PLE-4236

A 33-year old G3P1 at 36 weeks AOG was referred to your hospital due to abnormal placentation detected sonographically at 29 weeks AOG. She had CS for placenta previa 3 years ago. At the admitting section, the patient reports vaginal spotting but no severe abdominal complaints. Repeat ultrasound reveals a viable baby and CS was immediately performed. The surgeon however noted profuse bleeding that was not ameliorated by any means. Hysterectomy was done. This abnormal condition can be best explained by: