Unsuccessful Laparoscopic Management of a Spontaneous Second Trimester Heterotopic Pregnancy

Introduction

Heterotopic pregnancy is a clinical condition whereby intrauterine and extrauterine gestations coexist.^1,2 The extrauterine gestation can be tubal, cervical, ovarian, cornual, or abdominal, with the highest incidence being in the fallopian tubes. ³ The occurrence of heterotopic pregnancies is rare in spontaneous conceptions, occurring in approximately 1 in 30,000 pregnancies. ² However, with the increase in the use of assisted reproductive techniques (ARTs), the frequency of such pregnancies increases as well, reaching approximately 1 in 100. ³ Other predisposing conditions include tubal disease or pelvic inflammatory disease (PID). Heterotopic pregnancies are usually diagnosed incidentally or in cases of acute abdomen, despite the improved ultrasonic diagnostic techniques developed over the past years. The clinician needs to have a high index of suspicion in order to diagnose such cases early. This article presents a case of a spontaneous heterotopic pregnancy in a young woman who presented with nonspecific abdominal pain but later experienced tubal rupture.

Case

A 29-year-old primigravida Myanmese woman was seen at the emergency department for right-sided abdominal pain with cramps that lasted approximately 15 minutes, with a pain score of 5/10. She also complained of one episode of dysuria, which resolved spontaneously. There was no vaginal spotting. It was a spontaneous pregnancy and she had no surgical history of note.

On examination, the patient was stable with blood pressure (BP) of 114/70 mm Hg, pulse rate (PR) of 100 beats per minute (bpm), and a temperature of 37.4°C. There was slight right-sided lower abdominal tenderness; however no masses were present. Pelvic examination revealed a uterus that was anteverted, soft, and enlarged, corresponding to 8 weeks of pregnancy. There was no cervical excitation or cervical bleeding. An ultrasound was performed, showing an intrauterine pregnancy of 8 weeks' duration with positive fetal cardiac activity. The patient's discomfort resolved in a few hours and a provisional diagnosis of nonspecific abdominal pain in pregnancy was made. She was then given an appointment with a specialist at our hospital for further antenatal care.

She went for a first trimester screening (FTS) for Down syndrome 1 month later and a viable intrauterine pregnancy of 12 weeks' duration was seen. A 4.7-cm mass on the right adnexa was noted, with features strongly suspicious of a dermoid cyst. She was scheduled for a laparoscopic cystectomy 1 week later and the risk of miscarriage was duly explained.

Intraoperative findings revealed hemoperitoneum of 300 mL. The uterus was noted to be 14 weeks in size and multiple adhesions between the right tube and the uterus were seen, with the presence of Fitz-Hugh-Curtis perihepatic lesions. The right ovary was initially obscured by a large right adnexal solid and cystic mass that was bleeding profusely. An ectopic pregnancy was then suspected intraoperatively, and a laparoscopic partial salpingectomy was performed with products of conception (POC) removed. However, there was continuous bleeding from the right adnexae and hemostasis could not be adequately secured. The 14-weeks gravid uterus also restricted laparoscopic manipulation, anteversion, and access to the right ovarian fossa and pouch of Douglas. A decision to convert to a laparotomy was made, and total salpingectomy was performed. The histopathology report showed the presence of chorionic villi in the specimens and a postoperative diagnosis of heterotopic pregnancy was then confirmed. The patient's recovery was uneventful and the bedside ultrasound confirmed the presence of fetal cardiac activity in the intrauterine pregnancy. The patient was subsequently discharged from the general ward to be followed up regularly in the antenatal clinic.

Discussion

Heterotopic pregnancy is a very rare clinical condition, but does have certain predisposing factors, including previous ectopic pregnancy, cigarette smoking, tubal damage caused by PID or endometriosis, or previous tubal surgery.^3–6 However, the most significant risk factor is that of in-vitro fertilization (IVF), because the embryo transfer used in ART can result in embryos being placed in affected tubes and the peristaltic movements are unable to expel these misplaced embryos. ³

