Bioabsorable markers for use in biopsy procedures

• US 6,350,244 B1
• Filed: 02/21/2000
• Issued: 02/26/2002
• Est. Priority Date: 02/21/2000
• Status: Expired due to Term

• Current Assignee: Devicor Medical Products Incorporated (Danaher Corporation)
• Original Assignee: Biopsy Sciences LLC
• Inventors: Fisher, John S.
• Primary Examiner(s): Lacyk, John P.
• Assistant Examiner(s): MARMOR II, CHARLES ALAN
• Application Number:
  US09/507,052
• Time in Patent Office: 736 Days
• Field of Search: 600/407, 600/420, 600/431, 600/562, 600/564, 606/116, 606/117, 606/151, 606/219, 128/897
• US Class Current: 600/562
• CPC Class Codes: A61B 10/0233 Pointed or sharp biopsy instruments
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable, resorptive for implantable prostheses A61F2210/0004
• CPC Class Codes: A61B 2090/3908 Soft tissue, e.g. breast tissue
• CPC Class Codes: A61B 2090/3925 ultrasonic
• CPC Class Codes: A61B 2090/3933 Liquid markers
• CPC Class Codes: A61B 2090/395 with marking agent for marking skin or other tissue
• CPC Class Codes: A61B 2090/3987 Applicators for implanting markers
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers

Abstract

A bioabsorbable marker is placed in soft tissue such as breast tissue near a lesion during a biopsy procedure. If tests prove the lesion to be malignant, the marker indicates the location of the lesion and the marker is removed surgically together with the lesion. If tests prove the lesion to be benign, there is no need to surgically remove the marker due to its bioabsorbability. One or more markers may be carried in an elongate, flexible marker carrier that is ensheathed within an elongate, flexible outer sheath. The flexible outer sheath is slidingly introduced into the proximal end of a biopsy needle until its distal free end protrudes from a port formed in the distal end of the biopsy needle. Retraction of the outer sheath relative to the marker carrier then exposes the marker carrier. The markers exit the marker carrier under their own inherent bias or an auxiliary bias is employed to eject them from the marker carrier. In a first embodiment, the bioabsorbable markers are hollow spheres made of polylactite acid. They are filled with iodine or other radiopaque material so that they are visible under X-rays and/or ultrasound. The radiopaque material is also bioabsorbable. In an additional embodiment, the hollow spheres are filled with an easily visible dye so that, when punctured, they provide a visible indication of a lesion'"'"'s location. In another embodiment, they are filled with radioactive material and are inserted for therapeutic purposes in a lesion known to be malignant. Another embodiment provides solid markers, formed by pre-mixing together a radiopaque material and a bioabsorbable material. The solid markers may also include dyes and radioactive materials. In all embodiments, the markers may be spherical, cubical, pyramidal, pentagonal, or any other predetermined shape.

Claims

1. A method for delivering to a biopsy site a plurality of markers that indicate the location of a lesion in soft tissue, comprising the steps of:

providing an elongate, flexible outer sheath of generally tubular configuration;

providing an elongate, flexible marker carrier that is slideably received within said outer sheath;

forming a plurality of marker retaining means in said marker carrier and positioning a marker in each marker retaining means of said plurality of marker retaining means;

providing each marker in the form of a solid member of predetermined configuration, and forming each marker by pre-mixing together a bioabsorbable material and another material from the group including a radiopaque material, a dye, and a radioactive material;

introducing said outer sheath and marker carrier ensleeved therewithin into an open proximal end of a needle of a biopsy device and advancing said outer sheath until a distal free end thereof extends through a port formed in a distal end of said needle;

unsheathing said marker carrier by retracting said outer sheath with respect to said marker carrier;

providing a means for ejecting each marker from said marker carrier when said outer sheath is retracted relative to said marker carrier; and

ejecting each marker from said marker carrier;

whereby the position of said lesion is denoted by said markers.

2. The method of claim 1, wherein each marker is flexible and resilient and under compression when said marker carrier is ensheathed within said outer sheath, whereby said means for ejecting said markers includes the inherent bias of the markers when said outer sheath is retracted relative to said marker carrier.

3. An apparatus for depositing a plurality of markers in the vicinity of a lesion, comprising:

an elongate, flexible outer sheath of generally tubular configuration;

an elongate, flexible marker carrier slideably disposed within said outer sheath;

a plurality of markers formed of a flexible and resilient material;

each marker of said plurality of markers being formed of a bioabsorbable material, and including a material preselected from a group including a radiopaque liquid, a radioactive material, and a dye;

said marker carrier having a plurality of recesses of uniform predetermined depth formed in an outer surface thereof for respectively holding said plurality of markers;

said outer sheath having an internal diameter slightly greater than an external diameter of said marker carrier;

each marker of said plurality of markers having a predetermined thickness that exceeds the uniform predetermined depth of said recesses so that each marker is under compression when said marker carrier is ensleeved within said outer sheath;

whereby each marker is ejected from its recess under its inherent bias when said outer sheath is withdrawn relative to said marker carrier.

4. The apparatus of claim 3, wherein each marker is a solid member of predetermined configuration formed by pre-mixing together at least two materials including a bioabsorbable material and another material from the group including a radiopaque material, a dye, and a radioactive material.

5. The apparatus of claim 3, wherein each of said markers has a hollow construction including an outer wall formed of a biodegradable material and wherein each of said markers is filled with a detectable material.

6. An apparatus for depositing a plurality of markers in the vicinity of a lesion, comprising:

an elongate, flexible outer sheath of generally tubular configuration;

an elongate, flexible marker carrier slideably disposed within said outer sheath, said marker carrier having a generally tubular configuration and defining an interior bore of uniform diameter;

a plurality of marker retaining means formed in said marker carrier for holding a plurality of markers;

each marker of said plurality of markers being formed of a bioabsorbable material, and including a material selected from a group including a radiopaque liquid, a radioactive material, and a dye;

a push rod slideably disposed within said marker carrier, said push rod having an exterior diameter slightly less than an interior diameter of said marker carrier;

each marker having a radially innermost side that is positioned within said interior bore of said marker carrier;

whereby slideably introducing said push rod into said interior bore of said marker carrier respectively displaces each marker out of said marker retaining means so that each marker is deployed into said soft tissue and remains in said soft tissue when said marker carrier is withdrawn from said soft tissue.

7. The apparatus of claim 6, wherein each of said markers is solid and formed by pre-mixing together at least two materials including a bioabsorbable material and another material from the group including a radiopaque material, a dye, and a radioactive material.

8. The apparatus of claim 6, wherein each of said markers has a hollow construction including an outer wall formed of a biodegradable material and wherein each of said markers is filled with a detectable material.