This content provides a comprehensive overview of acute and chronic complications following Cesarean sections, focusing on their imaging appearances using ultrasound and CT, and highlighting the importance of recognizing normal post-operative findings to differentiate them from pathological conditions.
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My name is Dr. Mindy Haro. I'm a
radiologist in Philadelphia,
Pennsylvania at the Albert Einstein
Medical Center.
I'm going to be talking about the acute
and chronic complications related to to
cesarian sections and predominantly
CT. In this lecture, I will be
discussing ultrasound and CT of acute
and chronic complications related to cesarian
cesarian
section. Cesarian section, at least in
the United States, now accounts for
approximately one-third of all
births. Typical symptoms requiring
post-operative imaging acutely would be
fever with a poor response to
antibiotics, dropping hemoglobin, or
unexpected pain or bleeding. Acute
diagnoses are a variety from relatively
benign things such as small hematomas
and wound infections to much more
significant issues related to uterine
dehissence and possible rupture. Then
there are a whole variety of more
chronic related issues that are caused
by cesarian section and because of the
increased incidence of cesarian section
deliveries we're seeing these much more
often on ultrasound and need to be aware
of them. As a result I might add when we
do pelvic ultrasound in women we
specifically ask them if they have had a
history of a cesarian
section acute complications. The
overview for this section will include
the spectrum of normal after a cesarian
section, hematomas and infections. Other
non-related or other related but non gyn
issues such as uriteral and bowel
injuries I won't be discussing today.
The choice of imaging modality because
I'm going to be discussing issues of
ultrasound and CT depends upon the
clinical situation, cost, availability,
contraindications etc. And so there are
variety of different imaging modalities
that can be used including MR. My
experience is predominantly with
ultrasound and CT and hence that is what
will be covered in this lecture.
These are images from four different
patients who have essentially normal
studies. Uh and what might look grossly
abnormal in other patients is really
within the spectrum of normal after a
cesarian section. So in case number one,
you can actually see the sutures from
the incision of the cesarian section
with some overlying skin thickening. In
this situation within the uterus,
there's a little bit of slightly high
density material and that's blood in the
endometrial canal which is not
unexpected. This case has a small focus
of air in the endometrium or it could be
in the cervix and a few tiny fosi
centrally located within a few days of
surgery are also normal.
This last image is a sagittal reformat
of the uterus in a patient a few days
after cesarian section. So the front of
the patient is here and the spine is in
the back. This is a nice sagittal view
of the uterus. The low density region
right here is where the cesarian cut was
performed for the incision. And so
that's a normal finding. Here between
the bladder and the anterior aspect of
the uterus is a very small hematoma.
That is called a bladder flap hematoma.
It's a little bit of a misnomer. It's
not really in the bladder wall. But the
key point here is that a small amount of
hematoma in this location is just in the
spectrum of normal uh in these type of
patients. Here is CT and ultrasound of
the same patient after cesarian section
with similar normal findings. So a
sagittal reformat shows the area where
the cesarian section was made with a
little bit of a hematoma. And this is
the bladder. In transverse you can see
these low density areas in the part that
had the incision. And notice if you will
that the incisions are not always smack
in the middle of the uterus. They may
seem off to the side. Remember the
uterus was cut initially when it was
quite enlarged. This is the same uterus
in a transvaginal view and the fundus is
here. This is the place where the
cesarian section was made. And not only
can you see a little bit of fluid and
low and mixed high echogenicity material
in this region, but you can see in the
sagittal and even better in the
transverse view these little bright
linear echoes. And this is the suture
material which you can't really
appreciate on the CT scan because of the
resolution. But it's quite normal at
this stage to still see all the little
suture material in this location. And
finding. Small myometrial and extra
uterine hematas are shown in these two
sagittal views after cesarian section.
