4D flow cardiovascular magnetic resonance for monitoring of aortic valve repair in bicuspid aortic valve disease

Fig. 1. Intraoperative situs of aortic valve repair in bicuspid aortic valve (BAV) disease. The surgical repair consists of reduction of the aortic valve anulus using suture annuloplasty and correction of the prolapse of the fused cup. The aim is the recreation of the optimal aortic root geometry. This includes reduction of the basal ring diameter to less than 25 mm and restoration of effective cusp height (coaptation length) above 8 mm. a and b Correction of cusp prolapse by means of plication sutures (arrows). c Surgery results in a symmetric configuration of the bicuspid aortic valve (arrow heads) with a commissural angle of 180°, resembling a Sievers type 0 valve. In this patient, additional replacement of the aortic root with Dacron prosthesis for aneurysm has been performed

Fig. 2. 4D flow CMR-based characterization of flow dynamics in a 24-year-old man with bicuspid aortic valve before and after aortic valve repair. a Velocity-coded 4D flow CMR reveals an accelerated eccentric asymmetric flow jet (indicated by yellow and red streamlines) and a pronounced helical flow pattern (arrows) in the ascending aorta before surgery. The flow jet impacts and travels along the right aortic wall. b Extracted analysis plane (solid line) at the aortic valve level shows eccentric regurgitation of insufficient bicuspid valve (15.3%) (c) Extracted analysis plane (dashed line) at the level of the mid-ascending aorta shows the marked eccentric flow pattern (relative flow displacement: 0.43), resulting in increased global WSS (1.2 N/m2). d After surgery, velocity-coded 4D flow CMR shows reduced helical flow with a more cohesive central flow pattern more parallel to the vessel wall of the ascending aorta. e Extracted analysis plane at the aortic valve level after surgery shows decreased regurgitation (5.6%) (f) Extracted analysis plane at the level of the mid-ascending aorta demonstrates more centralized flow (relative flow displacement: 0.27), resulting in decreased global WSS…

Fig. 3. 4D flow CMR-based characterization of flow dynamics in a 30-year-old woman with unicuspid aortic valve before and after aortic valve repair. a Velocity-coded 4D flow CMR reveals an accelerated and highly eccentric asymmetric flow jet (indicated by yellow and red streamlines) and a pronounced helical (arrows) and vortical flow pattern (arrowhead) in the ascending aorta before surgery. The flow jet impacts and travels along the right-anterior aortic wall. b Extracted analysis plane (solid line) at the aortic valve level shows regurgitation of insufficient bicuspid valve (20%) (c) Extracted analysis plane (dashed line) at the level of the mid-ascending aorta shows the marked eccentric flow pattern (relative flow displacement: 0.37), resulting in increased global WSS (0.9 N/m2). d After surgery, velocity-coded 4D flow CMR shows reduced helical and vortical flow with a more cohesive central flow pattern more parallel to the vessel wall of the ascending aorta. e Extracted analysis plane at the aortic valve level shows decreased regurgitation (5.8%) after surgery (f) Extracted analysis plane at the level of the mid-ascending aorta demonstrates a more centralized flow (relative flow…

Fig. 4. Flow displacement in the ascending aorta before and after aortic valve repair in patients with adult congenital heart disease. Flow displacement was significantly reduced after surgery (0.3 ± 0.1 vs. 0.25 ± 0.1) at the level of the mid-ascending aorta (midAAo). There was no significant reduction in flow displacement at the level of the sinotubular junction (STJ) and the proximal aortic arch (proxAA). Red lines indicate patients with unicuspid aortic valves and diamonds indicate patients with additional aortic root remodeling

Fig. 5. Circumferential and segmental wall shear stress (WSS) in the thoracic aorta before and after aortic valve repair in patients with congenital heart disease. a Graphs of quantitative analyses of circumferential peak systolic WSS show a significant reduction at the level of the mid-ascending aorta (midAAo), proximal aortic arch (proxAA), and distal aortic arch (distAA). Red lines indicate patients with unicuspid aortic valves and diamonds indicate patients with additional aortic root remodeling. b Spider charts of segmental peak systolic WSS at eight standardized local anatomic positions of the vessel wall (A, anterior; LA, left anterior; L, left; LP, left posterior; P, posterior; RP, right posterior; R, right; RA, right anterior) before (red spiders) and after (blue spiders) surgery. Highest segmental WSS was observed in the anterior, right-anterior, and right segments in the mid-ascending aorta as well as in the anterior and left-anterior segments of the proximal aortic arch. Asterisks indicate segments with significantly reduced WSS after aortic valve surgery. Of note, changes in peak systolic segmental WSS values are co-located with the changes in localized outflow jets and the…