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Placenta percreta: time to close a 50-year-old “Pandora’s box”

Published:August 02, 2022DOI:https://doi.org/10.1016/j.ajog.2022.08.003
      We thank Drs Calvache and Benavides for their comments on our study and sharing their views on the diagnosis and management of placenta accreta spectrum (PAS). Their overall intention is to minimize the significance of histopathologic examination in the diagnosis of PAS in their studies. Although we understand that access to expert perinatal pathologists may not be available in most countries, including high-income countries, any clinical trial should stratify outcomes based on postoperative histologic confirmation of PAS and an assessment of the extent of the condition.
      Point #1: We agree that ultrasound imaging is useful in preoperative evaluation and surgical planning. However, imaging in general is not diagnostic of PAS. In expert hands, it can accurately identify high-risk patients, but imaging signs of uterine scarification (loss of clear zone, myometrial thinning, placental bulge, and bladder wall interruption) and superficial intraoperative features of dehiscence are not pathognomonic of accreta placentation.
      • Jauniaux E.
      • Hussein A.M.
      • Einerson B.D.
      • Silver R.M.
      Debunking 20th century myths and legends about the diagnosis of placenta accreta spectrum.
      If the placenta can be fully detached digitally during delivery, ie, without the need for partial myometrial resection (PMR), it should not be reported as PAS.
      Point #2: In our study, expert intraoperative assessment mischaracterized a subset of patients with simple uterine dehiscence as percreta.
      • Jauniaux E.
      • Hecht J.L.
      • Elbarmelgy R.A.
      • Elbarmelgy R.M.
      • Thabet M.M.
      • Hussein A.M.
      Searching for placenta percreta: a prospective cohort and systematic review of case reports.
      All our cases clinically classified as percreta were either abnormal placental attachment (creta or increta) associated with dehiscence or were not PAS (simple dehiscence) on final pathology. Our point was that true percreta, ie, transmural uterine villous invasion reaching the serosa and/or beyond the uterine wall probably does not exist. This Pandora’s box was opened by Lukes et al 50 years ago, who suggested that there were 3 grades of villous invasiveness, but the authors did not describe the histologic changes associated with placenta percreta.
      • Luke R.K.
      • Sharpe J.W.
      • Greene R.R.
      Placenta accreta: the adherent or invasive placenta.
      Points #3 & 4: We did not design our study to compare outcomes based on the type of management. Primary surgical outcomes in placenta previa, such as blood transfusion, are entirely dependent on the expertise of the surgical team and are not directly related to a diagnosis of PAS. The vast majority of clinical studies do not describe intraoperative or pathology findings. We showed that most if not all such cases are complex dehiscence with adjacent accreta areas or dehiscence without PAS. Although this opens the possibility of PMR in cases of localized dehiscence, studies of that approach must be evaluated with an account of the presence of PAS on postoperative pathology. This can be easily done on PMR specimens in conservative management cases.
      • Hecht J.L.
      • Baergen R.
      • Ernst L.M.
      • et al.
      Classification and reporting guidelines for the pathology diagnosis of placenta accreta spectrum (PAS) disorders: recommendations from an expert panel.

      References

        • Jauniaux E.
        • Hussein A.M.
        • Einerson B.D.
        • Silver R.M.
        Debunking 20th century myths and legends about the diagnosis of placenta accreta spectrum.
        Ultrasound Obstet Gynecol. 2022; 59: 417-423
        • Jauniaux E.
        • Hecht J.L.
        • Elbarmelgy R.A.
        • Elbarmelgy R.M.
        • Thabet M.M.
        • Hussein A.M.
        Searching for placenta percreta: a prospective cohort and systematic review of case reports.
        Am J Obstet Gynecol. 2022; 226: 837.e1-837.e13
        • Luke R.K.
        • Sharpe J.W.
        • Greene R.R.
        Placenta accreta: the adherent or invasive placenta.
        Am J Obstet Gynecol. 1966; 95: 660-668
        • Hecht J.L.
        • Baergen R.
        • Ernst L.M.
        • et al.
        Classification and reporting guidelines for the pathology diagnosis of placenta accreta spectrum (PAS) disorders: recommendations from an expert panel.
        Mod Pathol. 2020; 33: 2382-2396

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