These uh the fundus of the uterus is
here and there's a small echogenic
hematoma in the myometrium exactly where
the incision was made and a small
component outside in the adjacent fat.
process. This patient was four days
after a cesarian section that was
performed because of twins in breach
position and there was also an abruption
of the placenta. The patient has a fever
that is not responding well to
antibiotics. This is the transverse view
and the sagittal reformat in this
patient. First you can notice that you
can see the uterine incision. It looks
rather prominent. Um, and there is a
fair amount of uh uh he uh blood
products within the uterine cavity at
this point, but the incision itself is
fairly routine. The canal is expanded
with the complex fluid and there's air
in the subcutaneous incisions and
there's actually a little focus of air
in the uh bladder. So these are also
within the realm of normal imaging. On
CT in the immediate post C-section
patient, you can typically see the
uterine discontinuity. And other common
findings which are really not important
include small amounts of air, small
amounts of blood in the uterus, small
parimetrial collections, and small
bladder flap hematomas. If they're less
than 2 cm, they're within the range of
normal. Our recommendation and if you
notice from these slides is if you're
using CT for evaluation introvenous
contrast should really be used. If for
whatever reason IV contrast cannot be
given to the patient CT may not be the
study of choice at that point. In
addition, it is best to evaluate the
uterus perpendicular to the plane of the
incision and typically that requires
making sagittal and coronal reformatted
views of the uterus. So it may be quite
difficult to interpret what is exactly
happening in the typ in the axial images
that come from the
source. As far as ultrasound imaging
after cesarian section in the immediate
post-operative period the linear
echogenic fosi that are seen in the
incision are the sutures and that's a
typically normal thing. uh there may be
a mass-like area which is a small
hematoma also common and a normal
finding similar to the CT small bladder
flap hematomas are not uncommon and it's
fairly common to see some mixture of
clot and debris with a few fosi of air
within the endometrial cavity.
Therefore, the appearance of
endometritis and a normal endometrium
completely overlap and that diagnosis
should be really considered a clinical
diagnosis. Our recommendation for
ultrasound imaging is to use whatever
variety of transducers and transducer
frequencies necessary to obtain the
optimal images. Remember the uterus is
still fairly large at this point and
transvaginal imaging may or may not be
optimal. Transabdominal imaging will be
fine often even without a full bladder
and the woman may not be able to
maintain a full bladder. Uh you may
actually be able to use a higher
usual. Now let's look at some cases in
which there truly is uh more than just
the normal findings. This patient uh is
being imaged after an acute cesarian
section because of a decreasing
hemoglobin. And in this situation, the
hematas are out of the spectrum of
normal. In this transverse axial view,
the uterus is here and in front of it is
a a larger than should be bladder flap
hematoma. It's about the same uh density
as the uterus. In the sagittal view,
this is the bladder. Here's the uterus
with a small amount of fluid in the
endometrial cavity which nicely outlines
the scar the incision point and you can
see a little bit of the
hematoma. There's also some blood within
the peritineal cavity on either side. So
normal. Sometimes these hematas can
become infected. These are images from a
sonogram in such a patient who has a gas
containing collection in the bladder
flap region and was having persistent
pain and fever. On the transabdominal
view, you can see a little bit of urine
in the bladder. This is the uterus. And
so sort of between the bladder and the
uterus is a fairly large complex fluid
collection. There are fosi of air with a
little bit of dirty shadowing and some
other echoes within as well. On the
transvaginal, it's actually a little bit
harder to see the whole uterus because
it was large and out of the plane, but
you can see the collection with the
bubbles of gas which are now rising up.
The patient is lying down and a little
bit of complex fluid in the endometrial
cavity. Bladder flap hematomas are a
complication of the incision from the
cesarian section. This is covered by a
fold of paritonyium. Bleeding from the
incision comes into this region and is
usually confined by the paritinium but
if large can extend beyond as you saw
into the ligaments the retroparitinium
and the paritinium. These are considered
in the range of normal if they're
relatively small and are not infrequent.
Um surgical evacuation requires actually
an incision of the
paritinium. Now let's take a look at
some other hematomas. This is a patient.
