Impact of valve-sparing aortic root replacement on aortic fluid dynamics and biomechanics in patients with syndromic heritable thoracic aortic disease

Fig. 1. Flowchart of patient inclusion. sHTAD patients with indication for VSARR underwent preSx and postSx CMR and were compared with matched cohorts of sHTAD not meeting surgical criteria and HV to assess the impact of VSARR. CMR cardiovascular magnetic resonance, sHTAD syndromic heritable thoracic aortic disease, Sx indication for valve-sparing aortic root replacement, VSARR valve-sparing aortic root replacement, preSx prior to valve-sparing aortic root replacement, postSx after undergoing valve-sparing aortic root replacement, BSA body surface area, DescAo descending aorta, NSx no indication for aortic root replacement, HV healthy volunteers

Fig. 2. Ascending aorta distensibility (top) and longitudinal strain (bottom) quantification. Ascending aorta distensibility was computed at the level of the pulmonary artery bifurcation, from temporal evolution of the cross-sectional area in cine CMR. Longitudinal strain was obtained by tracking the aortic valve movement on sagittal, coronal, and aortic valve cine images. The three-dimensional displacement of the valve is obtained and averaged in the patient’s axis (LR left-right, AP anterior-posterior, FH feet-head) and then projected in the direction of the proximal aorta centreline. AD aortic distensibility, Amax maximum aortic area, Amin minimum aortic area, SBP brachial systolic blood pressure, DBP diastolic blood pressure, 3D three-dimensional, AscAo ascending aorta

Fig. 3. Flow dynamics along the thoracic aorta in sHTAD patients with (preSx) and without (NSx) indication for VSARR and in healthy volunteers. (A) Maximum velocity, (B) IRF, (C) SFRR, and (D) axial and (E) circumferential WSS. Lines are colored green for HV, blue for sHTAD-NSx, and orange for sHTAD-preSx. Symbols *, o, and + indicate statistically significant differences (p < 0.05) between sHTAD-NSx and HV, sHTAD-preSx and HV, and preSx and NSx, respectively. HV healthy volunteers, sHTAD syndromic heritable thoracic aortic disease, NSx no indication for aortic root replacement, preSx prior to valve-sparing aortic root replacement, AscAo ascending aorta, DescAo descending aorta, IRF in-plane rotational flow, SFRR systolic flow reversal ratio, WSS wall shear stress, pDescAo proximal DescAo, dDescAo distal DescAo, VSARR valve-sparing aortic root replacement

Fig. 4. Flow dynamics along the thoracic aorta in sHTAD patients undergoing VSARR before (preSx) and after (postSx) surgery, and in healthy volunteers. (A) Maximum velocity, (B) IRF, (C) SFRR, and (D) axial and (E) circumferential WSS. Lines are colored green for HV, orange for sHTAD patients, continuous for sHTAD-preSx, and dotted for sHTAD-postSx. Symbols o, *, and + indicate statistically significant differences (p < 0.05) between sHTAD-preSx and HV, sHTAD-postSx, and sHTAD-postSx and sHTAD-preSx, respectively. HV healthy volunteers, sHTAD syndromic heritable thoracic aortic disease, preSx prior to valve-sparing aortic root replacement, postSx after undergoing valve-sparing aortic root replacement, AscAo ascending aorta, DescAo descending aorta, IRF in-plane rotational flow, SFRR systolic flow reversal ratio, WSS wall shear stress, pDescAo proximal DescAo, dDescAo distal DescAo, VSARR valve-sparing aortic root replacement

Fig. 5. Systolic velocity streamlines in three patients with Marfan syndrome before (A) and after (B) undergoing valve-sparing aortic root replacement (VSARR). Increased velocity in the ascending aorta after VSARR is shown in all patients. Increased rotational flow from the distal ascending aorta is observed in patients 2 and 3. Vortical flow after VSARR is visible in the proximal-inner descending aorta in patient 3. preSx prior to valve-sparing aortic root replacement, postSx after undergoing valve-sparing aortic root replacement