Biocompatibility in clinical practice: predictable and unpredictable outcomes

At the present time, there is a significant public and political debate about the safety of implantable medical devices. The debate has centered on the biocompatibility of materials that are used in such devices. It has become clear that, whether the concerns expressed about adverse events in patients are actually caused by the devices or just coincidentally arise in these patients, we are usually unable to address and explain the phenomena that are described. This is very damaging to the medical device industry and the relevant clinical disciplines; it is, however, not surprising, since current ideas about the mechanisms of biocompatibility and the development of the host response are well out-of-date and do not take into account knowledge about inflammation, immunity and fibrosis. This perspectives paper discusses this new knowledge and presents the outline of new biocompatibility paradigms, involving mechanotransduction and sterile inflammation. Based on these ideas, totally new procedures for the determination of biological safety are proposed which, if implemented, could improve patient safety and confidence in the performance of implanted devices.