You can see the uterus here and the
sagittal reformat and the bladder. And
these hematomas are more anterior in the
subfascial region and within the
abdominal wall again at about the level
where the incision was made for the
cesarian section. This patient has
infected rectus muscle hematomas and uh
extending into the subfascial region.
You can see the bubbles of gas and very
goodsized hematomas in this area. Here
in the sagittal reformat is the uterus,
the bladder. A sort of slightly larger
than normal bladder flap hematoma, but a
much larger hematoma in the rectus
gas. Subfacial hematomas are an extra
perariteneal form of the hematoma.
you're they're typically related to the
to bleeding from the epigastric vessels
and their branches and a fair amount of
blood can accumulate in the prevesical
space in the rectus muscle posterior to
it and all of these areas uh often
several liters and they may not really
be clinically uh apparent because of the
big uterus and uh the patient's body
habitus. These can be evacuated without
entering the peritineal
cavity. This patient had a history of
premature rupture of the membranes and
coroamnneonitis and was running
persistent fevers on the transabdominal
images. This is the uterus in transverse
and this is another image more
superficially. You can see that there
are little bright echoes within the
incision in the uterus more than you
would expect just from sutures which you
typically don't see transabdominally.
And so this represents some gas in the
incision. Then there is a collection
anterior to the uterus mostly fluid but
also with some bubbles and bright echoes
and some funny little artifacts. And so
this is in the location of the bladder
flap hematoma but with gas at this
location as well as in the uterus. The
corresponding CT which was performed
subsequently shows the same thing. The
long line of gas within the myometrium
and extending into the bladder flap hematoma.
hematoma.
This is considered to be a uterine
dehissence and an infected bladder flap
hematoma. The patient higher up on the
CT also had dilated loops of bowel in an
ilas. The infection was resolved with
conservative management. A catheter was
placed into the bladder flap hematoma.
It was eventually evacuated. The gas
resolved. And this is the follow-up CT
several days later.
Unfortunately, the patient was
readmitted 12 days later for new purilin
drainage and distension and has gone on
to develop a larger bladder flap abscess
even than before which probably had
ruptured outside of the uterus. There is
smaller collections elsewhere gas where
it shouldn't be and unfortunately the
Uterine dehissence is therefore defined
as infected necrotic material in the
uterine incision leading to a dehissence
at the suture line but that continues to
have an intact cerosa. It's a difficult
diagnosis to make after a cesarian
section because there is some overlap
with the normal incision that as you saw
the gas is the major uh change between
the two. There are unfortunately not a
lot of series and large group reports in
the literature. People some compla claim
that MR is preferred over CT because of
the multiplaner capabilities and better
soft tissue contrast. We find that with
uh multi- detector CT you can obtain
good coronal and sagittal views and that
often CT is just more available acutely
uh in these patients. The tip off that
there may be a uterine dehissence is the
presence of a large bladder flap
hematoma especially if it has gas and
appears infected. But there is
difficulty differentiating partial and
complete dehissence. Mind you despite
its name it can often be treated uh
medically with drainage and not require a
a
hysterctomy. So our recommendation is to
look for gas in the incision and any
extra uterine incision and use the reformatted
reformatted
images. This is a situation that has
gone progressed beyond simple dehissence
in which the uterus has actually
ruptured and there's a hematoma in the
broad ligament and fairly large extra uh
peritineal hematomas. The uterine
incision is in this approximate area and
you can see that there's a large
hematoma coincident with the uterus
extending out of it. Higher up on the CT
scan, the uterus was deviated towards
the right and there was still a very
large hematoma in the extra and then retroparitinal
space. Amazingly enough, despite how
awful this looked, the patient was
treated conservatively. the hematoma is
resolved and this is the followup in
this patient. You can see as is common
the uterus often becomes tethered to the
