Outcome of Pregnancies After Balloon Occlusion of the Infrarenal Abdominal Aorta During Caesarean in 230 Patients With Placenta Praevia Accreta

Predicting postpartum hemorrhage in women undergoing planned cesarean section: A multicenter retrospective cohort study in Japan

Given Japan's unique social background, it is critical to understand the current risk factors for postpartum hemorrhage (PPH) to effectively manage the condition, especially among specific groups. Therefore, this study aimed to identify the current risk factors for PPH during planned cesarean section (CS) in Japan. This multicenter retrospective cohort study was conducted in two tertiary maternal-fetal medicine units in Fukushima, Japan and included 1,069 women who underwent planned CS between January 1, 2013, and December 31, 2022. Risk factors for PPH (of > 1000 g and > 1500 g) were assessed using multivariate logistic regression analysis, considering variables such as maternal age, parity, assisted reproductive technology (ART) pregnancy, pre-pregnancy body mass index (BMI), uterine myoma, placenta previa, gestational age at delivery, birth weight categories, and hypertensive disorders of pregnancy (HDP). Multivariate linear regression analyses were conducted to predict estimated blood loss during planned CS. ART pregnancy, a pre-pregnancy BMI of 25.0-29.9 kg/m2, and uterine myoma increased PPH risk at various levels. Maternal smoking increased the risk of >1500 g PPH (adjusted odds ratio: 3.09, 95% confidence interval [CI]: 1.16-8.20). Multivariate linear analysis showed that advanced maternal age (B: 83 g; 95% CI: 27-139 g), ART pregnancy (B: 239 g; 95% CI: 121-357 g), pre-pregnancy BMI of 25.0-29.9 kg/m2 (B: 74 g; 95% CI: 22-167 g), uterine myoma (B: 151 g; 95% CI: 47-256 g), smoking (B: 107 g; 95% CI: 13-200 g), and birth weight > 3,500 g (B: 203 g; 95% CI: 67-338 g) were associated with blood loss during planned CS. Considering a patient's clinical characteristic may help predict bleeding in planned CSs and help improve patient safety.

Application of Uterine Artery Embolization in Patients With Placenta Accreta Spectrum After Abdominal Aortic Balloon Occlusion

OBJECTIVE

To evaluate the application of different uterine artery embolization procedures under balloon occlusion of the abdominal aorta in patients with Placenta Accreta Spectrum (PAS) undergoing cesarean section.

MATERIALS AND METHODS

A retrospective analysis was performed on clinical data from 72 patients who underwent uterine artery embolization for hemostasis during cesarean section with PAS. The patients were divided into two groups according to the embolization method used during surgery: group A (n = 43) underwent uterine artery embolization by withdrawing the balloon and inserting a Cobra catheter into the uterine artery for embolization, while group B (n = 29) underwent uterine artery embolization with a Cobra catheter inserted via contralateral puncture of the femoral artery and balloon occlusion. General information, surgical data, and postoperative recovery were compared between the 2 groups.

RESULTS

The bleeding and transfusion volumes were lower in group B than in group A and the differences between the 2 groups were statistically significant. There were no significant differences in surgical duration, number of embolized vessels, length of hospital stay, postoperative complications, or menstrual recovery between the 2 groups.

CONCLUSION

For patients with PAS undergoing cesarean section, uterine artery embolization for hemostasis is preferably performed by inserting a Cobra catheter via contralateral puncture of the femoral artery under abdominal aortic balloon occlusion.

Clinical evaluation of the effect for prophylactic balloon occlusion in pregnancies complicated with placenta accreta spectrum disorder: A systematic review and meta-analysis

BACKGROUND

Placenta accreta spectrum (PAS) disorder is a critical and severe obstetric condition associated with high risk of intraoperative massive hemorrhage and cesarean hysterectomy. Severe obstetric hemorrhage is currently one of the leading causes of maternal death worldwide. Prophylactic balloon occlusions, including prophylactic balloon occlusion of the abdominal aorta (PBOAA) and prophylactic balloon occlusion of the internal iliac arteries (PBOIIA), are the most common means of controlling hemorrhage in patients with PAS disorder, but their effectiveness is still debated.

OBJECTIVE

A systematic review and meta-analysis were conducted to evaluate the clinical effectiveness of prophylactic balloon occlusion during cesarean section (CS) in improving maternal outcomes for PAS patients.

SEARCH STRATEGY

MEDLINE, EMBASE, OVID, PubMed and the Cochrane Library were systematically searched from the inception dates to June 2022, using the keywords "placenta accreta spectrum disorder/morbidly adherent placenta (placenta previa, placenta accreta, placenta increta, placenta percreta), balloon occlusion, internal iliac arteries, abdominal aorta, hemorrhage, hysterectomy, estimated blood loss (EBL), packed red blood cells (PRBCs)" to identify the systematic reviews or meta-analyses.

SELECTION CRITERIA

All articles regarding PAS disorders and including the application of balloon occlusion were included in the screening.

DATA COLLECTION AND ANALYSIS

Two independent researchers performed the data extraction and assessed study quality. EBL volume and PRBC transfusion volume was regarded as the primary endpoints. Random and fixed effects models were used for the meta-analysis (RRs and 95% CIs), and the Newcastle-Ottawa Scale was used for quality assessments.

MAIN RESULTS

Of 429 studies identified, a total of 35 trials involving the application of balloon occlusion for patients with PAS disorder during CS were included. A total of 19 studies involving 935 patients who underwent PBOIIA were included in the PBOIIA group, and 851 patients were included in control 1 group. Ten studies including 428 patients with PAS who underwent PBOAA were allocated to the PBOAA group, and 324 patients without PBOAA were included in control 2 group. Simultaneously, we compared the effect on PBOAA and PBOIIA including seven studies, which referred to 267 cases in the PBOAA group and 313 cases in the PBOIIA group. The results showed that the PBOIIA group had a reduced EBL volume (MD: 342.06 mL, 95% CI: -509.90 to -174.23 mL, I2 = 77%, P < 0.0001) and PRBC volume (MD: -1.57 U, 95% CI: -2.49 to -0.66 U, I2 = 91%, P = 0.0008) than that in control 1 group. With regard to the EBL volume (MD: -926.42 mL, 95% CI: -1437.07 to -415.77 mL, I2 = 96%, P = 0.0004) and PRBC transfusion volume (MD: -2.42 U, 95% CI: -4.25 to -0.59 U, I2 = 99%, P = 0.009) we found significant differences between the PBOAA group and control 2 group. Prophylactic balloon occlusion (PBOAA and PBOIIA) had a significant effect on reducing intraoperative blood loss and blood transfusion volume in patients with PAS. Moreover, PBOAA was more effective than PBOIIA in reducing intraoperative blood loss (MD: -406.63 mL, 95% CI: -754.12 to -59.13 mL, I2 = 92%, P = 0.020), but no significant difference in controlling PRBCs (MD: -3.48 U, 95% CI: -8.90 to 1.95 U, I2 = 99%, P = 0.210) between the PBOIIA group and the PBOAA group. Hierarchical analysis was conducted by differentiating gestational weeks and maternal age to reduce the high heterogeneity of meta-analysis. Hierarchical analysis results demonstrated the heterogeneities of the study were reduced to some extent, and gestational weeks and maternal age might be the cause of increased heterogeneity.

CONCLUSION

Prophylactic balloon occlusion is a safe and effective method to control hemorrhage and reduce PRBC transfusion volume for patients with PAS, and PBOAA could reduce more intraoperative blood loss than PBOIIA. However, we found no statistical difference in lessening packed red blood cell transfusion volume for PAS patients. Hence, preoperative prophylactic balloon occlusion is the recommended application for PAS patients in obstetric CSs. Furthermore, PBOAA is preferred for controlling intraoperative bleeding in patients with corresponding medical conditions.

Usefulness of resuscitative endovascular balloon occlusion of the aorta (REBOA) in controlling puerperal bleeding in patients with abnormal placental implantation

BACKGROUND AND AIMS

Abnormalities of placental implantation, which make up the spectrum of placenta accreta, are associated with high maternal morbidity and mortality due to massive bleeding during delivery. Placing aortic occlusion balloons helps control the bleeding, facilitating surgical intervention. A new device, resuscitative endovascular balloon occlusion of the aorta (REBOA), minimizes the risks and complications associated with the placement of traditional aortic balloons and is also efficacious in controlling bleeding. The aim of this study is to evaluate the usefulness, efficacy, and safety of REBOA in puerperal bleeding due to abnormalities of placental implantation.

MATERIAL AND METHODS

Between November 2019 and November 2021, our interventional radiology team placed six REBOA devices in six women scheduled for cesarean section due to placenta accrete.

RESULTS

Mean blood loss during cesarean section after REBOA (3507.5 mL) was similar to the amounts reported for other aortic balloons. The mean number of units of packed red blood cells required for transfusion was 3.5. Using REBOA provided the surgical team with adequate conditions to perform the surgery. There were no complications derived from REBOA, and the mean ICU stay was <2 days.

CONCLUSION

The technical characteristics of the REBOA device make it a safe and useful alternative for controlling massive bleeding in patients with placenta accreta.

Management of Postpartum Hemorrhage in Critical Care Transport

Postpartum hemorrhage is a relatively common and highly morbid complication of the postpartum period that often requires management by specialized providers at tertiary care facilities. Critical care transport teams may be tasked with transporting postpartum patients who are already experiencing postpartum hemorrhage, but they should also be aware that other peripartum patients may be at risk for developing postpartum hemorrhage while in the process of transport. As such, it is imperative that transport providers understand the signs, symptoms, causes, and complications of postpartum hemorrhage as well as the options for intervention and treatment. This article reviews the current clinical evidence regarding resuscitation and medical management strategies that transport teams should be familiar with as well as more advanced and invasive management techniques they may encounter and be expected to monitor during transport, such as balloon tamponade and aortic balloon occlusion.

