| abstract |
Vascular access systems and devices for facilitating repeated access to a blood vessel for the external treatment of blood, such as dialysis, and in intra-venous administration of medicines, such as heparin, for extended periods of time. The vascular access systems comprise an anastomosis graft vessel, an occlusal balloon, and a port device for accessing the occlusal balloon. Occlusal balloons can be nonpermeable or permeable to drive an osmotic gradient and to deliver agents, such as heparin, into the blood stream. In addition, occlusal balloons can adopt a distended and a collapsed configuration, the latter allowing for blood flow through the anastomosis graft vessel. |