Placenta accreta

Dr. Mohammed AbdallaDr. Mohammed Abdalla

Egypt, Domiat General HospitalEgypt, Domiat General Hospital

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definitionplacenta accreta occurs when there is a

defect of the decidua basalis, in conjunction with an imperfect development of the Nitabuch

membrane ( a fibrinoid layer that separates the decidua basalis from the placental villi). resulting in abnormally invasive implantation of the placenta

The ACOG committee

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incidence

from 1930 to 1950--one case in 30,000 deliveries.From 1950 to 1960, one in 19,000, deliveries.by 1980 to one in 7,000.the incidence has now risen to one in 2,500 deliveries,The ACOG committee

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The incidence of placenta accreta has increased 10-fold in the past 50 years, to a current frequency

of 1 per 2,500 deliveries.

largely as a result of the increase in the number of

cesarean sections

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it is reported to have a mortality rate of around

7 percent and is the most common indication

for birth-related hysterectomy.

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degrees of severity(1) Accreta vera, in which the placenta adheres to the myometrium without invasion into the muscle. (2) Increta, in which it invades into the myometrium. (3) Percreta, in which it invades the full thickness of the uterine wall and possibly other pelvic structures, most frequently the bladder.

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Risk factorsRisk factors for placenta accreta include :1. placenta previa with or without previous

uterine surgery.2. previous myomectomy.3. previous cesarean delivery. 4. Asherman's syndrome.5. submucous leiomyomata. 6. maternal age of 36 years and older.

The ACOG committee

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the risk of maternal and fetal complications increases

notably after the 35th week exceeding 90% after the 36th week as associated

with the degree of invasion.

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Higher riskThe association between

placenta praevia and placenta accreta is strong, with a relative

risk of 2,065 compared to women with a normally sited

placenta.

Am J Obstet Gynecol 1997;177:210-4.

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Placenta praevia itself raises the risk for accreta due to implantation over a highly

vascular, poorly contractile lower uterine segment; an existing scar in this same area, as well, obviously compounds the risk.

Highest risk

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Risk associationC.S (No.) P.P(%)P.P+ accreta

%

00.265

10.5624

21.840

33.047

410.067

Source: Modified from Clark SL, et al., , the American College of Obstetricians and Gynecologists.

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Prenatal risk probability

Because of the fact that many of these cases become evident only at the first

attempt to separate the placenta at delivery, it is essential to attempt to identify antenatally both placenta

accreta and its attendant risk factors, the most common of which is concurrent placenta previa.

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Placenta previa is less frequently diagnosed as gestational age advances due to the so-called

"placental migration" phenomenon. A diagnosis of placenta previa is unlikely to

change after 32 weeks' gestation,

placenta praevia

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incidence of placenta praevia fell with advancing gestational age :

• 76% at 17 weeks' gestation .

• 3% at term.

placenta praevia

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Prenatal diagnosis of this pathology relies on the capacity to visualize the internal cervical os and its relationship with the lowermost edge of the placenta.

Placenta previa exists when the placenta is inserted wholly or in part into the lower segment of the uterus.

placenta praevia

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If it encroaches on the cervical os it is considered

a major or complete praevia if not then minor or partial praevia exists.

placenta praevia

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The mode of delivery should be based on clinical judgement in

each situation….

complete or major placenta praevia,

should be delivered by c.s

Evidence level III , grade B recommendation RCOG

placenta praevia

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but in partial praevias a placenta encroaching

within 2cm of the internal os is a contraindication to

attempting vaginal delivery.

Evidence level III , grade B recommendation RCOG

Diagnosis of placenta accreta

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characterized by a hypoechoic boundary between the placenta and the urinary bladder that represents the myometrium and normal retroplacental myometrial vasculature.

The normal placenta has a homogenous appearance as well.