Is prophylactic intraoperative abdominal aortic balloon occlusion beneficial in pregnancies with placenta previa and placenta accreta spectrum during cesarean section? A 5-year retrospective study

OBJECTIVE

To assess whether prophylactic intraoperative abdominal aortic balloon occlusion (IAABO) is indeed beneficial in pregnancies with placenta previa (PP) and placenta accreta spectrum (PAS) during cesarean section.

METHODS

A retrospective case-control study included 251 pregnancies with PP and/or PAS. All enrolled patients were divided into a PP/PAS group, a PP + PAS group, and an IAABO group. The demographic characteristics and maternal and neonatal outcomes were compared.

RESULTS

There was no significant difference in blood loss and transfusion between the IAABO group and the PP + PAS group (P > 0.05). However, blood loss and red blood cell and fresh frozen plasma transfusion in the above two groups were significantly higher than in the PP/PAS group (P < 0.05). More pregnancies in the IAABO group had to undergo uterine artery embolization (29.2%) or hysterectomy (20.8%), and this percentage was significantly higher than that in the other two groups (P < 0.001). All neonatal characteristics did not show differences between the IAABO group and PP + PAS group (P > 0.05). IAABO led to femoral artery thrombosis in three cases and minor postoperative renal injury in one case.

CONCLUSION

IAABO only acted as a less important supporting technique during cesarean section. There was no evidence suggesting that IAABO could significantly control the massive hemorrhage in pregnancies with PP and PAS during cesarean delivery.

Association of MRI Features and Adverse Maternal Outcome in Patients With Placenta Accreta Spectrum Disorders After Abdominal Aortic Balloon Occlusion

BACKGROUND

MRI features may be associated with adverse maternal outcome in patients with placenta accreta spectrum (PAS) disorders even with abdominal aortic balloon occlusion (AABO).

PURPOSE

This study aimed to identify risk factors of MRI for association with adverse maternal outcome in patients with PAS disorders after AABO.

STUDY TYPE

Retrospective.

POPULATION

Clinical and MRI features of 80 patients were retrospectively reviewed from October 2016 to August 2021. A total of 40 patients had adverse maternal outcomes including intrapartum/peripartum bleeding >1000 mL and/or emergency hysterectomy after AABO.

SEQUENCE

Half-Fourier acquisition single-shot turbo spin echo and gradient echo imaging True fast imaging with steady-state precession (True-FISP) at 1.5T MR scanner.

ASSESSMENT

MRI features were evaluated by three radiologists and were tested for any association with adverse maternal outcome.

STATISTICAL TESTS

Interobserver agreement was calculated with kappa (k) statistics. Association between MRI features and adverse maternal outcomes were evaluated by univariate and multivariate analyses. A nomogram was constructed based on the logistic regression.

RESULTS

The interobserver agreement ranged from fair to substantial (k = 0.379-0.783). Multivariate analyses revealed that short cervical length (OR: 4.344), abnormal intraplacental vascularity (OR: 6.005), placental bulge (OR: 9.085), and myometrial interruption (OR: 9.550) were independent risk factors for adverse maternal outcomes. The combination of four risk factors together demonstrated the highest AUC of 0.851 (95% CI 0.769-0.933) with a sensitivity and specificity of 77.5% and 72.5%, respectively and then a nomogram composed of the above four risk factors was constructed to represent the probability of adverse maternal outcome.

DATA CONCLUSION

The nomogram demonstrated the association between MRI features and patient's poor outcome after undergoing AABO and C-section delivery for PAS.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 3.

Surgical Techniques for the Management of Placenta Accreta Spectrum

The surgical management of placenta accreta spectrum (PAS) is often challenging. There are a variety of techniques and management options described in the literature ranging from uterine sparing to cesarean hysterectomy. Following the inaugural meeting of the Pan-American Society for Placenta Accreta Spectrum a multidisciplinary group collaborated to describe collective recommendations for the surgical management of PAS. In this manuscript, we outline individual components of the procedure and provide suggested direction at key points of a cesarean hysterectomy in the setting of PAS. KEY POINTS: · The surgical management of PAS requires careful planning and expertise.. · Multidisciplinary team care for pregnancies complicated by PAS can decrease morbidity and mortality.. · Careful surgical techniques can minimize risk of significant hemorrhage by avoiding pitfalls..

rSO2 Measurement Using NIRS for Lower-Limb Blood Flow Monitoring and Estimation of Safe Balloon Occlusion/Deflation Time in Patients with PAS Who Underwent PBOA during CS

We examined the utility of regional oxygen saturation (rSO2) measurement using near-infrared spectroscopy (NIRS) for monitoring lower-limb blood flow and estimate the safe balloon occlusion/deflation time in patients with PAS who underwent prophylactic balloon occlusion of the abdominal artery (PBOA) during cesarean section (CS). During CS, the NIRS probes were positioned on either of the anterior tibial muscles. rSO2 was measured continuously during balloon occlusion/deflation. A cycle consisted of inflating the aortic balloon for 30 min and deflating it for 5 min. The rSO2 before/during balloon occlusion and after 5 min of balloon deflation were evaluated. Sixty-two lower limbs (fifteen women and data from 31 sessions of balloon inflation/deflation) were evaluated. rSO2 during balloon occlusion was significantly lower than rSO2 before balloon occlusion (57.9% ± 9.6% vs. 80.3% ± 6.0%; p < 0.01). There were no significant differences between rSO2 before balloon occlusion and rSO2 after 5 min of balloon deflation (80.3% ± 6.0% vs. 78.7% ± 6.6%; p = 0.07). Postoperatively, the lower limbs showed no ischemic symptoms. NIRS can assess lower-limb rSO2 during PBOA for PAS in real time to determine ischemia severity, duration, and recovery capacity.

Ultrasound-guided prophylactic abdominal aortic balloon occlusion for placenta accreta spectrum disorder: A case series

Placenta accreta spectrum (PAS) disorder is one of the most dangerous conditions that can affect pregnancy and its incidence is increasing secondary to rising cesarean section rates worldwide. The standard treatment is frequently elective hysterectomy at the time of cesarean delivery; however, uterine and fertility preserving surgery is becoming more common. In the pursuit of a reduction in blood loss and associated maternal morbidity, occlusive vascular balloons are increasingly used at the time of surgery, usually placed with fluoroscopic guidance. Occlusive balloons placed in the infrarenal aorta have been shown in the literature to be superior in terms of blood loss and hysterectomy rates than those placed more distally, such as within iliac or uterine arteries. We present the first five cases performed in Europe of ultrasound-guided infrarenal aortic balloon placement before cesarean for PAS disorder, and describe the technique we used, which provided reduced blood loss, a clearer operating field and avoided fetal and maternal exposure to radiation and intravenous contrast.

Evidences in Uterine Artery Embolization: A Radiologist's Primer

Uterine artery embolization is an established minimally invasive therapy for symptomatic fibroids. It has also been used for other diseases of the uterus, including adenomyosis, uterine arteriovenous malformation, ectopic pregnancy, abnormal invasive placenta, and postpartum hemorrhage. In this review, we provide an updated and comprehensive review of uterine artery embolization based on the evidence published. We review the indications, the role of MRI, technical aspects, and complications of the procedure. The issues with a future pregnancy, risk of infertility, and fetal radiation are discussed as well.

Association of the placenta accreta spectrum score and estimated blood loss in placenta accreta spectrum patients with placenta previa: a retrospective cohort study

PURPOSE

The placenta accreta spectrum (PAS) score calculated by the scoring system may predict patients with PAS. We aim to find the relationship between estimated blood loss and the PAS score. Further, find the inflection point, identify PAS patients with placenta previa who were at risk for major bleeding.

METHODS

The PAS patients with placenta previa, as diagnosed by color Doppler ultrasound, were divided into two groups according to their PAS scores using a new scoring system. Blood loss, transfusion requirements, the rate of Intra-Abdominal Balloon Occlusion (IABO), and other indicators were analyzed between groups.

RESULTS

The estimated blood loss, intraoperative transfusion, postoperative transfusion, operation time, and hospitalization time significantly increased in the group with a PAS score ≥ 9 (P < 0.05). The inflection point analysis revealed that a significant increase in estimated blood loss occurred when the PAS score was beyond 10 (crude) or 6 (adjusted for age, body mass index, and IABO).

CONCLUSION

There was a non-linear relationship between estimated intraoperative blood loss and PAS score. When the PAS score was greater than 9, hemorrhage, the risk of major bleeding, the need for transfusions, and the placement of an abdominal aortic balloon all increase significantly.

Efficacy of low extra-abdominal aortic block in cesarean section for placenta accreta spectrum disorders and its effect on the expression of MDA and SOD

OBJECTIVES

Placenta accreta spectrum disorders (PAS) refers to a group of abnormalities in placental adhesion and invasion, which may lead to serious complications such as intractable postpartum hemorrhage. The use of low-level extra-abdominal aortic temporary block during cesarean section may reduce intraoperative bleeding in patients with PAS, but it may also cause ischemia-reperfusion injury. In this study, we intend to investigate the efficacy of low extra-abdominal aortic block in cesarean section for placental implantation disease and its effect on malondialdehyde (MDA) level and superoxide dismutase (SOD) activity, and analyze the severity of ischemia-reperfusion injury caused by them.

