Management of Abnormally Invasive Placent

An expert is a person with significant experience in AIP and a high level of knowledge and/or skills relating to the condition.

(D)

Expectant outpatient management of women with AIP, even in the presence of placenta previa, is acceptable treatment, as long as the woman is asymptomatic and has been appropriately counseled.

(C)

Symptomatic women (eg, those with bleeding, uterine contractions, or other obstetric complications) should be cared for according to local protocols and expertise.

(D)

As soon as women are antenatally diagnosed with AIP, they should have their Hb level measured. If it is low (<110 g/L [11 g/dL] before 28 weeks’ gestation or <105 g/L [10.5 g/dL] after 28 weeks’ gestation), appropriate hematinic investigations should be undertaken and if indicated, iron supplementation (oral or intravenous) should be given to optimize their Hb level before surgery.

(D)

The timing of delivery should be tailored to each unique set of circumstances and based on the individual woman’s risk of emergent delivery. To reduce the risk of neonatal morbidity, it is reasonable to continue expectant management until after 36.0 weeks’ gestation for women with no previous history of preterm delivery (<36.0 weeks’) and who are stable with no vaginal bleeding, preterm premature rupture of the membranes (PPROM), or uterine contractions suggestive of preterm labor.

(D)

In the case of women with history of previous preterm birth, multiple episodes of small amounts of vaginal bleeding, a single episode of a significant amount of vaginal bleeding or PPROM, planned delivery at around 34.0 weeks’ gestation should be considered given the increased risk of emergent delivery.

(D)

An individualized approach for antenatal steroid administration should be employed, based on the current local guidelines for the specific gestation at delivery, irrespective of the suspicion or diagnosis of AIP.

(D)

The IS-AIP does not recommend undertaking routine preoperative cystoscopy. If preoperative cystoscopy is performed for insertion of ureteric stents, the appearance of the bladder should not change the (imaging- based) plan of management.

(D)

Placement of ureteric stents may be beneficial in preventing ureteric injury and early morbidity.

(B)

The effect of prophylactic arterial balloon catheters on bleeding and morbidity among women with a prenatal diagnosis of AIP has yet to be confirmed. Significant adverse events have been reported from this procedure. Larger, prospective, appropriately controlled studies are needed to demonstrate both the safety and efficacy of prophylactic balloon occlusion. Given this, the IS-AIP cannot recommend routine use of prophylactic pelvic arterial balloon catheters for all cases of suspected.

(B)

When hysterectomy is either planned or likely, the woman should be placed in a position in which the vagina is accessible (such as lithotomy or legs straight on the operating table but parted) to facilitate manipulation of the cervix, if required to assist the hysterectomy. This will also allow easier assessment of any blood lost vaginally.

(D)

There is no evidence of benefit for routine use of a vertical midline incision for all cases of antenatally diagnosed AIP. The decision regarding which type of skin incision is used should be made by the operating team. The location of the placenta, degree of invasion suspected, likelihood of intraoperative complications, maternal body habitus, gestational age, and preference of the operating surgeon/obstetrician should all be taken into consideration.

(D)

Avoiding placental transection when making the uterine incision is essential if AIP is clearly evident on opening the abdomen, and is reasonable for women with antenatally suspected AIP but with no definite evidence seen at laparotomy, even if it means making an upper segment or fundal incision, as it is likely to reduce maternal blood loss from the placental bed.

(D)

If the US scan is undertaken in an appropriately sterile manner, the small theoretical risk of introducing infection is outweighed by the benefit of ensuring the incision is made away from the placental bed. Therefore, intraoperative US of the exposed uterus should be used, where possible, to locate the placental edge and assist decision making regarding the uterine incision site.

(D)

Prophylactic administration of oxytocin immediately after delivery increases contraction of the uterus, which could be helpful for the assessment of placental separation. If the whole placental bed is abnormally invasive, uterine contraction will not result in any placental separation. If, however, the placenta is only partially adherent or invasive, uterine contraction may cause some separation, leading to increased blood loss, which could prompt the surgeon to either forcibly remove the rest of the placenta or perform a more hurried hysterectomy. In light of this risk, the IS-AIP recommend that when AIP is suspected antenatally, prophylactic uterotonic agents should not be routinely given immediately after delivery of the infant. Instead a full assessment should be made in accordance with the intraoperative diagnosis recommendations (see next topic). Only if the placenta is removed, either fully or partially, or if there is already significant bleeding, should uterotonics be given. (D)

When expectant management is planned and AIP confirmed at delivery, forced manual removal of the placenta should not be attempted.

