How To: Ectopic Pregnancy – Part 2 Case Study Video
– Hello, my name is Phil Perera and I'm the Emergency
Ultrasound Coordinator at the New York Presbyterian
Hospital in New York City and welcome to SoundBytes Cases. This module is ectopic pregnancy part two, where we'll go over the multiple ultrasound presentation
of ectopic pregnancies. Ectopic pregnancy is one of those conditions that we'll not infrequently encounter in a busy EM practice. The most common presentation of an ectopic pregnancy
will be an empty uterus, with or without free fluid
within the pelvic cul de sac or surrounding the uterus. We may be actually able to visualize the ectopic as a Bagel sign, which constitutes a
thickened Fallopian tube.
Other presentations of ectopics include a complex pelvic mass with a ring of fire on Doppler sonography, hemosalpinx or blood
within the Fallopian tube or we may be actually able to visualize the live ectopic in the adnexa, with a fetal pole and/or heartbeat. Here's a transvaginal long axis ultrasound for a woman who presented
with lower abdominal pain and a positive pregnancy test. Notice the uterus, as shown
in the long axis view, without an appreciable
intrauterine pregnancy and notice that it's surrounded by a large amount of free fluid. That dark or anechoic area surrounding the uterus both anteriorly to the left, posteriorly in the cul
de sac to the right. That is the presence of fresh blood. Notice also the presence of blood clots anteriorly or to the left,
that more echogenic area. So, given the absence of
an intrauterine pregnancy, we decided to scan out to the adnexa and notice here, the presence of a Bagel sign of a tubal ectopic pregnancy. We see fresh fluid here, above the Bagel, to the right, blood clot to the left and the more hyperechoic or lighter Bagel sign in
the middle of the image.
Occasionally it can be
difficult to discern the Bagel sign of a Fallopian tube ectopic from an ovarian cyst, as
show here to the right. But lets look closer
at the two video clips and notice that the Bagel sign has a more hyperechoic
or bright appearance, with the single hole more in the middle. Notice that the ovarian cyst
has a different appearance, with multiple small follicular cysts to the outer portion of the ovary and a single midline corpus luteum cyst. Very different than the Bagel sign. Here's another patient
with an ectopic pregnancy in a different presentation of ectopic. We're scanning here from
the more midline uterus, as show there to the left,
out to the right adnexa and notice as we scan
out to the right adnexa, we notice the presence of
a complex, pelvic mass. Notice also the relatively low serum B-HCG in this case, at 478. So, a complex pelvic mass with an absence of intrauterine pregnancy.
Very suspicious for an ectopic pregnancy. And what's interesting is, as we put Doppler flow on
that complex pelvic mass, we notice the presence
of the ring of fire, very suggestive of an ectopic pregnancy and the reasons for the ring of fire is that the ectopic pregnancy pulls a huge amount of vascularity towards it and using the Doppler, we can see the separate ectopic
from the ovary above it.
Here's another presentation
of an ectopic pregnancy. Again, we're scanning
at a short axis plane and we see there the uterus to the left and outside the uterus,
a separate structure. We note here the presence of
a thickened Fallopian tube and inside the thickened Fallopian tube, we see here a fetal
pole with a heart beat, consistent with a live
ampullary ectopic pregnancy. Unfortunately in this case, the presence of a fetal pole with a heart beat is a contraindication
of methotrexate therapy and this patient will
need to undergo surgery. We mentioned earlier that there are a variance of ectopic pregnancies that implant outside the
fundal region of the uterus, in an aberrant location.
This is a good example. This patient actually
has a bicornuate uterus and as we scan at a short
axis plane up the uterus, we notice that the two
limbs of endometrium that make up the two distinct cornua. As we go up the left cornua, we notice here the presence
of a cornual ectopic pregnancy and we see the that it's
located off to the side, way out to the left cornua, with a very thin myometrial mantle. If we actually put the calipers down and measure the endo-myometrial mantle, we find it's very thin,
at three millimeters, defining an abnormal pregnancy. A normal pregnancy should have a myometrial mantle greater
than eight millimeters.
Now this is a bicornuate uterus, so this is a cornual pregnancy. In a normal uterus, this would be known as an
interstitial pregnancy. So in conclusion, I'm glad
I could share with you this module on ectopic pregnancy part two, looking at the varied
presentations of ectopic pregnancy. Hopefully now you better understand what we're searching for
on bedside sonography when we're working up a patient with possible ectopic pregnancy. While visualization of the adnexa and the Fallopian tubes
is an advanced technique, but it is well within the scope of a busy emergency medicine practice.
As a final caveat, ectopic pregnancies can be seen at Beta-HCG levels
ranging from very low, less than 100, to very high, above 20,000 and thus we cannot use a Single Beta-HCG level to rule out ectopic pregnancy. It's really better to look at trends in the hormone level over time. With an intrauterine pregnancy, the levels should double in 48 hours, whereas in most ectopic pregnancy, it will not climb to the same degree. So, I hope that now you have a better understanding of how to work up the pregnant patient with a possible ectopic pregnancy.
