P71: Development Of A Novel Ex-vivo Perfusion System: Langendorff Perfusion – Lessons Learned

Background: Heart transplantation is the gold-standard treatment for end-stage heart failure; however, the waitlist exceeds the number of donor organs available. Currently, it remains difficult to obtain an assessment of organ viability for transplant in many donor circumstances. We have developed a system that can allow for assessment of organ viability and potentially expand the donor pool. Our device features normothermic perfusion in both Langendorff and “working heart” mode. The device will allow for ex vivo assessment of the heart in Langendorff, left heart, right heart, and physiologic perfusion. A prototype has been constructed and perfusion experiments initiated. The current focus is experimental methods to allow for extended perfusion. Methods: A brief series of Langendorff perfusion experiments were performed. Hearts were procured from research animals shortly after euthanasia. The hearts were given 500 mL of del Nido cardioplegia at an aortic root pressure of 200 mmHg. The hearts were transported from the OR to the laboratory and connected to the circuit which consisted of an integrated perfusion chamber/reservoir, a PediMag (Abbott) pump, and a Eurosets (Abbott) oxygenator. Whole blood from the donor animal was used as the perfusate with physiological correction guided by blood chemistries. The hearts were perfused at a predetermined aortic root pressure for 4 hours or until the heart lost viability. Results: Initial attempts resulted in significant myocardial edema resulting in loss of cardiac function. Recent attempts have successfully supported the heart for up to 2 hours. From the experiments, it is clear that additional iterations are necessary focusing on mitigating ischemia/reperfusion injury in prolonged warm perfusion models to allow for better assessment of cardiac function and viability prior to the initiation of “working heart” perfusion. Conclusion: The University of Pittsburgh Ex Vivo Perfusion Device is in development and having early successes. The device can successfully support a heart in Langendorff perfusion mode and is being developed to further advance in “full working heart” mode. Acknowledgements: The authors would like to acknowledge funding provided by the University of Pittsburgh Center for Medical Innovation, award F_275-2019, “Ex-Vivo Heart Perfusion System for Human Heart Support, Resuscitation, and Physiologic Testing.”