What Are The Specific Design Modifications That Were Made To The Jarvik-7 Total Artificial Heart Between Its First Human Implantation In 1982 And The FDA's Approval Of The Device In 1986, And How Did These Modifications Impact The Device's Hemodynamic Performance And Patient Outcomes In The Early Years Of Its Clinical Use?

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The Jarvik-7 total artificial heart underwent several design modifications between its first implantation in 1982 and FDA approval in 1986, aimed at improving hemodynamic performance, biocompatibility, and patient outcomes. Here are the key modifications and their impacts:

  1. Housing Material and Surface Finish:

    • Modification: The titanium alloy housing was smoothed and possibly coated to enhance biocompatibility.
    • Impact: Reduced blood clotting (thrombosis) and improved blood flow.

  2. Inflow-Outflow Connectors:

    • Modification: Rigid connectors were replaced with more flexible ones.
    • Impact: Reduced inflammation and improved blood flow, enhancing hemodynamic efficiency.

  3. Diaphragm Material:

    • Modification: Switched to a more durable polyurethane material.
    • Impact: Increased longevity and pumping efficiency of the artificial heart.

  4. Valve Design:

    • Modification: Replacement of the Björk-Shiley valve with the Medtronic Hall valve.
    • Impact: Lower risk of thrombosis and valve failure, reducing the need for anticoagulants and associated complications.

  5. Inflow-Outflow Conduit Redesign:

    • Modification: Conduits were enlarged and angled for optimal blood flow.
    • Impact: Improved hemodynamics and reduced risk of thrombosis.

  6. Patient Outcomes:

    • Early Issues: High rates of thromboembolism, strokes, and size-related complications.
    • Post-Modification Improvements: Reduced complications, longer survival, and better quality of life, though primarily used as a bridge to transplant due to size limitations.

These modifications collectively enhanced the device's reliability, reduced adverse events, and improved patient survival, contributing to FDA approval and its role as a bridge to transplantation.