1) Placenta accreta spectrum disorders occur when the placenta invades and is inseparable from the uterine wall, posing risks of heavy bleeding. The incidence has increased 10-fold in recent decades due to rising c-sections.
2) Risk factors include placenta previa, prior c-sections, and other uterine surgeries. Early diagnosis using ultrasound and MRI is important for management planning.
3) Management involves a multidisciplinary approach, with the goal of minimizing blood loss through techniques like arterial embolization and hysterectomy if needed. Conservative management is sometimes attempted but carries risks if failed.
2. IMPORTANCE OF
UNDERSTANDING THE PLACENTA
ACCRETA SPECTRUM
• During recent times it has come to notice that the incidence of
placenta accreta has increased 10-fold in the past 50 years
due to the increasing number of cesarean sections.
• It is now an important cause of maternal morbidity and
mortality and one of the leading causes of peripartum
hysterectomy.
• Thus the need for detailed understanding with timely
diagnosis and management of this topic arises.
3.
4. INTRODUCTION
• Placenta accreta spectrum is attributed to
defective decidualization of the implantation
site and the absence of both decidua basalis
and Nita Buch’s layer resulting in direct
attachment of the chorionic villi to the
myometrium.
• In simple terms, the clinical condition is
when part of the placenta, or the entire
placenta, invades and is inseparable from the
uterine wall.
• Earlier it was known as morbidly adherent
placenta.
5. • Placenta is a connection between the mother and fetus
during the intrauterine period.
• It allows maternal blood to supplement nutrients,
waste elimination, and gaseous exchange.
• Placental development starts from implantation and
completes by the 12th week of gestation.
• It presents two surfaces, fetal and maternal.
6.
7. PATHOPHYSIOLOGY
• The placenta consists of two plates: a chorionic plate
and a basal plate.
• Chorionic plate forms the fetal surface. It is covered by
a shiny translucent membrane and provides a site for
attachment to the umbilical cord.
• Chorionic plate forms the stem villi.
8.
9.
10.
11. The basal plate consists of the following structures:
• 1) Zona Compacta and Zona Spongiosa forming
the decidua basalis.
• 2) Nitabuch’s layer: fibrinoid degeneration of
outer syncytiotrophoblast.
• 3) Cytotrophoblast.
• 4) Inner syncytiotrophoblast.
12. • Placenta accreta presents when there is;
1. Absence of decidua basalis.
2. Absence of Nitabuch’s fibrinoid layer.
3. Varying degrees of penetration of villi in the
myometrium.
13. RISK FACTORS
• Placenta previa and the number of Prior C-sections are considered two major risk factors.
Placenta previa is when the placenta attaches inside the uterus but in a position near or over the
cervical opening.
Symptoms include vaginal bleeding in the second half of pregnancy.
The bleeding is bright red and tends to be painless.
14.
15. Other risk factors are :
• Previous uterine surgery,
• Previous dilatation and curettage,
• Previous history of manual removal of placenta,
• Previous myomectomy,
• Ashermann syndrome (endometrial defects),
• Submucous leiomyoma,
• Advanced maternal age (>35 years) and
multiparity (>6 pregnancies) etc.
16. INCIDENCE
• The incidence of the adherent placenta is
gradually increasing due to the increase in
cesarean section.
• The incidence of Cesarean section has increased
from 7% in 1990 to 21% in 2021 and is projected
to continue increasing in the current decade.
• As the number of previous cesarean sections
increases incidence of placenta accreta increases.
• Current estimates of incidence of placenta accreta
vary from 1.7 to 30 per 10,000 deliveries.
17. CLASSIFICATION
• Accreta (75%): The placenta is attached to the myometrium.
• Increta (17%): The placenta invades the myometrium but does not reach the serosa.
• Percreta (5-7%): The placenta penetrates through the entire myometrium and uterine
serosa. It can lead to the destruction of adjacent organs, most often the bladder, or surgical
injury of pelvic structures due to loss of tissue planes.
18.
19. PRESENTATION
• Placenta accreta can cause:
• Heavy vaginal bleeding:
Placenta accreta poses a major risk of severe vaginal bleeding (hemorrhage) before or
after delivery. The bleeding can cause a life-threatening condition that prevents your
blood from clotting normally (disseminated intravascular coagulopathy), as well as lung
failure (adult respiratory distress syndrome) and kidney failure. A blood transfusion will
likely be necessary.
• Premature birth:
Placenta accreta might cause labor to begin early.
• Difficulty in separation if diagnosed during delivery.
20. INVESTIGATIONS
Antenatal diagnosis of placenta accreta is made through
imaging modalities which include:
1)Ultrasound
Transvaginal ultrasound
Transabdominal ultrasound
2)MRI (magnetic resonance imaging)
21. ULTRASONOGRAPHY
• The primary diagnostic modality of antenatal
diagnosis of accreta spectrum is obstetrics
ultrasonography.
