AN ASYMMETRICAL POROUS PTFE FORM AND METHOD OF MAKING

• Main Authors: SIMMS, WILLIAM, J, KASIC, JAMES, F
• Format: Patent
• Language: English; French
• Published: 14.03.1996
• Edition: 6
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; BANDAGES, DRESSINGS OR ABSORBENT PADS; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS, ORSURGICAL ARTICLES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF,TUBULAR STRUCTURES OF THE BODY, E.G. STENTS; DISINFECTION, STERILISATION, OR DEODORISATION OF AIR; FILTERS IMPLANTABLE INTO BLOOD VESSELS; FIRST-AID KITS; FOMENTATION; HUMAN NECESSITIES; HYGIENE; INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULARARTICLES; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICALARTICLES; MEDICAL OR VETERINARY SCIENCE; METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS INGENERAL; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; PERFORMING OPERATIONS; PROSTHESES; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; TREATMENT OR PROTECTION OF EYES OR EARS; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

An asymmetrical form of porous PTFE having substantially different dimensions at different points along the length of the form. If the form is, for example, a tubular form, the different dimensions may be thickness or diameter or both. The form is preferably a tubular form which is preferably tapered having opposing ends with large and small inside diameters respectively wherein the wall thickness of the large diameter end is greater than or equal to the wall thickness of the small diameter end. Tapered PTFE tubes of this type are particularly useful as implantable vascular grafts. A method of producing these asymmetrical porous PTFE forms is also described. Une forme asymétrique en PTFE poreux présente des dimensions sensiblement différentes en différents points sur la longueur de la forme. Si la forme est une forme tubulaire, par exemple, les dimensions différentes peuvent être l'épaisseur, ou le diamètre ou les deux. La forme est de préférence une forme tubulaire qui est évasée aux extrémités opposées, avec des diamètres intérieurs grand et petit respectivement, où l'épaisseur de paroi de l'extrémité de grand diamètre est supérieure ou égale à l'épaisseur de paroi de l'extrémité de petit diamètre. Des tubes en PTFE évasés de ce type sont particulièrement utiles comme greffons vasculaires implantables. Un procédé de production de ces formes asymétriques en PTFE poreux est également décrit.