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

by Shigeki Matsubara, Hironori Takahashi, Hiroyasu Nakamura, Hideharu Sugimoto (matsushi@jichi.ac.jp)

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

Dear Editor,

We commend Li et al. [1] for demonstrating the effectiveness of intra-arterial balloon occlusion in surgery for placenta accreta. Balloon occlusion (internal iliac (IIA), common iliac (CIA), or infrarenal abdominal aorta (IAA)) reduced bleeding more than without it. Importantly, occlusion of CIA or IAA was more effective than that of IIA. We also employed balloon occlusion in accreta surgery for approximately one decade [2]: in a trial-and-error manner, we changed the occluding artery from IIA→CIA→IAA. Li et al.’s data were consistent with our experience. We have some concerns.

Firstly, Li et al.’s study population comprised patients for whom the balloon was actually inflated, suggesting that balloon was inflated in all patients in whom the balloon was preset. The pre-surgical diagnosis of placenta accreta is not 100%. Even if it becomes approximately 100%, whether “all” require inflation is doubtful: inflate/non-inflate should be determined depending on the intra-surgical findings based on the experienced surgeon’s decision [3]. A prophylactic balloon “preset” for suspicious cases is justifiable; however, “inflate for all” may not be [4]. “Inflate” is more likely to cause adverse events than “preset”. An “inflate for all” vs. “inflate for selected patients” strategy: we have been employing the latter. We wish to know which strategy Li et al. employed.

Secondly, if the latter was the case, patients with IAA may have some disadvantages. While a 6-French sheath was used for patients with IIA and CIA, a 12-French sheath was used for those with IAA. Patients with “preset but not inflate” must accept some demerits: 12-French is too large for them. We use a 7-French sheath (Rescue Balloon, Tokai Medical Products, Aichi, Japan) even for IAA. Although adverse events accompanying catheter procedure were rare in Li et al.’s study, a larger sheath is more likely to cause them, including after-bleeding and hematoma in the site. In cases whereby an IAA balloon is set and inflated in an appropriate patient with a beneficial outcome, even this large sheath may be acceptable, whereas only a preset IAA balloon with this large sheath may be less beneficial.

Thirdly, we wonder why one radiologist performed one arterial balloon handling: JS for IIA, KL for CIA, and YZ for IAA, showing a 1:1 correspondence. This is peculiar considering that this study was an attempt to compare the superiority of one procedure with that of others. Let us assume that two obstetricians (doctors A and B) perform procedures A and B for placenta accreta surgery, respectively: doctor A performs only A whereas doctor B only B. Comparison of the bleeding amount between procedure A vs. B may not test the superiority of one procedure over another but that of one doctor over another. We understand that in dealing with intraarterial balloon use, the technical differences among radiologists may not be so marked as those among surgeons; however, this may naturally affect the results.

Lastly, the Federation of International Gynecology and Obstetrics recently recommended the terminology of placenta accreta spectrum (PAS) disorders (creta, increta, percreta) [5,6], with which we can avoid the dual meaning of “accreta” (both narrow and broad sense). We hope that radiology researchers will also use this terminology.

Fundamentally, the standard treatment of placenta accreta has been considered to be cesarean hysterectomy [2]. This, however, deprives patients of their fertility. Balloon occlusion is a “boon” both for patients and doctors: uterus-preserving strategies may become a reality [7]. We wish to know further details of Li et al.’s study, which may help radiologists and obstetricians work hand in hand.