0:00

In patients with suspected placenta percreta,

0:03

it's particularly important

0:05

to try to identify any structures

0:07

that may be invaded by the placenta.

0:10

One of the most frequently invaded

0:12

structures is the bladder dome.

0:14

When evaluating the bladder dome,

0:16

it's important to evaluate the signal

0:18

of the bladder wall in its entirety.

0:20

So you can trace the signal of the bladder

0:22

wall, which should appear T2 hypointense.

0:26

Bladder dome invasion may be difficult to detect

0:29

because it often appears as a signal abnormality

0:32

on only a single slice of the images.

0:35

This may look like focal disruption

0:38

of the normal detrusor signal.

0:40

You can also see blurring or irregularity

0:43

of the bladder wall or the bladder mucosa.

0:46

As is the case in this patient with a low

0:48

lying placenta and placenta percreta, we see

0:51

focal disruption of the bladder wall signal.

0:53

With a small amount of focal protrusion of

0:56

placental signal into the bladder lumen.

0:59

In patients who have close approximation of

1:02

the bladder by the placenta, but not frank

1:04

invasion of the bladder dome, you may also see

1:07

prominent vessels in the supravesicular fat

1:09

pad, which will appear as T2 dark flow voids.

1:13

Identifying bladder dome invasion

1:15

is also particularly important.

1:18

Because at the time of delivery, if bladder dome

1:20

invasion is suspected, the surgeons will have

1:23

to make a cystotomy, or opening in the bladder

1:25

dome, and then repair it, which may require

1:28

involvement of urology at the time of surgery.

1:32

Another key feature that should be evaluated

1:34

in patients with suspected placenta

1:36

percreta is involvement of the parametrium

1:40

and recruitment of the uterine vessels.

1:43

The parametrium is a fibrous band of

1:45

tissue that separates the supravaginal

1:47

cervix from the urinary bladder.

1:50

You will not see the parametrium in a pregnant

1:53

patient because of all of the vascularity

1:55

that normally proliferates in the pelvis.

1:59

The parametrium extends between

2:00

the broad ligaments, and the uterine

2:02

arteries run within the parametrium.

2:05

So in patients who have placenta percreta, as

2:08

is the case here, if you see recruitment of

2:11

the uterine arteries by the aberrant placenta,

2:15

you can imply that the parametrium is involved.

2:18

So in this patient, we're at the level of the

2:21

urinary bladder on this T2-weighted axial image.

2:24

We can see a placental tissue mass in the lower

2:27

uterine segment near the internal cervical os.

2:31

The uterine arteries are branches off of the

2:34

anterior division of the internal iliac artery.

2:37

And we can see in this patient T2

2:39

dark vessels, which are extending

2:41

directly from the region of the uterine

2:43

arteries toward the abnormal placenta.

2:47

Identifying parametrial involvement and uterine

2:50

vascular recruitment is important because

2:52

it may necessitate radical hysterectomy.

2:55

If branches of the uterine arteries are

2:56

involved, the surgeon will have to take

2:58

a broader, more lateral vascular pedicle

3:01

rather than a traditional hysterectomy.