METHODS

Pregnant women with invasive placenta accreta spectrum disorders who delivered in the Department of Obstetrics and Gynecology of the Third Xiangya Hospital of Central South University from July 2017 to July 2021, were selected, and they were divided into 2 groups. Group A consisted of those who underwent low extra-abdominal aortic block during cesarean section (n=15) and group B consisted of those who did not undergo extra-abdominal aortic block (n=15). The intraoperative bleeding, blood transfusion, hysterectomy and complication rate, postoperative hospital stay and hospitalization expenses were compared between the 2 groups to analyze the efficacy of abdominal aortic block. The biochemical indexes related to ischemia-reperfusion, MDA content and total superoxide dismutase (T-SOD) activity, were measured at the corresponding time points in both groups. The time points of each test were: in group A, before the block of the low extra-abdominal aorta after delivery (A0), 0 h (A1, when the myometrium was started to be sutured), 0.5 h (A2), 2 h (A3), and 4 h (A4) after the open block; in group B, after delivery of the fetus (B0), 0 h (B1), 0.5 h (B2), 2 h (B3), and 4 h (B4) after the myometrium was started to be sutured. Total duration of abdominal aortic block in group A was also recorded. Both groups were observed for sings of edema, ischemia, necrosis and infection in the limbs after surgery. The severity of ischemia-reperfusion injury caused by abdominal aortic block were determined by detecting the relevant biochemical indexes at different moments of reperfusion.

RESULTS

The intraoperative bleeding and blood transfusion in group A were less than those in group B, and the difference was statistically significant (P<0.05). There was no significant difference in postoperative hospital stay and hospitalization expenses between the 2 groups (P>0.05). Surgical complications: in group A, the uterus was preserved in all cases, there was 1 bladder injury and 2 pelvic infections; while in group B, there was 1 hysterectomy, 3 bladder injuries, and 3 pelvic infections. Changes in T-SOD and MDA values: compared with A0 before block, the MDA level was significantly elevated in blood at time points A1, A2, and A3, while SOD activity was significantly decreased (P<0.05), and the 2 observed indexes basically returned to A1 level (ischemic period) at 4 h after open block (A4). There was no significant difference in the changes of T-SOD and MDA in group B (P>0.05). Comparison of T-SOD and MDA levels between group A and B: the difference of the 2 indexes was not statistically significant between A0 and B0 (P>0.05), MDA level was not statistically significant between A1 and B1, T-SOD activity at A1 was lower than B1, the difference was statistically significant, at the rest of the same time point, MDA level in group A were higher than that in group B, T-SOD activity in group A were lower than that in group B, the difference was statistically significant (P<0.05). No postoperative limb edema, ischemia, necrosis, or infection occurred in both groups.

CONCLUSIONS

Low-level extra-abdominal aortic block effectively reduces bleeding and transfusion during cesarean section for placenta accreta spectrum disorders, resulting in a transient MDA elevation and a decrease of SOD activity, which means causing transient ischemia-reperfusion injury without complications such as limb edema, ischemia, necrosis, and infection.

Clinical features of multifocal papillary thyroid carcinoma and risk factors of cervical metastatic lymph nodes

OBJECTIVE

To analyze the clinical features of multifocal papillary thyroid carcinoma (PTC) and the risk factors of cervical metastatic lymph nodes.

METHODS

A total of 1524 patients with papillary thyroid carcinoma admitted in Gansu Provincial Cancer Hospital from January 2020 to August 2021 were enrolled, including 492 cases of multifocal PTC and 1032 cases of unifocal PTC. The clinicopathologic features of multifocal PTC and unifocal PTC were analyzed by comparing their differences in gender, ethnicity, age, body mass index, accompanying diabetes mellitus, accompanying hypertension, preoperative thyroid stimulating hormone and thyroglobulin levels, location of lesions, maximum diameter of lesions, sum of lesion diameters, central metastatic lymph nodes, lateral cervical metastatic lymph nodes, presence of Hashimoto's thyroiditis, and thyroid capsule invasion. Patients were also assessed according to the presence or absence of central metastatic lymph nodes and lateral cervical metastatic lymph nodes to understand clinicopathological parameter differences, and multivariate logistic regression analysis was used to explore the risk factors.

RESULTS

Compared with unifocal PTC group, multifocal PTC group had significantly higher proportion of patients aged over 55 years, accompanying hypertension, central metastatic lymph nodes or cervical metastatic lymph nodes, Hashimoto's thyroiditis and capsule invasion (all P<0.05); 55.1% of patients with multifocal PTC had lesions distributed bilaterally, and the maximum diameter and diameter sum of the lesions were greater than those in unifocal PTC group (all P<0.01). Multivariate logistic regression analysis showed that male, maximum diameter of lesion more than 7 mm, capsular invasion were independent risk factors for central metastatic lymph nodes (all P<0.05); while male, maximum diameter of lesion more than 7 mm, preoperative thyroglobulin more than 55 ng/mL, and central metastatic lymph nodes were risk factors for lateral cervical metastatic lymph nodes in patients with multifocal PTC (all P<0.05).

CONCLUSION

Patients with multifocal PTC have significantly higher central and lateral cervical metastatic lymph nodes, particularly for male patients with a maximum diameter of lesion more than 7 mm, invasion of capsule, and preoperative thyroglobulin more than 55 ng/mL.

Effects and Long-Term Outcomes of a Modified Triple-P Procedure in Patients With Severe PAS: A Retrospective Cohort Study

Background

The distinguished Triple-P procedure has been reported as a conservative surgical alternative to peripartum hysterectomy for placental accreta spectrum (PAS). In this study, we modified the procedure combined with prophylactic abdominal aorta balloon occlusion and/or tourniquet and evaluated the effect and long-term outcomes.

Methods

This was a retrospective study involving pregnant patients with clinically confirmed severe PAS (including placenta increta and percreta) between January 1st, 2017 and June 30th, 2020 in the First Affiliated Hospital of Zhengzhou University. A total of 334 pregnant women were recruited in this study. The 142 women that were subjected to modified Triple P Procedure were regarded as the observation group while 194 pregnant women that were treated with other sutures were regarded as the control group. Demographic characteristics, placental accreta spectrum score (PAS score), estimated blood loss (EBL), operative time, blood transfusion rate and volume, neonatal weight, post-operative hospital stays and costs were evaluated. Short-term complications, including fever, hematoma, thrombus, bladder rupture and intensive care unit (ICU) transfer rate, as well as long-term outcomes including breast feeding, menstruation, intrauterine adhesion, and chronic abdominal pain among others were followed up in the outpatient clinic and by phone calls.

Results

For all cases, EBL was lower in the observation group than in the control group, 1,200 (687–1,812) ml and 1,300 (800–2,500) ml, respectively. The difference was statistically significant (P < 0.05). Operative time were statistically significantly shorter in the observation group [99.5 (84.0–120.0) min and 109.0 (83.8–143.0) min, P < 0.05]. Lengths of postoperative hospital stays were 4 (4–7) and 5 (4–7) days in the observation and control group, which was significantly shorter in the observation group (P < 0.05). There were no significant differences in PAS scores, blood transfusion volume, neonatal weight, fever, hematoma, thrombus, bladder rupture and ICU transfer rates between the two groups. All patients, except one in control group, had preserved uterus. There were no statistically significant differences in short-term and long-term complications between two groups.

Conclusion

In summary, when combined with tourniquet and/or prophylactic abdominal aorta balloon occlusion, modified Triple-P procedure may be effective in reducing intraoperative blood loss and hysterectomy in patients with placenta increta/percreta. It is a safe and effective surgical alternative to peripartum hysterectomy. However, the complications associated with interventional radiology service should be evaluated furthermore.

Maternal outcomes of abnormally invasive placenta in China and their association with use of abdominal aortic balloon occlusion

OBJECTIVE

To compare maternal outcomes of abnormally invasive placenta in China in 2012, 2015, and 2018, and further examine the association between use of abdominal aortic balloon occlusion (AABO) and the risk of maternal outcomes.

MATERIALS AND METHODS

A retrospective analysis included 830 women diagnosed as abnormally invasive placenta from 5 tertiary care centers in China in 2012, 2015 and 2018. Participants were divided into AABO group and non-AABO group according to whether they were treated with AABO or not. Logistic regression models were used to assess the association of use of AABO with postpartum hemorrhage, blood transfusion, hysterectomy and repeated surgery.

RESULTS

Among 830 participants, 66.0% (548/830) and 34.0% (282/830) of women were diagnosed with placenta increta and percreta, respectively; 33.3% (276/830) of women with abnormally invasive placenta were treated with AABO. In 2012, 2015, and 2018, the rate of blood transfusion was 83.1, 59.8, and 56.2%; the rate of hysterectomy was 50.8, 11.2, and 2.4%; and the rate of repeated surgery was 10.2, 9.4, and 0.9%. Use of AABO was associated with lower risk of postpartum hemorrhage (OR = 0.59, 95% CI: 0.35-0.99), blood transfusion (OR = 0.72, 95% CI: 0.52-0.99), hysterectomy (OR = 0.04, 95% CI: 0.01-0.14) and repeated surgery (OR = 0.14, 95% CI: 0.05-0.41) after adjustment for potential confounders.

CONCLUSION

The rates of blood transfusion, hysterectomy and repeated surgery progressively decreased from 2012 to 2018 in Chinese women with abnormally invasive placenta. Use of AABO was associated with lower risk of postpartum hemorrhage, blood transfusion, hysterectomy and repeated surgery.

