Balloon Catheters for Blood Loss in Placenta Accreta Cases

Prophylactic placement of balloon catheters or sheaths prior to planned cesarean delivery may reduce blood loss in women with placenta accreta spectrum disorder, according to a new systematic review of more than 5000 individuals.

Placenta accreta spectrum disorder occurs when the endometrial-myometrial interface of the uterus is damaged, wrote Lisanne R. Bonsen, MD, of Leiden University Medical Center, the Netherlands, and colleagues. As a result, the placenta fails to detach at the time of birth and can result in life-threatening postpartum hemorrhage, the researchers said.

The greater the depth of placental invasiveness, the more severe the maternal outcomes, the researchers noted. Previous cesarean delivery is the primary risk factor for placenta accreta spectrum disorder, and the incidence has increased along with the increased rates of cesarean delivery on a global level, they explained.

More research is needed on intrapartum strategies to improve maternal outcomes, and prophylactic radiologic intervention to reduce perioperative blood loss has been explored, the researchers wrote. However, placenta accreta spectrum disorder remains relatively rare in most pregnancy settings, and data on the effect of prophylactic radiologic interventions to reduce bleeding in this high-risk population are limited they said.

In the review published in Obstetrics & Gynecology, the researchers analyzed data from 50 studies of prophylactic radiologic interventions (48 observational studies and two randomized controlled trials) including 5962 women.

The primary outcome was perioperative blood loss; secondary outcomes included the number of red blood cells transferred within 24 hours after delivery, maternal mortality, adverse events related to the interventions, and surgical complications.

Blood loss was significantly lower in the intervention groups compared with the control groups for patients who underwent distal balloon occlusion (30 studies), proximal balloon occlusion (14 studies), or uterine artery embolization (5 studies), with mean differences in blood loss of 406 mL, 1041 mL, and 936 mL, respectively.

Results were similar with lower blood loss for intervention patients compared with controls in subgroup analyses of different types of placenta accreta spectrum disorder and those with placenta accreta spectrum disorder confirmed post partum.

Across the 35 studies that included data on blood transfusions, women who underwent any prophylactic radiologic intervention averaged fewer red blood cell units transferred than women who had no radiologic intervention, with a mean difference of 1.13, 1.90, and 1.86 units for distal prophylactic balloon occlusion, proximal prophylactic balloon occlusion, and prophylactic uterine artery embolization, respectively.

Data on adverse events related to the interventions were limited, but noted in approximately 2% of patients who underwent distal or proximal prophylactic balloon occlusion, and 45% of patients who underwent prophylactic uterine artery embolization. One maternal death was reported and attributed to diffuse intravascular coagulation. Three cardiac arrests occurred in control patients across different studies, and all were successfully resuscitated.

Most of the studies did not report data on the researchers’ predefined secondary outcomes, including shock, transfer to a higher level of care, coagulopathy, organ dysfunction, and patient-reported outcomes.

What Works Best

“Our main analysis reveals differences in outcomes among the three interventions, with proximal balloon occlusion demonstrating the strongest effect,” the researchers wrote. “Our results show a blood loss reduction of 406 mL by distal prophylactic balloon occlusion. An explanation for the differences between the results of prophylactic balloon occlusion–distal and prophylactic balloon occlusion–proximal could be that implementing occlusion at a distal level may be less effective because of bleeding from the collateral circulation,” they said.

The findings were limited by several factors including the observational design of most of the studies, variation in measurements of blood loss among studies and in inclusion criteria, and insufficient adverse event data to draw conclusions about safety, the researchers noted. More research is needed to examine efficacy and safety of the interventions according to different sensitivities of placenta accreta spectrum disorder, they added.

Results Support Judicious Intervention

“Although previous studies showed mixed results, our meta-analysis demonstrated that prophylactic radiologic interventions, particularly balloon occlusion (both distal and proximal), were associated with reduced perioperative blood loss and less red blood cell unit transfusion; this was most pronounced in women with confirmed placenta percreta,” Bonsen said in an interview. However, the heterogeneity across the included studies prevents generalizations about the overall effects of the interventions across different severities of placenta accreta spectrum disorder, she said.*

Despite these limitations, the overview of the currently available evidence provides insights for clinical decision making, said Bonsen. “Our study highlights that, if we were to be certain of the diagnosis of placenta accreta spectrum disorder antepartum, prophylactic radiologic intervention could help reduce peripartum blood loss,” she said.

Risks vs Benefits

“Given the challenges in performing randomized surgical trials in a pregnant patient population with an uncommon disorder, this level of evidence provides important data to assist with clinical decision making in patients with placenta accreta spectrum disorder,” despite the limitations of the observational studies, wrote Jocelyn S. Chapman, MD, and Arianna M. Cassidy, MD, both affiliated with the Multidisciplinary Approach to Placenta Accreta Spectrum Disorder Service (MAPS) at the University of California, San Francisco, in an accompanying editorial.

Previous research has shown an increased risk of severe maternal morbidity among women with placenta accreta spectrum disorder and previous intervention strategies have involved protocols, surgical techniques, and management strategies, they wrote.

Uterine artery embolization after cesarean delivery also has been associated with reduced hemorrhage and no adverse events, but this procedure was not included in the studies reviewed and is best conducted in a delivery setup not available in many hospital systems, the editorialists noted.

The current study illustrates the value of prophylactic balloon occlusion and placement of vascular sheaths to reduce blood loss and blood transfusion, but the risk of thrombosis and lumbosacral pain must be considered, they said. These risks may be a reasonable trade-off to avoid severe blood loss and ICU care, and to preserve the uterus, Chapman and Cassidy added.

“However, we would urge continued critical appraisal of each placenta accreta spectrum disorder case with a multidisciplinary team to evaluate the available evidence-based strategies most likely to mitigate clinically relevant complications while minimizing the introduction of new ones,” the editorialists concluded.

The study received no outside funding. The researchers had no financial conflicts to disclose. Dr Chapman and Dr Cassidy had no financial conflicts to disclose.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.