placenta accreta spectrum, Topic ppt

1. Morbidly Adherent Placenta
Kritika Jha
MD Resident
2079/10/04
1-2 pm

2. Introduction
• Derived from latin “ ac-+ crescere “ : to grow from adhesion
to adhere
• Abnormal trophoblastic invasion of part or all of the placenta
into the myometrium of the uterine wall
ACOG 2018
• Term revised as Placenta Accreta Spectrum

3. Introduction
Incidence
• 1 in 2,510 births : 1980s
• 1 in 731 births : 2015
• 1 in 22000 of vaginal delivery in absence of placenta previa
• 50 % recognised preoperatively
• Mortality rate : 4 – 7 % in placenta percreta
James High Risk Pregnancy 5th ed

4. Incidence
Number of CS Incidence of PAS
(%)
Rate of PAS if
placenta previa (%)
Rate of PAS if no
placenta previa (%)
1 0.24 3.3 0.03
2 0.31 11 0.2
3 0.5 40 0.1
4 2.13 61 0.8
5 2.33 67 0.8
>/= 6 6.74 67 4.7
Arias Practical Guide to High Risk Pregnancy

5. FIGO Classification (2019)
• Grade 1 : Abormally adherent placenta:
Placenta adherent or acreta 80%
• Grade 2 : Abnormally invasive placenta: increta 15%
• Grade 3 : Abnormally invasive placenta 5%
3a: limited to uterine serosa
3b: urinary bladder invasion
3c: invasion of other pelvic tissue/ organs

6. Cesarean scar pregnancy
• 1 in 2000 pregnancies
• If pregnancy continued 100 % chances for PAS

7. Pathogenesis
• Damage to decidua basalis and nitubach layer
• Failure of normal decidualisation and loss of normal
subdecidual myometrial layer
• Upregulation of VEGF and angiopoietin -2 and downregulation
of VEGF and angiopoietin receptor
High volume, high velocity flow  placental lacunae
Fibrinoid deposition around implanted villi at uteroplacental
interface loss of parts of physiological detachment

8. Fig 1 : Types of Morbidly Adherent placenta
Focal
Total

9. Fig 2 : Cesarean hysterectomy specimen of MAP

10. Risk factors
• Prior morbidly adherent
placenta 29 %
• Placenta previa 3 %
• Previous LSCS
• Prior uterine surgery:
Myomectomy
Hysteroscopic resection of
adhesion
Endometrial ablation
• Prior uterine curettage
• Advanced age, smoking
• Multiparity
• Uterine irradiation
• H/O manual removal of
placenta, postpartum
endometritis
• Uterine anomaly

11. Clinical features
• Undiagnosed before delivery : ½ to 2/3rd of cases
• Antepartum haemorrhage : 30 % in presence of placenta
praevia
• Profuse , life threatening hemorrhage on attempted placental
separation DIC, ARDS, AKI, massive blood transfusion ( 5 % )
• Intra abdominal bleeding, hematuria, bladder symptoms :
cases of percreta

12. Clinical features
Neonatal
• Preterm delivery
• Small for gestational age/ IUGR
• Malpresentation

13. Diagnosis
 Ultrasound
Absence of ultrasound findings does not preclude a diagnosis
of placenta accreta spectrum
Clinical risk factors equally important as predictors of placenta
accreta spectrum
ACOG 2018

14. Diagnosis : Ultrasound
First trimester :
 Low implantation of gestation sac
 Irregular placenta myometrial interface
 Anechoic placental areas with / without vascular flow
James High Risk Pregnancy 5th ed

15. Ultrasound
Ultrasound finding Sensitivity Specificity
Abnormal placental lacunae, turbulent flow, moth
eaten appearance
77.4 % 95.02 %
Loss of retroplacental hypoechoic zone
Myometrial thinning < 1 mm overlying placenta
65.02 % 95.8 %
Abnormalities of uterus-bladder interface
- Bulge - Focal exophytic mass
49.7 % 99.8 %
Color Doppler abnormalities
- Subplacental numerous closely packed tortuous
vessels
- Uterovesical hypervascularity
90.8 % 87.7 %
Done at 18 – 20 week  28- 30 weeks  32 – 34 weeks
ACOG 2018

16. Ultrasound Finding
Fig 4: Bridging vessel in uterine bladder interface
Fig 3 : Placental lacunae

17.  MRI:
Not an initial modality for evaluation of PAS
- Depth of invasion
- Parametrial involvement
- Posterior placentation
Sensitivity : 75 – 100 % Specificity : 65 – 100 %
Diagnosis Cont..

