Bioengineering arteries to improve the long-term success of bypass surgery

Arterial bioengineering of decellularised human saphenous veins to reduce early graft thrombosis and improve long-term patency rate

Bypass surgery is a common treatment to restore healthy blood flow to the heart or limbs when arteries have become diseased; where a healthy blood vessel is grafted into the circulation to bypass a diseased section. Usually bypass grafts are sections of patients’ own veins, or synthetic grafts. However, these tend to get blocked within a decade after surgery. Sections of artery would last longer, but they are difficult to source and therefore rarely used. In this project, Professor Raimondo Ascione and his team plan to make brand new arteries for this purpose, from veins that are left over from heart bypass operations. The researchers will remove all the cells from the veins to leave skeletons of connective tissue. These will then go into a ‘bioreactor’ under arterial conditions, where cells will attach to the skeleton, creating the artery wall. The engineered artery grafts must perform in conditions found in patients. To check this, they will be implanted into pigs that have very similar sized blood vessels operating at comparable pressure to humans. In the future, engineered arteries could vastly improve the longevity of bypass grafts, significantly reducing the need for patients to have repeated surgery.