Greater asymmetric wall shear stress in Sievers type 1/LR compared with 0/LAT bicuspid aortic valves after valve-sparing aortic root replacement

• Objective: To evaluate the role of commissure orientation on downstream blood flow patterns and ascending aortic wall shear stress (WSS) in patients with bicuspid aortic valves (BAV) after valve-sparing aortic root replacement (V-SARR). Methods: Nineteen BAV patients after V-SARR (9 Sievers type 1/LR [type 1 valve with fusion of the left and right cusps] and 10 Sievers type 0/LAT ["naturally perfect; type 0 valve without the presence of a raphe, and with the 2 commissures oriented right-anterior-to-left-posterior]) were imaged using time-resolved 3-D phase contrast magnetic resonance imaging. A control group of 5 unoperated tricuspid aortic valve patients were used for comparison purposes. Wall shear stress and eccentricity of flow normalized to aortic diameter were measured in planes placed perpendicular to the axis of the ascending aorta at the level of the sinotubular junction (proximal ascending), main pulmonary artery (mid-ascending), and origin of the brachiocephalic (distal ascending). Results: The ratio of WSS along the outer curvature to that along the inner curvature was greater in Sievers type 1/LR patients compared with Sievers type 0/LAT patients in the proximal (3.8 +/- 1.6 vs 2.1 +/- 0.9, P = .009) and mid-ascending aorta (4.5 +/- 2.4 vs 2.4 +/- 1.3, P = .027). Relative to control normal tricuspid patients, Sievers type 1/LR BAV patients had a higher WSS ratio in the mid-ascending aorta (4.5 +/- 2.4 vs 1.2 +/- 1.2, P = .007). Conversely, WSS in Sievers type 0/LAT patients was not different than in normal tricuspid patients. Conclusions: After V-SARR, BAV cusp morphology has a major impact on the pattern of blood flow and WSS in the ascending aorta.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Kardiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cardiac and Cardiovascular Systems (hsv//eng)

Nyckelord

Bicuspid aortic valve; valve-sparing aortic root replacement; 4D flow MRI; thoracic aorta

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