Developmental and Healing Processes of Uterine Artery Pseudoaneurysm After Non-Traumatic Delivery Followed by Transarterial Embolism: Sequential Observations in a Case Depicting Using Superb Microvascular Imaging.

We report a case of uterine artery pseudoaneurysm in which the developmental process of pseudoaneurysm was, for the first time to our knowledge, depicted using superb microvascular imaging (SMI). The patient became pregnant naturally and had an uneventful pregnancy. At 41 weeks of gestation, she spontaneously delivered a neonate and placenta, which had been attached to the posterior uterine wall. On the seventh postpartum day, SMI demonstrated a flow signal measuring 3×12 mm running straight through the posterior myometrium perpendicular to the endometrium, suggesting dilation of the radial artery. On the eighth postpartum day there was a moderate amount of vaginal bleeding. Color Doppler ultrasonography showed turbulent flow measuring 8 mm in diameter, located in the same posterior myometrial location as found on the previous day and bulging into the cavity. This finding indicated an uterine artery pseudoaneurysm, which was confirmed by pelvic arterial angiography. A follow-up SMI, three days after embolization, revealed the absence of the pseudoaneurysm, and normal radial arterial flows were restored by the 13th day after embolization.