Development of artificial blood vessels made of new materials, used for vascular access in renal dialysis

It can take many years to find a matched kidney donor and, in some cases, a matched donor is never found. Dialysis machines and methods of accessing a patient's cardiovascular system mean patients can live well whilst waiting for a transplant. Patients must undergo one of two surgical procedures before their first haemodialysis; receiving either an arteriovenous fistula or an arteriovenous graft, which join the artery to the vein and facilitate the transfer of blood from body to machine. If a graft is needed, an operation to insert a polytetrafluoroethylene (PTFE) based device is required but complications can arise in the form of blockages. Denan Jin, Department of Innovative Medicine, Osaka Medical and Pharmaceutical University, Japan, has spent years conducting research on the issues related to PTFE device blockage. He worked with his mentor Professor Mizuo Myazaki before his retirement and his colleague Professor Shinji Takai, and these collaborations led to understanding of the major causes of these blockages. Jin and his team are working to develop means to increase the longevity of PTFE grafts. The researchers have discovered two key mechanisms through which the grafts become blocked, which has led to the identification of two possible routes for preventing blockages. These relate to fibroblasts and the researchers have also identified the enzyme chymase as a key intermediate in the process of fibroblast recruitment. Jin and the team are proposing the use of an alternative to PTFE and the development of an effective chymase inhibitor to reduce the recruitment of fibroblasts to the graft site.