Novel histological findings in the uterus after interventional radiology: a case report of placenta accreta

Placenta accreta is one of the causes of postpartum hemorrhage (PPH). Recently, interventional radiology (IVR) techniques, such as arterial embolization and balloon occlusion, have become widely used to manage hemorrhage associated with placenta accreta. Although IVR techniques could prevent maternal death and even preserve the uterus in PPH, in pregnancies after IVR, there have been reports that the risk of placenta accreta is increased. In this case report, a 39-year-old primiparous patient underwent IVR for the treatment of a retained placenta after vaginal delivery. However, IVR failed to stop uterine bleeding. Hysterectomy was finally performed for the patient’s survival. Histological examination of the extirpated uterus after IVR showed changes in the expression of myosin heavy chain isoforms (SM1 and SMemb) in vascular smooth muscle cells due to inflammatory changes in the uterus following ischemic damage.