anterior abdominal wall. This is the
sonogram of that patient. You can see
the bladder and there's a little bit of
an adhesion at the site of the incision
but amazingly everything has healed quite
quite
well. Uterine rupture therefore is
defined as a complete muscular
separation of the myometrium. It is
typically accompanied by some degree of
hemoparitinium or other uh hematomas in
the area and in this situation the
morbidity and even the mortality
significantly increase. It is more
frequent in patients who are attempting
a vaginal delivery after a cesarian
section but any patient who has had a
cesarian section potentially is at risk
for this
complication. Here's another patient
with fever after cesarian section. In
this situation, uh the uterus is fairly
normal in appearance. There is some loia
centrally. There's no gas in the uterus,
but there's too much gas and increased
uh haziness and almost flegginous change
tissues. Here's another patient with a
wound infection and uh um the wound
itself is dehissing, not the uterus. You
can see in the scalp film from the CT
scan this gas at the incision site and
this is the axial image showing that the
incision is opening up and that there's
gas. There's small hematomas with gas in these
locations. Another patient had increased
bleeding and persistent fever one week
after a cesarian section. And these are
the CT images. The arrow points to the
approximate location of where the
incision was made. And you can see that
there's an infected hematoma uh
alongside of it. In addition, with
enhancement, there is a focal area here
that's quite brilliantly enhancing in
the endometri in the endometrium. So
that's more than just the lower soft
tissue density I've shown before. That
was blood. This is actually retained
products of conception and that
trophoblastic material it brightly
enhances with
contrast. This is the abscess on the
side. This patient had fever, abdominal
pain and free air on a chest x-ray two
weeks after a routine cesarian section.
And these are the CT images. Starting
from below, you can see the uterus.
There's a large bladder flap hematoma
with multiple fosi of air clearly
infected. As we progress uh higher in
the CT scan, there's gas here at the
level of the umbilycus and even higher
multiple fosi of gas in the upper
abdomen. So an infected bladder flap
abscess, infected ascites and
pumoparitinium. This is due to a rupture
of the bladder flap
abscess. Extrauterine infections
therefore include infected hematomas,
true abscesses. There can be cellulitis.
There often can be an infection at the
region of the incision which can extend
elsewhere. And the frequency and
severity of these infections are
significantly greater after cesarian
section compared to vaginal deliveries.
This patient had a history of coro
amomnonitis and failure to progress at
41 weeks gestation requiring a cesarian
section. She came with fever and these
are the CT images in the sagittal
reformat. Again you can see where the
cesarian section scar is only a small
amount of hematoma in the bladder flap
region. Um but if you notice this is a
transverse view higher up the aorta
inferior vennea and this is the right
ovarian vein. It's dilated and there's a
central area of hypo density. This is a
coronal reformat the inferior vennea and
its branches. And this is the ovarian
vein coming towards it. And again you
can see this low density material.
This patient has a septic
thromboflabitis of the right ovarian
vein. In addition, you may have noticed
a small high density focus here at the
endometrium junctional zone that was
retained products of
conception. This sonogram was performed
in a patient with unexplained postpartum
fever. The uterus is still a bit
enlarged, perhaps a little too large for
this stage. There's a little bit of
complex fluid in the endometrial cavity,
but nothing terribly unusual. In the
right adexal region, however, separate
from the ovary, which is down here, we
could see this little round echogenic
structure with a cystic center. And this
is a transverse view of one of the
ovarian veins filled with thrombus.
Other vessels in this area do have
flow. The CT was performed for
confirmation. And so you can see the
right ovary and here's the little vessel
with the brighten enhancing wall and the
low density center. And you can
see on the uh lower image as well. These
are much more difficult to see
sonographically than they are on c on
CT. Uh but if you know what to look for,
you may be able to figure it out. The
right ovarian vein um should be close to
the ovary.