Gray-scale sonographic signs of placenta accreta

normal placental

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Gray-scale sonographic signs of placenta accreta

• Loss of the retroplacental hypoechoic zone• Progressive thinning of the retroplacental

hypoechoic zone• Presence of multiple placental lakes ("Swiss

cheese" appearance)• Thinning of the uterine serosa-bladder wall

complex (percreta)• Elevation of tissue beyond the uterine serosa

(percreta)

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practical disadvantages of TAUS

• A bladder that is too full may distort the lower uterine segment by displacing it posteriorly; thus a low-lying placenta may erroneously appear to be covering the internal os.

• shadowing from the symphysis pubis or the fetus.

• suboptimal resolution when imaging patients who are obese.

• the presence of myometrial contractions that can distort the internal contour of the uterus, resulting in false-positive diagnoses.

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TVUSTransvaginal sonography. This simple,

widely available technique is now the preferred route for evaluating a patient suspected of having placenta previa.

sensitivity of 87.5%

specificity of 98.8%

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• Using a transvaginal probe, the cervix is evaluated in the sagittal plane.

• A small amount of urine in the bladder is desirable to help delineate the anterior cervical lip.

• The probe is placed under direct visualization and does not need to touch the cervix to obtain an adequate image. In fact, since the focal length of the probe is 2 to 3 cm, placing the probe too close to the cervix will blur the image.

TVUS

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Color Doppler signs suggestive of placenta accreta

Dilated vascular channels with diffuse lacunar flow.

Irregular vascular lakes with focal lacunar flow.

Hypervascularity linking placenta to bladder.

Dilated vascular channels with pulsatile venous flow over cervix.

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newly formed vessel + multiple placental lakes

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newly formed vessels + loss hypoechogenic security area

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The uterine segment is shown totally destroyed.

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multiple layers of newly formed vessel

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Newly formed vessel+ multiples lakes

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the multiple layers of newly formed vessel between uterus and the

bladder

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wickler and associates observed that when myometrial thickness was greater than 1 mm and large placental lakes existed, myometrial invasion could be predicted with a sensitivity and specificity of 100% and 72%, respectively.

Color Doppler signs suggestive of placenta accreta

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MRI

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certain occasions the information obtained by the ultrasound is not conclusive, particularly in the differentiation between the placenta accreta and percreta. In these cases, or in those in which additional anatomical information is wanted on the placental invasion, the vascularization or on the actual state of the uterine and vesicle wall, the Nuclear Magnetic Resonance (MRI) provides precise anatomic images.

MRI

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The study must be recommended in those patients with potential life risk during the surgical procedure. The examination should be done with the informed agreement of the patient.

MRI

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The analysis cost benefit in the risk cases is distinctly favorable for the resonance, especially when its result modifies the opportunity and the most adequate technique of vascular control.

MRI

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The information obtained by the Obstetric Magnetic Resonance has shown an excellent correlation with the surgical findings. Its use must be recommended in the planning of any surgery of placenta percreta, being indispensable when a conservative uterine treatment is planned.

MRI

Management of intractable haemorrhage associated with placenta

accreta

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Management

1.Medical

2.Surgical.

3.Uterine packing.

4.Conservative.

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In the sever cases of placenta percreta anterior, the uterovesical

vascular anastomotic net obliges to fundal hysterotomy and creates the

necessity of a vascular, proximal control of the iliac system,

impossible of reaching by a parietal incision of Pfannestiel.

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misoprostol• * Keep five 200-[micro]g tablets of

misoprostol in the delivery or operating room.

• * If uterine atony occurs and doesn't respond to oxytocin or ergometrine (or if ergometrine is contraindicated), place the patient in the frog-leg position, and while assessing the extent of vaginal bleeding, place five tablets in her rectum.

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A woman meets the criteria for the B-Lynch compression

suture if bimanual compression decreases the amount of uterine bleeding by abdominal and perineal

inspection.

