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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
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