P143. No Adverse Flow Alterations After Y-Incision Aortic Root Enlargement: A 4D Flow MRI Study

McCormick Place Lakeside Center  

Objective:
Impaired long-term outcomes after surgical aortic valve replacement result from patient-prothesis mismatch. Aortic root enlargement (ARE) techniques have been proposed to enable the implantation of larger prosthetic valves. However, increasing the valve size by two to three sizes may cause the valve to tilt to some degree, which could affect transvalvular flow haemodynamics and aortic wall shear stress. Therefore, this study aimed to assess aortic flow patterns in patients after the novel Yang ARE technique, comparing them to those of patients with size-matched bioprostheses in 4D flow magnetic resonance imaging (MRI).

Methods:
A total of ten patients underwent MRI at 3 Tesla 9.2±6.6 months following a Y-incision procedure (Yang; n=5) or bioprosthetic valve replacement with an INSPIRIS RESILIA valve (control group; n=5). The median upsizing during the Y-incision procedure was two valve sizes. The analysis planes were positioned at the level of the sinotubular junction (STJ), the mid-ascending aorta (mid-AAo) and the proximal arch (prox-AA). Flow displacement (FD) was estimated as a measure of flow eccentricity and wall shear stress (WSS) was also calculated.

Results
The mean age at the time of the procedure was significantly higher in the Yang group (67.8±8.6 years) than in the control group (48.4±6.9 years); p=0.002. One redo surgery was performed in each group. The mean gradient was 9.6±4.2 mmHg in the Yang group and 9.8±2.8 mmHg in the control group (p=0.931). 4D flow MRI revealed similar postoperative flow displacement in both groups at all levels (Yang vs. control): STJ (0.12±0.09 vs. 0.13±0.09;p=0.874), mid-AAo (0.33±0.09 vs. 0.38±0.04;p=0.343), and proximal-AA (0.34±0.07 vs. 0.37±0.04;p=0.427). WSS analysis also showed comparable parameters at all three levels: STJ: 0.46±0.15 N/m² vs. 0.36±0.12 N/m² (p=0.237); midAAo: 0.73±0.42 N/m² vs. 0.71±0.25 N/m² (p=0.923); proxAA: 0.65±0.19 N/m² vs. 0.56±0.21 N/m² (p=0.509).

Conclusion
The Y-incision aortic annular enlargement produces similar transvalvular flow patterns and wall shear stress in the ascending aorta compared to regular bioprosthetic valve replacement, as demonstrated by 4D flow MRI. Therefore, our preliminary data suggests that even excessive oversizing does not result in impaired haemodynamics. Implanting a larger bioprosthetic valve should be the ultimate goal for optimizing the long-term management of patients with aortic valve disease.

Authors
Johannes Petersen (1), Lukas Maximilian Huber (2), Harun Sarwari (3), Meltem Belik (3), Ashkan Naebian (4), Peter Bannas (5), Hermann Reichenspurner (1), Alexander Lenz (2), Evaldas Girdauskas (6)
Institutions
(1) University Heart & Vascular Center Hamburg, Hamburg, Hamburg, (2) Department of Radioloy, University Hospital Eppendorf, Hamburg, NA, (3) University Heart and Vascular Center, University Medical Center Hamburg-Eppendorf, Hamburg, NA, (4) University Heart & Vascular Center Hamburg, Hamburg, NA, (5) Department of Radioloy, University Hospital Eppendorf, Germany, Hamburg, NA, (6) University Hospital Augsburg, Augsburg, Germany

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Aortic Valve