This study showed that balloon occlusion of IIA in patients with pernicious placenta previa coexisting with placenta accreta did not reduce the hysterectomy rate during cesarean section, nor did it reduce blood loss and blood transfusion, but it prolonged the duration of the surgery and increased the total cost.
Although advances in obstetric care have led to a substantial improvement in pregnancy outcomes, the death rate from placenta accreta remains as high as 7%, largely due to massive haemorrhage[13, 14],which may then lead to disseminated intravascular coagulation, fluid overload, acute respiratory distress syndrome and infection. It seems logical that occlusion of the internal iliac arteries with prophylactically- placed balloon catheters would be a more effective treatment option, but reported results are controversial. Some retrospective studies [6–9] reported that intraoperative IIA balloon occlusion had benefits in reducing blood loss and the amount of blood transfusion. Some previous systematic reviews also reported that intraoperative IIA balloon occlusion had benefits in reducing blood loss, the volumes of blood transfusion and even the percentages of cesarean hysterectomy in women with accrete[5,15]. Nicholson et al. also reported that patients with IIA balloon occlusion had a decreased rate of hysterectomy compared to those without it[16]. Recently, Yao FAN and Soo BuemCho 's two randomized controlled studies also agree with this view[15,17]. However, randomized controlled studies[10,18]and several case control studies[11,12,19]did not find any benefit. Our findings accord with the previous randomized controlled trial conducted by Meng Chen et al[18].
In our study, we selected the most serious type of disease in the placenta previa spectrum--pernicious placenta previa with placenta accreta, and tried to exclude the heterogeneity caused by the study subjects; In addition, In addition, in our study, all patients are operated by the same surgeon, who has more than 20 years of experience and performs nearly 1,000 cesarean sections a year. They also received the same standard peripartum care apart from the insertion of iliac artery balloons which also eliminate the surgical procedural heterogeneity between surgeons and teams. This is the most significant advantage of our research, which has not been reported in other studies.
It is unclear why occlusion of the internal iliac arteries failed to reduce haemorrhage in our study. The uterine arteries account for most of the blood supply to the uterus, but the extensive collateral supply from the ovarian arteries will not be affected [20].It may also be possible that IIA balloon occlusion does not provide enough arterial flow attenuation in cases of severe abnormal placentation. In a recent case report, escalating from IIA balloon occlusion to common iliac artery balloon occlusion was found to be more effective in reducing operative blood loss during cesarean hysterectomy for morbidly adherent placenta[21] probably because common iliac artery balloon occlusion occluded more collateral arteries than IIA balloon occlusion. In addition, there may be a risk of balloon displacement. As the women were transferred from the interventional unit to the operating theatre after balloon insertion, and we were unable to perform real-time balloon imaging during the caesarean section, the possibility of balloon migration cannot be excluded. Teixidor has confirmed this in his research[22]. In order to avoid catheter displacement as much as possible, we used general anesthesia in the balloon group.
In our study, the transfusion rate was 91.3% in the balloon group and 100% in the control group, which was much higher than the 50% or so reported in the literature[23]. In our hospital, autologous blood transfusion is one of the necessary means to reduce the bleeding during the operation of pregnant women with placenta accreta spectrum. Therefore, nearly every pregnant woman in our study underwent autologous blood transfusion during cesarean section, which may be the reason for the increased transfusion rate in our study.
Our results show that the duration of surgery in the balloon group is significantly longer than in the control group, which should be interpreted with caution. Pregnant women in the balloon group needed an interventional surgeon to remove the balloon after surgery, whereas women in the control group did not.
This study has several limitations, including the retrospective, single-center nature of the investigation. The lack of randomization in the outcome could lead to more complex cases being selected for balloon lacement while the less severe cases may have tended to undergo standard caesarean delivery. Blood loss was estimated, and transfusion was performed based on surgeon preference, which may have varied based on practice.