Reply to the Letter to the Editor: Placenta accreta and intraarterial balloon occlusion: Preset or inflate and occlude where?

by Yu Zou (zouyuzju@zju.edu.cn)

Li, K., Zou, Y., Sun, J. et al. Eur Radiol (2018). https://doi.org/10.1007/s00330-018-5527-7

We thank Matsubara S. and colleagues for their comments on our recent article about prophylactic balloon occlusion (PBO) in patients with placenta accreta. First of all, our article is a retrospective study, in this period, balloons implanted in 5 patients did not need to be inflated, and no massive bleeding occurred during the caesarean delivery. Due to pathologically confirmed absence of placenta accreta, these 5 cases were all excluded from our study. MRI played an important role in our study, it helps to confirm the depth and range of placenta accreta before the operation of PBO. Although the preoperative diagnosis of MRI cannot be 100%, most placenta accreta, especially increta and percreta, can be diagnosed [1]. Therefore, these strictly selected patients in our study were all performed on with PBO, balloons were all inflated during the caesarean delivery.

Secondly, we totally agree with Matsubara S. et al that a smaller sheath is more likely to cause fewer adverse effects during PBO of infrarenal abdominal aorta (IAA). Currently, for certain reasons, we are unable to obtain a 7-F sheath or similar catheter sheath for PBO of IAA from our institution. In the future, we will apply for some similar devices from medical device manufacturers and use them in our study as the author suggested.

Finally, as to the methodology of grouping, “why one radiologist performed one arterial balloon handling: J. Sun. for IIA, K. Li. for CIA, and Y. Zou. for IAA” during procedures of PBO, we can provide a reasonable explanation: a) these three radiologists have different concepts for the treatment of placenta accreta; b) PBO procedure was relatively simple, meanwhile, these three radiologists are all experienced in interventional operations, PBO can be accomplished successfully; c) PBO procedure was only one part of this complex operation for patients with placenta accreta, we believe that caesarean delivery which was randomly completed by experienced obstetricians has the greatest influence on the estimated blood loss (EBL). Due to b) and c), the bias of the study results is not obvious.

We thank Matsubara S. et al again for their appreciation of our work and for this opportunity to discuss the important goal of fully understanding the procedures of PBO in the treatment of placenta accreta. At present, PBO is a novel technique to treat placenta accreta, we also operate this interventional technique “in a trial-and-error manner” during our early work. We anticipate and hope that our present study demonstrating the effectiveness of PBO in treatment of placenta accreta will stimulate additional studies to further elucidate the mechanisms through which PBO decrease EBL during caesarean delivery.