A team of doctors implanted a bioengineered blood vessel into a patient with late stage kidney disease at Duke University Hospital in June.
This is the first time ever that a human being in the United States has received a blood vessel grown in a laboratory.
The technology was developed in a collaboration between Duke University and Humacyte, a spin-off company developed to engineer the vein. The blood vessel was created by cultivating donated human cells in a tubular scaffold.
Why bioengineer a blood vessel?
"If you think broadly about vascular disease, it's still the leading cause of death in Western society. And that's vascular disease in the heart and in the brain and in the leg and in the kidneys," said Dr Jeffrey Lawson, a professor of surgery and pathology at Duke University, in an interview on the State of Things.
Much of Dr. Lawson's work as a surgeon involves replacing blood vessels. The current prevailing options involve harvesting veins from the patient's own body, which involves a separate surgical procedure and the risk of complications, or using a synthetic vascular graft, which is prone to clotting and rejection from the body.
Dr. Laura Niklason, a professor of anesthesia and biomedical engineering at Yale University and founder of Humacyte, first conceived of creating a bioengineered vein 18 years ago. As an anaesthesiologist, she observed bypass surgeries and noted that, in some patients, harvesting veins was particularly difficult.
"The initial thought that I had was that perhaps we can use some of what we know from science about how new blood vessels grow, take that knowledge and move it into the laboratory," Dr. Niklason said.
She and Dr. Lawson met in the operating room at Duke. They teamed up and combined their understanding of bioengineering and pathology to work to develop a prototype of a vein. Initially, they hoped to use the patient's own cells to bioengineer veins for them individually.
"We realized that just from a logistics standpoint, if we need three months to grow you a blood vessel, most of our vascular patients operationally don't have three months to wait," Dr. Lawson said.
Instead, the bioengineered vein is grown from donor cells seeded into a mesh in the shape of a tube. The mesh gradually dissolves, and collagen forms between the donor cells, binding them together. Then, the original donor cells are killed, leaving a non-living collagen structure. The collagen structure, because it is not alive, does not trigger an immune response from the body.
"This [collagen] structure then gets repopulated by your own cells once its implanted," said Dr. Lawson.
Dr. Lawson and Dr. Niklason hope that this may set the groundwork for how more complex organs are grown in the future.
You can watch a blood vessel being implanted here: