Molded silicone foam implant and method for making

• US 5,658,330 A
• Filed: 04/25/1995
• Issued: 08/19/1997
• Est. Priority Date: 12/23/1993
• Status: Expired due to Term

• Current Assignee: Allergan, Inc. (Canada) (Abbvie Incorporated)
• Original Assignee: McGhan Medical Corporation (Abbvie Incorporated)
• Inventors: Guillen, Blanca, Waybright, Richard S., Carlisle, Daniel Alan
• Primary Examiner(s): JONES, MARYBETH O
• Application Number:
  US08/428,882
• Time in Patent Office: 847 Days
• Field of Search: 623/1, 623/7, 623/8, 623/11, 623/16
• US Class Current: 623/11.11
• 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: A61F 2002/30187 D-shaped or half-disc-shaped
• CPC Class Codes: A61F 2230/0034 D-shaped
• CPC Class Codes: A61F 2250/0003 having an inflatable pocket filled with fluid, e.g. liquid or gas
• CPC Class Codes: B29C 44/3403 Foaming under special conditions, e.g. in sub-atmospheric pressure, in or on a liquid

Abstract

A breast prosthesis for implantation beneath the skin is disclosed. In one preferred embodiment the prosthesis has an outer elastic shell which encloses a biocompatible fluid and a silicone foam insert of unitary construction having the shape and approximate consistency of breast tissue. The foam insert occupies substantially the entire volume enclosed by the shell of the implantable prosthesis and consists of a foam body that is molded to the shape of the breast. The foam body has both open-cell and closed-cell characteristics. Portions of the foam insert are closed-cell with open-cell passageways threading themselves throughout the structure. The insert is of unitary construction and made by (a) heating a mold to an appropriate temperature; (b) mixing air bubbles into a dispersion of uncured silicone; (c) injecting the bubble-laden, uncured silicone into the preheated mold; and (d) applying a vacuum until the foam insert cures. The volume of the foam insert should preferably be substantially equal to the unstretched volume of the shell which surrounds the foam body. In another preferred embodiment only a portion of the volume enclosed by the shell is occupied by the foam insert. In this embodiment, one surface of the foam insert conforms to the curvature of at least a portion of the shell and may be affixed to the conforming inner surface of the shell thereby effectively thickening or reinforcing the overlying shell. In yet another embodiment a foam insert made as described above comprising an open-cell and closed-cell foam body may be directly implanted beneath the skin for breast augmentation or reconstruction without a shell. The inner surface of the mold may be textured to provide additional opportunity for desirable tissue ingrowth following implantation.

Claims

1. A prosthesis adapted for implantation beneath the skin of a person comprising a flexible elastomeric shell having an interior volume containing a fluid filler a unitary silicone foam shell body having both open-cell and closed-cell structure wherein said foam shell is enclosed within said elastomeric shell and is in fluid communication with said fluid filler.

2. A prosthesis adapted for implantation beneath the skin of a person, the prosthesis comprising a flexible elastomeric shell having an interior volume containing a fluid filler and a unitary silicone foam shell, said unitary silicone foam shell having both open-cell and closed-cell structure and being enclosed within said elastomeric shell and wherein said unitary silicone foam shell is in fluid communication with said fluid filler, said unitary silicone foam shell being made by:

(a) creating gaseous bubbles within a fluid silicone; and

(b) preheating a prosthesis mold having a shaped cavity to between 200°

F.-300°

F.; and

(c) injecting said silicone fluid containing said bubbles into said mold cavity; and

(d) reducing the pressure within said mold cavity; and

(f) maintaining said reduced pressure in said mold cavity and said temperature of said mold cavity between 200°

F. and 300°

F. for between 30 and 60 minutes; and

(g) removing said prosthesis from said mold cavity.