Caution with bilateral salpingectomy and consideration of tubal stump ectopic in IVF

Abstract

We report a 35-year-old female patient with a history of bilateral salpingectomy from ectopic pregnancies presenting with a positive serum beta-human chorionic gonadotropin (bhCG) result following in vitro fertilisation (IVF) treatment. Apart from per vaginal spotting, she remained asymptomatic. Initial ultrasound showed an empty uterus with a cystic mass on the right side of the uterus. Serum beta-hCG was trended. A follow-up pelvic ultrasound 1 week later showed a live pregnancy in the right adnexa. A diagnostic laparoscopy was performed, which revealed an unruptured right stump ectopic pregnancy that was successfully removed. As a stump ectopic pregnancy can be a potentially life-threatening occurrence, we emphasise caution with salpingectomy and the consideration of tubal stump ectopic pregnancies following IVF treatment.

Background

The prevalence of a stump ectopic following salpingectomy is rare at 0.4%. If ruptured, it can lead to life-threatening hypovolaemic shock and death. It can occur following spontaneous or in vitro fertilisation (IVF) pregnancies in patients with unilateral salpingectomy or in IVF pregnancies following bilateral salpingectomy. As it is a potentially life-threatening occurrence, a high degree of suspicion of a possible stump ectopic in patients should be entertained in pregnancies following a history of unilateral or bilateral salpingectomy.

Case presentation

A 35-year-old female patient with a previous history of asthma and bilateral salpingectomy due to ectopic pregnancies presented for routine follow-up after a positive serum human chorionic gonadotropin (hCG) result from IVF treatment. She reported having per vaginal bleeding for 2 weeks prior to her appointment, reducing only to per vaginal spotting at the point of consultation. Otherwise, she remained well and physical examination was unremarkable. Prior to her appointment, she had serum beta-hCG trending. A bedside pelvic ultrasound was performed, which showed a 15×15×15 mm cystic mass on the right side of her uterus, possibly containing a yolk sac. Serum beta-hCG was sent and she was given a 1-week follow-up appointment. She was well and asymptomatic at her 1-week review. A repeat pelvic ultrasound was performed, which showed a gestational sac containing a yolk sac and fetal pole of 5 mm with a positive fetal heart at the right adnexa. Her clinical notes were also reviewed and pre-IVF hysterosalpingography showed the absence of bilateral fallopian tubes. A repeat serum beta-hCG was sent and the patient was consented for emergency surgery.

Investigations

1. Pre-IVF hysterosalpingogram (figure 1): normal uterine cavity, bilateral fallopian tubes not opacified with no intraperitoneal spillage

2. Serum beta-hCG:

   • Day 17 post embryo transfer: 27.9 IU/L.

   • Day 22 post embryo transfer: 162.1 IU/L.

   • Day 24 post embryo transfer: 396.2 IU/L.

   • Day 31 post embryo transfer (first follow-up visit): 7903.2 IU/L.

   • Day 37 post embryo transfer (second follow-up visit and day of surgery): 31 563.4 IU/L.

3. Pelvic ultrasound:

Figure 1.

Pre-in vitro fertilisation hysterosalpingography showing absence of bilateral fallopian tubes.

First follow-up visit:

• A 15×15×15 mm cystic mass on the right side of her uterus, possibly containing a yolk sac, no free fluid in the pouch of Douglas.

Second follow-up visit:

• Empty uterus. A gestational sac containing a yolk sac and fetal pole of 5 mm with a positive fetal heart at the right adnexa is seen. No free fluid in the pouch of Douglas (figure 2).

Figure 2.

Ultrasound image showing a live right adnexal pregnancy.

Differential diagnosis

As this patient has had bilateral salpingectomies performed prior to her IVF, differentials included a stump ectopic, ovarian ectopic or a cornual ectopic pregnancy. We did not have any images from her previous surgeries and her pre-IVF hysterosalpingogram showed absence of bilateral tubes. Therefore, in order to make a diagnosis, a diagnostic laparoscopy and intraoperative hysteroscopy were performed. Diagnostic laparoscopy showed a pregnancy on the right side of the uterus (figure 3) with normal ovaries bilaterally (figures 3 and 4). Subsequently, a hysteroscopy was performed, which revealed a normal uterine cavity (figure 5), excluding the diagnosis of a cornual and interstitial pregnancy. She was diagnosed with a right tubal stump ectopic pregnancy.

Figure 3.

Diagnostic laparoscopy showing right stump ectopic pregnancy.

Figure 4.

Diagnostic laparoscopy showing normal left ovary and absent left fallopian tube.

Figure 5.

Diagnostic hysteroscopy showing normal uterine cavity.

