# US 5,732,572 A · Textile prostheses having particular knit configuration including two-needle overlap stitch > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,732,572 A - Document ID: US5732572A - Status: Granted - Kind: A - Application number: 08/530,182 - Filed: 1995-09-29 - Granted: 1998-03-31 - Earliest claimed: 1993-04-01 - Assignees: Vascutek Limited - Inventors: Michael Litton - Web page: https://patentgrep.com/patent/US5732572A ## CPC - A61F 2/06: Blood vessels - D04B 21/205: {Elongated tubular articles of small diameter, e.g. coverings or reinforcements for cables or hoses} - D10B 2509/06: Vascular grafts; stents - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - D04B: KNITTING - D10B: INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES ## Abstract The present invention relates to a fabric for the construction of knitted tubular grafts for use in cardiovascular surgery and to methods of manufacturing these grafts. The fabric of the present invention is constructed so that grafts formed from it will have an increased hoop modulus due to the fabric having a underlap of greater than two needle spaces in the bar nearer to the technical face of the fabric. ## Claims ### Claim 1 A tubular knitted fabric for a surgical graft, the fabric being defined by a technical face and a technical back, wherein, during knitting of the fabric, the route of yarn sheets in the fabric is determined by bars, and wherein the fabric contains a two-needle overlap chain and is knitted using a stitch which has an underlap of greater than two needle spaces in the bar nearer to the technical face. ### Claim 2 (depends on 1) A knitted fabric as in claim 1 which has one of the following constructions: two-needle overlap chain on 3.times.1 tricot; two-needle overlap chain on 4.times.1 tricot; two-needle overlap chain on 5.times.1 tricot. ### Claim 3 (depends on 1) A knitted fabric as claimed in claim 1 which is constructed from a polyester yarn. ### Claim 4 (depends on 1) A knitted fabric as claimed in claim 1 which is constructed from yarns having a weight per unit length of from 30 to 100 decitex. ### Claim 5 (depends on 4) A knitted fabric as claimed in claim 4, wherein the yarn has a weight per unit length of from 35 to 60 decitex. ### Claim 6 (depends on 1) A knitted fabric as claimed in claim 1 constructed from a multifilament yarn. ### Claim 7 (depends on 6) A knitted fabric as claimed in claim 6, wherein the yarn has a filament micron value of from 6 to 20. ### Claim 8 (depends on 1) A knitted fabric as claimed in claim 1 constructed from a flat yarn. ### Claim 9 (depends on 1) A knitted fabric as claimed in claim 1 constructed from a texturized yarn. ### Claim 10 (depends on 1) A knitted fabric as claimed in claim 1 constructed from a mix of texturized and flat yarns. ### Claim 11 (depends on 1) A knitted fabric as claimed in claim 1 comprising a marker. ### Claim 12 (depends on 11) A knitted fabric as claimed in claim 11, wherein the marker comprises a yarn of a different color from the rest of the fabric. ### Claim 13 A process for the production of a fabric, the process comprising the steps of: knitting a fabric in tubular form, said fabric defined by a technical face and a technical back; determining the route of yarn sheets in the fabric using bars; and using a stitch comprising a two-needle overlap chain and having an underlap of greater than two needle spaces in the bar nearer to the technical face. ### Claim 14 (depends on 13) A process as claimed in claim 13, in which the fabric is knitted as a straight tube. ### Claim 15 (depends on 13) A process as claimed in claim 13, in which the fabric is knitted as a bifurcated tube. ### Claim 16 (depends on 13) A process as claimed in claim 13, wherein the fabric is knitted on a machine having at least 20 needles per inch. ### Claim 17 (depends on 13) A process as claimed in claim 13, further comprising the step of forming corrugations in the tube. ### Claim 18 (depends on 13) A process as claimed in claim 13, further comprising the step of impregnating the tube with a water soluble physiologically acceptable material such as gelatin. ### Claim 19 A tubular surgical graft knitted from a fabric defined by a technical face and a technical back, wherein, during knitting of the fabric, the route of yarn sheets in the fabric is determined by bars, and wherein the fabric contains a two-needle overlap chain and is knitted using a stitch which has an underlap of greater than two needle spaces in the bar nearer to the technical face. ### Claim 20 (depends on 19) A knitted surgical graft as claimed in claim 19 which is a bifurcated tube.