• Transvaginal scans are more sensitive in
confirming placental location and diagnosing
placental abnormalities at 20 th week of gestation
than transabdominal scans.
22. Sonographic markers of placenta accreta
• Loss of normal hypoechoic retroplacental zone.
• Multiple vascular lacunae.
• Thinning of the myometrium.
• Abnormality of uterine serosa bladder interface.
• Bulging of the lower uterine segment.
24. Placental lacunae
• Moth-eaten appearance or Swiss
cheese appearance.
• One of the most reliable signs of
placenta accreta is exaggerated
placental lacunae.
28. MAGNETIC RESONANCE IMAGING(MRI)
• When to recommend MRI for diagnosis of placenta accreta?
Equivocal USG findings of abnormal placentation.
Evaluation of posterior placenta in patients with risk factors.
Obese patients.
Complimentary role in specifically delineating the extent of a USG-diagnosed placenta
percreta.
29.
30.
31. MANAGEMENT
• Early diagnosis and timely management of placenta
accreta provide the key to reducing maternal morbidity
and mortality.
• Once the placenta accreta is diagnosed its management
starts from the antenatal period way before the actual
time of delivery.
• This is to obtain maximum maternal and fetal well-
being.
32. MANAGEMENT
Antenatal management
• Counselling.
• Regular follow up and early diagnosis.
• Referral to a higher center for a multidisciplinary
approach.
• Preparation for cesarean delivery, need of a
hysterectomy.
33. • Antenatal management
• Need for hospitalization
Antenatal bleeding.
Preterm labor.
Preterm prelabour rupture of membranes.
• Associated with unscheduled delivery as well as maternal and neonatal morbidity and
mortality.
34. • Antenatal management
• A multidisciplinary team approach is relevant in managing these patients in order to reduce
morbidity and mortality associated with adherent placenta.
• Experienced obstetrician
• Experienced anaesthetist
• Interventional radiologist
• Urosurgeon
• Neonatologist
• ICU management
• Blood bank
35. • Antenatal management
• Use of antenatal corticosteroids.
Antenatal steroids have been shown to reduce the occurrence and
mortality of infant respiratory distress syndrome, a life-threatening
condition caused by underdeveloped lungs.
Common corticosteroids include dexamethasone and betamethasone.
36. • Timing of delivery
• Planned delivery from
• 34 weeks to 35weeks
with corticosteroid cover.
Ideally, pregnancy with suspected accreta complex should be terminated electively before
36+6 weeks as the risk of bleeding and landing in emergency hysterectomy increases after it.
37. PREOPERATIVE
• Maximisation of preoperative hemoglobin values.
• Specific timing of planned delivery.
• Preoperative ureteric stent placemen.
• Interventional radiology approach.
Internal iliac artery occlusion/ balloon arterial catheterization to decrease blood loss.
38. PREOPERATIVE
Blood transfusion service:
Average blood loss is 1500 to 5000ml.
Prepare for a massive transfusion:
6 U PRC
6 U FFP
6 U platelets
10 U cryoprecipitate
Blood transfusion is initiated based on an ongoing hemorrhage.
39. PREOPERATIVE
Anesthesiology
• General anesthesia is preferred due to anticipated prolonged surgical
time and for better hemodynamic control.
• Assess blood loss and readiness for massive blood transfusion.
• Epidural catheter for postoperative pain relief.
40. PREOPERATIVE
Urology
• Preoperative cystoscopy and placement of ureteric stent: In case
of PERCRETA. It has a role only when the bladder is invaded by
the placenta.
• It should be placed in the operating room just before surgery with
all the staff prepared.
41. PREOPERATIVE
Balloon artery catheterization:
• Need a specialist interventional radiologist.
• Inserted under fluoroscopic guidance.
• Prophylactic insertion and keep deflated.
• Inflate the balloon after baby delivery and before starting bladder dissection & and
hysterectomy.
It is widely used where the facility is available in an attempt to minimize blood loss.
43. TRANEXAMIC ACID
• Prophylactic tranexamic acid given at the time of delivery after cord clamping.
• It is an antifibrinolytic agent.
• Dose 1 gm IV.
• Second dose : half an hour later if bleeding persists.
45. UTERINE ARTERY LIGATION
• 1st ligature- uterine artery at the avascular site in broad
ligament near the junction of uterus and cervix.
• Uterine artery ligation is the first step in systematic
pelvic devascularization.
46. • 2nd ligature- utero ovarian artery ligation
junction of utero-ovarian ligament and lateral
uterine border.
• Artery is ligated just below the point where the
ovarian suspensory ligament joins the uterus.
47. INTERNAL ILIAC ARTERY LIGATION
• Requires skill in retroperitoneal surgery at the pelvic sidewall.
• Success rate to control bleeding 50-75%.
• It was first performed by Burchell in the 1960s after doing
various experiments to control bleeding in postpartum
hemorrhage.
• It converts pelvic circulation into a venous system, thereby
aiding clotting and controlling pelvic hemorrhage.
