Prenatal diagnosis of abdominal aortic aneurysm with pseudoaneurysm

A 34-year-old woman was referred to our hospital at 24+4 weeks of gestation for further evaluation of two cystic masses in the fetal abdomen. The patient had a history of antiphospholipid syndrome and was receiving aspirin for anticoagulation. No other medications were taken during organogenesis. Noninvasive DNA screening for Down syndrome yielded negative results. Whole exome sequencing and chromosome analysis revealed no abnormalities, and there was no family history of congenital anomalies. The upper pulsatile mass measured 41×35×30 mm and was located below the diaphragm and above the renal artery in the descending aorta. It exhibited characteristics consistent with a true aneurysm, such as a smooth wall, a wide communication with the descending aorta, and swirling blood flow within the cystic mass without a biphasic flow spectrum ([Fig. 1]A–C). The distal mass measured approximately 22×10×11 mm and was located below the renal artery. It exhibited a laceration approximately 5.3 mm wide between the mass and the abdominal aorta. Based on its irregular wall structure, uneven echogenicity, narrow laceration with the descending aorta, and the presence of a biphasic flow spectrum, we identified the lower mass as a pseudoaneurysm. A small normal arterial course was observed between these 2 masses.

Publication History

Received: 12 July 2024

Accepted after revision: 24 February 2025

Article published online:
14 March 2025