Intra-abdominal aortic balloon occlusion in the management of placenta percreta

Background:

Massive bleeding is the main concern for the management of placenta percreta (PP). Intra-abdominal aortic balloon occlusion (IABO) is one method for pelvic devascularization, but the efficacy of IABO is uncertain. This study aims to investigate the outcomes of IABO in PP patients.

Methods:

We retrospectively reviewed the clinical data of PP cases from six tertiary centers in China between January 2011 and December 2015. PP cases with/without the use of IABO were analyzed. Propensity score matching analysis was performed to reduce the effect of selection bias. Postpartum hemorrhage (PPH) and the rate of hysterectomy, as well as neonatal outcomes, were analyzed.

Results:

One hundred and thirty-two matched pairs of patients were included in the final analysis. Compared with the control group, maternal outcomes, including PPH (68.9% vs. 87.9%, χ² = 13.984, P < 0.001), hysterectomy (8.3% vs. 65.2%, χ² = 91.672, P < 0.001), and repeated surgery (1.5% vs. 12.1%, χ² = 11.686, P = 0.001) were significantly reduced in the IABO group. For neonatal outcomes, Apgar scores at 1 minute (8.67 ± 1.79 vs. 8.53 ± 1.68, t = −0.638, P = 0.947) and 5 minutes (9.43 ± 1.55 vs. 9.53 ± 1.26, t = 0.566, P = 0.293) were not significantly different between the two groups.

Conclusions:

IABO can significantly reduce blood loss, hysterectomies, and repeated surgeries. This procedure has not shown harmful effects on neonatal outcomes.

Fetal and neonatal outcomes following maternal aortic balloon occlusion for hemorrhage in pregnancy: A review of the literature

BACKGROUND

Hemorrhage is a leading cause of maternal death worldwide, with increased risk in women with abnormal placentation. Aortic balloon occlusion (ABO), including resuscitative endovascular balloon occlusion, has been used for obstetrical hemorrhage for 20 years, and is associated with decreased operative blood loss, fewer transfusions, and lower rates of hysterectomy. However, the effect of aortic occlusion on fetal/neonatal outcomes is not well known.

METHODS

A literature review on ABO for obstetrical or traumatic hemorrhage was performed. Cases were included if fetal/neonatal outcomes were reported. Data were collected on timing of balloon inflation (predelivery or postdelivery), fetal/neonatal mortality, and Apgar scores. Secondary maternal outcomes included blood loss, need for hysterectomy, ABO-related complications, and mortality.

RESULTS

Twenty-one reports of ABO in 825 cases of obstetrical hemorrhage were reviewed (nine case reports/series and twelve comparative studies). 13.5% (111/825) had aortic occlusion prior to delivery of the fetus. Comparative cohorts included 448 patients who underwent iliac artery balloon occlusion (n = 219) or no vascular balloon occlusion (n = 229). The most common neonatal outcome reported was Apgar scores, with no difference in fetal/neonatal outcomes between ABO and non-ABO patients in any study. One neonatal mortality occurred in the sole reported case of ABO use in a pregnant trauma patient at 24 weeks gestation. One maternal mortality occurred because of aortic dissection. Five comparative studies reported significantly decreased blood loss in ABO patients compared to non-ABO patients, and four studies reported significantly lower rates of hysterectomy in ABO patients. ABO-related complications were reported in 1.6% of patients (13/825).

CONCLUSION

Obstetrical hemorrhage is a devastating complication, and ABO may potentially decrease blood loss and reduce the hysterectomy rate without compromising fetal and neonatal outcomes. Further research is needed to determine the safety of predelivery aortic occlusion as this occurred in 14% of the cases.

The effect of prophylactic balloon occlusion in patients with placenta accreta spectrum: a Bayesian network meta-analysis

OBJECTIVES

Placenta accreta spectrum (PAS) can induce severe life-threatening obstetric hemorrhage. Herein, we conducted a Bayesian network meta-analysis of previous studies to evaluate the relative benefits of different prophylactic balloon occlusion (PBO) procedures.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science were searched from inception to July 2021. Blood loss volume, blood transfusion volume, and hysterectomy rate were regarded as the primary endpoints. The data were pooled using a Bayesian network and traditional pairwise meta-analysis.

RESULTS

Fifty-nine articles with a total sample size of 5150 patients were included. Compared with no PBO (non-PBO) intervention, PBO of the abdominal aorta (PBOAA, mean difference(MD) - 1.02, 95% credible interval (CrI) - 1.4 to - 0.67), common iliac artery (PBOCIA, MD - 0.84; 95%CrI - 1.36 to - 0.06) and internal iliac artery (PBOIIA, MD - 0.42; 95%CrI - 0.72 to - 0.13) significantly lowered blood loss volume, with PBOAA being more effective than PBOIIA (MD - 0.60; 95%CrI - 1.05 to - 0.17). PBOAA and PBOIIA also significantly decreased blood loss volume (MD - 2.33; 95%CrI - 3.74 to - 0.94, MD - 1.57; 95%CrI - 2.77 to - 0.47 respectively) and hysterectomy rate (OR 0.31; 95%CrI 0.16 to 0.54, OR 0.53; 95%CrI 0.29 to 0.92 respectively). PBOAA has the highest probability of being more effective in reducing the blood loss volume, blood transfusion volume, and hysterectomy rate.

CONCLUSIONS

Performing PBOAA, PBOCIA, or PBOIIA in PAS patients is an effective way to minimize blood loss volume, while PBOAA and PBOIIA also reduce blood transfusion volume and hysterectomy rate. PBOAA is a notably more effective strategy to reduce blood loss volume than PBOIIA.

KEY POINTS

• PBOAA, PBOCIA, and PBOIIA procedures can significantly reduce the blood loss volume compared to non-PBO intervention in PAS patients, of which PBOAA was more effective than the PBOIIA procedure. • PBOAA and PBOIIA could significantly reduce the blood transfusion volume and hysterectomy rate in contrast to the non-PBO intervention in patients with PAS. • According to our statistical treatment ranking, PBOAA was statistically superior in reducing blood transfusion volume, blood transfusion volume, and hysterectomy rate than other PBO procedures.

When the balloon goes up, blood transfusion goes down: a pilot study of REBOA in placenta accreta spectrum disorders

Background

Patients with placenta accreta spectrum (PAS) disorders often suffer massive hemorrhage during cesarean hysterectomies (CHyst). A novel strategy to decrease blood loss and minimize perioperative morbidity associated with PAS is utilization of ER-REBOA Catheter intraoperatively. In this study, we explore the use of ER-REBOA Catheter during CHyst with the goal of minimizing perioperative morbidity and packed red blood cell (PRBC) transfusions.

Methods

We conducted a retrospective case-control study at a regional referral center of consecutive patients with PAS undergoing CHyst. The primary outcomes were PRBC transfusions of ≥4 units. Secondary outcomes included surgical intensive care unit admissions, postoperative length of stay (LOS), postoperative ileus, and vascular complication rate. We also explored utilization of manual palpation and omission of precesarean fluoroscopy for resuscitative endovascular balloon occlusion of the aorta (REBOA) placement verification in distal aortic zone 3.

Results

90 patients were included in the study. REBOA and non-REBOA cases were similar in clinicodemographic characteristics. 17.7% of REBOA cases received ≥4 units of PRBC compared with 49.3% of non-REBOA cases (p=0.03). Zero REBOA patients developed postoperative ileus, whereas 18 (25%) non-REBOA patients did (p=0.02). LOS was reduced in the REBOA group. Postplacement fluoroscopy was omitted in all REBOA cases. Two postoperative arterial thrombotic events (2 of 19, 11% of REBOA patients) were identified in the REBOA group, one requiring a thrombectomy (1 of 19, 5%).

Discussion

Decrease in blood transfusions of ≥4 units of PRBC is demonstrated when ER-REBOA Catheter is placed in distal aortic zone 3 during CHyst performed for severe PAS disorders. The incidence of postoperative ileus and LOS are reduced in the ER-REBOA Catheter group. Placement and utilization of ER-REBOA Catheter during CHyst may be feasible without fluoroscopy when manual placement verification is performed by an experienced operator. Protocol modifications focusing on reducing thrombotic rate are ongoing.

Level of evidence

IV.

The "rail sign": an ultrasound finding in placenta accreta spectrum indicating deep villous invasion and adverse outcomes

BACKGROUND

Ultrasound has demonstrated a high accuracy in the prenatal diagnosis of placenta accreta spectrum. However, it is not known whether ultrasound findings can pinpoint the depths of villous invasion, recommend surgical strategies, and predict clinical outcomes.

OBJECTIVE

We described an ultrasound descriptor for the placenta accreta spectrum and investigated whether it can predict the severity of villous invasion and clinical outcomes.

STUDY DESIGN

The patients with placenta accreta spectrum in this retrospective cross-sectional study were diagnosed and managed in our hospital from 2002 to 2017. The placenta, with overlying myometrium and bladder, was mapped with color Doppler sonography while the patient's bladder was full. A "rail sign" was defined as 2 parallel neovascularizations depicted by color Doppler sonography over the uterovesical junction and bladder mucosa, with interconnecting bridging vessels perpendicular to both. The patients received serial ultrasound examinations and surgery at our hospital. An unpaired t test and Pearson chi-square test compared the pathology subtypes, surgical strategies, and clinical outcomes in patients with or without a rail sign.

