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Radiology
Placenta Accreta
Built from Obstetric Imaging
What’s inside
10 sections · 86 slides
Overview
- What this session covers
The placenta that will not let go
What placenta accreta spectrum actually is, and how the diagnosis is confirmed
- The problem in one idea
- The layer that normally lets go
- Three depths, one spectrum
- Why one umbrella term is used
- How the diagnosis is actually made
- Placental tissue left adherent to the uterine muscle
- What that specimen teaches
How common, and who is at risk
A condition that has multiplied fifteenfold in fifty years
- 1 in 2510-4017
- Reading those numbers
- The two risk factors that matter most
- Normal placental position compared with placenta previa
- Risk climbs with each previous caesarean
- The other risk factors
- What the spectrum looks like in practice
- Depth of placental attachment in normal and abnormal implantation
What goes wrong in the uterine wall
From a caesarean scar to a placenta that cannot separate
- How a normal placenta beds in
- The defect that starts it all
- The explanation has changed
- Depth drives severity
- Why that matters at the operation
How it shows up
Usually silent before birth, dramatic during it
- Suspicion is the first diagnostic step
- What patients feel before delivery
- What the surgeon may see on opening
- When it is only found in the third stage
- What massive bleeding can cost
Finding it on ultrasound
The primary screening and diagnostic tool, and its real limits
- Why prenatal detection is the whole game
- Who should be scanned for PAS
- Say why you are scanning
- The route from risk factor to safe delivery
- The earliest clue, in the first trimester
- Caesarean scar pregnancy, a close relative
- What happened when scar pregnancies were watched
- Telling scar pregnancy from a miscarriage
- Four agreed ultrasound markers
- Unpacking those markers
- Loss of the clear space between placenta and muscle
- Bladder line gone, and lacunae in the placenta
- Doppler shows the abnormal circulation
- How well each marker performs
- Range of Test Characteristics for Sonographic Markers of Invasive Placentation Reported in the Literature
- Reading that table
- The strongest single marker
- What colour Doppler adds
- A quantitative three-dimensional method
- Why the reported accuracy varies so much
- What happened when readers were blinded
- Trying to standardise the reading
- The honest summary on ultrasound
MRI, blood tests and look-alikes
Where the other tools help, and where they mislead
- Does MRI beat ultrasound?
- When MRI earns its place
- What the radiologist looks for on MRI
- Can a blood test predict it?
- What the biomarker studies found
- Things that mimic accreta on imaging
- A false positive is not a wasted alarm
Planning and performing the delivery
The team, the timing and the operation
- Why suspecting it early changes everything
- What an Accreta Center of Excellence means
- Who is round the table
- What the patient must be told
- Mode and timing of delivery
- Knowing where the placenta is before you cut
- Fundal hysterotomy at caesarean delivery
- Why the incision is made at the top
- The operation, step by step
- Uterine incision closed with a whipstitch before hysterectomy
- Leaving the placenta in place
- Balloon catheters: still unsettled
- How the babies do
Afterwards
Postoperative morbidity, uterine preservation and future pregnancies
- The commonest reason a womb is removed at caesarean
- Can the uterus be saved?
- When uterine preservation may be considered
- Talking about the next pregnancy
Take-home messages
What the referring physician needs to know
- What the referring physician needs to know
- Once accreta is suspected
- Key points
- Where this material comes from
- References
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- References (continued)
- Obstetric Imaging: Fetal Diagnosis and Care, 2nd Edition