Placenta Accreta

Preoperative Dx Can Save

Lives

Mickye Adams, M. D.

Perinatalogist

Alameda County Medical

Center

Case 1 – Placenta Previa

• Hx –

• 30 yo G3 P2-3 at 37 wks with 2

prior C/S

• Prenatal care at Community

Clinic

• Dx with Complete Previa in 2nd T

Risk Factors for Accreta

• Incidence• 1950S – 1:30,000

• 1990S – 1:500-2500

• Previa is major RF• Unscarred Ut 1-3%

• 1 prior C/S 11-25% (20)

• 2 prior C/S 35-47% (40)

• 4 or more C/S 50-67% (60)

• Other RF: AMA, Hi Parity, EM defects (Ashermans, Multiple D&Cs) Submuc Myomata

• Hi MSAFP (2.5 MOM) in 45% of Accreta• Hi MSAFP (unexplained) – 8 X increased risk

Diagram of Placental Invasion

The classification of placental

invasion into myometrium is as

follows:

Type

Invasion of

chorionic villi has

occurred

Accreta (adjacent)Superficially into

myometrium

Increta (invades)Deep into

myometrium

Percreta

(penetrates)

Through the

myometrium

Why make the Dx?

• Placenta Accreta

• Accounts for 2/3 of all emergency

c/hysterectomies

• Sequelae of C/Hyst

• Massive hemorrage

• DIC

• ARDS

• Renal Failure

• Death

Zelop et al. AJOG 1993; 168:1443.

What if it’s a Percreta?Series of 109 cases

• >10 unit transfusion (40%)

• Infection (28%)

• Perinatal Death (9%)

• Maternal Death (7%)

• This is data BEFORE preoperative diagnosis was available.

O’Brian et al. AJOG 1996; 175:1632

Sono For Accreta

• Ultrasound with Color Doppler most

tested and proven technique for Dx

Accreta

• Sensitivity 80%, Specificity 95%

• PPV about 70-80%, NPV near 100%

• Dx may be made in 1st T!

• Prior c/s and GS in LUS

• 6/7 had accreta

Sono For Accreta

• 20-24 wk sono best time

• Allows counseling

• Possible autodonation of blood

• Extensive planning for timing and location of delivery

− Possible Amnio at 35-36 wk

• Arrange Preoperative Balloon Catheter placement

• Other Surgeons available

• Late sono may clarify extent, help plan

Sono For Accreta

• Loss of Hypoechoic boundry

between Placenta and Myometrium

• Prominent Vascular Lakes

• Hypervascularity of Bladder and

Uterine Serosa

• Prominent Subplacental Venous

Complex

• Turbulent Blood Flow

Loss of Hypoechoic PU interface

Loss of UP

Interface

Posteriorly

Placental Lake gives

“moth eaten” appearance.

“Moth Eaten” Placental Lakes

Turbulent blood flow along bladder wall

Power Doppler – Flow in Lacunae

Color Doppler

Badness

MRI for Accreta

• Less established in isolation

• May help if• Sono unclear

• Posterior previa – placenta with scar

• Percreta – to define extent of invasion

• MR with Gadolinium• Sensitivity 88%, Specificity 100%

• MRI in combo with sono – Better prediction of extent• More “conservative” management (less

C/hyst)

MRI Criteria for Accreta

• Heterogeneous signal in

Placenta

• Probably lacunae

• Intraplacental Bands on T2W

• Uterine Bulging into Bladder

MRI Loss of

Placental

Interface and

Heterogeneous

Placenta

Placenta Accreta/Increta on Gross

Hysterectomy specimen with abnormal placentation. Chorionic villi are in

direct contact with smooth muscle, without an intervening layer of

decidua.

Microscopically, the placental villi interdigitate

directly with the uterine myometrium, without an

intervening decidual plate.

Management if Accreta

Percreta Suspected

• Counsel woman about Risks

• Massive transfusion

• Bladder, ureter, bowel involvment

• C Hysterectomy

• ICU care

• Consider Autodonation of 2-4 units

• Designated Donor Not Recommended

• Higher risk than Volunteer/Anon

• Schedule Delivery BEFORE labor

• 37 wks if low risk accreta

• 35-36 wks if high risk accreta

• Consider Amnio before

Management if Accreta

Percreta Suspected

• Location: Main OR, GETA, Hosp with IR capacity

• Personel• Pelvic Surgeon or GYN Onc Immediately

Available

• Cell Saver useful• Normovolemic Hemodilution controversial

• Place 3 way foley, ureteral stents available

• F VIIa may be helpful if massive hemorrhage• No data on accreta, seems helpful in other

causes of OB Hem

IR Balloon Cath Use for

Accreta-Percreta

• Preop place in Bilateral Int Iliac

• Deliver Baby• HIGH Uterine incision

• Inflate baloons

• Attempt either placental extraction or move to c/hyst

• Deflate balloons when hemostasis established• Max total time inflated 20 min –arbitrary

• Intraop Fluoro may ID bleeders and allow Gel• Don’t have to wait to PP

• Leave catheters in for PP bleeding control

IR Balloon Caths in both Int Illiacs

Postoperative – Left in for Selective embolization

IR Balloon Caths

Useful? Complications?

• Personal Experience• 5 without – 4-20 units, all hysts

• 5 with – 1-4 units, only 2 hysts in percretas

• In Practice – antecdotal – very helpful, used about 6-7 times at JM, ABMC

• Less blood loss, transfusion, OP time (not found in all series)

• 3/19 had compl from caths• Thromboses, stent placements

Placenta Previa and

Prior C/S – Conclusions

• MAKE THE DIAGNOSIS PREOP

• Know RF for Accreta• Previa and prior c/s

• Late 2nd T sono • SPECIFICALLY for R/O Accreta

• Perinate or Rads with experience

• MRI if any question on sono• Radiologist with experience

• Possible Gadolinium

• C/S incision ABOVE placental edge, avoid visible vasculature

Probable Accreta

• Consult – Anesthesia, Blood Bank, GYN Onc available, General Surg and Urologist if Bladder/Broad involved or percreta

• Place IR balloons preop, keep in Postop

• Don’t have to do c/hyst in all cases of accreta

• Leaving placenta in situ• Higher complication rate – delayed

bleeding

• MTX not helpful

• 27 yo G4 P2012

• Prior c/s X 2

• 20 wk sono = “low placenta,

recheck 3rd T”

• 32 wk sono = Anterior placenta,

“inferior edge completely

covers the internal os”

• Hg 7, Hct 24%, on FeSo4

• Clinic visit yesterday

• 34 wks gestation –

• CNM asks me about timing for

repeat c/s

What to do now?

• Anterior Placenta

• Marginal Previa

• Fetal size/AF normal

Myometrium well defined in this view.

Placental parenchema OK.

What do you see? Heterogeneous,

Ill-defined

lacunae, “moth eaten”

Turbulent high-flow in these lakes.

Right lateral LUS on greyscale

Same area with color doppler

XXXXXX

What now?

• Does she have an accreta?

• Yes, probably

• Maybe

• No, very low probability

• Next steps?

• MRI in progress now

• IV Iron Dextran ASAP

• Arrange consult for possible IR

balloon cath placement

• May need to transfer to AB for this

• Consent for possible c/hyst

• Cell saver intraop