Permanent percutaneous devices.

A percutaneous device (PD) constitutes a foreign material penetrating through the skin. It provides a connection between an internal organ or cavity and an extracorporeal device. PDs serving a multitude of clinical and research purposes are described. Breakdown of the PD-skin interface relatively soon after implantation is the failure mode of all present devices. Using the pertinent literature the present understanding of the pathophysiology of PD-skin interface behavior is discussed: the peculiarity of epidermal healing, lack of biomaterials compatible to epidermis, and mechanical stresses at the interface, each independently and in combinations are considered causative to this failure. Clinical reports on various permanent PDs are presented and ongoing research efforts at various centers are discussed.