Applications and failure modes of percutaneous devices: a review

Percutaneous devices (PD) are designed to serve a variety of clinical and biomedical research purposes. Characteristically they are objects that permanently penetrate through a defect in the skin. The histological aspects of the implant skin interfacial reactions are reviewed in this article. A short description is presented of common applications of PDs. The five presently identified interfacial failure modes are described histologically with the aid of schematic drawings. These failure modes are marsupialization, permigration , avulsion, infection, alone or in combination. Single or multiple etiological factors may be responsible for these failure modes. These factors can be surgically created skin defects around the penetrating foreign implant, epidermal healing characteristics that prevent the formation of a suitable seal at the implant-skin interface and mechanical forces that may disrupt dermal attempts to seal the interface. Eventually the interface becomes infected necessitating removal of the device. Terminology recommended for use in percutaneous device research is indexed and defined.