18. MRI findings:
• Dark bands on T2 weighted imaging
• Bulging or visible invasion beyond uterine serosa
• Uterine scar thinning
• Parametrium involvement
Diagnosis Cont..

19. Fig 5 : MRI finding of MAP showing dark linear bands

20. Diagnosis Contd..
 Serum markers :
• Maternal serum alpha fetoprotein : Poor predictor
• Others:
Pregnancy-associated plasma protein A
pro B-type natriuretic peptide, creatinine kinase
Troponin
Free β-hCG (mRNA)
Human placental lactogen (cell-free mRNA)
Nonspecific

21. Diagnosis : Histopathology
Fig 6 : HPE of hysterectomy specimen showing loss of decidual layer between
villi and myometrium

22. Management
• Comprehensive multidisciplinary approach
• Timing of delivery :
34 – 35 6/7 (ACOG)
35 – 36 +6 (RCOG)
• Earlier : Persistent bleeding, Labor, Rupture of membrane,
Fetal compromise
• Cesarean hysterectomy with placenta left in situ
ACOG 2018

23. Management in known Morbidly
Adherent Placenta

24. Antenatal
• Counselling :
Ultrasound findings
Complications
Regular follow up
Referral to higher centre for multidisciplinary approach
Cesarean delivery, need of hysterectomy
• Use of antenatal corticosteroid

25. Antenatal
• Need of hospitalization :
Antenatal bleeding
Preterm labor
Preterm prelabor rupture of membranes
Associated with unscheduled delivery as well as
maternal and neonatal morbidity
ACOG 2018

26. Criteria to deliver in accreta centre of excellence
• Suspicion for accreta from sonographic findings
• Placenta previa with abnormal sonographic appearance
• Placenta previa with > 3 prior cesarean deliveries
• Prior classical cesarean delivery and anterior placentation
• Prior endometrial ablation or pelvic radiation
• Inability to adequately evaluate or exclude placenta accreta
• Any other reason to suspect placenta accreta
Cuunigham and Gillstrap’s Operative Obstetrics

27. Criteria for Accreta Centre of Excellence
• Multidisciplinary team
Experienced obstetrician
Imaging experts
Pelvic surgeon – Gynecological
oncology, Urogynecology
Anesthesiologist
• Intensive care facilities
Urologist
General surgeon
Interventional radiologist
Neonatologist
• Blood availability

28. Preoperative
• Maximization of preoperative hemoglobin values
• Specific timing of planned delivery
• Identification of exact location of delivery (surgical suite and its
associated capabilities)
• Preoperative consultations
• Consideration of patient and family needs given temporary
relocation to placenta accreta spectrum center of excellence

29. Preoperative
• Preoperative ureteric stent placement : case evaluation
• Iliac artery occlusion : decrease blood loss in some
• Preoperative placement of catheters or balloons into pelvic
arteries : Recommendation cannot be made for or against
ACOG 2018
• Antenatal diagnosis of placenta accreta spectrum uncertain :
Intraoperative observation for spontaneous uterine placental
separation

30. Multidisciplinary team approach
• Blood transfusion service :
Average blood loss : 1750 – 5000 ml
Prepare for massive tranfusion : 6 U PRBC, 6 U FFP, 6 pack platelet,
10 U cryoprecipitate
1:1:1 or 1:2:4 :: PRBC: FFP :PRP ACOG 2018
Initiated based on ongoing hemorrhage
Recombinant factor VII a, EPO, Total dose iron : correct anemia
Preoperative hemodilution

