Pre-operative angioembolisation of a non-viable second trimester unruptured ovarian pregnancy

A 29-year-old gravida 5, para 4 (4004) patient exhibited a 3-day history of vaginal bleeding with multiple missed menstruations, a positive pregnancy test, and no accompanying symptoms. Her abdomen was soft with a non-tender irregular mass, more on the left. It measured approximately 15 x 13 x 10 cm with limited mobility.

Pre-procedural sonography showed a single foetus without cardiac activity outside the uterus. Its approximate age of gestation by composite ageing was almost 16.

An abdominal computed tomography angiogram (CTA) showed an ectopic pregnancy with an intact capsule and placenta. The latter is supplied predominantly by tortuous and prominent left ovarian and uterine arteries from both internal iliac arteries (Figure 1).

The uterus is elongated due to mass effects, but the contour appears intact otherwise (Figure 2).

In the diagnostic conventional angiography, the initial aortoiliac angiograms better delineated the vessels supplying the placenta: the communicating, dilated, and tortuous right and left uterine arteries, the dilated and tortuous left ovarian artery, and the small tortuous artery arising from the abdominal aorta, just above the left renal artery, likely the left superior capsular artery (Figure 3).

Background

Ovarian pregnancy (OP) is an unusual type of pregnancy, accounting for only 3% of all ectopic cases [1]. It usually ruptures before the end of the first trimester [2]. Hence, an unruptured second-trimester ovarian pregnancy is extremely rare.

Clinical Perspective

Its diagnosis is challenging, even with the help of imaging studies [1,3]. It is often misdiagnosed clinically and radiographically [3]. Literature states that some of these are just diagnosed intraoperatively [1].

The majority of OP undergo surgery, with advanced pregnancies treated with laparotomy [3], with surgery as the treatment of choice [3], specifically laparoscopy [2]. A referral for pre-operative embolisation was done for this case to limit blood loss on termination of pregnancy.

Endovascular Embolisation

The left uterine artery was super-selectively embolised using gel-foam particles (EGgel 710-1000). Silk particles were admixed to the gel foam during the later stage of the embolisation until complete cessation of flow was achieved (Figure 4).

The post-embolisation aortoiliac aortogram no longer showed hypervascularity of the abdominopelvic mass, with associated sluggish to no flow to the left ovarian artery and left superior renal capsular artery.

Outcome

Colour and power Doppler mapping of the previously noted heterogeneous mass showed that it was no longer hypervascular and had minimal to no blood flow.

Termination of the pregnancy was performed. During the operation, it was noted that the left ovary was not identifiable; furthermore, the left fallopian tube was stretched out over the products of conception. The contralateral ovary and fallopian tube were unremarkable. The placenta was located at the left broad ligament with extensions into the left pelvic sidewall and rectosigmoid area. The total blood loss (800 cc) did not exceed the estimated allowable amount (900 cc), beyond which blood transfusion is warranted.

Teaching Points

1. Pre-operative angioembolisation of a non-viable ovarian pregnancy is an effective tool to optimise patients for surgical termination of pregnancy.
2. Gel foam particles are adequate for temporary embolisation of the vessels supplying the placenta.
3. Abdominal CT angiogram before conventional angiography helps to precisely localise the arterial supplies of extrauterine pregnancies.

All patient data have been completely anonymised throughout the entire manuscript and related files.