University of Pittsburgh research collaboration works toward saving more organs for transplants

Each year, the United States suffers an extreme shortage of organ donations, with only a quarter of patients in need receiving a transplant. Many transplantable organs are lost when a donor's heart fails, and the organs stop receiving vital blood flow. Researchers at the University of Pittsburgh can potentially double the amount of successful organ donations by developing a novel stent to maintain blood flow to organs, even during the donor's final heart beats.

The National Institutes of Health awarded a four-year, $1.3 million R01 grant to a University of Pittsburgh research collaboration between the Department of Surgery and the Department of Industrial Engineering. The study titled "An Organ Perfusion Stent as an Alternative to Surgery in Donor Organ Recovery" will develop a dual chamber organ perfusion stent made of smart material to direct selective blood flow during transplant surgeries.

Leading the study are Principal Investigators Bryan W. Tillman, assistant professor in the Division of Vascular Surgery at University of Pittsburgh Medical Center (UPMC); Youngjae Chun, associate professor of industrial engineering and bioengineering; and Sung Kwon Cho, associate professor of mechanical engineering and materials science at Pitt's Swanson School of Engineering.

The stent will isolate visceral arteries--which supply blood to many major organs--without disturbing the heart. To make the stent, the research team will use a superelastic material with a flexible shape memory effect called nitinol, or nickel titanium.

"The shape memory behavior of nitinol is critical for endovascular devices such as stents, filters, and occluders, because at low temperatures, nitinol can easily be collapsed, inserted into a catheter, and delivered into the body," said Dr. Chun. "Once inside, the body heat will change nitinol's properties to be superplastic without any actuation force, which is really beneficial for a wide-range of catheter-based procedures."

The organ perfusion stent can be inserted by a clinician into the femoral artery after the delivery of a guide wire and a catheter. This small puncture or "needlestick" method allows clinicians to maintain selective blood flow to certain organs without disrupting others' natural functioning. The much larger organ stent in its compressed state can be delivered to the desired organ and deployed.

"We can target the kidneys, pancreas, and liver," said Dr. Chun. "Transplants involving any major organs connected to the main aorta will be able to benefit from this new technology."