50. • Even with the new techniques to decrease blood loss and uterus-preserving surgeries
CESAREAN HYSTERECTOMY is considered as the gold standard treatment for
invasive placenta although high rates of maternal morbidity(50%) and mortality (7%).
51. STEPS OF OBSTETRICS
HYSTERECTOMY
• Skin incision: Vertical midline incision is preferred over Pfannenstiel incision in obstetrics
hysterectomy. It provides sufficient exposure.
52. • Uterus incision: classical incision is preferred over transverse incision to avoid entry through
the placenta and prevent subsequent blood loss.
Classical incision with breech
extraction.
53. • After the baby is delivered,
• 1) The umbilical cord toward the maternal site is
ligated with linen stitch.
• 2) The uterine incision should be closed with WHIP
stitch with the placenta in situ.
• Total hysterectomy should be preferred over
subtotal hysterectomy to avoid the risk of
postpartum hemorrhage and further reexploration.
54. • Total hysterectomy- removal of the uterus with cervix.
• Subtotal hysterectomy / supracervical hysterectomy-
only the uterus is removed and the cervix is left in situ.
It requires less operative time.
58. IF BLADDER INVASION IS
CONFIRMED ?
• Instead of separating the bladder it can be intentionally
cut without touching the engorged vessels.
• Adopting a posterior approach may allow stepwise
devascularization of the uterus and may aid in a
hysterectomy.
59. COMPLICATIONS OF INVASIVE
SURGERY
• Median blood loss 1.5 to 3 litres
• Large volume of blood transfusion
• Genitourinary tract injury (7-48%)
• Admission to ICU
• Bowel injury
• Venous thromboembolism
• Surgical site infection
• Reoperation
• Maternal mortality
60. “UNEXPECTED” AND UNPLANNED
INTRAOPERATIVE RECOGNITION OF
PLACENTAACCRETA SPECTRUM
• Sometimes placenta accreta spectrum is unexpectedly recognized at
the time of cesarean delivery, either before the uterine incision
(optimal) or after the uterus is opened, the fetus is delivered, and
attempts to remove the placenta have failed.
• The level and capabilities of the response will vary depending on
local resources, timing, and other factors.
• If 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.
61. • In addition, the anesthesia team should be alerted and
consideration given to general anesthesia, additional intravenous
access should be obtained, blood products should be ordered, and
critical care personnel should be alerted.
• Patience on the part of the primary operative team is key, and they
should not proceed until circumstances are optimized.
• If mobilization of such a team is not possible, consideration of
stabilization and transfer is appropriate, assuming maternal and
fetal stability.
62. • Once the diagnosis of placenta accreta spectrum is
established and it is clear that placental removal will not
occur with usual maneuvers, then rapid uterine closure and
proceeding to hysterectomy as judiciously as possible
should be considered.
• Mobilization of appropriate resources should occur
concurrently with ongoing hysterectomy in conjunction with
the operating room nursing staff and anesthetic team.
63. CONSERVATIVE MANAGEMENT
• Indications of conservative management:
Preservation of fertility.
Hysterectomy carries an unacceptably high risk of
hemorrhage or injury to adjacent tissues.
• Important prerequisites:
Absence of predisposing factors of sepsis.
Patient is available for a close follow up and
understands the risk.
64. UTERINE PRESERVATION AND
EXPECTANT MANAGEMENT
• Leaving the placenta in situ: expectant management.
• Hysteroscopic resection of retained adherent placenta.
• Placental-myometrial en bloc excision and repair.
• Adjunctive procedures: Arterial occlusion, Methotrexate therapy.
• Delayed hysterectomy.
65. Triple P Procedure
• A novel uterine-sparing procedure used for placental myometrial en-block removal.
• Steps
1) Perioperative placental ultrasound localization of the superior edge of the placenta.
2) Pelvic devascularization: pre-operative placement of intraarterial balloon catheter.
3) Placental nonremoval with en block myometrial excision.
67. NEONATAL OUTCOME
• Neonatal outcome is mostly related to
prematurity.
• In case of bleeding placenta accreta where
emergency termination of pregnancy is required
irrespective of gestational age prematurity poses
an important threat for neonates.
• This also causes increased hospital stays and the
development of different neonatal complications
due to prematurity.
68. • Complications of prematurity in neonates
• Respiratory distress syndrome
• Bronchopulmonary dysplasia
• Apnoea of prematurity
• Patent ductus arteriosus
• Intraventricular haemorrhage
• Necrotising enterocolitis
• Sepsis
• Anemia
• Retinopathy of prematurity
69. THE DEADLY D’S OF ACCRETA
• DELAYED
• Delayed referral.
• Delayed cesarean i.e emergency.
• Delayed decision for hysterectomy.
• DEFICIENCY
• Deficiency of time availability: extensive adhesions, no time for pre-op devascularization.
• Deficiency of blood and blood product.
• Deficiency of ICU beds.
• Deficiency of multidisciplinary senior team.