An implant for marking a location within the tissue of a patient after
biopsy is self-anchoring. In one embodiment a strip of a shape memory
alloy such as Nitinol can be straightened to facilitate insertion through
a small gauge needle but, once exposed within the tissue to body
temperature, assumes a helical coil configuration, thereby mechanically
clamping to the tissue. In other embodiments the implants include barbs of
resilient, deformable metal which can be straightened for insertion into a
small gauge needle, but once the implant exits the forward end of the
needle the barbs spring outward, anchoring the implant within the tissue.
A method for implanting a plurality of markers within the tissues of a
patient involves a needle having a plurality of markers sequentially
loaded therewithin. The forward end of the needle is inserted into the
tissues of the patient and advanced to a first target location, at which
point a first marker is ejected into the tissues of the patient. The
forward end of the needle is then relocated to a second target site, and a
second marker is ejected into the tissues of the patient.
