Vein hope First DIY blood vessels could offer lifeline to heart bypass patients
15:45 GMT, 23 April 2012
Human veins have been grown from scratch in the lab in a breakthrough that could revolutionise heart bypass surgery.
The DIY blood vessels, which take just a few weeks to grow from a piece of skin taken from the back of the hand, could also help kidney patients dependent on dialysis while they wait for a transplant and babies with defective heart valves.
Blood vessels grown from a person's own cells may soon help kidney dialysis patients
The US scientists have used several techniques to make the ‘Cadillac of treatments’. The latest, and most bizarre, involves weaving them on a miniature loom on the lab.
As unusual as the approach sounds, it cuts production time, making large-scale production of off-the-shelf veins a real possibility.
Other research teams are also trying to make blood vessels but they have either had to use artificial materials or produced veins that aren’t strong enough to deal with the pressure of blood coursing through the body, a major scientific conference heard.
During heart bypass surgery, a vein from another part of the body is used to divert blood around narrowed or clogged blood vessels.
But many of the 26,000 Britons in need of this delicate operation each year do not have any healthy blood vessels suitable for grafting.
Synthetic versions are available but are prone to infection.
The new technique, unveiled at the Experimental Biology conference in San Diego, should cut the odds of infection. Patients would also have to undergo just one op rather than two.
The DIY veins are the brainchild of researchers at US firm Cytograft Tissue Engineering.
The basic process starts with a sample of skin cells taken from the back of the hand.
Threads or sheets of cells are rolled up and incubated with key nutrients
The cells, which produce large amounts of the strong but elastic protein collagen, are grown and multiplied in the lab until they form a thin sheet.
The sheet of cells is then rolled up, much like a roll of wrapping paper, and then incubated with key nutrients until the various layers fuse together to form a hollow tube.
The tube is then lined with a second type of cell, taken from a superficial vein that was part of the original skin sample.
Blood vessels up to 8 inches in length have been made using a patient’s own cells and using donor cells.
Use of donor cells would allow the veins to be produced on a large scale and stored in hospital fridges until ready for use.
Veins made from donor cells have been implanted into the arms of three patients with severe kidney disease, to allow better access for dialysis.
So far the transplants have been successful, with the first patient treated more than a year ago.
Speaking after those results were revealed Dr Frank Sellke, of the American Heart Association, said that despite the small number of patients, the results were ‘very good’, with few complications.
Heart surgeon Timothy Gardner, the association’s past president, said: ‘These are essentially off-the-shelf, ready to be used.
‘The thing that impressed me was that there was no evidence of any immune response or rejection associated with it.
‘I think it is a really interesting, promising new development.’
The process can be sped up by cutting out the step in which the sheet of cells is rolled up and left to form a tube.
Instead, the sheet of cells is cut into fine threads, which are visible to the naked eye. These are rolled onto spools and woven into tube shapes on a small but sterile loom.
Cytograft’s co-founder Dr Nicolas L’Heureux said: ‘What we are doing here is using a completely biological, completely human fibre from which we can now build all kinds of structures by weaving, knitting, braiding or a combination of techniques.’
Doing this slashes the time to make a blood vessel to just two months.
However, the process isn’t cheap, with each vein expected to cost several thousand pounds.
The technology, particularly that needed for the woven veins, is still at a relatively early stage and is will be five to ten years before the DIY veins are suitable for widespread use.