Aortic balloon occlusion and placenta percreta: Some concerns and clarifications
I read with great interest the article “Resuscitative endovascular balloon occlusion of the aorta for placenta percreta/previa” by Parra et al.1 In a patient with placenta previa percreta, cesarean hysterectomy was performed under temporary internal-iliac-artery-balloon occlusion at 37 weeks of gestation; massive bleeding occurred and intraaortic balloon occlusion achieved hemostasis. I have some concerns.
The first concern is regarding the timing of surgery. This patient had a history of four cesarean sections and current placenta previa. The risk of this patient having an abnormally invasive placenta (accreta, increta, percreta [AIP]) is considered to be approximately 60%.2 Image analysis indicates the irregular contour of the placenta-bladder interface and several “lacunae” (large blood containing space) within the placental parenchyma. These are typical signs of placenta increta/percreta, severer AIP. In fact, placenta percreta was confirmed in this case. Although the ideal timing of the surgery for AIP is yet to be determined, a decision tree analysis indicated that 34 weeks of gestation may be preferable.3 Earlier delivery may reduce antepartum bleeding, and, thus, emergent surgery, and also may reduce intrasurgical bleeding. This is why earlier planned surgery is preferable. In this case, the prenatal care was “erratic,” and thus, there may have been no time to schedule an “earlier surgery.” However, I would like to share with the readers the concept that “the timing of delivery is important to reduce the bleeding amount.”
Second, the term “conservative” management should be used appropriately. AIP management is classified into four: extirpative approach, partial uterine wall resection with the AIP attached to it followed by uterine repair, leaving the placenta in situ expecting spontaneous placental resolution, and hysterectomy. In the former, three approaches, uterus preservation is attempted, and all are referred to as a “conservative” approach.4 In this article, a “conservative” approach is used to express an “extirpative” approach, in which the placenta is removed forcibly. Although obstetricians use an “extirpative” approach in cases of “unexpected=undiagnosed” AIP, this approach has almost been abandoned in planned surgery for AIP.4
The third concern is that a “leaving the placenta in situ approach” should have been used or at least may have been a candidate. Although the standard management of AIP is cesarean hysterectomy, the “leaving the placenta in situ approach” is now attracting obstetricians' attention. Which of leaving the placenta or cesarean hysterectomy provides a better outcome is a “hot spot” of obstetrics and is yet to be determined.4 It depends on the situation, especially the situation on the caregivers' side, namely, the ability to prepare multidisciplinary team members. I have devised various procedures for cesarean hysterectomy for AIP,5 and I usually use cesarean hysterectomy; however, based on my four-decade experience, the leaving the placenta in situ approach may be better for the following three conditions: (i) the placenta invading the bladder mucosal surface, which is confirmed by cystoscopy; (ii) the placenta invading beyond the uterine wall in the pelvic wall direction (parametrial invasion); or (iii) the presence of engorged aberrant vessels, which communicates with abdominal-wall vessels. In (i), intentional cystotomy is needed. Although I devised an “open bladder technique” for this condition,5 it requires extensive experience. In (ii), hemostasis of the pelvic wall side is very difficult to achieve even under intraaortic balloon occlusion. In (iii), the collateral circulation comes from the aorta more cephalad to the renal arterial branching and, thus, infrarenal artery-aortic occlusion reduces bleeding to only a limited extent.