RESULTS

We enrolled 133 consecutive cases of placenta accreta spectrum confirmed either by surgical inspection or pathology examination. Patients with a rail sign had a significantly higher risk of an abnormally invasive placenta (placenta increta or placenta percreta) than those patients without a rail sign (83.3% [60 of 72] vs 27.9% [17 of 61]; odds ratio, 12.94; P<.001). In addition, patients with a rail sign had a higher probability of perioperative approaches, including preoperative vascular control (58.3% [42 of 72] vs 21.3% [13 of 61]; odds ratio, 5.17; P<.001) and uterine artery embolization (34.7% [25 of 72] vs 11.5% [7 of 61]; odds ratio, 4.1; P=.0002]. Furthermore, patients with a rail sign carried a higher risk of adverse clinical outcomes than patients without a rail sign, such as blood transfusion (80.6% [58 of 72] vs 36.1% [22 of 61]; odds ratio, 7.34; P<.001], admission to the intensive care unit (33.3% [24 of 72] vs 16.4% [10 of 61]; odds ratio, 2.55; P=.026), hysterectomy (75% [54 of 72] vs 24.6% [15 of 61]; odds ratio, 9.2; P<.001), and bladder invasion (16.7% [12 of 72] vs 4.9% [3 of 61]; odds ratio, 3.86; P=.033). Notably, the negative predictive value of bladder invasion was 95.1%, indicating a high confidence to reject bladder invasion while the rail sign was negative. When the rail sign was used as a screening test, the positive likelihood ratio of predicting deep villous invasion was 3.64 and correlated with an increased probability of 20% to 25%. Patients with a rail sign also had a greater blood loss (2944±2748 mL vs 1530±1895 mL; P<.001) and a longer hospital stay (11.9±10.9 days vs 8.6±7.1 days; P=.036) than patients without a rail sign.

CONCLUSION

A "rail sign" depicted by color Doppler sonography correlates with deeper villous invasion, additional perioperative approaches, and more adverse outcomes.

A multidisciplinary approach and implementation of a specialized hemorrhage control team improves outcomes for placenta accreta spectrum

INTRODUCTION

The main complication of placenta accreta spectrum (PAS) is massive bleeding. Endoarterial occlusion techniques have been incorporated into the management of this pathology. Our aim was to examine the endovascular practice patterns among PAS patients treated during a 9-year period in a low-middle income country in which an interdisciplinary group's technical skills were improved with the creation of a PAS team.

METHODOLOGY

A retrospective cohort study including all PAS patients treated from December 2011 to November 2020 was performed. We compared the clinical results obtained according to the type of endovascular device used (group 1, internal iliac artery occlusion balloons; group 2, resuscitative endovascular balloons of the aorta; group 3, no arterial balloons due to low risk of bleeding) and according to the year in which they were attended (reflects the PAS team level of experience). A fourth group of comparisons included the woman diagnosed during a cesarean delivery and treated in a nonprotocolized way.

RESULTS

A total of 113 patients were included. The amount of blood loss decreased annually, with a median of 2,500 mL in 2014 (when endovascular occlusion balloons were used in all patients) and 1,394 mL in 2020 (when only 38.5% of the patients required arterial balloons). Group 3 patients (n = 16) had the lowest bleeding volume (1,245 mL) and operative time (173 minutes) of the entire population studied. Group 2 patients (n = 46) had a bleeding volume (mean, 1,700 mL) and transfusions frequency (34.8%) slightly lower than group 1 patients (n = 30) (mean of 2,000 mL and 50%, respectively). They also had lower hysterectomy frequency (63% vs. 76.7% in group 1) and surgical time (205 minutes vs. 275 in group 1) despite a similar frequency of confirmed PAS and S2 compromise.

CONCLUSION

Endovascular techniques used for bleeding control in PAS patients are less necessary as interdisciplinary groups improve their surgical and teamwork skills.

LEVEL OF EVIDENCE

Therapeutic care management, level III.

Comparison of the safety and efficacy of PABO above or below the ovarian artery during cesarean delivery in patients with coexisting placenta accreta and placenta previa

Purpose

To determine the effect of ovarian arteries on the use of prophylactic abdominal aortic balloon occlusion (PABO) in patients with coexisting placenta accreta and placenta previa.

Methods

Thirty-two pregnant women with coexisting placenta accreta and placenta previa treated with PABO in our hospital during 2013-2020 were retrospectively analyzed. The patients were divided into two groups: one with infra-renal abdominal aortic balloon occlusion above the ovarian artery (Group A, n = 15) and the other with occlusion below the ovarian artery (Group B, n = 17). Medical records and relevant imaging of all patients were reviewed. All Cesarean deliveries were scheduled and we decided to perform hysterectomy based on the surgical findings.

Results

Patients in both groups were similar in terms of age, gravidity history, and status of placenta. Regarding their outcomes, estimated blood loss was not significantly different in both groups, although it was lower in Group B than in Group A (3949.5 vs. 4333.8 ml). The other tested parameters did not show any difference. The uterus was preserved in 13 (41%) patients. No access-related or balloon occlusion-related complications occurred in either group.

Conclusions

PABO was safe. However, the balloon location (above or below the ovarian arteries) did not influence the outcomes. Further evaluation and prospective studies are required to evaluate the safety and efficacy of balloon occlusion above or below the ovarian artery in patients with coexisting placenta accreta and placenta previa.

The clinical evaluation of preoperative abdominal aortic balloon occlusion for patients with placenta increta or percreta

OBJECTIVE

To evaluate the efficacy and safety of abdominal aortic balloon for pregnant women with placenta increta or percreta (PIP).

METHODS

Retrospective analysis of the parameters containing estimated blood loss, red cell suspension (RCS) transfusion volume, hysterectomy, surgery time, postoperative hospital days, neonatal status and complications between the two groups.

RESULTS

The patients with preoperative abdominal aortic balloon occlusion (AABO) had significant reduction in blood loss volume, red cell suspension transfusion volume and plasma transfusion volume compared to patients without balloon. Similarly, the surgery time and hysterectomy were obviously reduced in the AABO group. However, there were no difference in the Apgar scores and neonatal complications between the two groups, indicating that the abdominal aortic balloon has little adverse effect on the newborns.

CONCLUSION

AABO plays dramatic roles on reducing blood loss volume and blood transfusion volume and it is also a safe and effective technology providing new insight into the therapy of patient with PIP.

SYNOPSIS

Preoperative abdominal aortic balloon occlusion (AABO), as a new intravascular interventional therapy, is safe and effective in patients with placenta increta or percreta.

Placenta accreta spectrum-a catastrophic situation in obstetrics

Placenta accreta is a significant obstetric complication in which the placenta is completely or focally adherent to the myometrium. The worldwide incidence of placenta accreta spectrum (PAS) is increasing day by day, mostly due to the increasing trends in cesarean section rates. The accurate and timely diagnosis of placenta accreta is important to improve the feto-maternal outcome. Although standard ultrasound is a reliable and primary tool for the diagnosis of placenta accreta, the absence of ultrasound findings does not preclude the diagnosis of placenta accreta. Therefore, clinical evaluation of risk factors is equally essential for the prediction of abnormal placental invasion. Pregnant women with a high impression or established diagnosis of placenta accreta should be managed by a multidisciplinary team in a specialist center. Traditionally, PAS has been managed by an emergency obstetric hysterectomy. Previously, few studies suggested a satisfactory success rate of conservative management in well-chosen cases, whereas few studies recommended delayed hysterectomy to reduce the amount of bleeding. The continuously increasing trends of PAS and the challenges for its routine management are the main motives behind this literature review.

The effect prophylactic internal iliac artery balloon occlusion in patients with placenta previa or placental accreta spectrum: a systematic review and meta-analysis

BACKGROUND

Placenta previa describes a placenta that extends partially or completely over the internal cervical oss. Placenta previa is one of the leading causes of widespread postpartum hemorrhage and maternal mortality worldwide. Another cause of bleeding in pregnant women is Placenta accreta spectrum. Therefore, the aim of the present systematic review and meta-analysis is to determine the effect of prophylactic balloon occlusion of the internal iliac arteries in patients with placenta previa or placental accreta spectrum (PAS).

METHODS

In this systematic review and meta-analysis, to identify and select relevant studies, the SID, MagIran, ScienceDirect, Embase, Scopus, PubMed, Web of Science, and Google Scholar databases were searched, using the keywords of internal iliac artery balloon, placenta, previa, balloon, accreta, increta and percreta, without a lower time limit and until 2020. The heterogeneity of the studies was examined using the I² index, and subsequently a random effects model was applied. Data analysis was performed within the Comprehensive Meta-Analysis software (version 2).

RESULTS

In the review of 29 articles with a total sample size of 1140 in the control group, and 1225 in the balloon occlusion group, the mean difference between the two groups was calculated in terms of Intraoperative blood loss index (mL) and it was derived as 3.21 ± 0.38; moreover, in 15 studies with a sample size of 887 in the control group, and 760 in the balloon occlusion group, the mean difference between the two groups in terms of gestation index (weeks) was found as 2.84 ± 0.49; and also with regards to hysterectomy balloon occlusion after prophylactic closure of the iliac artery, hysterectomy (%) balloon occlusion was calculated as 8.9 %, and this, in the hysterectomy control group (%) was obtained as 31.2 %; these differences were statistically significant and showed a positive effect of the intervention (P < 0.05).

CONCLUSION

The results of this study show that the use of prophylactic internal iliac artery balloon occlusion in patients with placenta previa or Placenta accreta spectrum has benefits such as reduced intraoperative blood loss, reduced hysterectomy and increased gestation (weeks), which can be considered by midwives and obstetricians.

Open versus endovascular REBOA control of blood loss during cesarean delivery in the placenta accreta spectrum: A single-center retrospective case control study

OBJECTIVE

The aim of this study was to compare two vascular control options for blood loss prevention and hysterectomy during cesarean delivery (CD2): endovascular balloon occlusion of the aorta (REBOA3) and open bilateral common iliac artery occlusion (CIAO4) in women with extensive placenta accreta spectrum (PAS5).

