Biopsy site marker for limited migration

1 . A biopsy site marker, comprising:

(a) a carrier;

(b) a marker element,

wherein the carrier includes a first portion, a second portion, and a third portion, the third portion being disposed between the first portion and the second portion,

wherein the first portion and the second portion both include a first marker material and are separate from one another, wherein the third portion includes a second marker material, wherein the first marker material is configured to expand at a rapid rate relative to the second marker material in a presence of moisture, wherein the marker element is disposed within the third portion, wherein each of the first portion, the second portion, and the third portion is configured to expanded to an expanded configuration when in the presence of moisture, wherein each of the first portion and the second portion include a larger circumference than the third portion when each of the first portion, the second portion, and the third portion are in the expanded configuration; and

(c) a marker material interface including a first marker material interface and a second marker material interface, wherein the first marker material interface is disposed between the first portion and the third portion, and wherein the second marker material interface is disposed between the second portion and the third portion, the marker material interface coupling the first portion and the second portion to the third portion respectively, the marker material interface being configured to locally restrict expansion of an interior side of each of the first portion and the second portion, respectively.

2 . The marker of claim 1 , wherein the first portion and the second portion each includes a plurality of notches.

3 . The marker of claim 1 , wherein the first portion and the second portion are both configured to expand relative to the third portion to anchor the carrier within a tissue.

4 . The marker of claim 1 , wherein the carrier is configured to transition between a dehydrated configuration to an initially hydrated configuration, wherein the first marker material is configured to expand relative to the second marker material during the transition to the initially hydrated configuration such that the carrier forms a dumbbell-shaped profile.

5 . The marker of claim 1 , the first portion and the second portion defining a cylindrical shape, the cylindrical shape being interrupted by a plurality of axially extending notches, each notch of the plurality of notches being configured to grip a tissue.

6 . The marker of claim 1 , the first marker material being configured to rapidly absorb moisture relative to the second marker material.

7 . The marker of claim 6 , the first marker material including collagen, and the second marker material including hydrogel.

8 . The marker of claim 1 , the first portion, the second portion, and the third portion being arranged axially, and the first portion, the second portion, and the third portion together defining a cylindrical shape when in a dehydrated condition.

9 . The marker of claim 1 , the marker element being centered within the third portion.

10 . The marker of claim 1 , the marker element being centered both laterally and axially within the third portion.

11 . The marker of claim 1 , an exterior side of the first portion and an exterior side of the second portion, wherein each exterior side is configured to expand relative to the marker material interface.

12 . The marker of claim 1 , the first marker material including collagen, the second marker material including hydrogel, and the marker element being disposed in the hydrogel.

13 . The marker of claim 1 , the first marker material including collagen, the second marker material including hydrogel, and the marker element being disposed entirely in the hydrogel.

14 . The marker of claim 1 , the first marker material including collagen, the second marker material including hydrogel, the marker element being disposed within both a portion of the hydrogel and a portion of the collagen.

15 . A biopsy site marker, comprising:

(a) a carrier, the carrier including:

(i) an inner carrier portion defining a proximal end and a distal end,

(ii) a pair of outer carrier portions, each outer carrier portion being disposed on the proximal end and the distal end of the inner carrier portion, respectively,

(iii) a first interface disposed between the proximal end of the inner carrier portion and the corresponding outer carrier portion, and

(iv) a second interface disposed between the distal end of the inner carrier portion and the corresponding outer carrier portion; and

(b) a marker element extending from the inner carrier portion to at least one of the outer carrier portions,

the pair of outer carrier portions both including a first marker material, wherein the first marker material of each outer carrier portion extends continuously from corresponding first and second interfaces to respective terminal ends of the carrier, the inner carrier portion including a second marker material extending from the proximal end to the distal end, wherein the marker element is disposed in the second marker material, the first marker material being configured to expand at a rapid rate relative to the second marker material in a presence of moisture; and

the first interface and the second interface both being configured to restrict a diameter of each outer carrier portion near the first interface and the second interface, respectively.

16 . The marker of claim 15 , the first interface and the second interface both being configured to restrict a diameter of each outer carrier portion near the first interface and the second interface, respectively, to correspond to a diameter defined by the inner carrier portion.

17 . The marker of claim 15 , each outer carrier portion defining a respective outer end, each outer end being configured to flare outwardly relative to the first interface and the second interface, respectively, in the presence of moisture.

18 . The marker of claim 15 , the marker element being disposed within the inner carrier portion.

19 . A biopsy site marker, comprising:

(a) a carrier defining a proximal-most end and a distal-most end, the carrier including:

(i) an inner carrier portion defining a proximal end and a distal end,

(ii) a proximal outer carrier portion,

(iii) a distal outer carrier portion, the distal outer carrier portion and the proximal outer carrier portion being disposed on the distal end and the proximal end of the inner carrier portion, respectively,

(iv) a first interface disposed between the proximal end of the inner carrier portion and the proximal outer carrier portion, and

(v) a second interface disposed between the distal end of the inner carrier portion and the distal outer carrier portion; and

(b) a marker element disposed within the carrier,

the proximal outer carrier portion including a first marker material extending from the proximal-most end to the first interface and the distal outer carrier portion including the first marker material extending from the distal-most end to the second interface, the inner carrier portion including a second marker material extending from the first interface to the second interface, the first marker material being configured to expand at a rapid rate relative to the second marker material in a presence of moisture; and

the first interface and the second interface both being configured to locally restrict a size of the proximal outer carrier portion and the distal outer carrier portion near the first interface and the second interface, respectively.