Verbetering van de uitkomsten na de Ross-procedure: de biologie van levende klepsubstituten en de rol van externe versteviging bij het voorkomen van dilatatie van de pulmonale autogreffe

The Ross procedure is performed for aortic valve stenosis in both pediatric and adult patients and entails replacement of the aortic valve by the patient's own pulmonary valve (autograft) while a pulmonary allograft is implanted in pulmonary position. In growing children, the pulmonary autograft is able to grow and adapt to aortic hemodynamics while the risk of endocarditis is low. Furthermore, contrary to biological valves, there is no risk of rejection and contrary to mechanical valves, there is no need for systemic anticoagulation. While patient survival as well as autograft survival after the procedure are excellent, there are several mechanisms by which the procedure can fail. We will study mechanisms of failure in our centre and correlate these with the literature. Next, we will attempt to model anatomical and hemodynamic adaptation in the aortic autograft using pre- and postoperative patient data as well as cadaveric experiments using a mock circulation. As the most common cause of failure appears to be autograft dilatation, external reinforcement is performed by some surgeons. We will investigate the feasibility of personalized external reinforcement using a macroporous mesh in an animal model that we have previously studied at our centre and will refine further.