STUDY DESIGN

This was retrospective comparison of cases of PAS using either CIAO (October 2017 through October 2018) or REBOA (November 2018 through November 2019) to prevent pathologic hemorrhage during scheduled CD. Women with confirmed placenta increta/percreta underwent either CD then intraoperative post-delivery, pre-hysterectomy open vascular control of both CIA6 (CIAO group) or pre-operative, ultrasound-guided, fluoroscopy-free REBOA followed by standard CD and balloon inflation after fetal delivery (REBOA group). Intraoperative blood loss, transfusion volumes, surgical time, blood pressure, maternal and neonatal outcomes, hospitalization length and postoperative complications were compared.

RESULTS

The REBOA and CIAO groups included 12 and 16 women, respectively, with similar median age of 35 years and gestational age of 34-35 weeks. All REBOA catheters were successfully placed into aortic zone three under ultrasound guidance. The quantitated median intraoperative blood loss was significantly lower for the REBOA group, (541 [IQR 300-750] mL) compared to the CIAO group (3331 [IQR 1150-4750] mL (P = 0.001). As a result, the total volume of fluid and blood replacement therapy was significantly lower in the REBOA group (P < 0.05). Median surgical time in the REBOA group was less than half as long: 76 [IQR 64-89] minutes compared to 168 [IQR 90-222] minutes in the CIAO group (P = 0.001). None of the women with REBOA required hysterectomy, while 8/16 women in the CIAO group did (P = 0.008). Furthermore, the post-anesthesia recovery and hospital discharge times in the REBOA-group were shorter (P < 0.05). One thromboembolic complication occurred in each group. The only REBOA-associated complication was non-occlusive femoral artery thrombosis, with no surgical management required. No maternal or neonatal deaths occurred in either group.

CONCLUSION

Fluoroscopy-free REBOA for women with PAS is associated with improved vascular control, perioperative blood loss, the need for transfusion and hysterectomy and reduces surgical time when compared to bilateral CIAO.

Postpartum Hemorrhages: Prevention

The strict correlation between abnormal invasive placentation and postpartum hemorrhage suggests that a widespread antenatal diagnosis of placental anomalies would improve the management of these challenging patients; acting preventive solutions at the moment of delivery reduces blood loss and avoid hysterectomies. The role of endovascular procedures in this field has been encouraged by multiple studies reporting prophylactic uterine arteries embolization and iliac/aortic balloon catheters positioning. This paper aims to review the main imaging diagnostic findings of placental implant anomalies and summarize the principal preventive endovascular strategies proposed in literature.

Role of interventional radiology in placenta accreta spectrum (PAS) disorders

Placenta accreta spectrum (PAS) disorders are rare but potentially life-threatening obstetric conditions, which can result in severe post-partum haemorrhage (PPH). Traditional management necessitates peripartum hysterectomy, but this carries high rates of morbidity and mortality. More recently, interventional radiology techniques have been developed in order to reduce morbidity and preserve fertility. This article summarises and compares the various reported interventional radiology techniques. Arterial embolisation performed to treat PPH is the therapeutic option which is supported by the highest degree of evidence. The role of preventative procedures, such as temporary balloon occlusion of the internal iliac arteries or distal aorta, continues to be debated due to conflicting outcome data and concerns regarding associated morbidity. The choice of which, if any, interventional radiological technique is utilised is determined by local expertise, available resources and the planned obstetric approach. The most complex patients are likely to benefit from multidisciplinary management in high-volume centres.

Development and validation of nomograms for predicting blood loss in placenta previa with placenta increta or percreta

Background

To develop the risk prediction model of intraoperative massive blood loss in placenta previa with placenta increta or percreta.

Methods

This study included 260 patients, of whom 179 were allocated to the development group and 81 to the validation group. Univariate and multivariate logistic regression analyses were used to identify characteristics that were associated with massive blood loss (≥2,500 mL) during cesarean section. A nomogram was constructed based on regression coefficients. Receiver-operating characteristic curve, calibration curve, and decision curve analyses were applied to assess the discrimination, calibration, and performance of the model.

Results

Two models were constructed. The preoperative feature model (model A) consisted of vascular lacunae within the placenta and hypervascularity of the uterine-placental margin, uterine serosa-bladder wall interface, and cervix. The preoperative and surgical feature model (model B) consisted of an emergency cesarean section, no preoperative balloon placement of the abdominal aorta, and the previously mentioned four ultrasound signs. Model B had better discrimination than model A (area under the curve: development group: 0.839 vs. 0.732; validation group: 0.829 vs. 0.736). Model B showed a higher area under the decision curve than model A in both the training and validation groups.

Conclusions

The preoperative and surgical feature model for placenta previa with placenta increta or percreta can improve the early identification and management of patients who are at high risk of intraoperative massive blood loss.

Arterial thrombosis after REBOA use in placenta accreta spectrum: a case series

BACKGROUND

The use of resuscitative endovascular balloon of the aorta (REBOA) is a useful strategy for bleeding control in placenta accreta spectrum (PAS) management. The incidence of complications associated with this procedure is variable. We report three cases of arterial thrombosis associated with REBOA, and we also analyze the factors that facilitated its occurrence.

CASE REPORT

Three women with PAS, presented common femoral and external iliac arterial thrombosis after REBOA use. Among the contributing factors probably associated with thrombosis, we identified the absence of ultrasound guidance for vascular access and the not using of heparin during aortic occlusion.

CONCLUSIONS

REBOA use is not exempt from complications and must be performed by experienced groups applying strategies to reduce the risks of complications.

High-intensity focused ultrasound in management of placenta accreta spectrum: A systematic review

BACKGROUND

High-intensity focused ultrasound (HIFU) is a non-invasive procedure that has been studied in the management of placenta accreta spectrum (PAS).

OBJECTIVE

To appraise HIFU in the management of PAS and highlight the restrictions on converting uterus-preserving studies into evidence-based practice.

SEARCH STRATEGY

A search on Scopus, Cochrane, PubMed and Web of Science was conducted from date of inception to January 2020.

SELECTION CRITERIA

Studies on using HIFU in the management of PAS were eligible. Review articles, conference papers, and case reports were excluded.

DATA COLLECTION

A standardized sheet was used to abstract data from eligible studies. CON-PAS registry was used to include studies on other conservative modalities.

RESULTS

Four studies were eligible (399 patients). Average residual placental volume was 61.74 cm³ (6.01-339 cm³ ). Treatment was successful in all patients. Normal menstruation recovered after 48.8 days (15-150 days). No major complications were encountered. Sixty-one studies were retrieved from the CON-PAS registry; uterine artery embolization (23 studies), balloon placement (15 studies), compression sutures (10 studies), placenta in situ (7 studies), and uterine resection (6 studies) were successful in 83.7%, 92.9%, 87.9%, 85.2%, and 79.3% of cases, respectively.

CONCLUSIONS

HIFU may fit certain clinical situations in the management of PAS. A global research strategy is recommended to incorporate conservative approaches within a comprehensive management protocol.

Comparison of emergency cesarean hysterectomy with and without prophylactic placement of intravascular balloon catheters in patients with placenta accreta spectrum

OBJECTIVE

The objective of the study was to compare outcomes of women with placenta accreta spectrum(PAS) who underwent emergency cesarean hysterectomy with and without prophylactic intravascular balloon catheters.

Methods Sixty-three cases who had emergency hysterectomy related to PAS disorders were retrospectively analyzed. Subjects with prophylactic intravascular balloon catheter placement plus hysterectomy were compared with those who had hysterectomy alone. The cases were divided into three groups: infrarenal aortic artery balloon occlusion (IAABC) group (who had IAABC plus hysterectomy, n = 31), internal iliac artery balloon occlusion (IIABOC) group (who had IIABOC plus hysterectomy, n = 17), and hysterectomy alone group (control group n = 15).

RESULTS

Outcome measures were not significantly different between the IIABOC group and the control group. IAABC plus hysterectomy resulted in a better outcome than hysterectomy alone, with less amount of estimated blood loss (EBL) during cesarean section (2000 vs 3000 ml, p = .011) and 24 h after cesarean section (2010 vs 4520 ml, p = .004), less operation time(90 vs 106 min, p = .01), and a lower rate of major blood loss(42 vs 93%, p = .029). IAABC plus hysterectomy resulted in better outcomes than IIABOC plus hysterectomy, with less amount of EBL during cesarean section (2000 vs 3000 ml, p = .005) and 24 h after cesarean section (2010 vs 3000 ml, p = .035), a lower rate of major blood loss(42 vs 100%, p < .001), less operation time (90 vs 100 min, p = .038), and less fetus radiation dose（1.9 mGy vs 22.4 mGy, p < .001).

CONCLUSIONS

IAABC was more effective in emergency cesarean hysterectomy related to PAS disorders.

Pelvic arterial embolisation with cyanoacrylate during caesarean hysterectomy for placenta accreta

PURPOSE

To compare n-butyl cyanoacrylate (NBCA) and gelatine sponge (GS) as embolic materials for prophylactic pelvic arterial embolisation during caesarean hysterectomy for placenta accreta spectrum (PAS).

MATERIAL AND METHODS

This retrospective study comprised 12 women (age range, 23-42 years; mean, 34.1 years) who underwent caesarean hysterectomy for PAS. Following caesarean delivery, bilateral uterine and non-uterine parasitic arteries were embolized with GS in the first four cases (GS group) and primarily with NBCA mixed with iodized oil in the subsequent eight cases (NBCA group). Procedure time for embolisation and hysterectomy and total blood loss were compared between the two groups using Welch's t-test.

