Placenta Accreta Spectrum (PAS): Paradigm Shifts

Placenta accreta spectrum (PAS) is an abnormality of placental insertion. PAS is a major cause of severe obstetric haemorrhage and maternal death, even in the most developed countries. The risks of surgical complications are very high, regardless of the management strategy: bladder, ureteral, and digestive injuries, secondary hemoperitoneum, and fistulas. PAS is the direct iatrogenic consequence of previous uterine scarring, most often from caesarean sections. Since 1937, PAS has been thought to invade the uterus and surrounding organs. The pathophysiology of PA has been significantly re-evaluated since 2022, with direct implications for surgical strategies.

In cases of PA, caesarean hysterectomy, whether elective or emergency, is the primary treatment worldwide. The abandonment of placenta in situ, practised mainly in France since the early 2000s, is facing increasing criticism. One-stage resection and reconstruction, initially proposed in Argentina, is now a validated alternative: it allows for uterine preservation while avoiding the risks associated with placenta in situ. The team at the University Hospital of Nancy has been using a modified resection approach since 2019, with uterine preservation rates exceeding 90%.
I will present the new pathophysiological hypotheses and the paradigm shift that resection represents in PAS surgery.
Professor Olivier Morel,
Head of Department, University Hospital of Nancy
Secretary General of the CNGOF (French National College of Gynaecologists and Obstetricians) for Obstetrics
Chair of IS-PAS (International Society for Placenta Accreta Spectrum)