Surgical heart reconstructions using graft materials can do amazing things for patients, but in young children they have a serious limitation. The grafts don’t grow along with a growing heart, and so for procedures such as right ventricular outflow tract reconstructions repeat surgeries are required. Now researchers at University of Minnesota are reporting in journal Nature Communications on newly developed “off-the-shelf” vascular grafts that can grow as the tissue they’re connecting develops and matures.
The grafts are made of fibroblasts within a fibrin gel. These were then introduced to nutrients in a bioreactor which also stimulated the grafts mechanically, making them stronger and able to withstand lots of force. The cells were then washed away to produce the final graft that does not trigger an immune response.
The grafts were then implanted into three sheep only five weeks old and the animals monitored for almost a year. The results showed that the vessels grew by more than 50% in diameter and allowed more than twice as much blood to pass through. There was also more collagen formed within the grafts and there were no evidence of calcification, aneurysm, or stenosis.
Here’s video of the pumping bioreactor used to make the grafts:
Open article in journal Nature Communications: Tissue engineering of acellular vascular grafts capable of somatic growth in young lambs…