RESULTS

Although procedure time for embolisation tended to be longer in the NBCA group than in the GS group (111 ± 47 min versus 71 ± 32 min, p=.11), that for hysterectomy was significantly reduced in the NBCA group when compared to the GS group (158 ± 42 min versus 236 ± 39 min, p=.02). Total blood loss was significantly lower in the NBCA group than in the GS group (1375 ± 565 mL versus 2668 ± 587 mL, p=.01).

CONCLUSION

Procedure time for hysterectomy and total blood loss during caesarean hysterectomy can be reduced by using NBCA instead of GS in prophylactic pelvic arterial embolisation for PAS.

Minimizing surgical blood loss at cesarean hysterectomy for placenta previa with evidence of placenta increta or placenta percreta: the state of play in 2020

The evolution of multidisciplinary team-based care for women with placenta accreta spectrum disorder has delivered stepwise improvements in clinical outcomes. Central to this overall goal is the ability to limit blood loss at surgery. Placement of inflatable balloons within the pelvic arteries, most commonly in the anterior divisions of the internal iliac arteries, became popular in many centers, at the expense of prolonging surgical care and with attendant risks of vascular injury. In tandem, the need to expose pelvic sidewall anatomy to safely identify the course of the ureters re-popularized the alternative strategy of ligating the same anterior divisions of the internal iliac arteries. With incremental gains in surgical expertise, described in 5 steps in this review, our teams have witnessed a steady decline in surgical blood loss. Nevertheless, a subset of women has the most severe form of placenta accreta spectrum, namely placenta previa-percreta. Such women are at risk of major hemorrhage during surgery from vessels arising outside the territories of the internal iliac arteries. These additional blood supplies, mostly from the external iliac arteries, pose significant risks of major blood loss even in experienced hands. To address this risk, some centers, principally in China, have adopted an approach of routinely placing an infrarenal aortic balloon, with both impressively low rates of blood loss and an ability to conserve the uterus by resecting the placenta with the affected portion of the uterine wall. We review these literature developments in the context of safely performing elective cesarean hysterectomy for placenta previa-percreta, the most severe placenta accreta spectrum disorder.

Risk of vascular complications in prophylactic compared to emergent resuscitative endovascular balloon occlusion of the aorta (REBOA) in the management of placenta accreta spectrum

OBJECTIVE

To compare prophylactic and emergent resuscitative endovascular balloon occlusion of the aorta (REBOA) catheter placement in the management of placenta accreta spectrum (PAS).

STUDY DESIGN

Retrospective chart review of all patients with PAS (January 2018 to January 2020) at a single tertiary center who underwent prophylactic or emergent REBOA for cesarean hysterectomy for PAS.

RESULTS

A total of 16 pregnant patients with PAS underwent percutaneous REBOA placement by acute care surgeons in collaboration with a multi-disciplinary PAS team. The REBOA catheter was placed prophylactically in 11 cases and emergently in 5 cases. No complications occurred in the prophylactic placement group. In the emergent placement group, 3 of 4 surviving patients had vascular access site complications requiring intervention.

CONCLUSION

A multidisciplinary approach for the management of PAS utilizing REBOA is feasible in the setting of both planned and emergent cesarean hysterectomy and can aid in the control of acute hemorrhage. The risk for vascular access site complications related to REBOA catheter placement is higher in the emergent setting compared to prophylactic placement.

Prophylactic endovascular balloon occlusion of the aorta in cases of placenta accreta spectrum during caesarean section: points from the anaesthesiologist's perspective

Background

The placenta accreta spectrum (PAS) is a severe complication of pregnancy and is associated with massive haemorrhage, hysterectomy, and even perinatal maternal-foetal death. Prophylactic abdominal aortic balloon occlusion (PAABO) is a novel and efficient therapy for these patients. The aim of this study was to investigate the benefits, potential risks, and characteristics of anaesthesia management.

Methods

A total of 48 parturients with PAS were enrolled and divided into two groups. Group A (n = 25) received PAABO, and Group B (n = 23) underwent a normal operative procedure. The characteristics of the general parameters, anaesthesia, and operative procedure were noted. Data on vital signs including systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) during the operation were recorded. Before and after the procedure, hepatic and renal function and lactate dehydrogenase (LDH) were also measured.

Results

The characteristics of the groups were comparable. PAABO significantly reduced estimated blood loss, which was ≥ 1000 ml. Drastic fluctuations in SBP, DBP and HR were observed during inflation and deflation in Group B. After the operation, increased LDH and glutamic oxaloacetic transaminase (GOT) were observed in both groups, and increased glutamic-pyruvic transaminase (GTP) was observed in Group B.

Conclusions

PAABO reduced perioperative blood loss and the risk of hysterectomy among parturients with PAS. Sophisticated anaesthetic management should be implemented to prevent or reduce perioperative complications and address internal disorders that are caused by massive blood loss.

Successful management of uncontrolled postpartum hemorrhage due to morbidly adherent placenta with Resuscitative endovascular balloon occlusion of the aorta during emergency cesarean section - A case report

Background

Morbidly adherent placenta (MAP) may cause life-threatening postpartum hemorrhage (PPH) requiring massive transfusions. Furthermore, it could endanger the lives of both mother and baby. Despite various efforts, such as adjuvant endovascular embolization and hysterectomy, massive PPH due to MAP still occurs and is difficult to overcome.

Case

Herein, we described the case of a 40-year-old woman with placenta previa totalis who experienced massive bleeding during a cesarean section. We used resuscitative endovascular balloon occlusion of the aorta (REBOA) and it improved the condition of the surgical field and the hemodynamic stability of the patient temporarily. The patient was successfully managed without further complications.

Conclusions

REBOA can be used as a rescue procedure for uncontrolled bleeding situations in patients with MAPs. Anesthesiologists should consider and recommend REBOA as another resuscitative therapeutic option in the case of massive PPH.

Perioperative prophylactic internal iliac artery balloon occlusion in the prevention of postpartum hemorrhage in placenta previa: a randomized controlled trial

BACKGROUND

Placenta previa remains one of the major causes of massive postpartum hemorrhage and maternal mortality worldwide.

OBJECTIVE

To determine whether internal iliac artery balloon occlusion during cesarean delivery for placenta previa could reduce postpartum hemorrhage and other maternal complications.

STUDY DESIGN

This was a prospective randomized controlled trial conducted at a tertiary university obstetric unit in Hong Kong. Pregnant women who were diagnosed to have placenta previa at 34 weeks (defined as lower placenta edge within 2 cm from the internal os) and required cesarean delivery were invited to participate. Eligible pregnant women were randomized into internal iliac artery balloon occlusion (Occlusion) group or standard management (Control) group. Those randomized to the Occlusion group had internal iliac artery balloon catheter placement performed before cesarean delivery and then balloon inflation after delivery of the baby. The primary outcome was the reduction of postpartum hemorrhage in those with internal iliac artery balloon occlusion. Secondary outcome measures included hemoglobin drop after delivery; amount of blood product transfusion; incidence of hysterectomy; maternal complications including renal failure, ischemic liver, disseminated intravascular coagulation, and adult respiratory distress syndrome; length of stay in hospital; admission to intensive care unit; and maternal death.

RESULTS

Between May 2016 and September 2018, 40 women were randomized (20 in each group). Demographic and obstetric characteristics were similar between the 2 groups. In the Occlusion group, 3 women did not receive the scheduled procedure, as it was preceded by antepartum hemorrhage that required emergency cesarean delivery, and 1 woman had repeated scan at 36 weeks showing the placental edge was slightly more than 2 cm from the internal os. Intention-to-treat analysis found no significant differences between the Occlusion and the Control groups regarding to the median intraoperative blood loss (1451 [1024-2388] mL vs 1454 [888-2300] mL; P = .945), the median length of surgery (49 [30-62] min vs 37 [30-51] min; P = .204), or the need for blood transfusion during operation (57.9% vs 50.0%; P = .621). None of the patients had rebleeding after operation, complication related to internal iliac artery procedure, or any other maternal complications. Reanalyzing the data using on-treatment approach showed the same results.

CONCLUSION

The use of prophylactic internal iliac artery balloon occlusion in placenta previa patients undergoing cesarean delivery did not reduce postpartum hemorrhage or have any effect on maternal or neonatal morbidity.

The role of interventional radiology in the management of abnormally invasive placenta: a systematic review of current evidences

Abnormally invasive placenta (AIP) is a potentially severe condition. To date, arterial embolization in women with postpartum hemorrhage due to AIP is the treatment option for which highest degrees of evidence are available. However, other techniques have been tested, including prophylactic catheter placement, balloon occlusion of the iliac arteries and abdominal aorta balloon occlusion. In this systematic review, we provide an overview of the currently reported interventional radiology procedures that are used for the treatment of postpartum hemorrhage due to AIP and suggest recommendations based on current evidences. Owing to a high rate of adverse events, prophylactic occlusion of internal iliac arteries should be used with caution and applied when the endpoint is hysterectomy. On the opposite, when a conservative management is considered to preserve future fertility, uterine artery embolization should be the preferred option as it is associated with a hysterectomy rate of 15.5% compared to 76.5% with prophylactic balloon occlusion of the internal iliac arteries and does not result in fetal irradiation. Limited data are available regarding the application of systematic prophylactic embolization and no comparative studies with arterial embolization are available.

