Clinicians at Duke University Hospital are some of the first to implant a bioengineered blood vessel into a human patient. The vein was developed by Duke spinoff Humacyte.
The surgery is part of a larger phase 1 clinical trial on 20 patients with end-stage renal disease that Duke researchers are spearheading. The vessels are being implanted into the arms of the subjects to help with performing hemodialysis, and the researchers will be closely following up to analyze the safety and durability of the new grafts.
Current options have drawbacks. Synthetic vascular grafts are prone to clotting, leading to frequent hospitalizations, and harvesting veins from the patient’s own body involves a separate procedure, with the risk of infection and other complications.
If the bioengineered veins prove beneficial for hemodialysis patients, the researchers ultimately aim to develop a readily available and durable graft for heart bypass surgeries, which are performed on nearly 400,000 people in the United States a year, and to treat blocked blood vessels in the limbs.
Overcoming setbacks and frustrations, the researchers notched numerous advancements, starting with the biodegradable mesh as the scaffolding for the veins. The mesh, easily manipulated into any shape, is formed into a blood vessel of varying lengths and widths.
When seeded with smooth muscle cells, the mesh gradually dissolves as the cells grow in a special medium of amino acids, vitamins and other nutrients. One key improvement, which strengthens the bioengineered tissue, is a pulsing force introduced during the growth process, in which the nutrients are pumped through the tube in a heartbeat rhythm to build the physical properties that are similar to native blood vessels.
After a couple of months, a life-like vein results.
Using donated human tissue to seed the tubular matrix, they wash the resulting vein in a special solution to rinse out the cellular properties, leaving a collagen structure that does not trigger an immune response.
Link: Humacyte homepage…