31. • Anesthesiology:
Regional anaethesia: preferred
Need of GA
Anticipate prolonged surgical time
Epidural catheter for pain relief postoperatively
Assess blood loss and readiness for massive blood transfusion
Temperature control
Multidisciplinary team approach
Hypovolemia
Hypothermia Acidosis

32. • Urology
Preoperative cystoscopy and placement of ureteric stent :
Anterior percreta
Intentional cystotomy in uninvolved area to visualise area of
invasion :
Protect trigone and ureterovesical junction and excise
involved portion under direct visualisation
Multidisciplinary team approach

33. Intraoperative
• Verification of appropriate complement of surgical expertise
• Intraoperative availability of resources to optimize each case
– eg, Cell-saver, adequate surgical trays, and necessary urologic
equipment
• Verification of availability of related services as necessary (eg,
interventional radiology)
• Coordination of blood bank with scheduling or timing of case
• Close monitoring : urine output, blood loss, hemodynamic status

34. Fig 7 : Algorithm for management of placenta accreta spectrum
Cunnigham and Gillstrap’s Operative Obstetrics
Intraoperative observation
for spontaneous uterine
placental separation
Percreta

35. Steps in cesarean hysterectomy
• Midline vertical laparotomy and midline hysterotomy : enter uterus
to avoid placenta
• Superior devascularisation : divide and ligate utero ovarian pedicles
and round ligament
• Retroperitoneal dissection : incise down to paravesical space;
cephalad dissection to expose ureter and bifurcation of common
iliac arteries
• Bladder dissection : progress lateral to medial and down to vaginal
fornices
• Colpotomy : inferior dissection of paravesical space
Williams Obstetrics 27th ed

36. • When necessary, ureterolysis is carried out to protect the
ureters and allow step-by step devascularization of the lower
uterine segment followed by separation of the bladder and
uterus
• In cases with deep placental invasion, intentional cystotomy
and partial bladder excision is favored over persistent
attempts at bladder dissection and mobilization
• In some cases in which the percreta involves the lateral pelvic
sidewalls, staged intraoperative angiographic embolization is
done before beginning the hysterectomy
Steps in cesarean hysterectomy

37. Fig 8 : Fundal incision followed by breech extraction

38. Intraoperative : Minimize blood loss
• Tranexamic acid :
Prophylactic tranexamic acid given at the time of delivery
after cord clamping
ACOG 2018
Dose : 1 g intravenously
Second dose : 0.5–23.5 hours later if bleeding persists

39. • Uterotonic agents
Tab misoprost 1000 mcg per rectal
Carboprost 250 mcg in 20 ml NS
infiltrated in myometrium
Intravenous oxytocin infusion
• Torniquet :
Above placental edge
Intraoperative : Minimize blood loss
Fig 9 : Torniquet placement

40. Intraoperative : Minimize blood loss
Devascularisation
• Uterine artery ligation
At the level of the uterine
incision
Avascular site in broad
ligament
Second ligature : junction of
uteroovarian ligament and
lateral uterine border.
Fig 11 : Uterine Artery Ligation

41. Devascularisation
• Internal Iliac artery ligation
– Technically difficulty
– Requires skill in retroperitoneal
surgery at the pelvic sidewall
Success rate to control bleeding
50 – 75 %
Complications
- Ligation of internal iliac vein,
external iliac artery
- Ureteral injury
- Retroperitoneal hematoma
Intraoperative : Minimize blood loss
Fig 10 : Internal Iliac Artery Ligation

42. Intraoperative : Minimize blood loss
Interventional radiology
• Pelvic artery embolisation :
– Risk of uterine necrosis
– High failure rate ( 70 % in PPH )
• Internal iliac artery catheterisation: Effective in percreta
- Costly equipment
- Complex procedure
- Risk of maternal thromboembolic event
- Fetal radiation exposure

43. Interventional radiology
• Intra aortic balloon occlusion :
– minimally invasive and safe
– short fluoroscopy time
– No need of complex logistics
– Positive cardio circulatory effect
– No affect on fetal- placental circulation

