We performed a retrospective analysis of the medical and radiological records of 13 pregnant patients (n = 13) with placental disorders between May 2017 and January 2021. These placental disorders included placenta previa in three cases (n = 3), placenta increta in seven cases (n = 7), and placenta percreta in three cases (n = 3). Cesarean section was performed as an elective surgery in all cases and hysterectomy was planned and performed in five (n = 5) cases. Preoperative diagnoses were confirmed using transabdominal and transvaginal Doppler sonography and/or magnetic resonance imaging (MRI).
The typical ultrasound findings were based on the detection of at least two of the following characteristics:
- Loss/irregularity of the hypoechoic area between the uterus and the placenta.
- Thinning/interruption of the uterine serosa-bladder wall interface (Fig. 1).
- Myometrial thickness < 1 mm.
- Turbulent placental lacunae with high-velocity flow (>15 cm/seg).
- Increased vascularity of the uterine serosa-bladder wall interface.
- Irregular intraplacental vascularization.
The MRI findings were based on the detection of at least two of the following characteristics:
- Demonstration of uterine bulging and loss of the normal uterine contour.
- T2 sagittal images showing partial or total insertion of the placenta into the lower uterine segment (Fig. 2).
- T2 sagittal images showing focal thinning of the myometrium and interruption of the junctional zone.
All included patients were beyond 28 gestational weeks and were discussed by all involved teams in a roundtable meeting two weeks prior to the cesarean appointment. Gynecologists, interventional radiologists, anesthetists, pediatricians, and nurses planned every case in two possible scenarios (planned vs. emergency surgery) and discussed the step-by-step setting before, during, and after the cesarean section with perioperative prophylactic IIABO. All patients were fully informed of the study and surgical procedures by their doctors and then signed informed consent forms. This research project was approved by the biomedical ethics committee of the hospital.
Interventional Balloon Placement Technique
All interventions were performed in sterile preoperative conditions under standby local anesthesia with the assistance of the anesthesiology team (prior to the cesarean surgical event). First, a bilateral common femoral arterial puncture and access was performed with 7-Fr vascular sheaths (35-cm Super-Arrow Flex®, Athlone, ROI) under local anesthesia. Both internal iliac arteries were sequentially (first right and then left) cannulated using a crossover approach with a 4‑Fr Cobra C2 catheter (Cordis™, California, USA). In one case (n = 1), it was necessary to employ a 4-Fr Omniflush catheter for the crossover approach due to a sharp aortic bifurcation. After selective catheterization of the anterior branch of the internal iliac artery, approximately 15 mm after its origin, a 145-cm 0,035" stiff wire (Amplatz Super Stiff, USA) was placed and the 4-Fr catheter was exchanged for an 8.5-mm/11.5-mm x 80-cm occlusion balloon catheter (Berenstein, Boston Scientific, USA). Then, the wire was removed.
A balloon occlusion test was performed with 1.5 ml of diluted contrast media in each balloon, always unilaterally (never both balloons at the same time) and always under continuous monitoring of the fetal heart rate. The correct position and function of each balloon (positive occlusion balloon test) was determined if a column of contrast media was visible above the filled occlusion balloon in the internal iliac artery, indicating complete occlusion of the blood flow distal to the balloon (Fig. 2). During the procedure, we paid particular attention to the minimization of fetal radiation exposure using intermittent low-dose fluoroscopy. Both introducer/catheter systems were secured to the patient’s legs with sterilized transparent dressing tape (3M® USA), making them visible and accessible for further injection.
Cesarean Surgery and Balloon Inflation
After a surgical time-out with all teams present, the surgery was started with the interventional radiologist beside the surgical team in sterile conditions. Immediately after the cesarean delivery of the child, the balloons were inflated at the time of cord clamping to minimize the risk of fetal hypoxia with 1.5 ml fluid and without the use of fluoroscopy. The balloons remained inflated constantly throughout the surgery until no more bleeding was present. During this period, the interventional radiologist stayed in the operating room, monitoring distal leg pulses (dorsal pedis or tibialis posterior) with a portable Doppler probe. Balloon deflation was performed sequentially when bleeding risk was not more present by report of the surgical and anesthesiology teams; during this period, potential transvaginal bleeding was controlled for two minutes. If no further bleeding was observed, the balloons were not reinflated. When the surgery was finished, balloon catheter extraction was performed and closure devices (Proglide™, Abbott Vascular, USA, or Mynx™, Cardinal Health, USA) were used to ensure hemostasis of the common femoral arteries. If the patient presented with continuous bleeding after the surgery, the balloons remained inflated until another management action, such as uterine artery embolization (UAE), was taken.
The assayed variables of this study were:
- Estimated blood loss, the number of red blood cell transfusions, and the length of the hospital stay for mother and child.
- Reported and evaluated intervention time, balloon inflation time, surgical time, and fetal absorbed dose.
The degree of intraoperative blood loss was estimated with reference to the amount of blood collected by the suction system and the weight and number of surgical pads. This estimation was performed by anesthetists who were not part of the research team. We also reviewed the rates of emergency UAE and conservation of the uterus.
The FAD and the mother’s effective dose were calculated with PCXMX version 2.0  based on individual procedure conditions (dose area product/DAP and source-to-surface distance) and patient information (height and weight). Average field sizes (0.09 ± 0.01 m2) were used for all estimations. After the aforementioned data were entered into the program, the radiation dose absorbed by the uterus was calculated and used to represent the fetal absorbed dose. For statistical analysis, continuous variables were presented as means ± SDs. The main characteristics and outcomes are presented in Table 1.