Professor of Surgical Sciences, University College London
Stopping biological time
Prof. Barry Fuller
My name is Barry Fuller: I’m a professor at UCL medical school in the division of Surgery and Interventional Science. I became involved in transplantation in the early years of the service development, actually by the mid 1970s. I did a PhD with one of the pioneers of kidney transplantation called David Pegg. Possibly in a hospital 50 or 100 miles away. As the service has developed, I’ve been really excited by the possibilities of working together with the multidisciplinary team of surgeons, scientists, nurses, coordinators, managers. In some ways it’s a reflection I think of the best parts of the health service – people working together – and also must not forget that the patients themselves and their families showed a great courage embracing this technology in the early years, because whilst it offered a fantastic opportunity for treatment it was also an unknown entity. So everybody was moving forward, trying to help each other in this respect.
My own interest was organ preservation – being able to stop biological time. As a student I learnt from text books about the importance of all of the chemical reactions in our bodies and how they all had to be integrated, so the possibility of stopping that for 12 hours or 24 hours was almost unbelievable. And we managed to do that, in the early years as best we could, but there are still improvements needed to make sure that the quality of the organs that are being transplanted are at the highest level. And, on the horizon, there are new processes for organ perfusion, almost like an artificial circulation system outside the body as a way of improving, or maintaining, the organs while they’re outside the body.
We’ve talked about stopping biological time, and in the early part of transplantation we learnt to do that by using low temperatures and particular solutions that we could infuse into the blood supply of the organ to help stop the activity of all the cells in the organ. But, as you can imagine, that’s a rather crude way of dealing with a very sophisticated biological system like an organ. It would be much better to try and maintain at least some of the basic functions of the organ in that period when it’s outside the body. And one way to do that is to perfuse the organ with solutions in the same way as blood would perfuse the organ when the heart beats.
And it sounds a simple idea, but actually developing the machinery and the technologies to be able to do that has taken more than 20 years. Because we learnt early on that by introducing solutions into the organ you could actually damage the blood vessels in the organ. So, to be able to construct machines that could be sensitive enough to perfuse the organs the way a heartbeat would do it, but at different temperatures, and with a solution which is not blood, has taken a long time to develop. And we are approaching that now, there are systems that perfuse organs at lower temperatures, giving them the oxygen, and the nutrients that they require. And now there’s also the possibility that we can perfuse organs at the body temperature, so that actually they’re functioning almost identically as they would be inside the body when they’re in the machine. And of course part of the challenge has been making them portable, because many of the early systems are very interesting perfusion technologies, but they just could not be transported from hospital to hospital, which is one of the fundamental requirements for the organ donor pathway.
My own interest was organ preservation – being able to stop biological time. As a student I learnt from text books about the importance of all of the chemical reactions in our bodies and how they all had to be integrated, so the possibility of stopping that for 12 hours or 24 hours was almost unbelievable. And we managed to do that, in the early years as best we could, but there are still improvements needed to make sure that the quality of the organs that are being transplanted are at the highest level. And, on the horizon, there are new processes for organ perfusion, almost like an artificial circulation system outside the body as a way of improving, or maintaining, the organs while they’re outside the body.
We’ve talked about stopping biological time, and in the early part of transplantation we learnt to do that by using low temperatures and particular solutions that we could infuse into the blood supply of the organ to help stop the activity of all the cells in the organ. But, as you can imagine, that’s a rather crude way of dealing with a very sophisticated biological system like an organ. It would be much better to try and maintain at least some of the basic functions of the organ in that period when it’s outside the body. And one way to do that is to perfuse the organ with solutions in the same way as blood would perfuse the organ when the heart beats.
And it sounds a simple idea, but actually developing the machinery and the technologies to be able to do that has taken more than 20 years. Because we learnt early on that by introducing solutions into the organ you could actually damage the blood vessels in the organ. So, to be able to construct machines that could be sensitive enough to perfuse the organs the way a heartbeat would do it, but at different temperatures, and with a solution which is not blood, has taken a long time to develop. And we are approaching that now, there are systems that perfuse organs at lower temperatures, giving them the oxygen, and the nutrients that they require. And now there’s also the possibility that we can perfuse organs at the body temperature, so that actually they’re functioning almost identically as they would be inside the body when they’re in the machine. And of course part of the challenge has been making them portable, because many of the early systems are very interesting perfusion technologies, but they just could not be transported from hospital to hospital, which is one of the fundamental requirements for the organ donor pathway.