Managing placenta accreta
In the past, surgery was the only option for women with abnormally adherent placentae, but conservative medical management may be an alternative for select patients. Here, the authors review recent trends and describe medical and surgical options.
Opponents of medical management suggest that it increases the risk of sudden hemorrhage, infection, and/or emergent surgery. While there have been reports of infection, all cases were confined to endometritis and were well controlled with an oral antibiotic regimen. One case report describes a patient given MTX for 6 weeks (50 mg per week). Human chorionic gonadotropin levels decreased, the placental mass was resolving, and there was no evidence of vascularity on ultrasound. However, when a suction dilatation and curettage (D&C) was performed for mild bleeding at 8 weeks postpartum, a massive hemorrhage occurred. Ultimately, the patient required a transfusion of 18 units of packed red blood cells and emergent hysterectomy.16
Opponents of medical management suggest it increases the risk of sudden hemorrhage.
Surgical management
Surgical options for the management of placenta accreta are dictated by the patient’s clinical status, comorbidities, age, and parity, as well as the desire to preserve future fertility. Practitioners should be prepared to manage placenta accreta when suspicious radiologic findings or significant risk factors are present. However, radiologic studies are subject to interpretive errors and definitive diagnosis can be made only at the time of delivery. The physician should lay the groundwork for surgery by counseling the patient extensively regarding possible complications and outcomes.
If hemorrhage occurs, follow a stepwise approach to ensure hemostasis.
Preoperative considerations. The best way to decrease surgical complications is through adequate preparation. To that end, the following steps should be considered when planning an operative delivery for a patient with suspected placenta accreta17:
- Notify anesthesia staff of the potential for a prolonged procedure with significant blood loss.
- Assemble an adequate surgical team, including backup by an experienced gynecologist, gynecologic oncologist, general surgeon, or urologist.
- Notify the blood bank of the potential need for significant blood products in the form of packed cells, clotting factors, and platelets. (Blood should be present in the room at the start of the procedure.)
- Ensure that items such as compression boots, a warming blanket, and a 3-way Foley are available. (The 3-way catheter allows the bladder to be back-filled to check for incidental cystotomy.)
- Consider ureteral stent placement to aid in the identification and protection of ureters if significant dissection is indicated.5
- Consider preoperative placement of angiocatheters for intraoperative embolization of the hypogastric arteries to control operative bleeding.18,19
- If bladder involvement is suspected, preoperative cystoscopy can confirm the diagnosis, allowing mobilization of the urology team.
Intraoperative considerations. Thought also should be given to the actual surgical approach prior to beginning the procedure. Attention to seemingly mundane details can significantly reduce operative complications. Suggestions include the following:
- Make a vertical skin incision to provide optimal exposure to the surgical field.20
- Carefully examine the pelvis to identify any abnormal collateral blood supply and involvement of the sidewall by the placenta.
- Take the time to create a bladder flap, unless there are significant adhesions or clear involvement of the bladder by the invading placenta. The flap will make gravid hysterectomy easier to perform and reduce the possibility of incidental cystotomy.
- Carefully consider the type of uterine incision to be made. If at all possible, incisions should be made away from the placenta.5
- Attempt to develop a cleavage plane between the placenta and uterus.21 If this fails, as much of the placental mass as possible should be manually extracted. Areas of defect or bleeding should be oversewn with chromic suture in an attempt to gain hemostasis. This technique is most useful when there is partial separation of the placenta with only a focal accreta. If the area of the accreta is large but not deep, localized repair of any myometrial defects should be attempted. A sharp curettage of the area in question also may aid in removal of the placental mass, but likely will require oversewing the uterus in order to obtain hemostasis.
The obvious imperative in delivering a gravida with a known abnormal placentation is the safety of both the mother and fetus. The secondary goal is to minimize morbidity, which is tantamount to minimizing blood loss and avoiding disseminated intravascular coagulation (DIC). When faced with excessive hemorrhage, a stepwise approach to securing hemostasis should be pursued.
First, the physician should be aggressive with the administration of blood products to avoid cardiogenic shock and coagulopathy. Second, the uterus should be packed for persistent oozing and reassessed in 12 to 24 hours. The uterine blood supply should be sequentially ligated, beginning with the uterine arteries and proceeding to the lower uterine and ovarian vessels.22 While ligation of the hypogastric arteries may reduce blood flow to the uterus, both Clark and Evans reported that such ligation was associated with a failure rate (for controlling hemorrhage) exceeding 50% because of extensive collateral pelvic circulation.23,24
