AN IMPROVED LEFT-VENTRICULAR CANNULA FOR CHRONIC DYNAMIC BLOOD PUMP SUPPORT

Ventricular unloading with dynamic blood pumps can be markedly affecte d by the geometry of the cannula tip within the ventricular chamber. D ue to the ability of these pumps to develop significant negative inflo w pressure, existing cannula tips designed for passively filling blood pumps can be predisposed to inflow occlusion by intraventricular anat omic structures. A novel ''trumpet'' mouth cannula was constructed to overcome this limiting problem. This design was based on two criteria: to provide additional stenting to the ventricular apex, and to assure placement of the tip opening relative to the endocardial surface. Thi s prototype cannula was evaluated in vivo against conventional caged, blunt, and tapered designs to assess anatomic and hemodynamic interact ion within the ventricular apex. Post mortem examination revealed the inflow tract to be devoid of myocardial obstruction in all cases, Thes e initial studies indicate that a trumpet mouth cannula can provide sa tisfactory hemodynamic performance required by dynamic blood pumps.