Surgeons could use artificial blood vessels in several ways:
Coronary artery bypass grafts: If one of the heart’s arteries is blocked or diseased, a new vessel may be necessary. Surgeons can harvest arteries and veins from elsewhere in the patient’s body, but they’re in limited supply.
Peripheral bypass grafts: Atherosclerosis can narrow arteries beyond the heart. Again, the body has only so many options for replacement.
Kidney dialysis shunts: People on dialysis need an easily accessible vessel containing fast-moving blood. Doctors typically connect an artery and vein to make a shunt, but with repeated needle sticks the shunts wear out and eventually native blood vessels will not suffice.