Biofidelic Simulations of the Ross Procedure: Arterial Growth and Remodeling in an Anatomical Context.

The Ross procedure represents a promising alternative to conventional valve replacement techniques in young patients with aortic valve disease. Unlike mechanical or bioprosthetic substitutes, the pulmonary autograft retains living properties allowing growth and remodeling to systemic blood pressures. However, in aortic position, the mechanobiological adaptation processes of the pulmonary tissue can be unpredictable. Long-term failure of the Ross procedure is frequently associated with autograft dilation, inducing valve leakage and possible reoperation. The present work develops an image-based finite element pipeline to predict autograft growth and remodeling and its impact on leaflet closure. Realistic geometries are reconstructed from preoperative sheep MRI scans using automated scripts. Meshed autografts are combined with experimentally determined material properties to simulate the evolution of the pulmonary root under pulsatile systemic pressure conditions. The time-varying autograft diameter is then coupled with leaflet simulations to compute the regurgitant orifice area over time, a quantitative indicator of valve competence. Results demonstrate the ability of the model to reproduce in vivo autograft dilation in sheep, capturing both geometrical and biomechanical aspects. The predicted evolution of leaflet coaptation provides new insights into valve dysfunction after the Ross procedure. This framework has the potential to support surgical decision-making and optimize long-term outcomes by tailoring operative strategies to patient-specific physiology.