It is notoriously difficult to diagnose heterotopic pregnancies, as even an early transvaginal ultrasound scan might be unable to exclude an ex-utero gestation. The detection rate from transvaginal ultrasound scans varies from 41 to 84% and is influenced by factors such as availability and ease of access to ultrasound facilities. ² A review by Reece et al. determined that the clinical symptoms of abdominal pain, adnexal mass, peritoneum irritation, and enlarged uterus are suspicious for a heterotopic pregnancy, but can only be confirmed by actual visualization of positive fetal cardiac activity in both the intra- and extrauterine gestations. ⁵ It is difficult to differentiate an ectopic pregnancy from a hemorrhagic corpus luteal or endometriotic cyst, especially in the presence of an intrauterine gestation.^7,8 In this patient, a right adnexal mass was discovered on an ultrasound scan at 12 weeks' gestation, and was suspected to be a dermoid cyst instead of a possible ectopic pregnancy. A study by Sokalska et al. has shown a very high specificity and sensitivity of detection of dermoid cysts on ultrasound, although other adnexal pathologies cannot be confidently excluded. ⁹ Hence, there was a low index of suspicion for a heterotopic pregnancy in this case. In most patients, the normal embryo is not detectable on ultrasound in the early gestational weeks and the viability of most pregnancies at such an early stage are determined by the presence, size, and shape of the gestational sac. ¹⁰ An early diagnosis of heterotopic pregnancy is often a difficult process, especially in low-risk patients without any history of fertility treatment or tubal damage, in which cases early detailed scans are usually not performed. ²

The time of diagnosis of a heterotopic pregnancy varies from 5 to 34 weeks of pregnancy, and, according to a study by Tal et al., 70% were diagnosed between 5 and 8 weeks' gestation, 20% between 9 and 11 weeks' gestation, and 10% after 11 weeks of gestation. ¹¹ The patient in this case report was only diagnosed intraoperatively at nearly 14 weeks' gestation. A recent review by Barrenetxea et al. revealed that out of 80 cases of heterotopic pregnancy from 1994 to 2004, 21 were diagnosed by ultrasound and 59 were diagnosed by laparoscopy or laparotomy. ¹²

The management of heterotopic pregnancy depends largely upon the clinical presentation of the patient. The treatment options are broadly classified into two categories: medical and surgical. ⁴ Only hemodynamically stable patients with unruptured ectopic pregnancies should consider medical instead of surgical treatment.

For medical therapy, potassium chloride (KCl) or hyperosmolar glucose can be injected directly into the ectopic gestational sac or fetus via laparoscopy or guided by transvaginal ultrasound. However there is a high risk of abortion of the intrauterine gestation related to the procedure and this should be explained to the patient.^6,10,13 Two previous studies have shown that out of the 4 cases of heterotopic cornual pregnancies managed by transvaginal embryo reduction using potassium chloride, 2 intrauterine fetuses were delivered at term and 2 resulted in miscarriages. ⁶ Other drugs commonly used in the medical management of ectopic pregnancies, such as methotrexate, mifepristone, and prostaglandins, cannot be used in cases of heterotopic pregnancies if the intrauterine pregnancy is to be preserved, because of the high likelihood that the drugs will have harmful effects on the intrauterine pregnancy as well. ⁴ In this patient, KCl therapy was not an option as there was a low index of suspicion for a heterotopic pregnancy preoperatively and intraoperative findings revealed significant blood loss and active bleeding from the site of the ectopic pregnancy, which necessitated quick and immediate surgical measures to prevent further deterioration.

Surgical options include laparoscopy and laparotomy, but both aim to stabilize the patient hemodynamically, with minimal manipulation of the uterus in order to preserve the intrauterine pregnancy. In recent years, laparoscopy has been the favored choice of management for most patients as the postoperative recovery is shorter and more tolerable than with laparotomy. The use of laparoscopy in heterotopic pregnancies is confirmed by data from Pschera and Kandemir, as well as by Chen et al., whose reviews concluded that laparoscopic surgery is an appropriate modality for both the diagnosis and treatment of heterotopic pregnancies.^7,14 Some patients require laparotomy if there is significant hemoperitoneum or if they are hemodynamically unstable. A laparotomy can allow the ectopic pregnancy to be removed and the bleeding points arrested in the shortest time possible, with minimal trauma to the uterus, and thus the risk of intrauterine miscarriage caused by the surgery is reduced. ⁴ This was the case in our patient, whose initial laparoscopic surgery was converted to a laparotomy, in view of excessive bleeding and obstructed access caused by the gravid uterus.

Conclusions

Heterotopic pregnancy can occur spontaneously, even in the absence of predisposing factors. Presence of a viable intrauterine gestation does not exclude a coexisting extrauterine gestation, but it is difficult to diagnose on transvaginal ultrasound scans and can easily be confused with a hemorrhagic corpus luteal, endometriotic, or dermoid cyst, as was seen in this patient. Most heterotopic pregnancies are managed successfully via medical therapy or laparoscopy, with preservation of the intrauterine pregnancy. Laparotomy is usually only performed in hemodynamically unstable patients or in cases of severe intra-abdominal bleeding