Clinical outcomes and anesthetic management of pregnancies with placenta previa and suspicion for placenta accreta undergoing intraoperative abdominal aortic balloon occlusion during cesarean section

Background

This retrospective study aimed to compare the clinical outcomes of parturients with placenta previa (PP) and placenta accreta (PA) according to their severity, when they were managed with intraoperative abdominal aortic balloon occlusion (IAABO) during cesarean section.

Methods

We retrospectively examined 57 cases of PP and suspicion for PA in which IAABO was performed during cesarean section between April 2014 and June 2016. Based on preoperative examination and clinical risk factors, patients were divided into the low suspicion PA group and the high suspicion PA group. We compared the demographic characteristics, methods of anesthesia, intra- and postoperative parameters, and maternal and neonatal outcomes.

Results

The two groups showed similar demographic characteristics and intraoperative outcomes. Four women underwent cesarean hysterectomy. Eight neonates were admitted to the neonatal intensive care unit and three did not survive. Neonatal Apgar scores were significantly higher in the low suspicion PA group. Eight patients experienced postoperative femoral artery thrombosis and one patient complicated hematoma in the front wall of the common femoral artery. Patients who received neuraxial anesthesia showed significantly lower intraoperative blood loss, lower intraoperative, postoperative and total blood transfusion and shorter surgery than patients who received general anesthesia.

Conclusions

Our data suggested that the severity of aberrant placental position does not affect intraoperative blood loss during a cesarean section while the IAABO is performed. We propose that neuraxial anesthesia is preferred for conducting these surgeries without contraindications.

A retrospective analysis of the treatment on abdominal aortic balloon occlusion-related thrombosis by continuous low-flow diluted heparin

Thrombosis is one of the serious complications related to prophylactic balloon occlusion of the abdominal aorta (PBOAA). This study aims to retrospectively analyze the efficacy and safety of continuous low-flow infusion of diluted heparin saline to prevent this complication related to PBOAA and further to provide the theory and evidences for using PBOAA.A study was carried out at our hospital from March 2016 to December 2018. Women with pernicious placenta previa (PPP) were treated PBOAA to prevent massive bleeding during CS. According to whether continuous low-flow infusion of diluted heparin saline was used to prevent catheter-related thrombosis or not, they were divided into 2 groups, the test group and the control group. The incidence of thrombosis between the 2 groups was compared and the effective treatment of thrombosis was also discussed. The comparison of nonparametric values was accomplished by using Fisher exact test. Statistical significance was set at P < .05.There were 31 women with PPP who received PBOAA during CS who were included in our study. Six of 19 women in control group (31.6%) developed thrombotic complications, while none of 12 women in test group. There were statistically significant differences in the incidence of thrombosis between the 2 groups (P = .037). There was no statistically significant difference in the amount of estimated blood loss and blood transfusion during CS between the 2 groups, nor was there statistically significant difference in the hospital days after CS (P > .05). All 6 women with thrombotic complications had no positive symptoms and thrombotic sequelae. The managements of thrombus included systemic anticoagulation, catheter-directed thrombolysis, and catheter-directed anticoagulation. One of the 6 women was lost to follow-up, and the thrombus of the other 5 women were completely dissolved. No other adverse outcomes or complications related to PBOAA were observed in all women in this study.Continuous low-flow infusion of diluted heparin saline is a safe procedure when PBOAA is performed for patients with PPP. It can effectively reduce or even avoid thrombosis without increasing intraoperative blood loss during CS for PPP patients.

Outcomes of balloon occlusion in the University of California Morbidly Adherent Placenta Registry

BACKGROUND

Morbidly adherent placenta, also known as placenta accreta spectrum, is associated with severe maternal morbidity and mortality. Multiple adjunctive procedures have been proposed to improve outcomes, and at many institutions, interventional radiologists will play a role in assisting obstetricians in these cases.

OBJECTIVE

The objective of the study was to evaluate the outcomes of women with morbidly adherent placenta who underwent cesarean hysterectomy with aortic balloon occlusion or internal iliac artery balloon occlusion catheters, compared with cesarean hysterectomy with surgical ligation of the iliac arteries, or cesarean hysterectomy without adjunctive procedures.

STUDY DESIGN

A retrospective review of women with morbidly adherent placenta treated with cesarean hysterectomy was performed at 5 institutions from May 2014 to April 2018. The balloon occlusion group had either prophylactic aortic or iliac balloons placed prior to cesarean hysterectomy. Comparison groups included those who underwent internal iliac artery ligation prior to hysterectomy or a control group if they underwent cesarean hysterectomy without adjuvant procedures. Evaluated outcomes include estimated blood loss, transfusion requirements, intensive care unit admission, and adverse event rates.

RESULTS

There were 171 women with morbidly adherent placenta included in the study. Twenty-eight had balloon placement prior to cesarean hysterectomy, 18 had intraoperative internal iliac artery ligation, and there were 125 control women who underwent cesarean hysterectomy without any adjunctive procedures. Compared with the women who underwent cesarean hysterectomy without adjunctive procedures, women who underwent aortic or iliac artery balloon occlusion prior to hysterectomy had significantly lower estimated blood loss (30.9% decrease, P < .001), transfusion requirements (76.8% decrease, P < .001), intensive care unit admission rates (0% vs 15.2%, P < .001), and intensive care unit stay lengths (0.0 vs 3.1 days, P < .001). Compared with women who underwent surgical ligation of the internal iliac arteries prior to hysterectomy, women who underwent aortic or iliac artery balloon occlusion prior to cesarean hysterectomy had lower estimated blood loss (54.2% decrease, P < .01), transfusion requirements (90.5% decrease, P < .001), operating room times (40.0% decrease, P < .01), intensive care unit admissions rates (0% vs 77.8%, P < .001), intensive care unit stay lengths (0.0 vs 1.4 days, P < .001), and adverse events (3.6% vs 44.4%, P < .01).

CONCLUSION

Aortic and iliac artery balloon occlusion are associated with lower estimated blood loss, transfusion requirements, intensive care unit admission rates, and adverse event rates compared with women who underwent internal iliac artery ligation prior to cesarean hysterectomy or women who had no adjunctive interventions prior to cesarean hysterectomy for morbidly adherent placenta.

Comparison of the efficacy of prophylactic balloon occlusion of the abdominal aorta at or below the level of the renal artery in women with placenta accreta undergoing cesarean section

OBJECTIVE

To compare the safety and efficacy of prophylactic balloon occlusion of the abdominal aorta (PBOA) performed at the level of the renal artery (PBOA-ARA) or below this level (PBOA-BRA) for the management of placenta accreta.

METHODS

We conducted a retrospective investigation of 57 women scheduled for cesarean delivery who underwent PBOA at our hospital between October 2015 and July 2017. The balloon occlusion was performed at (PBOA-ARA group; n = 30) or below (PBOA-BRA group; n = 27) the renal artery origin. The perioperative data of the two groups were compared.

RESULTS

Estimated blood loss was lower in the PBOA-ARA group than in the PBOA-BRA group (p > .05). There were no intergroup differences in intraoperative blood transfusion volume, hemoglobin reduction, urine output, and serum levels of creatinine and blood urea nitrogen. Postballoon release hemorrhage occurred in eight patients of the PBOA-BRA group, but in none of the PBOA-ARA group, indicating a significant difference (p = .007). Subgroup analysis of placenta types revealed that the estimated blood loss among women with placenta increta in the PBOA-ARA group was less than that in the PBOA-BRA group (p = .015), which was reflected by a significant difference in the reduction of hemoglobin levels (p = .042).

CONCLUSIONS

PBOA at the level of the renal artery entailed lesser blood loss than that performed below the renal artery origin, particularly in the case of placenta increta; this, in turn, reduces the risk of postpartum hemorrhage from ovarian arteries and subsequent blockade of the ovarian artery origin.

Prophylactic abdominal aortic balloon occlusion in patients with pernicious placenta previa during cesarean section: a systematic review and meta-analysis from randomized controlled trials

PURPOSE

Pernicious placenta previa induces severe hemorrhage during cesarean section. Abdominal aorta balloon occlusion (AABO) is considered as an effective operation for patients with pernicious placenta previa. The aim of this study was to investigate the clinical application of abdominal aortic balloon occlusion in the placenta previa and cesarean section by systematic review and meta-analysis.

METHODS

MEDLINE, EMBASE, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), WAN-FANG DATA and CQVIP were searched from inception to Jan. 15th, 2019. Operative time, intraoperative blood loss volume, postoperative hospitalization duration, intraoperative blood transfusion volume, hysterectomy rate, lower extremity thrombosis rate, ICU admission rate, adverse reaction rate, neonatal birth weight, Apgar 1-min and 5-min scores were regarded as the endpoints. Randomized controlled trials (RCT) were used for meta-analysis.

RESULTS

Fourteen articles were retrieved from total 650 articles, and the results of meta-analysis showed that application of intraoperative AABO had the ability to reduce the operative time (WMD = - 16.581, 95% CI - 26.690 to - 6.472; P = 0.001), the intraoperative blood loss volume (WMD = - 1202.69, 95% CI - 1732.25 to - 673.12; P < 0.001), the intraoperative blood transfusion volume (WMD = - 1202.69, 95% CI - 1732.25 to - 673.12; P < 0.001). The hysterectomy rate (RR = 0.279, 95% CI 0.164-0.474; P < 0.001), postoperative hospitalization duration (WMD = - 1.423, 95% CI - 2.070 to - 0.776; P < 0.001) and the balloon preset time (WMD = - 13.793, 95% CI - 15.341 to - 12.244; P < 0.001; I² = 0.0%) were also reduced in AABO group.

CONCLUSIONS

Application of AABO in patients with pernicious placenta previa is safe and effective, which is worthy of clinical promotion.