Aortic jet lesion: new insights with multimodal imaging

A 26-year-old woman was referred for an enlarging ascending aortic aneurysm (+6 mm in 6 years) and severe aortic stenosis (peak velocity: 5.2 m/s) associated with exertional dyspnoea NYHA 3.

Preoperative CT (Panels A, D, and G, arrows) disclosed a 51-mm aortic aneurysm at the tubular level and a 3-mm mural thickening on the antero-right aortic wall. Two aortic commissures appeared partially fused on the 3D volume rendering technique endoluminal view (Panel F, asterisks, calcifications in blue), suggesting a unicuspid phenotype.

4D flow magnetic resonance imaging (MRI) without contrast (Panels B, C, and E) revealed an eccentric high-velocity outflow hitting the aortic wall at a 90° angle, at the site of mural thickening. The outflow then split into two separate jets, of which one flowed backward to the sinuses (Panel C and Supplementary material online, Video S1).

At surgery, the unicuspid valve was confirmed, without possible repair. The Ross procedure was conducted successfully, as the patient planned a pregnancy.

Surgery confirmed aortic linear thickening (Panel H, arrows) and histology disclosed a focal scar with intimal hyperplasia, fibroblastic proliferation (Panel F, arrowheads), and elastic fibre fragmentation. The endothelium and media were normal.

Aortic flow-related lesions play an important role in the pathogenesis of aortic aneurysms with bicuspid valve. Intimal hyperplasia has not yet been reported in this setting. In our patient, 4D flow MRI showed a link between the congenital aortic valve anomaly and the wall changes detected by computed tomography. Multimodal imaging might thus help to better assess the individual risk of dissection, as compared to aortic diameter alone.

Supplementary material is available at European Heart Journal online.

Funding: the authors report no specific funding related to this article.

Conflict of interest: The authors have submitted their declaration which can be found in the article Supplementary Material online.