Treatment

The patient was consented for diagnostic laparoscopy and removal of ectopic pregnancy. The alternative of methotrexate was discussed; however, it was not the recommended treatment for this patient as her serum beta-hCG was very high and the ultrasound had revealed the presence of fetal heart activity in the ectopic pregnancy. Therefore, methotrexate would most likely fail. A diagnostic laparoscopy would also help us make a final diagnosis as well as reassess her fallopian tubes prior to her next IVF treatment. Intraoperatively, we diagnosed an unruptured right tubal stump ectopic, which we proceeded to remove and subsequently proceeded to repair the defect from the stump ectopic (figure 6).

Figure 6.

Post removal of ectopic and repair. Of note is the absence of the right fallopian tube.

Outcome and follow-up

She recovered uneventfully and was subsequently discharged well the following day. She was reviewed 4 weeks postoperatively and had recovered well from her surgery. Histology confirmed an ectopic pregnancy with products of conception seen. She was then listed for an IVF thaw cycle with our reproductive medicine department specialist.

Discussion

An ectopic pregnancy refers to a pregnancy that has implanted outside the uterus. It can potentially become a life-threatening occurrence in any women of reproductive age. However, with medical advances, easy access to hospital care and awareness among the population, earlier detection and treatment of this problem is made possible, resulting in a reduction in case fatalities. According to the recent Royal College of Obstetricians and Gynaecologists’ guidelines on the diagnosis and management of ectopic pregnancy, the incidence of ectopic pregnancies in women attending early pregnancy units is 2%–3%.¹

Risk factors include a previous ectopic pregnancy, smoking, pelvic infection, the use of an intrauterine device and pregnancies from assisted reproductive techniques (ARTs). Ectopic pregnancies can occur among 2%–5% of patients who get pregnant through ART.^{2 3} The most common site of occurrence for an ectopic pregnancy is the fallopian tube. Other possible sites of implantation include the ovary, cornua of the uterus, abdominal cavity, cervix and caesarean section scar. An interstitial ectopic pregnancy is a pregnancy that is implanted in the interstitial part of the fallopian tube and the reported incidence is between 1% and 6.3% of ectopic pregnancies.^4–6 It can occur with or without a history of previous salpingectomy. With a previous salpingectomy performed, it occurs as a tubal stump ectopic. The prevalence of a stump ectopic following salpingectomy is rare at 0.4%.⁷

Ultrasound can be a useful modality in the diagnosis of an interstitial and tubal stump pregnancy.⁸ Three sonographic criteria were proposed by Lau and Tulandi in making this diagnosis, mainly: (1) an empty uterine cavity, (2) a chorionic sac seen separately and >1 cm from the most lateral edge of the uterine cavity and (3) a thin myometrial layer surrounding the chorionic sac.⁹ According to their report, these parameters had a specificity of 88%–93% but only 40% sensitivity in achieving the diagnosis of an interstitial or tubal stump ectopic pregnancy. The presence of an interstitial line sign, which is a thin echogenic line extending from the central uterine cavity echo to the periphery of the interstitial sac has been shown to have a sensitivity of 80% and a specificity of 98% for the diagnosis of interstitial ectopic pregnancy.⁹

The management of a tubal stump ectopic is either medical with methotrexate or with surgery. The recommended choice of management is dependent on the ultrasound and serum beta-hCG findings. Should surgical management be decided on, the mode and method of surgery is dependent on patient stability, surgeon preference and training. It has become standard practice among most gynaecologists to adopt a laparoscopic approach as opposed to open surgery. More recently, a mini-laparoscopic approach was reported by Casarin et al which could be considered in a stable patient to achieve a scarless surgery.¹⁰ To date, several reports are available in the literature of successful laparoscopic removal of stump ectopic pregnancies with good prognosis.^11–13 Following surgical treatment, successful intrauterine pregnancy rates of up to 60% have been reported up to 24 months post surgery.¹⁴

We recommended surgical management with laparoscopy with our patient as despite being clinically stable, she did not fulfil the criteria for medical management. Moreover, it is important to highlight that the interstitial region of the tube is highly vascular as it receives a significant amount of blood supply from the uterine as well as ovarian arteries and if ruptured, can lead to life-threatening hypovolaemic shock.^{15 16} Therefore, caution with initial salpingectomy should be exercised to reduce the occurrence of tubal stump ectopic pregnancies and the consideration of the possibility of a stump ectopic should be entertained in patients who have had pregnancies following salpingectomies either from spontaneous or ART pregnancies.

Learning points.

• Caution should be exercised when performing salpingectomy. It is important to completely remove the fallopian tube to avoid the possibility of stump ectopic pregnancies in the future.

• In patients with a previous salpingectomy, it is important to have a high index of suspicion should the ultrasound show an eccentrically located pregnancy.

• If there is uncertainty that the pregnancy is intrauterine, a follow-up ultrasound should be performed for re-evaluation along with serum beta-human chorionic gonadotropin trending.

• Stump ectopic pregnancies can occur following assisted reproductive techniques (ART) in patients who have had unilateral or bilateral salpingectomies performed.