Methods, devices, and kits for creating bloodstream access in patients are provided. A patients vessel is accessed surgically and blood flow is stopped. A short incision is made through the wall of one side of the vessel where the blood flow was stopped. A puncturing instrument is pushed through the incision across the lumen and through the vessel wall at a site opposite the incision. After the puncturing instrument is removed, a vessel wall traversing device which can be shaped like a blunt-ended nail with a hollow shank and a head of a larger diameter than the shank is inserted in the puncture hole blunt end first such that the shank traverses the puncture hole with the blunt end being positioned exterior to the outer surface of the vessel and the head of the device abutting inner surface of the vessel at the puncture hole. The portion of the shank that projects outwards from the vessel wall is connected to one end of a flexible cannula, and the other end of the cannula is passed through the surrounding tissue such that the end of the cannula opposite the vessel wall traversing device protrudes through the skin of the patient. A portion of the cannula protruding from the patient is clamped off, the incision is closed, and blood flow is restored to the vessel. Blood within the vessel is than accessible via the portion of the cannula protruding from the patient.