44. Temporary management of uncontrolled
hemorrhage
• Cessation of surgery
temporarily
• Infrarenal aortic clamping
• Pelvic packing
• Closure of skin with towel
clip
• Aggressive resuscitation
with blood product
• Patient warming
• Waiting for reversal of
coagulopathy before
resuming surgery : best
option
• Patient to be shifted in
monitoring bed until return to
operating room
• Placing abdominal drain

45. Postoperative
• Assurance that critical care services are engaged and available
for postoperative care
• Identification of the need for identification of primary service
responsible for postoperative care
• Need of thromboprophylaxis

46. Post Operative Period
• Clinical vigilance for complications :
- Renal failure
- Liver failure
- Infection
- Unrecognized ureteral, bladder, or bowel injury
- Pulmonary edema
- Disseminated intravascular coagulation
- Sheehan syndrome

47. Management in Unexpected MAP
• Placenta accreta spectrum is suspected based on uterine
appearance and there are no extenuating circumstances
mandating immediate delivery, the case should be
temporarily paused until optimal surgical expertise arrives
• Additional intravenous access should be obtained, blood
products should be ordered, and critical care personnel
should be alerted

48. Unexpected MAP
Fig 12 : Placenta percreta at time of laparotomy

49. Management in Unexpected MAP
• Accreta :
Hemostasis in myometrial
bed using Cho suture
Suturing inverted cervical
tissue over the area of
bleeding placental bed
Compression suture
Fig 13 : B- Lynch compression suture

50. Conservative and Expectant management
• Candidate
- Desire to preserve fertility
Counsel regarding risks of hemorrhage, infection, need of
hysterectomy, recurrence in subsequent pregnancy and
even death
- High risk of hemorrhage and other organ injury during
hysterectomy
- Placental resection : Focal accreta
Fundal or posterior placenta

51. Conservative management Contd.
• Expectant management
- Placenta left in situ
ACOG 2018:
Attempt only rarely as a part of approved
clinical trial in fully informed patients

52. • Delayed interval hysterectomy
Not recommended
Option in
- Severe life threatening cases
- When immediate hysterectomy is dangerous
Extent of placental invasion (percreta)
Lack of resources
Conservative management Contd.

53. Conservative Management : Placental
myometrial en bloc excision and repair
• Candidate : Clearly delineated focal area of involvement
• Triple P : Preoperative placental localisation
Pelvic devascularisation with preoperative placement
of intraarterial balloon catheter with inflation after
delivery / ligation of uterine artery
Placenta removed with Enbloc myometrial excision
and repair

54. Adjunct to conservative or expectant
• Devascularization:
– Uterine artery balloon placement
– Embolization or ligation
• Postdelivery methotrexate administration
• Hysteroscopic resection
• High intensity focussed ultrasound : not recommended

55. • Methotrexate
MOA: Disruption of folic acid pathway in rapidly dividing cells such as
trophoblasts
Proliferation of trophoblasts in later stages of pregnancy :
no role in placental growth
Use of methotrexate may not reduce placental volume
Adverse effects : Increased risk of infection and sepsis
Pancytopenia
Nephrotoxicity
Conservative management Contd.

56. Conservative management : Methotrexate
therapy
• Methotrexate adjuvant therapy should not be used for
expectant management as it is of unproven benefit and has
significant adverse effects.
RCOG Green top guideline 2018
• Methotrexate therapy should not be used
ACOG 2018

57. Follow up
The pattern of follow-up for the conservative management of
placenta accreta spectrum is not supported by RCTs and is not
stratified according to the depth and lateral extension of villous
myometrial invasion
• Clinical :Temperature monitoring
Per vaginal bleeding,
Foul smelling per vaginal discharge
Pain abdomen
• Lab parameter : Serial b-HCG , CBC, High vaginal swab
• Radiology : Ultrasound

58. Outcome of conservative management
Median time to placental
involution : 13.5 weeks
Complications :
• Severe vaginal bleeding 53 %
• Sepsis 6 %
• Secondary hysterectomy 19%
• Death 0.3 %
• Subsequent pregnancy 67%
• Recurrence 22-29 %
Cunnigham and Gilstrap’s Operative Obstetrics

