Mammary implant having shell with unitary rough-textured outer layer

• US 5,674,285 A
• Filed: 12/12/1995
• Issued: 10/07/1997
• Est. Priority Date: 11/04/1986
• Status: Expired due to Term

• Current Assignee: Allergan, Inc. (Canada) (Abbvie Incorporated)
• Original Assignee: Medical Products Development, Inc.
• Inventors: Quaid, Joel
• Primary Examiner(s): ISABELLA, DAVID J
• Application Number:
  US08/570,802
• Time in Patent Office: 665 Days
• Field of Search: 623/1, 623/11, 623/12, 623/66, 623/7, 623/8
• US Class Current: 623/8
• CPC Class Codes: A61F 2/0077 Special surfaces of prostheses, e.g. for improving ingrowth A61F2/30767 takes precedence
• CPC Class Codes: A61F 2/12 Mammary prostheses and implants
• CPC Class Codes: A61L 27/18 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: C08J 2201/0446 Elimination of NaCl only
• CPC Class Codes: C08J 2383/04 Polysiloxanes
• CPC Class Codes: C08J 9/26 by elimination of a solid phase from a macromolecular composition or article, e.g. leaching out
• CPC Class Codes: C08L 83/04 Polysiloxanes

Abstract

A medical implant with an external surface layer of silicone elastomer and having an open-cell structure is made by applying solid particles to the external surface layer of the implant before it is cured, curing the external surface layer with the solid particles embedded therein and then dissolving the solid particles with a solvent that does not dissolve the silicone elastomer. An implant having such an external surface layer is expected to help prevent capsular contraction, to help prevent scar formation, and to help in anchoring the implant within the body.

Claims

1. An implantable mammary device comprising:

a substantially homogeneous silicone elastomer flexible shell of unitary construction defining an interior therein, the shell comprising at least a base layer of silicone elastomer and an outer layer of silicone elastomer, the base layer and outer layer being vulcanized together to form a unitary and homogeneous structure; and

means for filling the interior,

wherein the shell has defined unitarily therein a rough-textured external surface comprising randomly formed interconnected cells varying in diameter from about 10 microns to about 600 microns and located at and near the surface to a depth of about 1800 microns to simulate an open-cell foam for promoting ingrowth of tissue and for preventing capsular contracture.

2. An implantable mammary device according to claim 1, wherein most of the external surface is rough-textured.

3. An improved silicone elastomer shell for a mammary prosthesis, the improvement comprising:

a substantially homogeneous silicone elastomer flexible shell of unitary construction defining an interior therein, the shell comprising at least a base layer of silicone elastomer and an outer layer of silicone elastomer, the base layer and outer layer being vulcanized together to form a unitary homogeneous structure, wherein the shell has defined unitarily therein a rough-textured external surface comprising randomly-formed interconnected cells varying in diameter from about 10 microns to about 600 microns and located at and near the surface to a depth of about 1800 microns to simulate an open-cell foam for promoting ingrowth of tissue and for preventing capsular contracture.

4. An improved silicone elastomer shell according to claim 3, wherein most of the external surface is rough-textured.

5. An implantable mammary device comprising:

a substantially homogeneous silicone elastomer shell of unitary construction defining an interior therein; and

means for filling the interior,

wherein the shell includes a base layer of substantially homogeneous silicone elastomer and an outer layer, the base layer and outer layer being vulcanized together to form a unitary homogeneous structure, the shell having an external surface and comprising a substantially homogeneous silicone elastomer, and having defined internally therein a first group of cells varying in diameter from about 10 microns to about 600 microns formed therein and a second group of cells varying in diameter from about 10 microns to about 600 microns formed therein relative to the first group, the first group being in direct communication with the external surface and having a range of depths down to about 600 microns below the external surface, and the second group having a range of depths down to about 1800 microns below the external surface, wherein the first and second groups of cells are disposed for creating an open-cell structure, wherein the first group of cells open directly to the external surface, and the second group of cells communicate with the external surface only through cells which open directly to the external surface to simulate an open-cell foam for promoting ingrowth of tissue and for preventing capsular contracture.

6. An improved silicone elastomer shell for a mammary prosthesis, the improvement comprising a shell formed of at least a base layer of silicone elastomer, and an outer layer of silicone elastomer, the base layer and outer layer being vulcanized together to form a unitary homogeneous structure, the shell having an external surface with at least a portion of said external surface having defined unitarily therein an open-cell structure including a first group of cells varying in diameter from about 10 microns to about 600 microns formed therein and a second group of cells varying in diameter from about 10 microns to about 600 microns formed therein relative to the first group, the first group being in direct communication with the external surface and having a range of depths down to about 600 microns below the external surface, and the second group having a range of depths down to about 1800 microns below the external surface, the first and second groups of cells creating a network of cells to achieve the open-cell structure, wherein the first group of cells open directly to the external surface and the second group of cells communicate with the external surface only through cells which open directly to the external surface to simulate an open-cell foam for promoting tissue ingrowth and for preventing capsular contracture.

7. An improved silicone elastomer shell according to claim 6, wherein most of the external surface has the open-cell structure.