Considerations for management of interstitial ectopic pregnancies: two case reports

A 28-year-old gravida 1 para 0 white woman with a past medical history significant for polycystic ovarian syndrome and a history of laparoscopic gastric bypass surgery, presented to our emergency department with vaginal bleeding. She reported clomiphene citrate use and was 8 weeks 6 days pregnant by last menstrual period. She had a benign pelvic examination. Her beta hCG level was 39,745 mIU/mL. A transvaginal ultrasound revealed an eccentrically located gestational sac with 3 mm of myometrium in the left posterior cornu. A yolk sac and embryo with a crown-rump length (CRL) of 6.2 mm were also seen but no fetal cardiac activity was demonstrated. The diagnoses of probable early pregnancy loss (EPL) and interstitial location of the pregnancy were explained to the patient. As this was a highly desired pregnancy, she declined intervention and elected for expectant out-patient management. Subsequent follow-up ultrasound 48 hours later demonstrated a CRL of 7 mm without cardiac activity and 3 mm of myometrium in the thickness area, posterior to the sac. The diagnosis of EPL of an interstitial pregnancy based on CRL >7 mm without fetal cardiac activity was discussed with her. She was counseled on all available management options including expectant and medical management. She elected to proceed with surgical management and gave consent for the following potential procedures: examination under anesthesia, dilation and curettage (D&C), diagnostic laparoscopy, possible operative laparoscopy, possible exploratory laparotomy, possible cornual wedge resection with salpingectomy, and possible hysterectomy. She was informed that D&C is not the standard treatment modality for interstitial pregnancies. However, after a family planning specialist and a radiologist reviewed her images, it was felt that the inferior aspect of the sac might be accessible with a cannula angled towards the cornua. Since this was an EPL, pre-procedure methotrexate was not offered because there was no evidence indicating that it would facilitate removal.

Laparoscopic confirmation of her interstitial pregnancy was performed first to ensure that no interval interstitial rupture had occurred. Laparoscopy revealed the left cornu of her uterus to be thin and tensely distended with a gestational sac; a large blood vessel was seen overlying the cornu (Fig. 1). Her cervix was then dilated to 7 mm and a 7 mm flexible cannula was placed just inferior to the gestational sac under direct ultrasound guidance. Manual vacuum aspiration was performed and the POC were removed with two passes. Afterwards, her uterus appeared completely normal on laparoscopic visualization (Fig. 1). She tolerated the procedure well and was discharged home on the same day without further complications. Pathology was consistent with POC. Postoperative beta hCG were monitored weekly until <5 mIU/mL.

A 33-year-old gravida 3 para 1021 (one term pregnancy, no preterm pregnancies, one ectopic pregnancy and one spontaneous miscarriage, and one living child) Hispanic woman with a history of a previously diagnosed cornual ectopic pregnancy in a unicornuate uterus presented for evaluation and treatment of suspected persistent POC in the left cornu of a unicornuate uterus. Her pregnancy history is notable for a term uncomplicated vaginal delivery and prior early first trimester miscarriage managed with expectant management. She had no other significant medical or surgical history. She was diagnosed with a left interstitial pregnancy and treated with systemic methotrexate, receiving a total of four doses. Given her desire to conceive again, she underwent a gynecologic ultrasound, which revealed a persistent gestational sac and fetal pole in the left cornu despite multiple confirmatory hCG values <5. She was asymptomatic but was referred to the reproductive endocrinology service for management of this residual mass given her desire to try to conceive again and the potential to utilize assisted reproductive technology in future cycles. Ultrasound revealed a gestational sac in the left cornu measuring 10×7 mm with generalized reactive muscular echogenicity surrounding the sac and a fetal pole measuring 6.2 mm (Fig. 2). Ultrasound findings were suggestive that these persistent POC would be accessible via suction D&C based on its continuity with the endometrial stripe on ultrasound.

She was counseled regarding the following options: further expectant management with serial ultrasound monitoring given no known evidence that persistent POC can result in uterine rupture, and surgery. She elected to proceed with definitive surgical treatment given her desire to conceive and the potential catastrophic nature of uterine rupture in her unicornuate uterus. Intraoperative transvaginal and transabdominal ultrasound again confirmed persistent left interstitial pregnancy with POC within surrounding decidualized endometrium. A family planning specialist was consulted during this case. First, suction D&C was attempted. A 7 mm flexible cannula was inserted to the fundus under transvaginal ultrasound guidance. The left cornu was unable to be accessed despite multiple attempts with transabdominal and transvaginal ultrasound guidance. This was also attempted with a 7 mm rigid curved cannula but similarly was unsuccessful.

Hysteroscopy was then performed using a 5 mm Karl Storz operative hysteroscope with a 2.9 mm 30° lens, 5mm sheath, and 5-Fr operating port with normal saline as the distending media. Upon entry of the hysteroscope into her uterus, tubal ostium was identified. However, no gross POC were visualized within her uterine cavity. Next, a Novy™ Cornual Cannulation Set (Cook Medical) was passed hysteroscopically into the left cornual region under hysteroscopic and ultrasound guidance (Fig. 3). Although the device was successfully cannulated into the left cornu, no tissue was able to be aspirated (Fig. 4). As an alternative intended to grasp and remove the POC, a Tricep™ extra-strength hooked-prong grasping forceps (Boston Scientific) with a 3.0-Fr sheath and 120-cm working length (urologic stone retrieval basket) was suggested based on prior cornual procedures with a similar device [7]. This device was placed into the left cornu under both hysteroscopic and ultrasound guidance (Fig. 3); it was opened and closed within the cornual region several times. Dense fibrous tissue was grasped and removed with visible POC. This was repeated several times in a similar fashion. Karl Storz 5-Fr hysteroscopic grasping forceps were also used to grasp tissue extruding from this cornu several times (Fig. 5). At the end of the case, ultrasound revealed resolution of the myometrial decidual reaction with removal of persistent POC (Fig. 2). Safety was assured during the case with constant hysteroscopic visualization; transabdominal ultrasonography was also utilized to assure excellent visualization at all times. Laparoscopy was not necessary in this case due to combined hysteroscopic and ultrasonographic visualization during the case. The patient was counseled that the resolution of the persistent POC on ultrasound and hysteroscopy decreased the risk of uterine rupture but she was cautioned regarding the continued potential for rupture. Pathology revealed fragments of necrotic chorionic villi and decidua. She was discharged home the same day and had an uncomplicated postoperative course. Postoperative beta hCG was measured again postoperatively and was <5 mIU/mL.