(B)

Expectant management appears to be associated with less blood loss and lower transfusion requirements than both hysterectomy and uterus-conserving surgery and will be successful for between 60% and 93% of women, with the remainder undergoing hysterectomy, usually for secondary PPH or infection.

(B)

There is no evidence of benefit from the use of methotrexate when the placenta left in situ. As there is evidence for potential significant harm including maternal mortality, the IS-AIP do not recommend the use of methotrexate for conservative management of AIP.

(B)

There is no evidence for prophylactic uterine artery embolization increasing efficacy of conservative management, and 2 cases of uterine necrosis have been reported in 2 cohort studies (level 2b evidence). Therefore, the IS-AIP do not recommend prophylactic uterine artery embolization in women undergoing conservative management.

(B)

There is no evidence to demonstrate that routine local resection in all cases of AIP reduces maternal morbidity or mortality compared to other treatment methods. However, in appropriately selected cases, local resection appears to be reasonably successful (level 2b evidence), and may reduce blood loss and maternal morbidity compared to hysterectomy (level 2b/4 evidence) and requirement for emergency hysterectomy compared with conservative management (level 3b evidence). Therefore, local resection should be considered in appropriately selected cases. (B)

There is, however, some evidence to suggest that attempting local resection may be detrimental in cases involving invasion into the uterine cervix and/or parametrium (level 4 evidence). Therefore, local resection should be considered only where there is no invasion into the parametrium and/or uterine cervix.

(C)

The IS-AIP expert consensus of what constitutes an “appropriate case” for local resection is focal disease with an adherent/ invasive area which is <50% of the anterior surface of the uterus.

(D)

There is no evidence to demonstrate that routine subtotal hysterectomy in all cases of AIP reduces maternal morbidity or mortality compared to total hysterectomy; in fact, the largest study published suggested that subtotal might be associated with a higher maternal mortality rate (level 2b evidence).
The type of hysterectomy performed, therefore, should be individualized on a case-by-case basis, taking into account the site and degree of invasion both suspected antenatally and found at laparotomy, amount of bleeding, stability of the woman, and the skills, experience and preference of the operating team.
(C)

Given the evidence for the success of expectant management for AIP, the IS-AIP recommend that the surgical choice should be between immediate surgical management (hysterectomy or local resection) and expectant management. There is no evidence of benefit of planned delayed hysterectomy, and the potential complications of performing a second intentional surgical procedure in a stable patient outweigh the benefits. (D)

Uterotonics should be considered in accordance with local protocols whenever massive uterine bleeding occurs until either hemostasis is achieved or the uterus is removed. Hemostatic/procoagulant agents can also be used in accordance with local protocols where the surgeon believes they will be of benefit. (D)

Tranexamic acid should be administered whenever massive hemorrhage occurs, preferably as soon as possible after onset of significant bleeding.

(A)

If the woman is stable, the bleeding is not imminently life threatening, and a conservative approach was planned (either for maternal request or if hysterectomy is anticipated to be at very high risk of surgical complications), surgical uterusconserving procedures should be attempted before resorting to hysterectomy. The simplest techniques with the lowest complications should be performed first. (D)

If the placenta has been removed, intrauterine tamponade (eg, balloon tamponade) should be the first-line management. If this fails, or the placenta remains in situ, uterine devascularization, with or without uterine compressive sutures, should be tried. Internal iliac artery ligation has the highest risk of postoperative complications and therefore should be performed only if the previous steps have failed to control the bleeding. (D)

If the woman is unstable or the bleeding is life threatening, treatment must be focused on the source of the blood loss; this will most often be the placental bed, so emergency hysterectomy should be performed as rapidly as possible. Vascular compression (common iliac arteries or aorta) can be used as a temporary measure to gain time to resuscitate the woman and to complete definitive treatment. (D)

In case of persistent pelvic bleeding following hysterectomy, internal iliac artery ligation and/or pelvic tamponade should be considered. Pelvic tamponade should be performed with appropriate, sterile equipment such as large abdominal swabs and broad-spectrum antibiotics given while the packing remains in situ. (D)

Women wishing to preserve their fertility should be counseled that this is possible.

(B)

If conservative management is successful, the subsequent pregnancy rate is between 86% and 89%.

(B)

Women wishing for fertility preservation should be managed by a team with appropriate resources and experience in conservative management according to that team’s local protocols.

(D)