The metra™ represents a real advance on current clinical practice where livers are retrieved, flushed with a cold preservation solution, packed on ice and then rushed between donor hospital and transplant centre, with the result that many livers are discarded due to logistical constraints, an inability to assess liver quality, or organ damage resulting from being placed ‘on ice’. By preserving liver quality for an extended period of time — up to 24 hours — the system could double the number of organs available for transplant by preserving the quality of organs which before would have been declared unsuitable.
Designed to maintain the liver in a fully functioning state during transport and storage, the metra™ provides blood flow, oxygen, carbon dioxide control, nutrients and temperature control within physiological parameters, while also monitoring factors such as bile production. By mimicking the body, the system can potentially store the liver for up to 24 hours while providing real-time and cumulative data which the surgeon can use to assess liver function and viability, something which has never been possible before.
The development process began in 2009 when OrganOx, a University of Oxford spinout, appointed Team to assist in the design and development of the system in order to move from proof of concept to commercial manufacture. ‘When first set up, OrganOx was a very small company, closely linked to the University, and it needed system design and development capability in order to take its invention ‘from bench to bedside’,’ explains Stuart Kay, Team’s Head of Electro-Mechanical Engineering.
“These first clinical cases confirm that we can support human livers outside the body.”
“Our primary focus was to turn the original, large, manual, clinician-dependent process into a robust, autonomous system controlled by embedded multi-tasking software with a safety-critical architecture — which meant that if a peripheral system component failed for any reason then the core system would continue to function. We had to create a small system which could survive road and air transport, a wide variety of weather conditions as it was moved around, and also — of great importance — a system which was quick and easy to set up and use, despite its complexity and sophistication.”
Team supported OrganOx throughout the core design and development phases until verification testing activities had been completed. While the complete process took four years between the original meeting and MHRA approval to conduct clinical trials, Team delivered the first fully autonomous proof of principle system in just nine months, which helped OrganOx secure further funding. The first transplant took place as part of a controlled clinical study at King’s College Hospital in London, home to Europe’s largest liver transplant centre which carries out over 200 transplants every year. It is hoped that the device could be useful for all patients needing liver transplants, and Professor Constantin Coussios, OrganOx Technical Director and one of the system’s original inventors, is delighted:
“These first clinical cases confirm that we can support human livers outside the body, keep them alive and functioning on our machine and then, hours later, successfully transplant them into a patient. The system is the very first completely automated liver perfusion device of its kind; the organ is perfused with oxygenated red blood cells at normal body temperature, just as it would be inside the body and can, for example, be observed making bile which makes it an extraordinary feat of engineering. It was astonishing to see an initially cold grey liver flushing with colour once hooked up to our machine and performing as it would within the body. What was even more amazing was to see the same liver transplanted into a patient who is now walking around.”
Mr Wayel Jassem, Consultant Liver Transplant Surgeon who performed both transplant operations, was also impressed: “There is always huge pressure to get a donated liver to the right person within a very short space of time. For the first time, we now have a device that is designed specifically to give us extra time to test the liver, to help maximise the chances of the recipient having a successful outcome. This technology has the potential to be hugely significant, and could make sure livers are available for transplant and, in turn, save lives.”
Team’s Stuart Kay explained that the system could also provide a platform for future development. “We have designed a safety-critical system which is robust, reliable and simple to use, and which meets some very demanding requirements. A system of this type had never been attempted before, and is a testament to our design and engineering capabilities and to the dedication of the whole project team.”
Ian Christie (62) was the first person to receive a transplanted liver kept alive by the OrganOx™ metra™ system as part of a controlled clinical study:
“In May 2012, I was told I had cirrhosis of the liver and without a transplant I had an estimated 12-18 months to live. I was placed on the waiting list but I was told there was about 12-18 months to wait for a liver of my type. I was very worried it was cutting it a bit too fine and I wouldn’t get a transplant. The waiting is horrible … You’re waiting for the phone to ring, wondering: Are they ever going to call me?”
“I took part in the trial because if the device can help more people in my situation in the future, it’s my duty to help. I feel better than I’ve felt for 10-15 years, even allowing for the pain and wound that’s got to heal. I’m getting better day by day. I just feel so alive!”