Development of pseudoaneurysm in cesarean section scar pregnancy: a case report and literature review.

Cesarean scar pregnancy (CSP) is a rare type of ectopic pregnancy. It is becoming more common, but it can lead to uterine rupture and severe hemorrhage. Here, we report a case of a 37-year-old woman with CSP complicated with pseudoaneurysm. The pseudoaneurysm emerged following focal injection of methotrexate (MTX) and potassium chloride with systemic MTX treatment. Due to a risk of sudden bleeding, uterine artery embolization (UAE) was recommended, but the patient hoped to avoid this if possible. Because the serum human chorionic gonadotropin level and the gestational sac were still persistent, dilation and curettage were performed with interventional radiologists on standby. Severe hemorrhage occurred and continued during the procedure, which necessitated emergent UAE. We reviewed six CSP case reports with vascular abnormalities, and all of them necessitated UAE, surgical excision, or hysterectomy. In the case of CSP combined with pseudoaneurysm, treatment should be planned carefully considering the risk of massive hemorrhage.