Risk factors for chronic biofilm-related infection associated with implanted medical devices.

BACKGROUND: The use of implanted medical devices is associated with a small but clinically important risk of foreign body infection. A key question is: why do some patients develop chronic infection associated with an implanted device, but most do not? AIMS: The literature on patient-specific risk factors for chronic infections associated with five types of implants was surveyed to glean clues about the etiology of these infections. SOURCES: Data were collected from 47 articles through calendar year 2017 for five categories of device-related infections: cardiovascular implantable electronic devices (CIEDs), hernia meshes, prosthetic hip and knee joints, prosthetic shoulder joints and breast implants. CONTENT: Important risk factors include immunomodulation/steroid therapy, diabetes, smoking, and renal disease/haemodialysis-findings that point to a critical role of a compromised innate immune response in determining vulnerable subpopulations. IMPLICATIONS: A model of biofilm-related device infection is presented that posits defects in the innate immune response both systemically and locally, in the immediate vicinity of an abiotic biomaterial. The limitations of in vitro and animal models of chronic device-related infections are discussed in this context as are implications for research and clinical practice.