Placenta accreta/increta/percreta: Ways to stop life-threatening bleeding

Part 2

Part 1 of this two-part article (Contemporary OB/GYN, April 2008 ), "Placenta accreta, increta and percreta: A team-based approach starts with prevention," covered how early diagnosis of pregnancies with these abnormal types of placental attachment can help the obstetric team prepare for and coordinate efforts to control bleeding and plan for scheduled cesarean delivery (CD). Part 2 gives your team the latest practical strategies to combat these complications in an emergency-and keep your patient from bleeding to death.

Death in childbirth, sadly, is a tragic complication of pregnancies, even in the 21st century. Even now, three out of every 100,000 American women who give birth to a live baby will die, as we pointed out in Part 1. A key reason for this is the occurrence of an abnormally adherent placenta, which may present clinically as placenta accreta, placenta increta, or placenta percreta. Because these three complications are more likely in women with a previous CD, you may be facing more cases, given increasing CD rates.

1. Placenta accreta is characterized by superficial attachment of trophoblastic villi to the myometrium,

2. Placenta increta is invasion of villi into the myometrium, and

3. Placenta percreta is characterized by full penetration through the myometrial wall, with possible invasion into adjacent structures.

Last month, we emphasized the importance of early diagnosis through imaging. In Part 2, as we determine the roles of pelvic pressure packs, aortic clamping, internal iliac artery embolization, and intraoperative blood replacement, we will focus on the latest evidence about their effectiveness and potential risks for stopping life-threatening blood loss.

Peri-operative measures

Pelvic artery balloon placement has been proposed to reduce blood loss and to assist in conservative management to avoid hysterectomy.¹ Some investigators assessing the use of prophylactic occlusion balloons in the internal iliac arteries with selective arterial embolization have reported a greater than 80% success rate in controlling postpartum hemorrhage.^2,3 Other research supports these findings with normal resumption of menses within 3 to 6 months and subsequent uncomplicated pregnancies.^4-7 Because preoperative internal iliac balloon catheters could theoretically interfere with uterine blood flow and cause acute fetal distress, they should not be inflated until after delivery.

Recent data on prophylactic catheter placement and balloon occlusion during hysterectomy for placenta accreta indicate no benefit, when compared with patients who underwent hysterectomy without vascular occlusion.⁸ Furthermore, two recent case reports have highlighted the potential for common iliac and femoral artery thrombosis with placement of internal iliac catheters for this indication.^9,10

Some clinicians prefer intraoperative internal iliac artery ligation for hemorrhage prophylaxis to prophylactic catheter placement. However, only physicians comfortable with this technique should perform this maneuver. In addition, internal iliac artery ligation removes the option for subsequent uterine artery embolization.

Also consider whether adequate suction devices are available to assist with visualization during heavy blood loss. Another perioperative consideration is the rapid availability of intraoperative blood testing (e.g., hematocrit, platelets, acid-base parameters, coagulation function). In the face of significant blood loss, for example, the i-Stat portable monitoring system (PCA; i-STAT Corp., Princeton, NJ) allows rapid bedside assessment, which facilitates timely monitoring of the effects of transfusions and a patient's status. We have found that assigning a specific team member to document these values on a regular basis (every 15–30 minutes during heavy bleeding) helps to elucidate trends and identify the need for changes in strategy in response to heavy intraoperative bleeding.