Textured silicone implant prosthesis

• US 4,955,909 A
• Filed: 01/31/1989
• Issued: 09/11/1990
• Est. Priority Date: 01/31/1989
• Status: Expired due to Term

• Current Assignee: Intellectual Property International Limited
• Original Assignee: Bioplasty, Inc.
• Inventors: Beisang, Arthur A. III, Ersek, Robert A., Beisang, Arthur A.
• Primary Examiner(s): Cannon, Alan W.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/304,764
• Time in Patent Office: 588 Days
• Field of Search: 623/7, 623/8, 623/11, 623/66
• US Class Current: 623/23.74
• CPC Class Codes: A61F 2/12 Mammary prostheses and implants

Abstract

Capsular contracture causing firmness of soft silicone implants is a serious problem that may result from several causative factors that have as their final pathway, the development of increased scar tissue. The present invention has altered the formation of this scar encapsulation of silicone implants by texturing the silicone surface in order to gain fibroblast ingrowth into the interstices and thus prevent micromotion at the host prosthesis interface. It has been found that this produces a thinner fibrous capsule. Previously published work pertaining to animals and man has shown that similar texturing of tetrafluoroethylene (Teflon) and other substances achieves these goals. In accordance with work leading up to the present invention, textured silicone samples have been implanted in the subcutaneous layer of rabbits, the capsule formation and the host-prosthesis interface studied histologically. A difference between the smooth surface and the textured surface could be measured wherein the textured surface had a thinner capsule without contracture and the smooth surface had a thicker capsule with contraction.

Claims

1. In a soft, pliable three-dimensional prosthesis means for implantation in humans and comprising a three-dimensional solid with an outer layer of silicone rubber and having outer surfaces of the silicone rubber layer treated for formation of host-prosthesis interface, the improvement comprising:

(a) interstices formed on said outer silicone rubber surfaces to produce a substantially continuous, textured surface and characterized by a net-like, three-dimensional grid structure with pores having multi-planar, random axis orientation to provide for mechanical ingrowth of host fibrous tissue into and around said surface pores and interstices;

(b) the said net-like surface grid structure of said silicone rubber layer including substantially randomly placed formed pillars of non-uniform length and area extending outwardly from a base plane and with valleys disposed between said pillars, said pillars further having irregular outer end surfaces with indentations formed therein; and

(c) said pillars and indentations generally providing a textured surface which approximates a surface having average pore size ranging from between about 20 and l00 microns.

2. The soft, pliable three-dimensional prosthesis means as defined in claim 1 being particularly characterized in that said soft, pliable three-dimensional prosthesis is a breast prosthesis.

3. The soft, pliable three-dimensional prosthesis means as defined in claim 1 being particularly characterized in that said prosthesis means includes an outer layer of silicone rubber enclosing a hollow core, and wherein the hollow core is filled with liquid silicone gel.

4. The soft, pliable three-dimensional prosthesis means as defined in claim 1 being particularly characterized in that said pillars are separated by valley zones, and wherein said pillars extend outwardly between about 20 microns and 800 microns from the surface of the valleys.

5. The soft, pliable three-dimensional prosthesis means as defined in claim 4 being particularly characterized in that pores formed at the outer ends of said pillars are between about 20 microns and 800 microns in depth.