Abstract: A ventricular assist device for a heart includes a compression band-stay-pad assembly for encircling substantially the entire heart perimeter and comprising an elongated band member or chain disposed in a sealed protective structure filled with a lubricating medium. The band member may be fixed at one end and wound upon, or unwound from, a rotatable spool by a drive motor through a speed reducer. Force-transmitting support or stay assemblies are disposed in the protective structure between the band member and a resilient pad assembly for encircling the heart and promoting heart tissue ingrowth therein. The force-transmitting stay assemblies are biased circumferentially, and thus radially outward, by compression return springs disposed therebetween.

Abstract: A ventricular assist device may include a cardiac compression assembly which comprises a gel-filled pad of generally concave configuration, mounted on a pressure plate with peripheral portions of the pad extending beyond the periphery of the plate, to preclude damage to the heart by the peripheral edges of the plate. The gel-filled pad may have undulating opposite sides formed by intersecting rows of raised dimples. The pad also includes portions for suturing the pad to a heart ventricle, and at least some of the dimples on the side of the pad facing the heart ventricle are provided with ventricle tissue growth-promoting islands. An electrode, in the form of a grid having intersecting strips which define dimple-receiving openings therebetween, also may be mounted on the venticle side of the pad. As many as eight circumferentially arranged cardiac compression assemblies, having lower ends pivotally mounted on a support member adapted to be located adjacent the apex of a heart ventricle, may be provided.

Abstract: A process for the preparation of polyurethane resins particularly suitable for electrostatic spinning which comprises forming a prepolymer of polyether glycol and a diisocyanate reacted in a molar ratio of about 1:2, and thereafter reacting the prepolymer with additional diisocyanate and a diol extender, the final molar ratio of the polyether, isocyanate and diol reactants being approximately 1:3.7:2.5. The reaction is conducted in an organic solvent at a temperature of about 45.degree. C. to obtain a polymer having an inherent viscosity of from about 2.0 to 2.4 in a solution of 25 to 30 percent solids. The solution is diluted to about 15 percent solids prior to spinning.

Abstract: A plastic band is secured around the outside of a prosthetic heart valve adjacent the sewing cushion to protect the valve leaflet material against inadvertent needle punctures and tears while sutures are being placed through the sewing cushion. The band is held in place by a single retention suture which passes through the band and sewing cushion of the valve and extends across the valve orifice. The protector is especially desirable for use with pericardial tissue valves having the tissue mounted on the outside of the valve stent where the tissue is particularly exposed and susceptible to needle damage.

Abstract: A method for preparing an aortic heart valve for implantation wherein the area of the septal shelf of the right coronary cusp extending into the valve orifice is substantially reduced. The excised value is prepared for fixation by pressurizing the valve to close the valve cusps, and thereafter inverting the aortic vestibule tissue over a valve stent or other cylindrical form circumscribing the valve. As the vestibule tissue is inverted, the septal shelf muscle is pulled toward the outside wall of the valve. When the septal shelf has been displaced to the maximum extent possible while maintaining coaption of the valve leaflets, the valve is fixed with a tanning solution. The resulting valve, after being trimmed and mounted for implantation, has improved flow characteristics.

Abstract: A plastic stent for a prosthetic trileaflet heart valve consisting of a cylindrical body section terminating at one end in three apical, commissure posts, and at the other end, in an outward-extending flange. The flange is provided with an interrupted channel encircling the base of the cylindrical section. An optional metal ring may be mounted adjacent the flange and spaced from the base of the cylindrical section. A cloth cover is secured to the stent by stitching directly through the flange in the area of reduced thickness resulting from the interrupted channel.

Abstract: Natural tissues fixed with a tanning solution such as glutaraldehyde and intended for implantation in humans, e.g., porcine heart valve prosthetic devices, are treated with a solution of a water soluble salt of a sulfated higher aliphatic alcohol such as sodium dodecyl sulfate to inhibit mineralization, particularly calcification, of the tissue after implantation.