Lynch suture B-

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Lynch suture B-

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the B-Lynch suturing technique

The uterus is exteriorised and rechecked to identify any bleeding point.

where no obvious bleeding point is observed then bimanual compression is first tried to assess the potential chance of success of the B-Lynch, suturing technique. The vagina is swabbed out to confirm adequate control of bleeding.

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1. A 70 mm round bodied hand needle on which a No. 2 chromic catgut suture is mounted is used to puncture the uterus 3 cm from the left lower edge of the uterine incision and 3 cm from the left lateral border.

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2. The mounted No. 2 chromic catgut is threaded through the uterine cavity to emerge at the upper incision margin 3 cm above and approximately 4 cm from the lateral border (because the uterus widens from below upwards).

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3. The chromic catgut now visible is passed over to compress the uterine fundus approximately 3 - 4 cm from the left cornual border.

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4. The catgut is fed posteriorly and vertically to enter the posterior wall of the uterine cavity at the same level as the upper anterior entry point.

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5. The chromic catgut is pulled under moderate tension assisted by manual compression exerted by the first assistant. The length of the catgut is passed back posteriorly through the same surface marking as for the right side the suture lying horizontally.

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6. The catgut is fed through posteriorly and vertically over the fundus to lie anteriorly and vertically compressing the fundus on the right side as occurred on the left. The needle is passed in the same fashion on the right side through the uterine cavity and out approximately 3 cm anteriorly and below the lower incision margin on the right side.

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7.The two lengths of catgut are pulled taught assisted by bi-manual compression to minimise trauma and to achieve or aid compression. During such compression the vagina is checked that the bleeding is controlled.


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8-As good haemostasis is secured and whilst the uterus is compressed by an experienced assistant the principal surgeon throws a knot (double throw) followed by two or three further throws to secure tension.


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9-The lower transverse uterine incision is now closed in the normal way, in two layers, with or without closure of the lower uterine segment peritoneum.


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Uterine Artery LigationUterine Artery Ligation

Uterine artery ligation involves taking large purchases

through the uterine wall to ligate the artery at the

cervical isthmus above the bladder flap .

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Hypogastric Artery Ligation

1. The hypogastric artery is exposed by ligating and cutting the round ligament and incising the pelvic sidewall peritoneum cephalad, parallel to the infundibulopelvic ligament

2. The ureter should be visualized and left attached to the medial peritoneal reflection to prevent compromising its blood supply.

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.3.The common, internal, and external iliac arteries must be identified clearly.

4.The hypogastric vein, which lies deep and lateral to the artery, may be injured as instruments are passed beneath the artery, resulting in massive, potentially fatal bleeding.

Hypogastric Artery LigationHypogastric Artery Ligation

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5. The hypogastric artery should be completely visualized.

6. A blunt-tipped, right-angle clamp is gently placed around the hypogastric artery, 2.5 to 3.0 cm distal to the bifurcation of the common iliac artery.

7. Passing the tips of the clamp from lateral to medial under the artery is crucial in preventing injuries to the underlying hypogastric vein .


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8. The artery is double-ligated with a nonabsorbable suture, with 1-0 silk, but not divided .

9. The ligation is then performed on the contralateral side in the same manner.


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prospective study was done in the Obstetrics and Gynecology Department of Dhaka Medical College and Hospital, Bangladesh, between July 2001 and December 2002.152 cases of PPH were identified; 109 were managed medically; 20 were managed using the B-Lynch procedure, and 23 were managed using the condom catheter. Patients in whom PPH due to atonicity or morbid adhesion (accreta) could not be controlled by medical treatment or the surgical approach were selected for intervention with the condom catheter.

Posted 9/11/2003

uterine packinguterine packingUse of condom

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1. Under aseptic precautions a sterile rubber catheter was inserted within the condom and tied near the mouth of the condom by a silk thread.

2. Urinary bladder was kept empty by indwelling Foley's catheter.

Use of a Condom to Control Massive Postpartum Hemorrhage

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3. After putting the patient in the lithotomy position, the condom was inserted within the uterine cavity.

