Modeling study of aortic root for ross procedure: a structural finite element analysis.

BACKGROUND AND AIM OF THE STUDY

The Ross procedure involves replacing the diseased aortic valve with the patient's own pulmonary valve (autograft) to form the neoaortic valve, reimplanting the coronary arteries, and inserting a cadaveric homograft into the pulmonary position.

METHODS

In order to model a neoaortic root for the Ross procedure in patients with aortic valve disease, the three-dimensional geometry of a reference aortic valve was reconstructed (reference model A). The diameters of the sinotubular junction (STJ) and maximum sinus were then modified to create four geometric models named B, C, D, and E, with different dimensions. The mechanical behavior of the aortic root was simulated, and the performance of the aortic leaflets assessed in terms of maximum geometric orifice area (GOA) during all cardiac cycle and leaflet contact pressure during closing phase.

RESULTS

The neoaortic valve model showed a maximum GOA of 274.4 mm2 and a maximum leaflet stress of 682 kPa. For models B and C, the leaflet contact pressure was increased by 27.4% and decreased by 4.42%, with STJ diameter increased 1.1-fold and decreased 0.9-fold compared to reference model A. The leaflet contact pressure in models D and E was increased by 3.04% and decreased by 11.5%, while the sinus diameter was increased 1.1-fold and decreased 0.9-fold compared to model A.

CONCLUSION

Increasing the STJ and sinus diameters within a range of 10% can increase the leaflet contact pressure for the aortic root, and vice versa. This may be the reason why neoaortic valve insufficiency occurs long after patients have undergone the Ross procedure.