Case Study

A process designed to reduce the risk of rejection in heart surgery patients receiving donated aortic valves is now also being applied to pulmonary valves.

The decellularisation process, in which cellular material is removed from tissue before a patient’s own cells repopulate the remaining matrix, was developed by Professor Eileen Ingham and colleagues at the University of Leeds. It was first designed for the aortic valve, which pumps blood around the body. Physiologically the aortic valve works hardest and is more likely to need replacing in patients.

Often a surgeon will take the pulmonary valve, which supplies blood to the lungs, and switch it over to the aortic side, using a donor valve to replace the pulmonary one. Donor valves wear out over time, but this happens more slowly on the pulmonary side and is usually caught through monitoring symptoms.

In conversations with a Brazilian heart surgeon and collaborator, the question arose as to whether the decellularisation process could also work on the pulmonary valve. The IKC has supported early testing of decellularised porcine pulmonary valves in a sheep model, with largely positive results.

The community is rightly cautious about using decellularised porcine valves because of earlier failures in this area by a US company. While any new approach will take time to be accepted, the team is working with long-term partner NHS Blood and Transplant to apply the technology to human valves.