Management of Hypervascular Retained Products of Conception With Massive Bleeding.

Retained products of conception (RPOC) could be a factor for massive postpartum hemorrhage; however, a management protocol is yet to be established. Performing a surgical intervention is controversial due to the potential for natural healing. Herein, we report the management of a hypervascular RPOC case with massive bleeding. Abortion was performed in a 40-year-old patient with gravida 2 and para 0, at 20 weeks and five days of gestation following the detection of Down's syndrome on prenatal screening. Post-delivery transvaginal ultrasonography identified an intrauterine mass measuring 4cm × 5cm × 5cm. The patient was then followed up in the outpatient department. One month after the abortion, the patient developed abnormal vaginal bleeding. Transvaginal ultrasonography revealed a hypervascular myometrial RPOC with turbulent flow. Although the bleeding stopped upon her admission to our hospital, the patient developed recurrent abnormal vaginal bleeding after nine days of hospitalization, which resulted in a hemoglobin level drop to 5.9 g/dL. CT and MRI scan findings raised the suspicion of hypervascular RPOC or uterine artery pseudoaneurysm. Uterine artery embolization was performed, leading to diminished vascularity in the RPOC, which was confirmed through color Doppler ultrasonography. The remnant placenta was successfully resected hysteroscopically, and a subsequent transvaginal ultrasonography showed a decrease in blood flow. In conclusion, hypervascular RPOC, previously reported as uterine artery pseudoaneurysms, should be considered when detecting hypervascular myometrial lesions in postpartum ultrasonography. Hypervascular RPOC with hemorrhage might benefit from hysteroscopic resection after achieving hemostasis with uterine artery embolization. This case report highlights the potential risks of awaiting spontaneous resolution in large RPOC and suggests that timely surgical intervention is both effective and essential.