As an ectopic pregnancy, treatment could be surgical, medical or expectant. For the medical approach, methotrexate comes first, and might even be confidently preferred before surgery in a ruptured ectopic with a hemodynamically stable patient []. For this case, the lesion size and β-hCG level indicated that it was in an active state, and the patient had the desire for future fertility, so we chose laparoscopic excision of the lesion. In the procedure, we occluded one uterine artery at the main trunk level first, which temporarily reduced the local blood supply and achieved satisfactory control of bleeding.