Elastomeric sheet materials for heart valve and other prosthetic implants

• US 4,340,091 A
• Filed: 02/27/1980
• Issued: 07/20/1982
• Est. Priority Date: 05/07/1975
• Status: Expired due to Term

• Current Assignee: Albany International Corporation, Washington University In St Louis
• Original Assignee: Albany International Corporation, Washington University In St Louis
• Inventors: Davis, Robert B., Skelton, John, Clark, Richard E.
• Primary Examiner(s): Kee Chi, James
• Application Number:
  US06/125,120
• Time in Patent Office: 874 Days
• Field of Search: 139/383 R, 139/387 R, 139/421-423, 87/8.9, 3/1.4, 3/1.5, 428/231, 428/230, 528/301
• US Class Current: 139/383.00R
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2/24 Heart valves ; Vascular valves, e.g. venous valves; Heart implants, e.g. passive devices for improving the function of the native valve or the heart muscle; Transmyocardial revascularisation [TMR] devices; Valves implantable in the body
• CPC Class Codes: A61F 2/2412 with soft flexible valve members, e.g. tissue valves shaped like natural valves check valves with flexible valve members in general F16K15/14
• CPC Class Codes: A61F 2/2418 Scaffolds therefor, e.g. support stents
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61L 27/14 Macromolecular materials
• CPC Class Codes: A61L 27/18 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: B21F 45/008 of medical instruments, e.g. stents, corneal rings medical science A61
• CPC Class Codes: C08L 67/00 Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain of polyester-amides C08L77/12; of polyester-imides C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 67/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence
• CPC Class Codes: C08L 75/00 Compositions of polyureas or polyurethanes; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 83/04 Polysiloxanes
• CPC Class Codes: D03D 15/283 synthetic polymer-based, e.g. polyamide or polyester fibres cellulose-based artificial fibres D03D15/225
• CPC Class Codes: D03D 15/33 Ultrafine fibres, e.g. microfibres or nanofibres
• CPC Class Codes: D03D 15/56 elastic
• CPC Class Codes: D03D 3/02 Tubular fabrics
• CPC Class Codes: D03D 7/00 Woven fabrics designed to be resilient, i.e. to recover from compressive stress
• CPC Class Codes: D10B 2331/06 polyethers
• CPC Class Codes: D10B 2509/00 Medical; Hygiene

Abstract

Sheet materials for cardiovascular and other prosthetic implants are fabricated of synthetic elastomers. These materials are characterized by molecular configurations that produce a nonlinear tensile modulus characteristic similar in shape to that of natural tissue. Selected elastomers, when formed as sheet material of appropriate geometrical configuration, promote the formation of natural tissue thereon which is appropriate for the mechanical characteristics desired.

Claims

1. A flexible and extensible textile sheet material for cardiovascular and prosthetic implants, said sheet material consisting of warp yarns and yarns interlaced therewith, said yarns comprising a synthetic elastomer and forming a fibrous reticular blood-contacting face wherein at least 50 percent of the superficial area contains a substantially uniform distribution of foramina having a maximum lateral aperture dimension of 40 microns, said yarns having an average tensile modulus up to a strain of 10% which is between 0.05 and 5.0 grams per denier.

2. A textile sheet material according to claim 1 having a face to face thickness of about 0.06 cm.

3. A textile sheet material according to claim 1, comprising a fabric of N yarns per centimeter of fabric width, each yarn comprising a plurality of filaments arranged effectively in rows, the thickness of the fabric being less than 12 times the filament diameter d, and wherein N is limited by the expression ##EQU4## in which "c" is between 20×

10^-4 cm and 40×

10^-4 cm, and "b" is effectively the number of filaments per row in each yarn.

4. A textile sheet material according to claim 3, in which the filaments of the yarns are separated to an extent sufficient to make the apertures between the yarns no greater than the apertures between the filaments of each yarn, whereby the maximum lateral dimensions of the foramina are defined by the interstitial spacing of filaments.

5. A textile sheet material according to claim 1, in which the elastomer is a segmented random block polyether ester copolymer in fibrous form, said copolymer further comprising crystallizable tetramethylene terephthalate hard segments and amorphous elastomeric polyalkylene ether terephthalate soft segments.

6. A textile sheet material according to claim 1, in which the yarns comprise multifilament yarns.

7. A textile sheet material according to claim 6 in which the yarns are woven.

8. A textile sheet material according to claim 6 in which the yarns are braided.

9. A textile sheet material according to claim 6, in which the yarns have filaments of a denier between 0.5 and 20.

10. A textile sheet material according to claim 1, having an average tensile modulus up to a load level of 150 grams per centimeter of width which is between 500 and 7200 grams per centimeter of width.

11. A textile sheet material according to claim 3, in which the yarns comprise multifilament yarns and said sheet material has a thickness "t" given by