One-Step Conservative Surgery for Abnormal Invasive Placenta (Placenta Accreta–Increta–Percreta)

Fifty years ago, placenta accreta was an obstetric rarity. Today, however, placenta accreta and its variations represent one of the principal causes of maternal morbidity and mortality. That this is the case is often attributed to the increased number of cesarean deliveries, but close examination of the numbers involved suggests that other factors may also be in operation. The potential for the compromise of neighboring organs, as well as the development of neovascularization, implies specific technical difficulties associated with the treatment of placenta accreta, all of which directly relate to morbidity and mortality secondary to hemorrhage. Placenta accreta, characterized by the abnormal adherence of the placenta to the myometrium, may present different degrees of invasion, which are categorized as placenta accreta, increta and percreta. Since these terms are all based on histological examination, their proper use should be postoperative as well as retrospective. From a clinical perspective, the different degrees of invasion are more appropriately termed placenta accreta or abnormal invasive placenta. The most common location of placenta accreta is the anterior lower uterine wall, especially when associated with a prior cesarean scar1–3. This association implies difficulties from a technical surgical point of view including adherence to bladder, development of neovascularization, destruction of myometrial tissue and access to the pelvic subperitoneal spaces. The uteroplacental tissues of placenta accreta are noticeably fragile and tend to bleed excessively. Absence of surgical planes for dissection makes it difficult or nearly impossible to apply the usual hemostatic procedures if an accurate tissue dissection between invaded tissues cannot be made. Understanding the behavior and development of placenta accreta is essential in order to plan an appropriate surgical approach. Various vascular occlusive mechanisms have been used to reduce the tendency for bleeding4–6, but they have not always been effective and, in some cases, have been deficient. Issues such as these have led to the need for a detailed study of each aspect related to the treatment of placenta accreta. One of the most important is to understand how both the pelvic anastomotic system and the collateral uterine vascular anastomoses work (see Chapters 1 and 22). Predicting the surgical difficulty, as well as understanding the specific invaded areas, is essential in order to know which vascular pedicles are involved in a given case. A combination of vascular control, fascial dissection and identification of specific pelvic elements (ureter or specific vessels) makes it possible to prevent injuries and to avoid complications. Once a primary diagnosis has been arrived at, the next priority is to know how and where the placenta invades the adjacent tissues. Designing a one-time surgery implies solving all the problems caused by placenta accreta at one operation. This involves vascular disconnection of the invaded organs (uterus, placenta and bladder), correct compartment exposure of the pelvic organs (necessary for the hemostatic procedures), total resection of the invaded myometrium and, finally, uterine and vesical reconstruction7. One-step conservative surgery for abnormal placentation (OSCS) was first implemented in 1990 and, 20 years later, has been applied in more than 450 patients. This series includes the most diverse types and degrees of placental invasion, operated upon electively as well as in emergency circumstances. To date, 106 consecutive postrepair pregnancies have been reported; of these, only two cases of partial recurrence were noted. This number represents the lowest relapse rate reported for conservative treatments in abnormal invasive placenta.