Other patients sometimes show diffuse
septic pelvic thrombophabitis in any
number of the veins in the pelvis and
they look like these little Cheerios,
these little echogenic round structures
with low density centers. In contrast,
here's the external iliac artery and
vein and this vein is completely and
normally enhancing. These veins have
throi in them and you can see them here
as well. In addition, you might notice
that this patient had a um breakdown of
the incision and herniation of the
enlarged uterus at the
site. Septic pelvic
thromboplabitis occurs at least probably
in one out of 600 deliveries in the
United States, though possibly
underestimated. It is commonly
unilateral. For some reason, the right
more than the left and the thrombus in
the right ovarian vein can extend to and
even higher in the inferior vennea. CT
and MR have become the techniques of
choice. It is more difficult to
appreciate on ultrasound, but if this is
the only modality available or
appropriate for the patient, you can use
it. Findings include the enlarged
ovarian and other pelvic veins with low
density thrombus. Often the vessel wall
is enhancing or inflamed in appearance
and there also may be adjacent
inflammation in the surrounding
fat. Now we'll turn to chronic
complications following cesarian
section. So these are patients well out
of the immediate post-operative uh time
period. We'll look at what the scar
looks like longterm after uh cesarian
section on both ultrasound and CT and
then a variety of issues related to that scar.
scar.
In some patients, for whatever reason,
the adhesions and scarring can cause
significant distortion in the position
of the uterus. Because of the tethering
of the anterior uterus to the anterior
abdominal wall, the cervix becomes
elongated and the lower uterus is stuck
there. Transvaginal imaging therefore
allows an excellent visualization of the
cervix. But often the body of the uterus
is somewhat out of the plane and far
from the transducer and difficult to
visualize. Unfortunately, in this
situation, transabdominal imaging is
also limited because the distended
bladder will no longer serve as a
sonographic window. In this situation,
our recommendation is to try a higher
frequency transabdominal transducer to
see the body of the uterus assuming that
the patient's body habitus
permits. So let's take a look at this.
Here is uh transabdominal images of the
uterus in a patient with a history of
prior cesarian section. This is a
transverse view and a sagittal view. And
the uterus looks very distorted. Instead
of being smooth and round, you can
actually have a sense that the anterior
lower portion is pulled up and stuck to
the anterior abdominal wall. In the
sagittal view, you have vagina, cervix,
somewhat elongated, the bladder, and
this is where the adhesion is. And no
matter how big the bladder would get, it
would just keep pushing up at the uterus
and never cover the uterus to provide a
These are CTs and a diagram to explain
the problem that happens in transvaginal
imaging in these patients. So in this
axial image, the uterus is here and this
is the adhesion to the anterior
abdominal wall. In a sagittal reformat,
the cervix is elongated. The body of the
uterus then sort of falls posteriorly
and you can actually see the small
adhesion to the anterior abdominal wall.
Imagine now if we put a transvaginal
probe right
here and this is the section that we are
able to image the distance that we can
see the transvaginal image will
predominantly show the cervix and much
of the body of the uterus will be well
view. So if I flip the CT image the way
we look at ultrasound images, you can
see that and we put them side by side on
the transvaginal, I have a wonderful
view of the cervix, better than we
usually see, but that unfortunately the
much of the uterus is poorly imaged
because this is the part that's fallen
back. This is another patient. She had
prior uh cesarian sections and the
position of the uterus is not distorted
but the person scanning was concerned
that there was a round mass in the
anterior uterus and considered that this
may have been a
myoma. However, if you look carefully
this is the location of the scar from
the cesarian section right here. And
sometimes because it is pulled up, it
causes some distortion in the adjacent
myometrium and makes it look like a
round mass which can be mistaken as a
myoma. Another patient with prior
C-section. The question is, is there
some sort of odd endometrial
abnormality? The endometrium is seen
nicely here and is smooth and right here
it looks a little thicker and perhaps a
little irregular. Could this be a polip?
