Abstract: An organ support apparatus includes: (a) a fluid circuit defining upstream and downstream legs adapted to be connected to an organ to be supported; (b) a circulation pump connected to the fluid circuit for circulating a process fluid through the fluid circuit and the organ; and (c) a first waveform generator connected to the fluid circuit for impressing a preselected pressure waveform on the process fluid.
Abstract: This invention relates to processes of preparing heterogeneous graft material from animal tissue. Specifically, the invention relates to the preparation of animal tissue, in which the tissue is cleaned and chemically cross-linked using both vaporized and liquid cross-linking agents, resulting in improved physical properties such as thin tissue and lowered antigenicity, thereby increasing the ease of delivering the tissue during surgery and decreasing the risk of post-surgical complication, respectively.
Abstract: A bioreactor and a method for growing engineered tissue provide facing surfaces in a vessel for containing cell-culture media. The facing surfaces are equidistant and define a gap therebetween while providing substrates for cell tissue growth. By maintaining conditions within the vessel conducive to cell tissue growth and moving the surfaces relative to one another within such cell culture media, tissue growing thereupon is subjected to physiological flow and shear stress, preferably through the use of oscillating motion, and engineered tissue is produced.
Abstract: A treatment for bioprosthetic tissue used in implants or for assembled bioprosthetic heart valves to reduce in vivo calcification is disclosed. The method includes preconditioning, pre-stressing, or pre-damaging fixed bioprosthetic tissue in a manner that mimics the damage associated with post-implant use, while, and/or subsequently applying a calcification mitigant such as a capping agent or a linking agent to the damaged tissue. The capping agent suppresses the formation of binding sites in the tissue that are exposed or generated by the damage process (service stress) and otherwise would, upon implant, attract calcium, phosphate, immunogenic factors, or other precursors to calcification. The linking agent will act as an elastic reinforcement or shock-absorbing spring element in the tissue structure at the site of damage from the pre-stressing.
Abstract: A heart valve prosthesis for use as an aortic or pulmonary replacement valve, or as a mitral or tricuspid valve includes leaflets that are reinforced through the use of oriented fiber components in a laminated composite, in which the leaflets of the valve are reinforced with fiber-reinforcing materials oriented along lines of stress in the material, thus to provide a long-lived valve that provides strength at points of maximal stress that have hitherto been foci for material failure. In a preferred embodiment involving a stentless valve, the reinforcing materials are optimized in terms of the density and orientation of the fibers in the composite materials, thus to extend the life of a stentless valve, with the valve requiring no anti-coagulants as is the case with mechanical valves and exhibiting no hemolysis in which red cells are damaged by the action of mechanical valves. Longevity exceeds thirty five years in most cases, making replacement of such a valve a remote possibility.
Abstract: A device for exploration of the cardiovascular system of human or animal bodies includes a generally transparent blind tube delimiting a cavity in which can be disposed an optical display device, the open end of the tube being shaped to be ensleeved axially in a sealed manner in the passage of an artery or of a vein having first been at least partially sectioned such that the cavity of the tube in the interior of the artery or of the vein form a common chamber at least partially closeable by a cardiac valve. The tube, maintained in ensleeved position by a suitable securement member, includes at least one supplemental opening for the introduction into the cavity of the tube of a physiological liquid under pressure.
Abstract: An apparatus is disclosed for differentially treating a medical device. One portion of the device is treated with a first fluid and a separate portion is treated with a second fluid. The second fluid generally is substantially different from the first fluid. The first fluid can be contacted with an flow region of the medical device. The apparatus can include a conduit system, where fluid flowing through the conduit system flows through the flow region. Sheet material can be treated differentially on the opposite surfaces of the sheet. The medical device can include vascular tissue.
March 9, 2001
September 6, 2001
R. Brian Williams, Richard F. Schroeder, Matthew F. Ogle
Abstract: A minimally invasive approach for surgery on portions of the heart and great vessels located between a point approximately three centimeters above supra annular ridge and the mid ventricular cavity. A parasternal incision is made extending across a predetermined number of costal cartilage, e.g., a right parasternal incision extending from the lower edge of the second costal cartilage to the superior edge of the fifth costal cartilage. One or more costal cartilages, e.g., the third and fourth, are then excised to provide access to the portion of the heart or great vessels of interest, and a desired procedure completed. The minimally invasive approach enables repair or replacement of the mitral or aortic valve.