4D flow characterization of aortic blood flow after valve sparing root reimplantation procedure.

Valve-sparing aortic root replacement (VSRR) with reimplantation technique is an effective alternative for young patients with dilated roots and preserved cusps, which avoids the risks of lifelong anticoagulation or valve degeneration. New grafts with anatomically-shaped sinuses have been developed in order to preserve aortic root physiology, which could decrease complication rates and improve durability. However, controversy remains regarding the effect of recreation of the sinuses of Valsalva during VSRR on long-term outcomes. The novel 4D flow technique, exploiting its unique ability to combine anatomical evaluation of the root with fluid-dynamic assessment of aortic flow, enables integrated analysis of the close interaction between graft design, valvular morphology and three-dimensional (3D) flow characteristics. Early experimental studies have shown how graft shape affects the aortic root flow pattern, formation of vortexes and helicity of downstream flow; however, the clinical significance of these findings is yet to be clarified. Various and still unexplored knowledge can be obtained from the qualitative and quantitative analysis of these complex datasets, that could shed more light on which is the best among myriad surgical techniques and grafts adopted in VSRR. The extraordinary potential 4D flow imaging opens new boundless horizons in the perspective of an increasingly patient-tailored surgical planning.