Ex Vivo Heart Perfusion: Keeping Donor Hearts Alive Outside the Body

What Is Ex Vivo Perfusion?

Ex vivo perfusion (EVP) is a technique that maintains a donor heart in a near-physiologic, beating state outside the body by connecting it to a portable machine that delivers oxygenated, nutrient-rich solution and removes waste.

How It Works

• Cannulation: Aorta and pulmonary artery connected to perfusion circuit.
• Perfusate: Oxygenated, blood-based or acellular solution (e.g., Steen solution) at 34–37°C.
• Monitoring: Real-time hemodynamics (flow, pressure, coronary flow), lactate, pH, contractility.
• Duration: Currently 4–12+ hours (vs. 4–6 hours for static cold storage).

Clinical Applications

• Extended Preservation: Allows longer transport distances, better donor-recipient matching.
• Organ Assessment: Functional evaluation of marginal/extended-criteria hearts (e.g., older donors, downtime).
• Reconditioning: Pharmacologic/therapeutic interventions (e.g., gene therapy, stem cells) to improve graft function.
• Research: Drug testing, ischemia-reperfusion injury studies, device development.

Key Systems

• TransMedics OCS Heart: FDA-approved, portable, normothermic perfusion.
• XVIVO Heart Assist Transport: Similar normothermic platform.

Limitations

• High cost, technical complexity, specialized team required.
• Not indefinite—hearts eventually require transplantation.
• Long-term outcome data still accumulating.

EVP is transforming heart transplantation by expanding the donor pool and enabling objective organ assessment.