Neointima-inducing inflow cannula with titanium mesh for left ventricular assist device.

The formation of wedge thrombus is a crucial problem in any left ventricular assist device (LVAD) with a left ventricle apical inflow cannula. We therefore developed a new titanium mesh wrapped inflow cannula expecting to induce autologous neointima to avoid such wedge thrombus formation. We performed animal experiments to evaluate the feasibility of this newly developed inflow cannula with titanium mesh for the induction of autologous neointima. Four calves were implanted with the inflow cannula as well as an EVAHEART centrifugal pump LVAD (Sun Medical Technology Research Corp., Nagano, Japan) for a duration of about 2 months. The titanium mesh was enveloped with neointimal tissue grown from the ventricular endocardium. There was no thrombus formation in any of the blood pumps or around the outside of the inflow cannulas. The histological findings showed that the neointimal tissue consisted of a layer of endothelial cells and fibroblasts. The newly developed inflow cannula using a titanium mesh induces autologous neointima formation, avoiding wedge thrombus formation.