Bioengineered Blood Vessels Could Replace Synthetic Grafts for Treating Vascular Injuries

Every year, approximately 185,000 people in the U.S. undergo amputation, with an estimated 45% of these patients having experienced a vascular injury. Surgeons typically prefer using a patient's own veins for vascular repair, often harvesting them from the legs. However, factors such as previous surgeries, poor vein quality, and other issues can make this approach unfeasible. Additionally, harvesting veins can be time-consuming, which is particularly problematic in trauma cases where quick restoration of blood flow is crucial. The longer the limb is deprived of blood flow, the greater the risk of dysfunction or loss of the limb. The availability of a readily accessible, infection-resistant vessel option could significantly reduce these complications. A new type of bioengineered blood vessel has now shown promising results in treating severe vascular injuries, potentially offering vascular surgeons a superior alternative to synthetic grafts when a patient’s veins are unsuitable for use in repairs.

These vessels, known as acellular tissue-engineered vessels (ATEVs), are cultivated in a lab using human cells and undergo treatment to prevent immune rejection. The bioengineered vessels are produced using smooth muscle cells derived from donor aortic tissue, which are cultured under specific conditions that encourage them to form a vessel-like structure. When implanted, the patient’s own cells gradually populate the vessel, making it more resistant to infection compared to synthetic grafts. The vessel’s ability to integrate with the patient's tissue is believed to be a key factor in its success. After implantation, the grafts show signs of being populated by the patient's cells, forming a living blood vessel. This feature helps explain why they are more resistant to infection than synthetic alternatives.

In a Phase II trial conducted at Rutgers Health and other institutions, the bioengineered vessels demonstrated superior infection resistance and better limb preservation than historical data on conventional synthetic grafts. The research combined two trials: one with 51 civilian patients at trauma centers in the U.S. and Israel, and another with 16 military patients in Ukraine. After 30 days, approximately 91.5% of the vessels remained open and functioning, compared to 78.9% for synthetic grafts in prior studies. Only about 4.5% of patients required amputation, a significant improvement over the 24.3% amputation rate seen with synthetic grafts. The bioengineered vessels also showed strong resistance to infection, with less than 1% becoming infected compared to 8.4% for synthetic grafts.

Although the research team emphasized that the studies were single-arm trials, meaning all participants received the bioengineered tissue rather than randomized comparisons between bioengineered tissue and synthetic material, the consistently positive outcomes across both civilian and military settings suggest the technology could significantly improve vascular trauma care. The potential applications extend beyond trauma cases: researchers are also exploring the use of these vessels in dialysis patients and for other forms of arterial reconstruction. This broader application could address a major medical need, as many patients require multiple vascular procedures throughout their lives.

"This is the first bioengineered or grown blood vessel tested in human arterial reconstruction for traumatically injured vessels," said Michael Curi, the chief of vascular surgery at Rutgers New Jersey Medical School. "It adds a new option for repairing damage and will help a subset of patients who lack good standard options.

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