High-intensity USG with hysteroscopic resection to treat ret
Retained placenta is a condition where the placenta or membranes remain in the uterus during or after the third stage of labor. It is one of the major causes of delayed postpartum hemorrhage. Many retained placenta cases involve placenta accreta, an abnormal adherence of placental villi to the myometrium. The increasing number of cesarean sections has caused the incidence of placenta accreta to increase. Ultrasonography has traditionally been a good method for diagnosing placenta accreta. However, magnetic resonance imaging has become more popular for diagnostic accuracy. Additionally, the incidence of conservative treatment such as uterine artery embolization or methotrexate has gradually increased, replacing hysterectomy. Furthermore, although patients prefer to undergo conservative treatment rather than hysterectomy, the disadvantages of conservative treatment include the risk of hemorrhage or infection and the risk of needing a secondary hysterectomy.
We presented a case of retained placenta accreta. It was diagnosed by ultrasound and MRI and was treated by high-intensity focused ultrasound (HIFU) ablation followed by hysteroscopic resection.

Case report
A 33-year-old woman presented with intermittent vaginal bleeding, menorrhagia and dysmenorrhea after a cesarean section at 38 gestational weeks in October 2010. The patient was diagnosed as submucosal myoma based on ultrasonography and was transferred for further evaluation and management on July 28, 2011. The obstetrics history of the patient included 1 cesarean section and 1 artificial abortion. She also received a myomectomy in 2003. She had irregular menstrual cycles, menorrhagia and severe dysmenorrhea. There was nothing remarkable about her general appearance or nutritional state. Her vital signs were stable. On physical examination, the abdomen was soft and the previous operation scar was noted.....