| 主权项 |
1. A vascular access device adapted to connect an artery to a vein in a mammal, the device comprising:
a) a substantially tubular graft having a first lumen, which graft comprises a biocompatible material and is adapted to conduct fluid in the lumen between a first end and a second end of the graft, wherein the substantially tubular graft is anastomosed at its first end to a first artery of the mammal, and is anastomosed at its second end to a first vein of the mammal; and b) at least a first and at least a second ring disposed around at least a first portion of the substantially tubular graft, and comprising a substantially magnetic or paramagnetic material, wherein the first ring is in at least substantial proximity to a first end of a cannulation site within the graft, and the second ring is also in at least substantial proximity to at least a second end of the first cannulation site within the graft, wherein the graft is implanted entirely subcutaneously in the mammal, is adapted and configured to be penetrated substantially into a first lumen of the first cannulation site by at least a first needle or cannula, and can be localized within the body of the mammal by a detector comprising at least one magnet sized and dimensioned to detect the first ring, when the detector is placed in proximity to the skin of a patient into which the vascular graft has been implanted. |
