Abstract: A method of weaving tubular textile articles, comprising: forming first, second, third and fourth superposed layers of warp threads; weaving by weft insertion through sheds formed in said layers, the weaving being performed by first and second weft threads inserted by first and second needles from one side of said warp layers; each weft thread being inserted alternately through a selected pair of said warp layers; and the weft loops at the other side of said layers being knitted together, the first layer with the second layer and the third layer with the fourth layer, to form a pair of selvedges. A tubular textile article formed by the method is provided. A needleloom for weaving such articles is also provided.

Abstract: A prosthesis that resiliently engages a body passage includes an annular clamping ring which may be folded along a diametric axis for insertion into the body passage. The clamping ring is adapted to resiliently spring outwardly, once in position inside the body passage, and to be continually resiliently biased against the interior surface of the body passage. One or more of the clamping rings may be attached to opposed ends of a tubular graft. The rings and connected graft may be positioned in the body passage using a applicator which selectively permits expansion and/or in some embodiments contraction of the annular ring in position within a body passage. Alternatively a retaining member may be used to retain the annular ring in a compressed condition until it is in a desired position within a body passage. Among other potential uses, the present invention may be useful as a vascular stent for treating abdominal aortic aneurysms.

Abstract: A prosthesis that resiliently engages a body passage includes an annular clamping ring which may be folded along a diametric axis for insertion into the body passage. The clamping ring is adapted to resiliently spring outwardly, once in position inside the body passage, and to be continually resiliently biased against the interior surface of the body passage. One or more of the clamping rings may be attached to opposed ends of a tubular graft. The rings and connected graft may be positioned in the body passage using a applicator which selectively permits expansion and/or in some embodiments contraction of the annular ring in position within a body passage. Alternatively a retaining member may be used to retain the annular ring in a compressed condition until it is in a desired position within a body passage. Among other potential uses, the present invention may be useful as a vascular stent for treating abdominal aortic aneurysms.

Abstract: A prosthetic aortic conduit for replacing a root portion of an aorta is provided. The conduit comprises a first tubular portion and a second tubular portion which are connected together along a substantially common axis. The second tubular portion does not substantially deform in a longitudinal direction and has resilient means which allow said second portion to be expandable in a lateral direction. This second portion is able to deform laterally to mimic the function of the sinuses of Valsalva. The method of manufacturing such a conduit comprises the steps of: a) providing a first tubular conduit suitable for use in heart surgery and having a longitudinal axis and first resilient means allowing some expansion in the longitudinal direction only; b) securing to one of the ends of this first conduit a second tubular conduit suitable for use in heart surgery, this second conduit having second resilient means which allows some expansion in the lateral direction only.

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.

Abstract: Surfaces of polymers, particularly polyesters, can be fluorinated by deposition of a fluorocarbon from solution. The fluorocarbon may be an amorphous fluoropolymer, such as the copolymer of tetrafluoroethylene and bis-2,2-trifluoromethyl-4,5-difluoro-1,2-dioxole sold under the trademark TEFLON AF.RTM., which is soluble in fluorinated alkanes and other fluorinated liquids such as those sold under the trademark FLUORINERT.RTM.. Surface-fluorinated polyesters, particularly in knitted fabric form, are useful as vascular grafts: the fluorinated surface reduces thrombogenicity and complement activation. The disadvantages of known surface fluorination methods, such as the cold plasma or glow discharge process, are avoided.

Abstract: A method of producing a vascular graft comprises impregnating a tube of flexible porous material with gelatinous material which contains a gelatin with has been treated to cause it to contain a predetermined number of amino groups less than that normally present in untreated gelatin then treating the impregnated tube to cause the amino groups to form cross links with one another. The gelatin may be treated by reacting it with the anhydride or the chloride of a polycarboxylic acid.

Abstract: A vascular prosthesis intended to act as a substitute blood vessel comprises a porous corrugated tube (1) of textile material presenting a pattern of a series of axially disposed markings (3,4 or 5) on the corrugations (2) so disposed that the appearance of the pattern changes when the prosthesis is extended. The change in the appearance of the pattern as the tube is extended provides an indication to the user when the prosthesis has been extended to the desirable extent.