These are nebian cysts. In transverse,
you have this odd sort of sort of
triangular shape of the endometrium at
this location. And once you realize that
this is the site of the cesarian section
scar, it's clear that the endometrium is
being pulled into the site of the scar
where there is thinning and irregularity
of the overlying
myometrium. So there's nothing
intrinsically wrong with the
endometrium. it's just pulled and
tethered into the
scar. To take this one step further, if
there is endometrium in the scar, then
clearly blood could accumulate in that
region related to menses or potentially
to some other procedures. And this blood
can accumulate and be in this location
as a reservoir providing uh a means for
or causing intermenstrual bleeding.
These are two separate patients and you
can see the blood in the lower
endometrial cavity and a little bit in
the cervix extending to the cesarian
section scar. Here's another patient.
You can see the blood almost seems to
extend all the way through the
myometrium to the cerosal edge. Both of
these patients when asked gave a history
of spotting after menes. They they
complained of the menes being too prolonged.
prolonged.
Depending on the position of the uterus,
you have to look in different places.
Here's the retroverted retroflexed
uterus. And so the scar is over here.
This is the transvaginal view of that
patient. And there's fluid in the scar
which is here. And the patient also had
uh bleeding after
menes. This patient came with a history
of very heavy menes and some
intermenstrual bleeding. On transvaginal
imaging, we had a hard time seeing the
endometrium because there seemed to be a
large mass with shadowing in this
region. And so the patient came to have
a sono uh histogram. Uh fluid was
instilled into the endometrial cavity
via a catheter. And you can see very
nicely outlined this in fairly almost
completely intracavary myoma. In
addition, however, the fluid also filled
this little niche or scar from the pri
prior cesarian
section during the sonoy
histogram. This cesarian scar pouch or
niche as some authors have described can
be filled with fluid and the fluid may
be there during the routine transvaginal
scanning. Um if fluid fills this area
during sono hysterography, it can allow
one to actually measure the size of the
defect. And people have found that this
correlates well on
hysteroscopy. The scar can therefore act
as a reservoir for blood and cause
abnormal bleeding in patients. What
percentage of women with a cesarian
section will actually have a de
demonstrable niche is unknown. But if
the patients give this history, it's
it's important to look for the uh
possibility of this
niche. This patient happened to have an
immediate post-section CT after the the
cesarian section which occurred in 2005
and the incision was actually off to the
side at about 9:00 in this
uterus. She returned in 2006 and was
having a CT scan for other reasons. And
in between she had had an intrauterine
contraceptive device placed. If you
notice here's the IUD and it's exactly
at about the location of the site of the
prior cesarian section incision. It
should have been in the endometrial
cavity which is this place right over
here. And in the sagittal reformat, you
can see it's in the in the lower uterus,
but none of the IUD was located in the upper
uterus. This is an example of an IUD
that is
malpositioned related to the cesarian
section scar. The patient went on to
have a transvaginal and a transabdominal
sonogram and again demonstrates most of
the IUD was in the lower uterus and a
portion of one of the side portions of
it was stuck in the scar from the prior
cesarian section. This is the
transvaginal and this is the
transabdominal of the same patient.
Clearly important for the patient who is
not fully protected given the location
of the IUD.
Here's another patient with a
malpositioned IUD at the cesarian
section scar. Again, most of the IUD in
the cervix. And here are the side
portions of it at the level of the
cesarian section scar. This patient did
end up with the complication related to
this because when we scanned her, she
was pregnant. And here's the gestational
sack higher up in the uterus. She was
not protected by this IUD.
This patient is another one who had had
a CT scan several days after a cesarian
section for unexplained fever. This is
the coronal reformat showing the
incision. This is the bladder. This is
the axial image. And there was a fairly
normallook uh sight of the incision.
There was no complication
here. Several months later, the patient
returns for imaging. She's now pregnant
and she's having some bleeding. This is
the transvaginal view of her uterus.
There is a gestational sack and it's
located right here. So it is in the
uterus but if you look very carefully
it's not exactly where you would expect
it in the uterus. This is the
endometrium and this is the gestational
sack. You can see the yolk
sack. This is the gestation that is
implanted in the cesarian section scar.
