We commend Peng et al. for devising "stage operation" for placenta accreta. They placed a pressure band, reduced the blood flow, and removed the placenta cephalad to it, with the remaining placenta left in situ. Although 2 of 19 patients required hysterectomy after cesarean section (CS), the uterus was preserved in remaining 17. Four patients required dilatation and evacuation after CS and the placenta was resolved or discharged in remaining 13.
International Federation of Gynecology and Obstetrics recently recommended the usage of the terminology of "placenta accreta spectrum (PAS) disorders (creta, increta, percreta)",[2,3] thereby avoiding the ambiguity of the term "accreta", which has been used in a double sense, narrow and wide. Sub-classification of PAS (creta, increta, percreta) should be made only by histological examination after hysterectomy. When hysterectomy was not performed, "PAS" (without sub-classification) should be used. Thus, Peng et al. performed this two-stage surgery to patients with PAS. We have clarification and concern.
Our clarification is: PAS surgery can be categorized into four:[4,5] i) forcible placental removal (extirpative approach), ii) partial resection of the uterine wall, with the PAS-placenta adhering to the uterine wall to be resected, iii) placenta left in situ approach, iv) hysterectomy either cesarean or intentionally delayed. The uterus is preserved in i)-iii) and resected in iv). Peng et al.'s procedure is a combination of i) and iii). The removal of the partial placenta reduces the uterine volume, accelerating uterine contraction and thus involution. Reduction of the total placental volume left in situ may reduce the possibility of placental infection. Nobody, to our knowledge, has proposed this concept. This procedure may become an option for PAS surgery.
Our concern is: this partial placental removal is performed effectively and successfully when i) the placental part cephalad to the pressure band is relatively thin, ii) this part is removable, and iii) its removal actually reduces the volume of the remaining placenta (caudal to the band). Figure 1a illustrates this scenario 1. In the scenario 2 (Figure 1b), contrary to the scenario 1, the placenta exists just adjacent to the internal ostium in a lump and even the "cephalad" part also has severer PAS (diffuse increta/percreta). Then, one can hardly separate the "cephalad" part of the placenta, and even if one can do it, the removed part of the placenta is small. This "forcible" placental removal may cause marked bleeding even with the use of the pressure band or some hemostatic techniques. In short, if the removal part is large to the extent that it reduces the uterine/placental volume, partial removal may be effective, whereas if its removal may not reduce their volume and may cause marked bleeding, partial removal is not effective but rather dangerous. Although scenario 1 vs. 2 illustrates an extreme example, less experienced obstetricians may not be able to discern whether the placenta of an individual patient belongs to type (scenario) 1 or 2. This should be clarified for Peng et al.'s procedure to be reproducible. It regards the indication of this new surgery.
Shigeki Matsubara, Hironori Takahashi
Director and Professor, Department of Obstetrics and Gynecology,
 Peng Q, Zhang W, Liu Y. Clinical application of stage operation in patients with placenta accreta after previous caesarean section. Medicine (Baltimore). 2018;97:e10842.
 Jauniaux E, Silver RM, Matsubara S. The new world of placenta accreta spectrum disorders. Int J Gynaecol Obstet. 2018;140:259-60.
 Matsubara S, Jauniaux E. Placenta accreta spectrum disorders: A new standardized terminology better defining the condition. J Obstet Gynaecol Res. 2018 Apr 19. doi: 10.1111/jog.13649.
 Sentilhes L, Goffinet F, Kayem G. Management of placenta accreta. Acta Obstet Gynecol Scand. 2013;92:1125-34.
 Matsubara S, Takahashi H. Intentional placental removal on suspicious placenta accreta spectrum: still prohibited? Arch Gynecol Obstet. 2018;297:1-2.
Figure 1. Schema of two extreme types of placenta accreta spectrum (PAS) disorders.
- The placenta widely covers the anterior uterine wall. The placenta cephalad to the pressure band is without PAS or less severe PAS (creta). The removal of this placental part is easy and may reduce the uterine and remaining placental volume.
2. The placenta locates adjacent to the internal ostium in a lump with diffuse increta or percreta. The removable placental parts are small and their forcible removal may cause marked bleeding.