Placenta Accreta Spectrum (PAS): Diagnosis, Clinical Presentation, Therapeutic Approaches, and Clinical Outcomes

Abstract

Placenta accreta spectrum (PAS) refers to the abnormal adhesion of the placenta to the myometrium, with varying degrees of severity. Placenta accreta involves adhesion to the myometrium, placenta increta invades the myometrium, and placenta percreta extends through the serosa to adjacent organs. The condition is linked to deficient decidualization in scarred uterine tissue, and the risk increases when placenta previa is present and with each prior cesarean delivery. Other risk factors include advanced maternal age, IVF, short intervals between cesareans, and smoking. PAS incidence has risen due to the increase in cesarean deliveries. Placenta previa combined with PAS significantly raises the risk of severe peripartum bleeding, often necessitating a cesarean section with a total hysterectomy. Recognizing PAS prepartum is essential, with sonographic indicators including intraplacental lacunae and uterovesical hypervascularization. However, PAS can be present without sonographic signs, making clinical risk factors crucial for diagnosis. Effective management requires a multidisciplinary approach and proper infrastructure. This presentation covers PAS cases treated at University Hospital Freiburg, detailing patient conditions, diagnostic methods, treatments and outcomes.

Keywords: abnormal adhesion; cesarean delivery; placenta praevia; server peripartum bleeding.

Figure 1

Schematic presentation of PAS. Silver and Branch NEJM April 2018. Placenta accreta: attachment of the placenta to the myometrium without an intervening decidua), Placenta increta: invasion of the trophoblast into the myometrium, Placenta percreta: invasion through the myometrium, serosa, and surrounding structures.

Figure 2

Irregular and large lacunae: Sonographic imaging reveals irregularly shaped and enlarged lacunae within the placenta. Hypervascularity: Increased vascularity is observed within the placenta, indicating abnormal blood flow. Turbulent flow in lacunae: Doppler imaging demonstrates turbulent blood flow within the lacunae, suggestive of abnormal vascularization. Changes in diameter: Variations in the diameter of lacunae may be noted on sonographic examination, reflecting the dynamic nature of placental vascularization in PAS.

Figure 3

Intraoperative photodocumentation of the uterus and cell saver system. During the postoperative assessment, we identified anemia with a hemoglobin level of 6.0 g/dL. The patient was administered another unit of red blood cells. The Bakri balloon was removed the next day without any complications. The patient was discharged in good general condition with a hemoglobin level of 7.4 g/dL.

Figure 4

shows suspected placenta increta with dehiscence in the area of scar tissue from the previous uterotomy.

Figure 4

shows suspected placenta increta with dehiscence in the area of scar tissue from the previous uterotomy.

Figure 5

Reveal placenta previa with placenta increta. The earlier suspected dehiscence was confirmed.

Figure 6

Schematic drawing illustrating the small uterine rupture with a portion of placental tissue protruding from the rupture site, which was the source of bleeding.

Figure 7

Revealed the following sonographic findings:

Figure 8

Depict the uterus during and after hysterectomy performed for placenta increta.

Figure 9

Irregular, large lacunae within the placenta, Hypervascularity, Turbulent flow inside the lacunae Diameter gaps.

Figure 10

depict the uterus after hysterectomy with placenta previa and increta extending to the serosa. These images show the following findings:

Figure 11

Increased placental blood flow on 2D ultrasound. Red color represents increased placental blood flow moving to the transducer; blue color represents placental blood flow moving leaving away from the transducer.

Figure 12

Enlarged vascular spaces within the placenta; A focal mass invading the myometrium, suggestive of placenta accreta; Hypervascularity noted at the interface between the serosa (outer uterine layer) and bladder.

Figure 13

According to the standardized description of the European Working Group on Abnormally Invasive Placenta for ultrasound anomalies, the following anomalies may be seen: Loss of the “clear zone”—partially more in the middle (N/3):

Figure 14

Separation from uterus is unclear on the right lateral wall and posterior wall, and so PAS cannot be excluded.

Figure 15

An approximately 5 cm fundal wall defect at the site suspected from the ultrasound after removal of the increta placenta; Suturing the defect with sutures without increased bleeding.