Methods for external treatment of blood

Abstract

Vascular access systems, devices and methods for facilitating repeated access to a blood vessel. These systems, devices and methods can be used in external blood treatment, such as dialysis, and in intra-venous administration of medicines, such as heparin, for extended periods of time, while avoiding deleterious effects such as those derived from repeated puncturing of the blood vessel tissues or exposure of such tissues to abnormal fluid flows. The vascular access systems comprise an anastomosis graft vessel, an occlusal device, such as an occlusal balloon, and a port device for accessing the occlusal device. Occlusal devices can be self-contained, they can rely on osmosis, and they can serve as the support of an agent to which the blood stream is exposed, either by transport or by mere contact. In addition, occlusal devices can adopt a distended and a collapsed configuration, the latter allowing for blood flow through the anastomosis graft vessel.