4. Inner end of the catheter remained within the condom.

5. Outer end of the catheter was connected with a saline set and the condom was inflated with 25-500 mL of running normal saline.


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6. Bleeding was observed, and when it was reduced considerably, further inflation was stopped and the outer end of the catheter was folded and tied with thread.


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7. Uterine contraction was maintained by oxytocin drip for at least 6 hours after the procedure.

8. The uterine condom was kept tight in position by ribbon gauze pack or another inflated condom placed in the vagina.

if the concern for concealed hemorrhage still exists, ultrasound can more effectively detect a developing hematoma when the contrast is a fluid-filled balloon .


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9. The condom catheter was kept for 24-48 hours and then was deflated gradually over (10-15 minutes) and removed.

10.Patient was kept under triple antibiotic coverage (amoxicillin [500 mg every 6 hrs] + metronidazole [500 mg every 8 hrs] + gentamicin [80 mg every 8 hrs]) administered intravenously for 7 days.


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Main Outcome Measures

In all 23 cases in which the condom catheter was used, bleeding stopped within 15 minutes. No patient needed further intervention. No patient went into irreversible shock. There was no intrauterine infection as documented by clinical signs and symptoms and culture and sensitivity of high vaginal swab.

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Conclusion: The hydrostatic condom catheter can control PPH quickly and effectively.

It is simple to use, inexpensive, and safe.


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Use of Foley catheter or a

Sengstaken-Blakemore tube

Balloon tamponade using either a Foley catheter or a Sengstaken-

Blakemore tube has been shown to effectively control postpartum bleeding--and may be useful in several settings: uterine atony, retained placental tissue, and

placenta accreta.

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A Foley catheter

• A Foley catheter with a 30-mL balloon capacity is easy to acquire -----Using a No. 24F Foley catheter, the tip is guided into the uterine cavity and inflated with 60 to 80 mL of saline.

Additional Foley catheters can be inserted if necessary.

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the Sengstaken-Blakemore tube

• the Sengstaken-Blakemore tube has the advantage over the Foley

catheter due to the larger capacity of its balloon tip.

• unlike the Foley catheter, this device may be more difficult to obtain in an emergency setting

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hysterectomyhysterectomyResort to hysterectomy Resort to hysterectomy

SOONER RATHER THAN SOONER RATHER THAN LATERLATER (especially in cases of (especially in cases of placenta accreta when future placenta accreta when future

fertility is out of concern) fertility is out of concern)

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Intraoperatively, bleeding is rarely a problem until an attempt is made to remove the placenta. Accordingly, the uterine incision should be made vertically and above the placental insertion site.

hysterectomyhysterectomy

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Following delivery of the infant, the cord is clamped and the uterine incision is oversewn circumferentially to decrease blood loss. A hysterectomy is then performed with meticulous attention to securing haemostasis. Electrocautery and vascular clips may be of significant benefit during the dissection.

hysterectomyhysterectomy

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Selective arterial embolization

• While the availability of SAE varies from institution to

institution, if it is available at your institution, here are some tips to keep in mind:

1. Ascertain the hours when SAE is available and establish protocols of accessibility.

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2. If a patient is at risk for PPH, we advise pre-delivery consultation with the interventional radiology team. Place embolization catheters prior to the procedure if indicated, and make the team aware of the potential need for SAE to help them prepare for it.

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3.Make the decision to move to the interventional radiology suite as quickly as possible, keeping in mind that transfer can take 15 minutes and embolization can take 30 minutes.


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An alternative but unsubstantiated treatment is to leave the placenta undelivered

and treat the patient with methotrexate.

Conservative treatment of placenta accreta

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Conservative treatment of placenta accreta

Conservative treatment of placenta accreta appears to be an efficient way to preserve fertility with an associated treatment in most of cases (Bilateral hypogastric artery ligation , medical treatment with methotrexate or uterine artery embolization).

Health & Medicine

Placenta accreta