59. Case presentation
• Mrs Bhatta 33 years
Referred case from Kailali for Placenta Previa
• Presenting complaint : Pregnancy for 8 months
Per vaginal bleeding for 2 weeks
• Obstetric history : P 1 – Em LSCS for oligohydraminos 3.5 years back
• USG: Anterior low lying placenta 1.3 cm from os with placental lake
• MRI : Complete placenta previa

60. Case presentation Contd.
Cesarean hysterectomy for placenta previa with focal placenta
accreta with right pelvic hematoma with PPH at 37 weeks of
gestation
• POF : Placenta completely covering os and anterior focal acreta in
right lower segment
• Following delivery of placenta  bleeding from placental bed
secured by hemostatic suture bleeding continued and hematoma
developed in lower uterine segment  cesarean hysterectomy
• Blood loss : 2 litres
• Blood transfusion : 2 pint WB + 3 pint PRP
• Post operative : ICU stay * 2 days
Blood transfused: 3 pint WB + 2 pint FFP
HPE : Endometrium showed decidualised stroma with thick muscular
wall. No chorionic villi

61. Conservative management of placenta increta in a primigravida:
A case report
Waheed et al 2019 JPMA
• In July 2017, Mrs. ABC, 25 yr, primigravida booked at 36 WOG
• Ultrasound showed a S/L /F 36 wog, adequate AFI, fundal placenta
with no evidence of myometrial invasion
• At 38 wog : Presented in emergency with labour pain
os: 3 cm, Cardiotocogram( CTG) showed variable decelerations
ARM: meconium stained liqour
Emergency caesarean section decided

62. Case Report Contd
• Delay in the delivery of
placenta
After waiting for 30 minutes,
10 U oxytocin given in
umbilical cord
• Again tried to deliver the
placenta but no plane of
cleavage identified
• Uterus exteriorized and
placenta found to be invading
the myometrium at fundus,
sparing only serosa of uterus

63. • Management options discussed including the need for a
Caesarean hysterectomy in case of massive haemorrhage
Approximate blood loss in surgery - 1 litre
Vitals- Stable.
Bilateral uterine artery ligation done
• Conservative management was planned
Planned for emergency hysterectomy if any problem such as
haemorrhage or infection during the course of treatment
Case Report Contd

64. CBC, LFT, RFT : normal
Injection methotrexate at 6hours of surgery
Intravenous antibiotic
• Discharged on 4 th post op day
• Temperature : Twice daily.
• Monitor for vaginal bleeding , contact if heavy bleeding.
• Weekly CBC and bHCG tests : first 4 weeks.
• Ultrasounds : Twice weekly.
• Intravenous antibiotic continued to avoid sepsis.
• Weekly visits to doctor
Case Report Contd

65. • Vitals stable and investigations normal
2nd dose of methotrexate given : after 1 week
Intravenous antibiotics for another 4 weeks
3rd dose of methotrexate given: after 2 weeks
TLC normal throughout visits
bHCG normalised in 2 months
Ultrasound (5 months) : no retained piece of placenta
Conservative management of placenta increta : successful
Case Report Contd

66. Take home message
• Risk factors for placenta accreta spectrum should be assessed
• History of previous cesarean section and placenta previa are
most common association
• Antenatal diagnosis in patient with suspicion for PAS should be
done by ultrasound
• Undiagnosed case in which plane of separation can not be felt
should not be attempted with manual removal of placenta

67. • Peripartum / cesarean hysterectomy remain choice of treatment in
placenta increta and percreta
• Referral to centre equipped with trained personnel and availability
of blood product
• In elective case, pelvic artery catherisation should be considered
• If conservative management is planned , counselling should be
done regarding complications and need of hysterectomy
Take home message

68. References
• William’s Textbook of Obstetrics 26th edition
• James High Risk Pregnancy 5th ed
• Arias Practical Guide to High risk pregnancy
• Cuunigham and Gillstrap’s Operative Obstetrics
• ACOG Guidelines placenta accreta spectrum 2018
• RCOG Green Top Guidelines 2018
• Recent advances in Obstetrcs and Gynecology 26

69. THANK YOU