PI: Bryan Tillman
Co-I: Young Jae Chun
Title: An Organ Perfusion Stent as an Alternative to Surgery in Donor Organ Recovery
Description: In the United States, there is a critical shortage of organs for transplant, with only a quarter of the 120,000 patients in need of an organ actually receiving one. The cost of patients awaiting transplant to the healthcare system totals tens of billions of dollars each year. Meanwhile, thousands of organs are discarded each year as a result of injury from inadequate blood flow (ischemic injury) as the donor is dying. The traditional paradigm for consented Donation after Cardiac Death donors has been to discontinue cardiopulmonary life support, leaving organs without adequate blood perfusion until the heart stops. This contrasts with the usual end of life care options for patients who are not donors, in which patients and their families can elect to withhold life support for some body functions (CPR, agents to maintain blood pressure, dialysis, or intubation) while at the same time maintaining life support for other organs. Our proposal details an innovative needlestick approach to maintain selective blood flow to the organs while allowing the donor heart to fail on its own terms. This contrasts to previously reported approaches which would accelerate cardiac death, against ethical principles. We have examined a commercial hybrid prototype Organ Perfusion Stent (OPS) in a pilot study and shown improved blood delivery to organs without a negative impact on cardiac function. Recognizing the logistical challenges of current imaging for device placement in a critically ill patient, such as a donor, we have also developed a portable radiofrequency (RF) approach for stent positioning at bedside. The primary objective of the current approach is to demonstrate that a novel custom made OPS provides objective protection against ischemic organ injury. Our investigation will begin with optimizing the mechanical properties of this novel dual-chambered stent to ensure rapid deployment, successful isolation of the visceral arteries, and simplified retrieval. Next, we will optimize the hemodynamics of the stent to ensure uniform blood flow to the organs. A miniaturized RF antenna will then be directly printed onto the stent structure. In a porcine model of the organ donor, an OPS will be deployed by a needlestick access while under close cardiac monitoring. Positioning approaches using both portable X-ray and RF tag approaches will be compared to gold standard angiography for device positioning. Following a 60 minute period of simulated malperfusion with interval biopsies, both stented and control animals will be recovered with daily assessment to monitor organ function. At two days postoperatively, liver, pancreas and kidney biopsies will be evaluated for ischemic changes histologically. To investigate this device in a human context, an OPS calibrated for human anatomy will then be evaluated for successful deployment and organ perfusion in a heart beating human cadaver model. In summary, we expect that ultimately, an Organ Perfusion Stent may allow every consented donor to successfully donate organs for transplant while respecting the ethics of organ recovery.
Source: National Institute of Biomedical Imaging and Bioengineering
Term: September 15, 2017 – August 31, 2021