It is a cesarian section scar ectopic.
The patient was treated with systemic
methtoresate and five days later had a
follow-up which unfortunately showed
that the pregnancy was growing
appropriately. There was now not only a
yolk sack but now we could visualize an
embryo that had cardiac activity. And
again you can see the measurement being
made here of the thickness of the
myometrium that overlies this
gestational sack. And from having seen
the other images images I showed this is
clearly at the location of the cesarian
section. So she was given a second dose
of methtoresate. Unfortunately two days
after that the pregnancy was still alive
and surgery was
required. Another patient with a history
of only one prior cesarian section came
in. She was pregnant and having
bleeding. There is a gestational sack
low in the uterus and it was empty and
interpreted as an abortion in progress.
She returned however one month later
with bleeding and this is the
transabdominal view of her uterus. The
endometrium is normal. There's no
gestational sack but there's sort of a
mixed complex low and high echogenicity
collection exactly at the
location of this gestational sack on the
prior study. When we put color Doppler
on it was exuberantly beautifully
vascular in this region. So what we're
dealing with here is a patient who had a
cesarian scar implantation but most of
the sack passed in a spontaneous
abortion. Unfortunately the retained
products of conception are at the site
of the cesarian section
scar. This type of ectopic pregnancy is
rare but increasing in incidence as the
number of cesarian sections increases.
It is defined as a gestation completely
surrounded by myometrium but separate
from the endometrium and separate from
the fallopian tube. Several reports show
that this can occur within months of the
delivery and therefore incomplete
healing of the scar may contribute to
it. The ultrasound findings are those of
an empty uterine cavity, an empty
cervical canal and a gestational sack in
the lower uterus. The differential
diagnosis, as you can see, includes a
spontaneous abortion in progress and a
cervical ectopic pregnancy. The problem
is that rupture can occur and often the
diagnosis is delayed in part due to lack
of uh education about the possibility of
this but also the overlap with the other
diagnosis. It's despite an increased
incidence, it is still such a rare
ectopic pregnancy that are there are no
specific guidelines for treatment.
Medical therapy can be tried but often a
required. This patient was 30 weeks
pregnant and started to have gross
hematuria and this is ultrasound imaging
of the lower uterus and bladder. This
case was graciously lent to me by Dr.
Sandra Allison of Georgetown University.
If you look at the posterior wall of the
bladder, you can see these cystic areas
which with color doppler show that they
are vessels and exuberant flow. On
transverse imaging through here, there's
echogenic material and cystic areas with
blood flow. This is an example of a
placenta percreta or placental invasion
of the bladder and it is related to
prior to the prior cesarian section. So
these are all in the realm of placenta
accreta and accreta is when the villi
are in direct contact with the
myometrium without any intervening
decidua. Increta is a deeper myometrial
invasion and percreta is invasion to the
cerosa and occasionally occasionally to
the bladder and bowel. Uh the major risk
factor nowadays is prior cesarian
section but obviously instrumentation uh
can also uh predispose to this. It can
result in life-threatening hemorrhage at
delivery or even before because the
placenta will not separate from the
myometrium. Modalities that can be used
to make this diagnosis include
ultrasound and MR. It's usually done
without gatalinium if the patient when
the patient is pregnant. Um it's unclear
which has better sensitivity and
specificity because it is an unusual and
I must say a difficult diagnosis to
make. If the placenta is anterior,
ultrasound is better. If the placenta is
posterior, MR may be better. The
criteria for suspecting placental
invasion on ultrasound include loss of
the retrop placental hypocoic myometrial
zone, numerous vascular lacun in the
placenta, a disruption of the echogenic
boundary, and nodular projections beyond
the uterine edge.
If you think about it, there are some
similarities between placenta and creta,
which is myometrial invasion of placenta
and a c-section ectopic, which is an
abnormal implantation site of the actual pregnancy.
