Biology and bioresorbable materials in cardiac surgery: why could they be important in the current era of innovations and technology?

In the era of implantable vascular devices and minimally invasive technologies, several aspects of the biological response of cardiovascular structures to surgical procedures and materials seem to be neglected. However, especially in pediatric cardiac surgery, the main mechanisms underlying the most frequently encountered complications are to be found in an inadequate biological adaptation of the heart vascular structures to the conduits and surgical materials used. In particular, inability of the grafts used to follow somatic growth, exuberant scar tissue formation, presence of non-viable tissue at the anastomosis site or impaired tissue viability of the conduits are claimed to be the most significant factors. Biocompatible materials might constitute a useful adjunct in this context as providing at the same time a valid tissue surrogate and a biological support to orientate and improve the physiologically occurring biological processes imposed by surgical corrections or vascular replacements. We explored the use of bioresorbable materials in an experimental model of Ross procedure and of neopulmonary trunk reconstruction with encouraging results. Reinforcement of pulmonary autograft with a polydioxanone mesh prevented graft dilation and induced a structural remodeling leading to the formation of a neo-vessel comparable to the native aorta. A similar approach applied to the reconstruction of the pulmonary trunk with pericardium during arterial switch operations, prevented occurrence of subvalvular pulmonary stenosis and warranted the formation of an hemodynamically effective neo-conduit. Understanding, ameliorating or just exploiting naturally occurring processes through ad hoc designed biocompatible materials might constitute a keystone in several pathological conditions.